1 /* 2 * NSA Security-Enhanced Linux (SELinux) security module 3 * 4 * This file contains the SELinux hook function implementations. 5 * 6 * Authors: Stephen Smalley, <sds@epoch.ncsc.mil> 7 * Chris Vance, <cvance@nai.com> 8 * Wayne Salamon, <wsalamon@nai.com> 9 * James Morris <jmorris@redhat.com> 10 * 11 * Copyright (C) 2001,2002 Networks Associates Technology, Inc. 12 * Copyright (C) 2003-2008 Red Hat, Inc., James Morris <jmorris@redhat.com> 13 * Eric Paris <eparis@redhat.com> 14 * Copyright (C) 2004-2005 Trusted Computer Solutions, Inc. 15 * <dgoeddel@trustedcs.com> 16 * Copyright (C) 2006, 2007, 2009 Hewlett-Packard Development Company, L.P. 17 * Paul Moore <paul@paul-moore.com> 18 * Copyright (C) 2007 Hitachi Software Engineering Co., Ltd. 19 * Yuichi Nakamura <ynakam@hitachisoft.jp> 20 * 21 * This program is free software; you can redistribute it and/or modify 22 * it under the terms of the GNU General Public License version 2, 23 * as published by the Free Software Foundation. 24 */ 25 26 #include <linux/init.h> 27 #include <linux/kd.h> 28 #include <linux/kernel.h> 29 #include <linux/tracehook.h> 30 #include <linux/errno.h> 31 #include <linux/sched.h> 32 #include <linux/security.h> 33 #include <linux/xattr.h> 34 #include <linux/capability.h> 35 #include <linux/unistd.h> 36 #include <linux/mm.h> 37 #include <linux/mman.h> 38 #include <linux/slab.h> 39 #include <linux/pagemap.h> 40 #include <linux/proc_fs.h> 41 #include <linux/swap.h> 42 #include <linux/spinlock.h> 43 #include <linux/syscalls.h> 44 #include <linux/dcache.h> 45 #include <linux/file.h> 46 #include <linux/fdtable.h> 47 #include <linux/namei.h> 48 #include <linux/mount.h> 49 #include <linux/netfilter_ipv4.h> 50 #include <linux/netfilter_ipv6.h> 51 #include <linux/tty.h> 52 #include <net/icmp.h> 53 #include <net/ip.h> /* for local_port_range[] */ 54 #include <net/tcp.h> /* struct or_callable used in sock_rcv_skb */ 55 #include <net/net_namespace.h> 56 #include <net/netlabel.h> 57 #include <linux/uaccess.h> 58 #include <asm/ioctls.h> 59 #include <linux/atomic.h> 60 #include <linux/bitops.h> 61 #include <linux/interrupt.h> 62 #include <linux/netdevice.h> /* for network interface checks */ 63 #include <linux/netlink.h> 64 #include <linux/tcp.h> 65 #include <linux/udp.h> 66 #include <linux/dccp.h> 67 #include <linux/quota.h> 68 #include <linux/un.h> /* for Unix socket types */ 69 #include <net/af_unix.h> /* for Unix socket types */ 70 #include <linux/parser.h> 71 #include <linux/nfs_mount.h> 72 #include <net/ipv6.h> 73 #include <linux/hugetlb.h> 74 #include <linux/personality.h> 75 #include <linux/audit.h> 76 #include <linux/string.h> 77 #include <linux/selinux.h> 78 #include <linux/mutex.h> 79 #include <linux/posix-timers.h> 80 #include <linux/syslog.h> 81 #include <linux/user_namespace.h> 82 #include <linux/export.h> 83 #include <linux/msg.h> 84 #include <linux/shm.h> 85 86 #include "avc.h" 87 #include "objsec.h" 88 #include "netif.h" 89 #include "netnode.h" 90 #include "netport.h" 91 #include "xfrm.h" 92 #include "netlabel.h" 93 #include "audit.h" 94 #include "avc_ss.h" 95 96 #define NUM_SEL_MNT_OPTS 5 97 98 extern struct security_operations *security_ops; 99 100 /* SECMARK reference count */ 101 static atomic_t selinux_secmark_refcount = ATOMIC_INIT(0); 102 103 #ifdef CONFIG_SECURITY_SELINUX_DEVELOP 104 int selinux_enforcing; 105 106 static int __init enforcing_setup(char *str) 107 { 108 unsigned long enforcing; 109 if (!strict_strtoul(str, 0, &enforcing)) 110 selinux_enforcing = enforcing ? 1 : 0; 111 return 1; 112 } 113 __setup("enforcing=", enforcing_setup); 114 #endif 115 116 #ifdef CONFIG_SECURITY_SELINUX_BOOTPARAM 117 int selinux_enabled = CONFIG_SECURITY_SELINUX_BOOTPARAM_VALUE; 118 119 static int __init selinux_enabled_setup(char *str) 120 { 121 unsigned long enabled; 122 if (!strict_strtoul(str, 0, &enabled)) 123 selinux_enabled = enabled ? 1 : 0; 124 return 1; 125 } 126 __setup("selinux=", selinux_enabled_setup); 127 #else 128 int selinux_enabled = 1; 129 #endif 130 131 static struct kmem_cache *sel_inode_cache; 132 133 /** 134 * selinux_secmark_enabled - Check to see if SECMARK is currently enabled 135 * 136 * Description: 137 * This function checks the SECMARK reference counter to see if any SECMARK 138 * targets are currently configured, if the reference counter is greater than 139 * zero SECMARK is considered to be enabled. Returns true (1) if SECMARK is 140 * enabled, false (0) if SECMARK is disabled. 141 * 142 */ 143 static int selinux_secmark_enabled(void) 144 { 145 return (atomic_read(&selinux_secmark_refcount) > 0); 146 } 147 148 /* 149 * initialise the security for the init task 150 */ 151 static void cred_init_security(void) 152 { 153 struct cred *cred = (struct cred *) current->real_cred; 154 struct task_security_struct *tsec; 155 156 tsec = kzalloc(sizeof(struct task_security_struct), GFP_KERNEL); 157 if (!tsec) 158 panic("SELinux: Failed to initialize initial task.\n"); 159 160 tsec->osid = tsec->sid = SECINITSID_KERNEL; 161 cred->security = tsec; 162 } 163 164 /* 165 * get the security ID of a set of credentials 166 */ 167 static inline u32 cred_sid(const struct cred *cred) 168 { 169 const struct task_security_struct *tsec; 170 171 tsec = cred->security; 172 return tsec->sid; 173 } 174 175 /* 176 * get the objective security ID of a task 177 */ 178 static inline u32 task_sid(const struct task_struct *task) 179 { 180 u32 sid; 181 182 rcu_read_lock(); 183 sid = cred_sid(__task_cred(task)); 184 rcu_read_unlock(); 185 return sid; 186 } 187 188 /* 189 * get the subjective security ID of the current task 190 */ 191 static inline u32 current_sid(void) 192 { 193 const struct task_security_struct *tsec = current_security(); 194 195 return tsec->sid; 196 } 197 198 /* Allocate and free functions for each kind of security blob. */ 199 200 static int inode_alloc_security(struct inode *inode) 201 { 202 struct inode_security_struct *isec; 203 u32 sid = current_sid(); 204 205 isec = kmem_cache_zalloc(sel_inode_cache, GFP_NOFS); 206 if (!isec) 207 return -ENOMEM; 208 209 mutex_init(&isec->lock); 210 INIT_LIST_HEAD(&isec->list); 211 isec->inode = inode; 212 isec->sid = SECINITSID_UNLABELED; 213 isec->sclass = SECCLASS_FILE; 214 isec->task_sid = sid; 215 inode->i_security = isec; 216 217 return 0; 218 } 219 220 static void inode_free_security(struct inode *inode) 221 { 222 struct inode_security_struct *isec = inode->i_security; 223 struct superblock_security_struct *sbsec = inode->i_sb->s_security; 224 225 spin_lock(&sbsec->isec_lock); 226 if (!list_empty(&isec->list)) 227 list_del_init(&isec->list); 228 spin_unlock(&sbsec->isec_lock); 229 230 inode->i_security = NULL; 231 kmem_cache_free(sel_inode_cache, isec); 232 } 233 234 static int file_alloc_security(struct file *file) 235 { 236 struct file_security_struct *fsec; 237 u32 sid = current_sid(); 238 239 fsec = kzalloc(sizeof(struct file_security_struct), GFP_KERNEL); 240 if (!fsec) 241 return -ENOMEM; 242 243 fsec->sid = sid; 244 fsec->fown_sid = sid; 245 file->f_security = fsec; 246 247 return 0; 248 } 249 250 static void file_free_security(struct file *file) 251 { 252 struct file_security_struct *fsec = file->f_security; 253 file->f_security = NULL; 254 kfree(fsec); 255 } 256 257 static int superblock_alloc_security(struct super_block *sb) 258 { 259 struct superblock_security_struct *sbsec; 260 261 sbsec = kzalloc(sizeof(struct superblock_security_struct), GFP_KERNEL); 262 if (!sbsec) 263 return -ENOMEM; 264 265 mutex_init(&sbsec->lock); 266 INIT_LIST_HEAD(&sbsec->isec_head); 267 spin_lock_init(&sbsec->isec_lock); 268 sbsec->sb = sb; 269 sbsec->sid = SECINITSID_UNLABELED; 270 sbsec->def_sid = SECINITSID_FILE; 271 sbsec->mntpoint_sid = SECINITSID_UNLABELED; 272 sb->s_security = sbsec; 273 274 return 0; 275 } 276 277 static void superblock_free_security(struct super_block *sb) 278 { 279 struct superblock_security_struct *sbsec = sb->s_security; 280 sb->s_security = NULL; 281 kfree(sbsec); 282 } 283 284 /* The file system's label must be initialized prior to use. */ 285 286 static const char *labeling_behaviors[6] = { 287 "uses xattr", 288 "uses transition SIDs", 289 "uses task SIDs", 290 "uses genfs_contexts", 291 "not configured for labeling", 292 "uses mountpoint labeling", 293 }; 294 295 static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry); 296 297 static inline int inode_doinit(struct inode *inode) 298 { 299 return inode_doinit_with_dentry(inode, NULL); 300 } 301 302 enum { 303 Opt_error = -1, 304 Opt_context = 1, 305 Opt_fscontext = 2, 306 Opt_defcontext = 3, 307 Opt_rootcontext = 4, 308 Opt_labelsupport = 5, 309 }; 310 311 static const match_table_t tokens = { 312 {Opt_context, CONTEXT_STR "%s"}, 313 {Opt_fscontext, FSCONTEXT_STR "%s"}, 314 {Opt_defcontext, DEFCONTEXT_STR "%s"}, 315 {Opt_rootcontext, ROOTCONTEXT_STR "%s"}, 316 {Opt_labelsupport, LABELSUPP_STR}, 317 {Opt_error, NULL}, 318 }; 319 320 #define SEL_MOUNT_FAIL_MSG "SELinux: duplicate or incompatible mount options\n" 321 322 static int may_context_mount_sb_relabel(u32 sid, 323 struct superblock_security_struct *sbsec, 324 const struct cred *cred) 325 { 326 const struct task_security_struct *tsec = cred->security; 327 int rc; 328 329 rc = avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM, 330 FILESYSTEM__RELABELFROM, NULL); 331 if (rc) 332 return rc; 333 334 rc = avc_has_perm(tsec->sid, sid, SECCLASS_FILESYSTEM, 335 FILESYSTEM__RELABELTO, NULL); 336 return rc; 337 } 338 339 static int may_context_mount_inode_relabel(u32 sid, 340 struct superblock_security_struct *sbsec, 341 const struct cred *cred) 342 { 343 const struct task_security_struct *tsec = cred->security; 344 int rc; 345 rc = avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM, 346 FILESYSTEM__RELABELFROM, NULL); 347 if (rc) 348 return rc; 349 350 rc = avc_has_perm(sid, sbsec->sid, SECCLASS_FILESYSTEM, 351 FILESYSTEM__ASSOCIATE, NULL); 352 return rc; 353 } 354 355 static int sb_finish_set_opts(struct super_block *sb) 356 { 357 struct superblock_security_struct *sbsec = sb->s_security; 358 struct dentry *root = sb->s_root; 359 struct inode *root_inode = root->d_inode; 360 int rc = 0; 361 362 if (sbsec->behavior == SECURITY_FS_USE_XATTR) { 363 /* Make sure that the xattr handler exists and that no 364 error other than -ENODATA is returned by getxattr on 365 the root directory. -ENODATA is ok, as this may be 366 the first boot of the SELinux kernel before we have 367 assigned xattr values to the filesystem. */ 368 if (!root_inode->i_op->getxattr) { 369 printk(KERN_WARNING "SELinux: (dev %s, type %s) has no " 370 "xattr support\n", sb->s_id, sb->s_type->name); 371 rc = -EOPNOTSUPP; 372 goto out; 373 } 374 rc = root_inode->i_op->getxattr(root, XATTR_NAME_SELINUX, NULL, 0); 375 if (rc < 0 && rc != -ENODATA) { 376 if (rc == -EOPNOTSUPP) 377 printk(KERN_WARNING "SELinux: (dev %s, type " 378 "%s) has no security xattr handler\n", 379 sb->s_id, sb->s_type->name); 380 else 381 printk(KERN_WARNING "SELinux: (dev %s, type " 382 "%s) getxattr errno %d\n", sb->s_id, 383 sb->s_type->name, -rc); 384 goto out; 385 } 386 } 387 388 sbsec->flags |= (SE_SBINITIALIZED | SE_SBLABELSUPP); 389 390 if (sbsec->behavior > ARRAY_SIZE(labeling_behaviors)) 391 printk(KERN_ERR "SELinux: initialized (dev %s, type %s), unknown behavior\n", 392 sb->s_id, sb->s_type->name); 393 else 394 printk(KERN_DEBUG "SELinux: initialized (dev %s, type %s), %s\n", 395 sb->s_id, sb->s_type->name, 396 labeling_behaviors[sbsec->behavior-1]); 397 398 if (sbsec->behavior == SECURITY_FS_USE_GENFS || 399 sbsec->behavior == SECURITY_FS_USE_MNTPOINT || 400 sbsec->behavior == SECURITY_FS_USE_NONE || 401 sbsec->behavior > ARRAY_SIZE(labeling_behaviors)) 402 sbsec->flags &= ~SE_SBLABELSUPP; 403 404 /* Special handling for sysfs. Is genfs but also has setxattr handler*/ 405 if (strncmp(sb->s_type->name, "sysfs", sizeof("sysfs")) == 0) 406 sbsec->flags |= SE_SBLABELSUPP; 407 408 /* Initialize the root inode. */ 409 rc = inode_doinit_with_dentry(root_inode, root); 410 411 /* Initialize any other inodes associated with the superblock, e.g. 412 inodes created prior to initial policy load or inodes created 413 during get_sb by a pseudo filesystem that directly 414 populates itself. */ 415 spin_lock(&sbsec->isec_lock); 416 next_inode: 417 if (!list_empty(&sbsec->isec_head)) { 418 struct inode_security_struct *isec = 419 list_entry(sbsec->isec_head.next, 420 struct inode_security_struct, list); 421 struct inode *inode = isec->inode; 422 spin_unlock(&sbsec->isec_lock); 423 inode = igrab(inode); 424 if (inode) { 425 if (!IS_PRIVATE(inode)) 426 inode_doinit(inode); 427 iput(inode); 428 } 429 spin_lock(&sbsec->isec_lock); 430 list_del_init(&isec->list); 431 goto next_inode; 432 } 433 spin_unlock(&sbsec->isec_lock); 434 out: 435 return rc; 436 } 437 438 /* 439 * This function should allow an FS to ask what it's mount security 440 * options were so it can use those later for submounts, displaying 441 * mount options, or whatever. 442 */ 443 static int selinux_get_mnt_opts(const struct super_block *sb, 444 struct security_mnt_opts *opts) 445 { 446 int rc = 0, i; 447 struct superblock_security_struct *sbsec = sb->s_security; 448 char *context = NULL; 449 u32 len; 450 char tmp; 451 452 security_init_mnt_opts(opts); 453 454 if (!(sbsec->flags & SE_SBINITIALIZED)) 455 return -EINVAL; 456 457 if (!ss_initialized) 458 return -EINVAL; 459 460 tmp = sbsec->flags & SE_MNTMASK; 461 /* count the number of mount options for this sb */ 462 for (i = 0; i < 8; i++) { 463 if (tmp & 0x01) 464 opts->num_mnt_opts++; 465 tmp >>= 1; 466 } 467 /* Check if the Label support flag is set */ 468 if (sbsec->flags & SE_SBLABELSUPP) 469 opts->num_mnt_opts++; 470 471 opts->mnt_opts = kcalloc(opts->num_mnt_opts, sizeof(char *), GFP_ATOMIC); 472 if (!opts->mnt_opts) { 473 rc = -ENOMEM; 474 goto out_free; 475 } 476 477 opts->mnt_opts_flags = kcalloc(opts->num_mnt_opts, sizeof(int), GFP_ATOMIC); 478 if (!opts->mnt_opts_flags) { 479 rc = -ENOMEM; 480 goto out_free; 481 } 482 483 i = 0; 484 if (sbsec->flags & FSCONTEXT_MNT) { 485 rc = security_sid_to_context(sbsec->sid, &context, &len); 486 if (rc) 487 goto out_free; 488 opts->mnt_opts[i] = context; 489 opts->mnt_opts_flags[i++] = FSCONTEXT_MNT; 490 } 491 if (sbsec->flags & CONTEXT_MNT) { 492 rc = security_sid_to_context(sbsec->mntpoint_sid, &context, &len); 493 if (rc) 494 goto out_free; 495 opts->mnt_opts[i] = context; 496 opts->mnt_opts_flags[i++] = CONTEXT_MNT; 497 } 498 if (sbsec->flags & DEFCONTEXT_MNT) { 499 rc = security_sid_to_context(sbsec->def_sid, &context, &len); 500 if (rc) 501 goto out_free; 502 opts->mnt_opts[i] = context; 503 opts->mnt_opts_flags[i++] = DEFCONTEXT_MNT; 504 } 505 if (sbsec->flags & ROOTCONTEXT_MNT) { 506 struct inode *root = sbsec->sb->s_root->d_inode; 507 struct inode_security_struct *isec = root->i_security; 508 509 rc = security_sid_to_context(isec->sid, &context, &len); 510 if (rc) 511 goto out_free; 512 opts->mnt_opts[i] = context; 513 opts->mnt_opts_flags[i++] = ROOTCONTEXT_MNT; 514 } 515 if (sbsec->flags & SE_SBLABELSUPP) { 516 opts->mnt_opts[i] = NULL; 517 opts->mnt_opts_flags[i++] = SE_SBLABELSUPP; 518 } 519 520 BUG_ON(i != opts->num_mnt_opts); 521 522 return 0; 523 524 out_free: 525 security_free_mnt_opts(opts); 526 return rc; 527 } 528 529 static int bad_option(struct superblock_security_struct *sbsec, char flag, 530 u32 old_sid, u32 new_sid) 531 { 532 char mnt_flags = sbsec->flags & SE_MNTMASK; 533 534 /* check if the old mount command had the same options */ 535 if (sbsec->flags & SE_SBINITIALIZED) 536 if (!(sbsec->flags & flag) || 537 (old_sid != new_sid)) 538 return 1; 539 540 /* check if we were passed the same options twice, 541 * aka someone passed context=a,context=b 542 */ 543 if (!(sbsec->flags & SE_SBINITIALIZED)) 544 if (mnt_flags & flag) 545 return 1; 546 return 0; 547 } 548 549 /* 550 * Allow filesystems with binary mount data to explicitly set mount point 551 * labeling information. 552 */ 553 static int selinux_set_mnt_opts(struct super_block *sb, 554 struct security_mnt_opts *opts) 555 { 556 const struct cred *cred = current_cred(); 557 int rc = 0, i; 558 struct superblock_security_struct *sbsec = sb->s_security; 559 const char *name = sb->s_type->name; 560 struct inode *inode = sbsec->sb->s_root->d_inode; 561 struct inode_security_struct *root_isec = inode->i_security; 562 u32 fscontext_sid = 0, context_sid = 0, rootcontext_sid = 0; 563 u32 defcontext_sid = 0; 564 char **mount_options = opts->mnt_opts; 565 int *flags = opts->mnt_opts_flags; 566 int num_opts = opts->num_mnt_opts; 567 568 mutex_lock(&sbsec->lock); 569 570 if (!ss_initialized) { 571 if (!num_opts) { 572 /* Defer initialization until selinux_complete_init, 573 after the initial policy is loaded and the security 574 server is ready to handle calls. */ 575 goto out; 576 } 577 rc = -EINVAL; 578 printk(KERN_WARNING "SELinux: Unable to set superblock options " 579 "before the security server is initialized\n"); 580 goto out; 581 } 582 583 /* 584 * Binary mount data FS will come through this function twice. Once 585 * from an explicit call and once from the generic calls from the vfs. 586 * Since the generic VFS calls will not contain any security mount data 587 * we need to skip the double mount verification. 588 * 589 * This does open a hole in which we will not notice if the first 590 * mount using this sb set explict options and a second mount using 591 * this sb does not set any security options. (The first options 592 * will be used for both mounts) 593 */ 594 if ((sbsec->flags & SE_SBINITIALIZED) && (sb->s_type->fs_flags & FS_BINARY_MOUNTDATA) 595 && (num_opts == 0)) 596 goto out; 597 598 /* 599 * parse the mount options, check if they are valid sids. 600 * also check if someone is trying to mount the same sb more 601 * than once with different security options. 602 */ 603 for (i = 0; i < num_opts; i++) { 604 u32 sid; 605 606 if (flags[i] == SE_SBLABELSUPP) 607 continue; 608 rc = security_context_to_sid(mount_options[i], 609 strlen(mount_options[i]), &sid); 610 if (rc) { 611 printk(KERN_WARNING "SELinux: security_context_to_sid" 612 "(%s) failed for (dev %s, type %s) errno=%d\n", 613 mount_options[i], sb->s_id, name, rc); 614 goto out; 615 } 616 switch (flags[i]) { 617 case FSCONTEXT_MNT: 618 fscontext_sid = sid; 619 620 if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid, 621 fscontext_sid)) 622 goto out_double_mount; 623 624 sbsec->flags |= FSCONTEXT_MNT; 625 break; 626 case CONTEXT_MNT: 627 context_sid = sid; 628 629 if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid, 630 context_sid)) 631 goto out_double_mount; 632 633 sbsec->flags |= CONTEXT_MNT; 634 break; 635 case ROOTCONTEXT_MNT: 636 rootcontext_sid = sid; 637 638 if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid, 639 rootcontext_sid)) 640 goto out_double_mount; 641 642 sbsec->flags |= ROOTCONTEXT_MNT; 643 644 break; 645 case DEFCONTEXT_MNT: 646 defcontext_sid = sid; 647 648 if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid, 649 defcontext_sid)) 650 goto out_double_mount; 651 652 sbsec->flags |= DEFCONTEXT_MNT; 653 654 break; 655 default: 656 rc = -EINVAL; 657 goto out; 658 } 659 } 660 661 if (sbsec->flags & SE_SBINITIALIZED) { 662 /* previously mounted with options, but not on this attempt? */ 663 if ((sbsec->flags & SE_MNTMASK) && !num_opts) 664 goto out_double_mount; 665 rc = 0; 666 goto out; 667 } 668 669 if (strcmp(sb->s_type->name, "proc") == 0) 670 sbsec->flags |= SE_SBPROC; 671 672 /* Determine the labeling behavior to use for this filesystem type. */ 673 rc = security_fs_use((sbsec->flags & SE_SBPROC) ? "proc" : sb->s_type->name, &sbsec->behavior, &sbsec->sid); 674 if (rc) { 675 printk(KERN_WARNING "%s: security_fs_use(%s) returned %d\n", 676 __func__, sb->s_type->name, rc); 677 goto out; 678 } 679 680 /* sets the context of the superblock for the fs being mounted. */ 681 if (fscontext_sid) { 682 rc = may_context_mount_sb_relabel(fscontext_sid, sbsec, cred); 683 if (rc) 684 goto out; 685 686 sbsec->sid = fscontext_sid; 687 } 688 689 /* 690 * Switch to using mount point labeling behavior. 691 * sets the label used on all file below the mountpoint, and will set 692 * the superblock context if not already set. 693 */ 694 if (context_sid) { 695 if (!fscontext_sid) { 696 rc = may_context_mount_sb_relabel(context_sid, sbsec, 697 cred); 698 if (rc) 699 goto out; 700 sbsec->sid = context_sid; 701 } else { 702 rc = may_context_mount_inode_relabel(context_sid, sbsec, 703 cred); 704 if (rc) 705 goto out; 706 } 707 if (!rootcontext_sid) 708 rootcontext_sid = context_sid; 709 710 sbsec->mntpoint_sid = context_sid; 711 sbsec->behavior = SECURITY_FS_USE_MNTPOINT; 712 } 713 714 if (rootcontext_sid) { 715 rc = may_context_mount_inode_relabel(rootcontext_sid, sbsec, 716 cred); 717 if (rc) 718 goto out; 719 720 root_isec->sid = rootcontext_sid; 721 root_isec->initialized = 1; 722 } 723 724 if (defcontext_sid) { 725 if (sbsec->behavior != SECURITY_FS_USE_XATTR) { 726 rc = -EINVAL; 727 printk(KERN_WARNING "SELinux: defcontext option is " 728 "invalid for this filesystem type\n"); 729 goto out; 730 } 731 732 if (defcontext_sid != sbsec->def_sid) { 733 rc = may_context_mount_inode_relabel(defcontext_sid, 734 sbsec, cred); 735 if (rc) 736 goto out; 737 } 738 739 sbsec->def_sid = defcontext_sid; 740 } 741 742 rc = sb_finish_set_opts(sb); 743 out: 744 mutex_unlock(&sbsec->lock); 745 return rc; 746 out_double_mount: 747 rc = -EINVAL; 748 printk(KERN_WARNING "SELinux: mount invalid. Same superblock, different " 749 "security settings for (dev %s, type %s)\n", sb->s_id, name); 750 goto out; 751 } 752 753 static void selinux_sb_clone_mnt_opts(const struct super_block *oldsb, 754 struct super_block *newsb) 755 { 756 const struct superblock_security_struct *oldsbsec = oldsb->s_security; 757 struct superblock_security_struct *newsbsec = newsb->s_security; 758 759 int set_fscontext = (oldsbsec->flags & FSCONTEXT_MNT); 760 int set_context = (oldsbsec->flags & CONTEXT_MNT); 761 int set_rootcontext = (oldsbsec->flags & ROOTCONTEXT_MNT); 762 763 /* 764 * if the parent was able to be mounted it clearly had no special lsm 765 * mount options. thus we can safely deal with this superblock later 766 */ 767 if (!ss_initialized) 768 return; 769 770 /* how can we clone if the old one wasn't set up?? */ 771 BUG_ON(!(oldsbsec->flags & SE_SBINITIALIZED)); 772 773 /* if fs is reusing a sb, just let its options stand... */ 774 if (newsbsec->flags & SE_SBINITIALIZED) 775 return; 776 777 mutex_lock(&newsbsec->lock); 778 779 newsbsec->flags = oldsbsec->flags; 780 781 newsbsec->sid = oldsbsec->sid; 782 newsbsec->def_sid = oldsbsec->def_sid; 783 newsbsec->behavior = oldsbsec->behavior; 784 785 if (set_context) { 786 u32 sid = oldsbsec->mntpoint_sid; 787 788 if (!set_fscontext) 789 newsbsec->sid = sid; 790 if (!set_rootcontext) { 791 struct inode *newinode = newsb->s_root->d_inode; 792 struct inode_security_struct *newisec = newinode->i_security; 793 newisec->sid = sid; 794 } 795 newsbsec->mntpoint_sid = sid; 796 } 797 if (set_rootcontext) { 798 const struct inode *oldinode = oldsb->s_root->d_inode; 799 const struct inode_security_struct *oldisec = oldinode->i_security; 800 struct inode *newinode = newsb->s_root->d_inode; 801 struct inode_security_struct *newisec = newinode->i_security; 802 803 newisec->sid = oldisec->sid; 804 } 805 806 sb_finish_set_opts(newsb); 807 mutex_unlock(&newsbsec->lock); 808 } 809 810 static int selinux_parse_opts_str(char *options, 811 struct security_mnt_opts *opts) 812 { 813 char *p; 814 char *context = NULL, *defcontext = NULL; 815 char *fscontext = NULL, *rootcontext = NULL; 816 int rc, num_mnt_opts = 0; 817 818 opts->num_mnt_opts = 0; 819 820 /* Standard string-based options. */ 821 while ((p = strsep(&options, "|")) != NULL) { 822 int token; 823 substring_t args[MAX_OPT_ARGS]; 824 825 if (!*p) 826 continue; 827 828 token = match_token(p, tokens, args); 829 830 switch (token) { 831 case Opt_context: 832 if (context || defcontext) { 833 rc = -EINVAL; 834 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG); 835 goto out_err; 836 } 837 context = match_strdup(&args[0]); 838 if (!context) { 839 rc = -ENOMEM; 840 goto out_err; 841 } 842 break; 843 844 case Opt_fscontext: 845 if (fscontext) { 846 rc = -EINVAL; 847 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG); 848 goto out_err; 849 } 850 fscontext = match_strdup(&args[0]); 851 if (!fscontext) { 852 rc = -ENOMEM; 853 goto out_err; 854 } 855 break; 856 857 case Opt_rootcontext: 858 if (rootcontext) { 859 rc = -EINVAL; 860 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG); 861 goto out_err; 862 } 863 rootcontext = match_strdup(&args[0]); 864 if (!rootcontext) { 865 rc = -ENOMEM; 866 goto out_err; 867 } 868 break; 869 870 case Opt_defcontext: 871 if (context || defcontext) { 872 rc = -EINVAL; 873 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG); 874 goto out_err; 875 } 876 defcontext = match_strdup(&args[0]); 877 if (!defcontext) { 878 rc = -ENOMEM; 879 goto out_err; 880 } 881 break; 882 case Opt_labelsupport: 883 break; 884 default: 885 rc = -EINVAL; 886 printk(KERN_WARNING "SELinux: unknown mount option\n"); 887 goto out_err; 888 889 } 890 } 891 892 rc = -ENOMEM; 893 opts->mnt_opts = kcalloc(NUM_SEL_MNT_OPTS, sizeof(char *), GFP_ATOMIC); 894 if (!opts->mnt_opts) 895 goto out_err; 896 897 opts->mnt_opts_flags = kcalloc(NUM_SEL_MNT_OPTS, sizeof(int), GFP_ATOMIC); 898 if (!opts->mnt_opts_flags) { 899 kfree(opts->mnt_opts); 900 goto out_err; 901 } 902 903 if (fscontext) { 904 opts->mnt_opts[num_mnt_opts] = fscontext; 905 opts->mnt_opts_flags[num_mnt_opts++] = FSCONTEXT_MNT; 906 } 907 if (context) { 908 opts->mnt_opts[num_mnt_opts] = context; 909 opts->mnt_opts_flags[num_mnt_opts++] = CONTEXT_MNT; 910 } 911 if (rootcontext) { 912 opts->mnt_opts[num_mnt_opts] = rootcontext; 913 opts->mnt_opts_flags[num_mnt_opts++] = ROOTCONTEXT_MNT; 914 } 915 if (defcontext) { 916 opts->mnt_opts[num_mnt_opts] = defcontext; 917 opts->mnt_opts_flags[num_mnt_opts++] = DEFCONTEXT_MNT; 918 } 919 920 opts->num_mnt_opts = num_mnt_opts; 921 return 0; 922 923 out_err: 924 kfree(context); 925 kfree(defcontext); 926 kfree(fscontext); 927 kfree(rootcontext); 928 return rc; 929 } 930 /* 931 * string mount options parsing and call set the sbsec 932 */ 933 static int superblock_doinit(struct super_block *sb, void *data) 934 { 935 int rc = 0; 936 char *options = data; 937 struct security_mnt_opts opts; 938 939 security_init_mnt_opts(&opts); 940 941 if (!data) 942 goto out; 943 944 BUG_ON(sb->s_type->fs_flags & FS_BINARY_MOUNTDATA); 945 946 rc = selinux_parse_opts_str(options, &opts); 947 if (rc) 948 goto out_err; 949 950 out: 951 rc = selinux_set_mnt_opts(sb, &opts); 952 953 out_err: 954 security_free_mnt_opts(&opts); 955 return rc; 956 } 957 958 static void selinux_write_opts(struct seq_file *m, 959 struct security_mnt_opts *opts) 960 { 961 int i; 962 char *prefix; 963 964 for (i = 0; i < opts->num_mnt_opts; i++) { 965 char *has_comma; 966 967 if (opts->mnt_opts[i]) 968 has_comma = strchr(opts->mnt_opts[i], ','); 969 else 970 has_comma = NULL; 971 972 switch (opts->mnt_opts_flags[i]) { 973 case CONTEXT_MNT: 974 prefix = CONTEXT_STR; 975 break; 976 case FSCONTEXT_MNT: 977 prefix = FSCONTEXT_STR; 978 break; 979 case ROOTCONTEXT_MNT: 980 prefix = ROOTCONTEXT_STR; 981 break; 982 case DEFCONTEXT_MNT: 983 prefix = DEFCONTEXT_STR; 984 break; 985 case SE_SBLABELSUPP: 986 seq_putc(m, ','); 987 seq_puts(m, LABELSUPP_STR); 988 continue; 989 default: 990 BUG(); 991 return; 992 }; 993 /* we need a comma before each option */ 994 seq_putc(m, ','); 995 seq_puts(m, prefix); 996 if (has_comma) 997 seq_putc(m, '\"'); 998 seq_puts(m, opts->mnt_opts[i]); 999 if (has_comma) 1000 seq_putc(m, '\"'); 1001 } 1002 } 1003 1004 static int selinux_sb_show_options(struct seq_file *m, struct super_block *sb) 1005 { 1006 struct security_mnt_opts opts; 1007 int rc; 1008 1009 rc = selinux_get_mnt_opts(sb, &opts); 1010 if (rc) { 1011 /* before policy load we may get EINVAL, don't show anything */ 1012 if (rc == -EINVAL) 1013 rc = 0; 1014 return rc; 1015 } 1016 1017 selinux_write_opts(m, &opts); 1018 1019 security_free_mnt_opts(&opts); 1020 1021 return rc; 1022 } 1023 1024 static inline u16 inode_mode_to_security_class(umode_t mode) 1025 { 1026 switch (mode & S_IFMT) { 1027 case S_IFSOCK: 1028 return SECCLASS_SOCK_FILE; 1029 case S_IFLNK: 1030 return SECCLASS_LNK_FILE; 1031 case S_IFREG: 1032 return SECCLASS_FILE; 1033 case S_IFBLK: 1034 return SECCLASS_BLK_FILE; 1035 case S_IFDIR: 1036 return SECCLASS_DIR; 1037 case S_IFCHR: 1038 return SECCLASS_CHR_FILE; 1039 case S_IFIFO: 1040 return SECCLASS_FIFO_FILE; 1041 1042 } 1043 1044 return SECCLASS_FILE; 1045 } 1046 1047 static inline int default_protocol_stream(int protocol) 1048 { 1049 return (protocol == IPPROTO_IP || protocol == IPPROTO_TCP); 1050 } 1051 1052 static inline int default_protocol_dgram(int protocol) 1053 { 1054 return (protocol == IPPROTO_IP || protocol == IPPROTO_UDP); 1055 } 1056 1057 static inline u16 socket_type_to_security_class(int family, int type, int protocol) 1058 { 1059 switch (family) { 1060 case PF_UNIX: 1061 switch (type) { 1062 case SOCK_STREAM: 1063 case SOCK_SEQPACKET: 1064 return SECCLASS_UNIX_STREAM_SOCKET; 1065 case SOCK_DGRAM: 1066 return SECCLASS_UNIX_DGRAM_SOCKET; 1067 } 1068 break; 1069 case PF_INET: 1070 case PF_INET6: 1071 switch (type) { 1072 case SOCK_STREAM: 1073 if (default_protocol_stream(protocol)) 1074 return SECCLASS_TCP_SOCKET; 1075 else 1076 return SECCLASS_RAWIP_SOCKET; 1077 case SOCK_DGRAM: 1078 if (default_protocol_dgram(protocol)) 1079 return SECCLASS_UDP_SOCKET; 1080 else 1081 return SECCLASS_RAWIP_SOCKET; 1082 case SOCK_DCCP: 1083 return SECCLASS_DCCP_SOCKET; 1084 default: 1085 return SECCLASS_RAWIP_SOCKET; 1086 } 1087 break; 1088 case PF_NETLINK: 1089 switch (protocol) { 1090 case NETLINK_ROUTE: 1091 return SECCLASS_NETLINK_ROUTE_SOCKET; 1092 case NETLINK_FIREWALL: 1093 return SECCLASS_NETLINK_FIREWALL_SOCKET; 1094 case NETLINK_SOCK_DIAG: 1095 return SECCLASS_NETLINK_TCPDIAG_SOCKET; 1096 case NETLINK_NFLOG: 1097 return SECCLASS_NETLINK_NFLOG_SOCKET; 1098 case NETLINK_XFRM: 1099 return SECCLASS_NETLINK_XFRM_SOCKET; 1100 case NETLINK_SELINUX: 1101 return SECCLASS_NETLINK_SELINUX_SOCKET; 1102 case NETLINK_AUDIT: 1103 return SECCLASS_NETLINK_AUDIT_SOCKET; 1104 case NETLINK_IP6_FW: 1105 return SECCLASS_NETLINK_IP6FW_SOCKET; 1106 case NETLINK_DNRTMSG: 1107 return SECCLASS_NETLINK_DNRT_SOCKET; 1108 case NETLINK_KOBJECT_UEVENT: 1109 return SECCLASS_NETLINK_KOBJECT_UEVENT_SOCKET; 1110 default: 1111 return SECCLASS_NETLINK_SOCKET; 1112 } 1113 case PF_PACKET: 1114 return SECCLASS_PACKET_SOCKET; 1115 case PF_KEY: 1116 return SECCLASS_KEY_SOCKET; 1117 case PF_APPLETALK: 1118 return SECCLASS_APPLETALK_SOCKET; 1119 } 1120 1121 return SECCLASS_SOCKET; 1122 } 1123 1124 #ifdef CONFIG_PROC_FS 1125 static int selinux_proc_get_sid(struct dentry *dentry, 1126 u16 tclass, 1127 u32 *sid) 1128 { 1129 int rc; 1130 char *buffer, *path; 1131 1132 buffer = (char *)__get_free_page(GFP_KERNEL); 1133 if (!buffer) 1134 return -ENOMEM; 1135 1136 path = dentry_path_raw(dentry, buffer, PAGE_SIZE); 1137 if (IS_ERR(path)) 1138 rc = PTR_ERR(path); 1139 else { 1140 /* each process gets a /proc/PID/ entry. Strip off the 1141 * PID part to get a valid selinux labeling. 1142 * e.g. /proc/1/net/rpc/nfs -> /net/rpc/nfs */ 1143 while (path[1] >= '0' && path[1] <= '9') { 1144 path[1] = '/'; 1145 path++; 1146 } 1147 rc = security_genfs_sid("proc", path, tclass, sid); 1148 } 1149 free_page((unsigned long)buffer); 1150 return rc; 1151 } 1152 #else 1153 static int selinux_proc_get_sid(struct dentry *dentry, 1154 u16 tclass, 1155 u32 *sid) 1156 { 1157 return -EINVAL; 1158 } 1159 #endif 1160 1161 /* The inode's security attributes must be initialized before first use. */ 1162 static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry) 1163 { 1164 struct superblock_security_struct *sbsec = NULL; 1165 struct inode_security_struct *isec = inode->i_security; 1166 u32 sid; 1167 struct dentry *dentry; 1168 #define INITCONTEXTLEN 255 1169 char *context = NULL; 1170 unsigned len = 0; 1171 int rc = 0; 1172 1173 if (isec->initialized) 1174 goto out; 1175 1176 mutex_lock(&isec->lock); 1177 if (isec->initialized) 1178 goto out_unlock; 1179 1180 sbsec = inode->i_sb->s_security; 1181 if (!(sbsec->flags & SE_SBINITIALIZED)) { 1182 /* Defer initialization until selinux_complete_init, 1183 after the initial policy is loaded and the security 1184 server is ready to handle calls. */ 1185 spin_lock(&sbsec->isec_lock); 1186 if (list_empty(&isec->list)) 1187 list_add(&isec->list, &sbsec->isec_head); 1188 spin_unlock(&sbsec->isec_lock); 1189 goto out_unlock; 1190 } 1191 1192 switch (sbsec->behavior) { 1193 case SECURITY_FS_USE_XATTR: 1194 if (!inode->i_op->getxattr) { 1195 isec->sid = sbsec->def_sid; 1196 break; 1197 } 1198 1199 /* Need a dentry, since the xattr API requires one. 1200 Life would be simpler if we could just pass the inode. */ 1201 if (opt_dentry) { 1202 /* Called from d_instantiate or d_splice_alias. */ 1203 dentry = dget(opt_dentry); 1204 } else { 1205 /* Called from selinux_complete_init, try to find a dentry. */ 1206 dentry = d_find_alias(inode); 1207 } 1208 if (!dentry) { 1209 /* 1210 * this is can be hit on boot when a file is accessed 1211 * before the policy is loaded. When we load policy we 1212 * may find inodes that have no dentry on the 1213 * sbsec->isec_head list. No reason to complain as these 1214 * will get fixed up the next time we go through 1215 * inode_doinit with a dentry, before these inodes could 1216 * be used again by userspace. 1217 */ 1218 goto out_unlock; 1219 } 1220 1221 len = INITCONTEXTLEN; 1222 context = kmalloc(len+1, GFP_NOFS); 1223 if (!context) { 1224 rc = -ENOMEM; 1225 dput(dentry); 1226 goto out_unlock; 1227 } 1228 context[len] = '\0'; 1229 rc = inode->i_op->getxattr(dentry, XATTR_NAME_SELINUX, 1230 context, len); 1231 if (rc == -ERANGE) { 1232 kfree(context); 1233 1234 /* Need a larger buffer. Query for the right size. */ 1235 rc = inode->i_op->getxattr(dentry, XATTR_NAME_SELINUX, 1236 NULL, 0); 1237 if (rc < 0) { 1238 dput(dentry); 1239 goto out_unlock; 1240 } 1241 len = rc; 1242 context = kmalloc(len+1, GFP_NOFS); 1243 if (!context) { 1244 rc = -ENOMEM; 1245 dput(dentry); 1246 goto out_unlock; 1247 } 1248 context[len] = '\0'; 1249 rc = inode->i_op->getxattr(dentry, 1250 XATTR_NAME_SELINUX, 1251 context, len); 1252 } 1253 dput(dentry); 1254 if (rc < 0) { 1255 if (rc != -ENODATA) { 1256 printk(KERN_WARNING "SELinux: %s: getxattr returned " 1257 "%d for dev=%s ino=%ld\n", __func__, 1258 -rc, inode->i_sb->s_id, inode->i_ino); 1259 kfree(context); 1260 goto out_unlock; 1261 } 1262 /* Map ENODATA to the default file SID */ 1263 sid = sbsec->def_sid; 1264 rc = 0; 1265 } else { 1266 rc = security_context_to_sid_default(context, rc, &sid, 1267 sbsec->def_sid, 1268 GFP_NOFS); 1269 if (rc) { 1270 char *dev = inode->i_sb->s_id; 1271 unsigned long ino = inode->i_ino; 1272 1273 if (rc == -EINVAL) { 1274 if (printk_ratelimit()) 1275 printk(KERN_NOTICE "SELinux: inode=%lu on dev=%s was found to have an invalid " 1276 "context=%s. This indicates you may need to relabel the inode or the " 1277 "filesystem in question.\n", ino, dev, context); 1278 } else { 1279 printk(KERN_WARNING "SELinux: %s: context_to_sid(%s) " 1280 "returned %d for dev=%s ino=%ld\n", 1281 __func__, context, -rc, dev, ino); 1282 } 1283 kfree(context); 1284 /* Leave with the unlabeled SID */ 1285 rc = 0; 1286 break; 1287 } 1288 } 1289 kfree(context); 1290 isec->sid = sid; 1291 break; 1292 case SECURITY_FS_USE_TASK: 1293 isec->sid = isec->task_sid; 1294 break; 1295 case SECURITY_FS_USE_TRANS: 1296 /* Default to the fs SID. */ 1297 isec->sid = sbsec->sid; 1298 1299 /* Try to obtain a transition SID. */ 1300 isec->sclass = inode_mode_to_security_class(inode->i_mode); 1301 rc = security_transition_sid(isec->task_sid, sbsec->sid, 1302 isec->sclass, NULL, &sid); 1303 if (rc) 1304 goto out_unlock; 1305 isec->sid = sid; 1306 break; 1307 case SECURITY_FS_USE_MNTPOINT: 1308 isec->sid = sbsec->mntpoint_sid; 1309 break; 1310 default: 1311 /* Default to the fs superblock SID. */ 1312 isec->sid = sbsec->sid; 1313 1314 if ((sbsec->flags & SE_SBPROC) && !S_ISLNK(inode->i_mode)) { 1315 if (opt_dentry) { 1316 isec->sclass = inode_mode_to_security_class(inode->i_mode); 1317 rc = selinux_proc_get_sid(opt_dentry, 1318 isec->sclass, 1319 &sid); 1320 if (rc) 1321 goto out_unlock; 1322 isec->sid = sid; 1323 } 1324 } 1325 break; 1326 } 1327 1328 isec->initialized = 1; 1329 1330 out_unlock: 1331 mutex_unlock(&isec->lock); 1332 out: 1333 if (isec->sclass == SECCLASS_FILE) 1334 isec->sclass = inode_mode_to_security_class(inode->i_mode); 1335 return rc; 1336 } 1337 1338 /* Convert a Linux signal to an access vector. */ 1339 static inline u32 signal_to_av(int sig) 1340 { 1341 u32 perm = 0; 1342 1343 switch (sig) { 1344 case SIGCHLD: 1345 /* Commonly granted from child to parent. */ 1346 perm = PROCESS__SIGCHLD; 1347 break; 1348 case SIGKILL: 1349 /* Cannot be caught or ignored */ 1350 perm = PROCESS__SIGKILL; 1351 break; 1352 case SIGSTOP: 1353 /* Cannot be caught or ignored */ 1354 perm = PROCESS__SIGSTOP; 1355 break; 1356 default: 1357 /* All other signals. */ 1358 perm = PROCESS__SIGNAL; 1359 break; 1360 } 1361 1362 return perm; 1363 } 1364 1365 /* 1366 * Check permission between a pair of credentials 1367 * fork check, ptrace check, etc. 1368 */ 1369 static int cred_has_perm(const struct cred *actor, 1370 const struct cred *target, 1371 u32 perms) 1372 { 1373 u32 asid = cred_sid(actor), tsid = cred_sid(target); 1374 1375 return avc_has_perm(asid, tsid, SECCLASS_PROCESS, perms, NULL); 1376 } 1377 1378 /* 1379 * Check permission between a pair of tasks, e.g. signal checks, 1380 * fork check, ptrace check, etc. 1381 * tsk1 is the actor and tsk2 is the target 1382 * - this uses the default subjective creds of tsk1 1383 */ 1384 static int task_has_perm(const struct task_struct *tsk1, 1385 const struct task_struct *tsk2, 1386 u32 perms) 1387 { 1388 const struct task_security_struct *__tsec1, *__tsec2; 1389 u32 sid1, sid2; 1390 1391 rcu_read_lock(); 1392 __tsec1 = __task_cred(tsk1)->security; sid1 = __tsec1->sid; 1393 __tsec2 = __task_cred(tsk2)->security; sid2 = __tsec2->sid; 1394 rcu_read_unlock(); 1395 return avc_has_perm(sid1, sid2, SECCLASS_PROCESS, perms, NULL); 1396 } 1397 1398 /* 1399 * Check permission between current and another task, e.g. signal checks, 1400 * fork check, ptrace check, etc. 1401 * current is the actor and tsk2 is the target 1402 * - this uses current's subjective creds 1403 */ 1404 static int current_has_perm(const struct task_struct *tsk, 1405 u32 perms) 1406 { 1407 u32 sid, tsid; 1408 1409 sid = current_sid(); 1410 tsid = task_sid(tsk); 1411 return avc_has_perm(sid, tsid, SECCLASS_PROCESS, perms, NULL); 1412 } 1413 1414 #if CAP_LAST_CAP > 63 1415 #error Fix SELinux to handle capabilities > 63. 1416 #endif 1417 1418 /* Check whether a task is allowed to use a capability. */ 1419 static int cred_has_capability(const struct cred *cred, 1420 int cap, int audit) 1421 { 1422 struct common_audit_data ad; 1423 struct av_decision avd; 1424 u16 sclass; 1425 u32 sid = cred_sid(cred); 1426 u32 av = CAP_TO_MASK(cap); 1427 int rc; 1428 1429 ad.type = LSM_AUDIT_DATA_CAP; 1430 ad.u.cap = cap; 1431 1432 switch (CAP_TO_INDEX(cap)) { 1433 case 0: 1434 sclass = SECCLASS_CAPABILITY; 1435 break; 1436 case 1: 1437 sclass = SECCLASS_CAPABILITY2; 1438 break; 1439 default: 1440 printk(KERN_ERR 1441 "SELinux: out of range capability %d\n", cap); 1442 BUG(); 1443 return -EINVAL; 1444 } 1445 1446 rc = avc_has_perm_noaudit(sid, sid, sclass, av, 0, &avd); 1447 if (audit == SECURITY_CAP_AUDIT) { 1448 int rc2 = avc_audit(sid, sid, sclass, av, &avd, rc, &ad, 0); 1449 if (rc2) 1450 return rc2; 1451 } 1452 return rc; 1453 } 1454 1455 /* Check whether a task is allowed to use a system operation. */ 1456 static int task_has_system(struct task_struct *tsk, 1457 u32 perms) 1458 { 1459 u32 sid = task_sid(tsk); 1460 1461 return avc_has_perm(sid, SECINITSID_KERNEL, 1462 SECCLASS_SYSTEM, perms, NULL); 1463 } 1464 1465 /* Check whether a task has a particular permission to an inode. 1466 The 'adp' parameter is optional and allows other audit 1467 data to be passed (e.g. the dentry). */ 1468 static int inode_has_perm(const struct cred *cred, 1469 struct inode *inode, 1470 u32 perms, 1471 struct common_audit_data *adp, 1472 unsigned flags) 1473 { 1474 struct inode_security_struct *isec; 1475 u32 sid; 1476 1477 validate_creds(cred); 1478 1479 if (unlikely(IS_PRIVATE(inode))) 1480 return 0; 1481 1482 sid = cred_sid(cred); 1483 isec = inode->i_security; 1484 1485 return avc_has_perm_flags(sid, isec->sid, isec->sclass, perms, adp, flags); 1486 } 1487 1488 /* Same as inode_has_perm, but pass explicit audit data containing 1489 the dentry to help the auditing code to more easily generate the 1490 pathname if needed. */ 1491 static inline int dentry_has_perm(const struct cred *cred, 1492 struct dentry *dentry, 1493 u32 av) 1494 { 1495 struct inode *inode = dentry->d_inode; 1496 struct common_audit_data ad; 1497 1498 ad.type = LSM_AUDIT_DATA_DENTRY; 1499 ad.u.dentry = dentry; 1500 return inode_has_perm(cred, inode, av, &ad, 0); 1501 } 1502 1503 /* Same as inode_has_perm, but pass explicit audit data containing 1504 the path to help the auditing code to more easily generate the 1505 pathname if needed. */ 1506 static inline int path_has_perm(const struct cred *cred, 1507 struct path *path, 1508 u32 av) 1509 { 1510 struct inode *inode = path->dentry->d_inode; 1511 struct common_audit_data ad; 1512 1513 ad.type = LSM_AUDIT_DATA_PATH; 1514 ad.u.path = *path; 1515 return inode_has_perm(cred, inode, av, &ad, 0); 1516 } 1517 1518 /* Check whether a task can use an open file descriptor to 1519 access an inode in a given way. Check access to the 1520 descriptor itself, and then use dentry_has_perm to 1521 check a particular permission to the file. 1522 Access to the descriptor is implicitly granted if it 1523 has the same SID as the process. If av is zero, then 1524 access to the file is not checked, e.g. for cases 1525 where only the descriptor is affected like seek. */ 1526 static int file_has_perm(const struct cred *cred, 1527 struct file *file, 1528 u32 av) 1529 { 1530 struct file_security_struct *fsec = file->f_security; 1531 struct inode *inode = file->f_path.dentry->d_inode; 1532 struct common_audit_data ad; 1533 u32 sid = cred_sid(cred); 1534 int rc; 1535 1536 ad.type = LSM_AUDIT_DATA_PATH; 1537 ad.u.path = file->f_path; 1538 1539 if (sid != fsec->sid) { 1540 rc = avc_has_perm(sid, fsec->sid, 1541 SECCLASS_FD, 1542 FD__USE, 1543 &ad); 1544 if (rc) 1545 goto out; 1546 } 1547 1548 /* av is zero if only checking access to the descriptor. */ 1549 rc = 0; 1550 if (av) 1551 rc = inode_has_perm(cred, inode, av, &ad, 0); 1552 1553 out: 1554 return rc; 1555 } 1556 1557 /* Check whether a task can create a file. */ 1558 static int may_create(struct inode *dir, 1559 struct dentry *dentry, 1560 u16 tclass) 1561 { 1562 const struct task_security_struct *tsec = current_security(); 1563 struct inode_security_struct *dsec; 1564 struct superblock_security_struct *sbsec; 1565 u32 sid, newsid; 1566 struct common_audit_data ad; 1567 int rc; 1568 1569 dsec = dir->i_security; 1570 sbsec = dir->i_sb->s_security; 1571 1572 sid = tsec->sid; 1573 newsid = tsec->create_sid; 1574 1575 ad.type = LSM_AUDIT_DATA_DENTRY; 1576 ad.u.dentry = dentry; 1577 1578 rc = avc_has_perm(sid, dsec->sid, SECCLASS_DIR, 1579 DIR__ADD_NAME | DIR__SEARCH, 1580 &ad); 1581 if (rc) 1582 return rc; 1583 1584 if (!newsid || !(sbsec->flags & SE_SBLABELSUPP)) { 1585 rc = security_transition_sid(sid, dsec->sid, tclass, 1586 &dentry->d_name, &newsid); 1587 if (rc) 1588 return rc; 1589 } 1590 1591 rc = avc_has_perm(sid, newsid, tclass, FILE__CREATE, &ad); 1592 if (rc) 1593 return rc; 1594 1595 return avc_has_perm(newsid, sbsec->sid, 1596 SECCLASS_FILESYSTEM, 1597 FILESYSTEM__ASSOCIATE, &ad); 1598 } 1599 1600 /* Check whether a task can create a key. */ 1601 static int may_create_key(u32 ksid, 1602 struct task_struct *ctx) 1603 { 1604 u32 sid = task_sid(ctx); 1605 1606 return avc_has_perm(sid, ksid, SECCLASS_KEY, KEY__CREATE, NULL); 1607 } 1608 1609 #define MAY_LINK 0 1610 #define MAY_UNLINK 1 1611 #define MAY_RMDIR 2 1612 1613 /* Check whether a task can link, unlink, or rmdir a file/directory. */ 1614 static int may_link(struct inode *dir, 1615 struct dentry *dentry, 1616 int kind) 1617 1618 { 1619 struct inode_security_struct *dsec, *isec; 1620 struct common_audit_data ad; 1621 u32 sid = current_sid(); 1622 u32 av; 1623 int rc; 1624 1625 dsec = dir->i_security; 1626 isec = dentry->d_inode->i_security; 1627 1628 ad.type = LSM_AUDIT_DATA_DENTRY; 1629 ad.u.dentry = dentry; 1630 1631 av = DIR__SEARCH; 1632 av |= (kind ? DIR__REMOVE_NAME : DIR__ADD_NAME); 1633 rc = avc_has_perm(sid, dsec->sid, SECCLASS_DIR, av, &ad); 1634 if (rc) 1635 return rc; 1636 1637 switch (kind) { 1638 case MAY_LINK: 1639 av = FILE__LINK; 1640 break; 1641 case MAY_UNLINK: 1642 av = FILE__UNLINK; 1643 break; 1644 case MAY_RMDIR: 1645 av = DIR__RMDIR; 1646 break; 1647 default: 1648 printk(KERN_WARNING "SELinux: %s: unrecognized kind %d\n", 1649 __func__, kind); 1650 return 0; 1651 } 1652 1653 rc = avc_has_perm(sid, isec->sid, isec->sclass, av, &ad); 1654 return rc; 1655 } 1656 1657 static inline int may_rename(struct inode *old_dir, 1658 struct dentry *old_dentry, 1659 struct inode *new_dir, 1660 struct dentry *new_dentry) 1661 { 1662 struct inode_security_struct *old_dsec, *new_dsec, *old_isec, *new_isec; 1663 struct common_audit_data ad; 1664 u32 sid = current_sid(); 1665 u32 av; 1666 int old_is_dir, new_is_dir; 1667 int rc; 1668 1669 old_dsec = old_dir->i_security; 1670 old_isec = old_dentry->d_inode->i_security; 1671 old_is_dir = S_ISDIR(old_dentry->d_inode->i_mode); 1672 new_dsec = new_dir->i_security; 1673 1674 ad.type = LSM_AUDIT_DATA_DENTRY; 1675 1676 ad.u.dentry = old_dentry; 1677 rc = avc_has_perm(sid, old_dsec->sid, SECCLASS_DIR, 1678 DIR__REMOVE_NAME | DIR__SEARCH, &ad); 1679 if (rc) 1680 return rc; 1681 rc = avc_has_perm(sid, old_isec->sid, 1682 old_isec->sclass, FILE__RENAME, &ad); 1683 if (rc) 1684 return rc; 1685 if (old_is_dir && new_dir != old_dir) { 1686 rc = avc_has_perm(sid, old_isec->sid, 1687 old_isec->sclass, DIR__REPARENT, &ad); 1688 if (rc) 1689 return rc; 1690 } 1691 1692 ad.u.dentry = new_dentry; 1693 av = DIR__ADD_NAME | DIR__SEARCH; 1694 if (new_dentry->d_inode) 1695 av |= DIR__REMOVE_NAME; 1696 rc = avc_has_perm(sid, new_dsec->sid, SECCLASS_DIR, av, &ad); 1697 if (rc) 1698 return rc; 1699 if (new_dentry->d_inode) { 1700 new_isec = new_dentry->d_inode->i_security; 1701 new_is_dir = S_ISDIR(new_dentry->d_inode->i_mode); 1702 rc = avc_has_perm(sid, new_isec->sid, 1703 new_isec->sclass, 1704 (new_is_dir ? DIR__RMDIR : FILE__UNLINK), &ad); 1705 if (rc) 1706 return rc; 1707 } 1708 1709 return 0; 1710 } 1711 1712 /* Check whether a task can perform a filesystem operation. */ 1713 static int superblock_has_perm(const struct cred *cred, 1714 struct super_block *sb, 1715 u32 perms, 1716 struct common_audit_data *ad) 1717 { 1718 struct superblock_security_struct *sbsec; 1719 u32 sid = cred_sid(cred); 1720 1721 sbsec = sb->s_security; 1722 return avc_has_perm(sid, sbsec->sid, SECCLASS_FILESYSTEM, perms, ad); 1723 } 1724 1725 /* Convert a Linux mode and permission mask to an access vector. */ 1726 static inline u32 file_mask_to_av(int mode, int mask) 1727 { 1728 u32 av = 0; 1729 1730 if (!S_ISDIR(mode)) { 1731 if (mask & MAY_EXEC) 1732 av |= FILE__EXECUTE; 1733 if (mask & MAY_READ) 1734 av |= FILE__READ; 1735 1736 if (mask & MAY_APPEND) 1737 av |= FILE__APPEND; 1738 else if (mask & MAY_WRITE) 1739 av |= FILE__WRITE; 1740 1741 } else { 1742 if (mask & MAY_EXEC) 1743 av |= DIR__SEARCH; 1744 if (mask & MAY_WRITE) 1745 av |= DIR__WRITE; 1746 if (mask & MAY_READ) 1747 av |= DIR__READ; 1748 } 1749 1750 return av; 1751 } 1752 1753 /* Convert a Linux file to an access vector. */ 1754 static inline u32 file_to_av(struct file *file) 1755 { 1756 u32 av = 0; 1757 1758 if (file->f_mode & FMODE_READ) 1759 av |= FILE__READ; 1760 if (file->f_mode & FMODE_WRITE) { 1761 if (file->f_flags & O_APPEND) 1762 av |= FILE__APPEND; 1763 else 1764 av |= FILE__WRITE; 1765 } 1766 if (!av) { 1767 /* 1768 * Special file opened with flags 3 for ioctl-only use. 1769 */ 1770 av = FILE__IOCTL; 1771 } 1772 1773 return av; 1774 } 1775 1776 /* 1777 * Convert a file to an access vector and include the correct open 1778 * open permission. 1779 */ 1780 static inline u32 open_file_to_av(struct file *file) 1781 { 1782 u32 av = file_to_av(file); 1783 1784 if (selinux_policycap_openperm) 1785 av |= FILE__OPEN; 1786 1787 return av; 1788 } 1789 1790 /* Hook functions begin here. */ 1791 1792 static int selinux_ptrace_access_check(struct task_struct *child, 1793 unsigned int mode) 1794 { 1795 int rc; 1796 1797 rc = cap_ptrace_access_check(child, mode); 1798 if (rc) 1799 return rc; 1800 1801 if (mode & PTRACE_MODE_READ) { 1802 u32 sid = current_sid(); 1803 u32 csid = task_sid(child); 1804 return avc_has_perm(sid, csid, SECCLASS_FILE, FILE__READ, NULL); 1805 } 1806 1807 return current_has_perm(child, PROCESS__PTRACE); 1808 } 1809 1810 static int selinux_ptrace_traceme(struct task_struct *parent) 1811 { 1812 int rc; 1813 1814 rc = cap_ptrace_traceme(parent); 1815 if (rc) 1816 return rc; 1817 1818 return task_has_perm(parent, current, PROCESS__PTRACE); 1819 } 1820 1821 static int selinux_capget(struct task_struct *target, kernel_cap_t *effective, 1822 kernel_cap_t *inheritable, kernel_cap_t *permitted) 1823 { 1824 int error; 1825 1826 error = current_has_perm(target, PROCESS__GETCAP); 1827 if (error) 1828 return error; 1829 1830 return cap_capget(target, effective, inheritable, permitted); 1831 } 1832 1833 static int selinux_capset(struct cred *new, const struct cred *old, 1834 const kernel_cap_t *effective, 1835 const kernel_cap_t *inheritable, 1836 const kernel_cap_t *permitted) 1837 { 1838 int error; 1839 1840 error = cap_capset(new, old, 1841 effective, inheritable, permitted); 1842 if (error) 1843 return error; 1844 1845 return cred_has_perm(old, new, PROCESS__SETCAP); 1846 } 1847 1848 /* 1849 * (This comment used to live with the selinux_task_setuid hook, 1850 * which was removed). 1851 * 1852 * Since setuid only affects the current process, and since the SELinux 1853 * controls are not based on the Linux identity attributes, SELinux does not 1854 * need to control this operation. However, SELinux does control the use of 1855 * the CAP_SETUID and CAP_SETGID capabilities using the capable hook. 1856 */ 1857 1858 static int selinux_capable(const struct cred *cred, struct user_namespace *ns, 1859 int cap, int audit) 1860 { 1861 int rc; 1862 1863 rc = cap_capable(cred, ns, cap, audit); 1864 if (rc) 1865 return rc; 1866 1867 return cred_has_capability(cred, cap, audit); 1868 } 1869 1870 static int selinux_quotactl(int cmds, int type, int id, struct super_block *sb) 1871 { 1872 const struct cred *cred = current_cred(); 1873 int rc = 0; 1874 1875 if (!sb) 1876 return 0; 1877 1878 switch (cmds) { 1879 case Q_SYNC: 1880 case Q_QUOTAON: 1881 case Q_QUOTAOFF: 1882 case Q_SETINFO: 1883 case Q_SETQUOTA: 1884 rc = superblock_has_perm(cred, sb, FILESYSTEM__QUOTAMOD, NULL); 1885 break; 1886 case Q_GETFMT: 1887 case Q_GETINFO: 1888 case Q_GETQUOTA: 1889 rc = superblock_has_perm(cred, sb, FILESYSTEM__QUOTAGET, NULL); 1890 break; 1891 default: 1892 rc = 0; /* let the kernel handle invalid cmds */ 1893 break; 1894 } 1895 return rc; 1896 } 1897 1898 static int selinux_quota_on(struct dentry *dentry) 1899 { 1900 const struct cred *cred = current_cred(); 1901 1902 return dentry_has_perm(cred, dentry, FILE__QUOTAON); 1903 } 1904 1905 static int selinux_syslog(int type) 1906 { 1907 int rc; 1908 1909 switch (type) { 1910 case SYSLOG_ACTION_READ_ALL: /* Read last kernel messages */ 1911 case SYSLOG_ACTION_SIZE_BUFFER: /* Return size of the log buffer */ 1912 rc = task_has_system(current, SYSTEM__SYSLOG_READ); 1913 break; 1914 case SYSLOG_ACTION_CONSOLE_OFF: /* Disable logging to console */ 1915 case SYSLOG_ACTION_CONSOLE_ON: /* Enable logging to console */ 1916 /* Set level of messages printed to console */ 1917 case SYSLOG_ACTION_CONSOLE_LEVEL: 1918 rc = task_has_system(current, SYSTEM__SYSLOG_CONSOLE); 1919 break; 1920 case SYSLOG_ACTION_CLOSE: /* Close log */ 1921 case SYSLOG_ACTION_OPEN: /* Open log */ 1922 case SYSLOG_ACTION_READ: /* Read from log */ 1923 case SYSLOG_ACTION_READ_CLEAR: /* Read/clear last kernel messages */ 1924 case SYSLOG_ACTION_CLEAR: /* Clear ring buffer */ 1925 default: 1926 rc = task_has_system(current, SYSTEM__SYSLOG_MOD); 1927 break; 1928 } 1929 return rc; 1930 } 1931 1932 /* 1933 * Check that a process has enough memory to allocate a new virtual 1934 * mapping. 0 means there is enough memory for the allocation to 1935 * succeed and -ENOMEM implies there is not. 1936 * 1937 * Do not audit the selinux permission check, as this is applied to all 1938 * processes that allocate mappings. 1939 */ 1940 static int selinux_vm_enough_memory(struct mm_struct *mm, long pages) 1941 { 1942 int rc, cap_sys_admin = 0; 1943 1944 rc = selinux_capable(current_cred(), &init_user_ns, CAP_SYS_ADMIN, 1945 SECURITY_CAP_NOAUDIT); 1946 if (rc == 0) 1947 cap_sys_admin = 1; 1948 1949 return __vm_enough_memory(mm, pages, cap_sys_admin); 1950 } 1951 1952 /* binprm security operations */ 1953 1954 static int selinux_bprm_set_creds(struct linux_binprm *bprm) 1955 { 1956 const struct task_security_struct *old_tsec; 1957 struct task_security_struct *new_tsec; 1958 struct inode_security_struct *isec; 1959 struct common_audit_data ad; 1960 struct inode *inode = bprm->file->f_path.dentry->d_inode; 1961 int rc; 1962 1963 rc = cap_bprm_set_creds(bprm); 1964 if (rc) 1965 return rc; 1966 1967 /* SELinux context only depends on initial program or script and not 1968 * the script interpreter */ 1969 if (bprm->cred_prepared) 1970 return 0; 1971 1972 old_tsec = current_security(); 1973 new_tsec = bprm->cred->security; 1974 isec = inode->i_security; 1975 1976 /* Default to the current task SID. */ 1977 new_tsec->sid = old_tsec->sid; 1978 new_tsec->osid = old_tsec->sid; 1979 1980 /* Reset fs, key, and sock SIDs on execve. */ 1981 new_tsec->create_sid = 0; 1982 new_tsec->keycreate_sid = 0; 1983 new_tsec->sockcreate_sid = 0; 1984 1985 if (old_tsec->exec_sid) { 1986 new_tsec->sid = old_tsec->exec_sid; 1987 /* Reset exec SID on execve. */ 1988 new_tsec->exec_sid = 0; 1989 1990 /* 1991 * Minimize confusion: if no_new_privs and a transition is 1992 * explicitly requested, then fail the exec. 1993 */ 1994 if (bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS) 1995 return -EPERM; 1996 } else { 1997 /* Check for a default transition on this program. */ 1998 rc = security_transition_sid(old_tsec->sid, isec->sid, 1999 SECCLASS_PROCESS, NULL, 2000 &new_tsec->sid); 2001 if (rc) 2002 return rc; 2003 } 2004 2005 ad.type = LSM_AUDIT_DATA_PATH; 2006 ad.u.path = bprm->file->f_path; 2007 2008 if ((bprm->file->f_path.mnt->mnt_flags & MNT_NOSUID) || 2009 (bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS)) 2010 new_tsec->sid = old_tsec->sid; 2011 2012 if (new_tsec->sid == old_tsec->sid) { 2013 rc = avc_has_perm(old_tsec->sid, isec->sid, 2014 SECCLASS_FILE, FILE__EXECUTE_NO_TRANS, &ad); 2015 if (rc) 2016 return rc; 2017 } else { 2018 /* Check permissions for the transition. */ 2019 rc = avc_has_perm(old_tsec->sid, new_tsec->sid, 2020 SECCLASS_PROCESS, PROCESS__TRANSITION, &ad); 2021 if (rc) 2022 return rc; 2023 2024 rc = avc_has_perm(new_tsec->sid, isec->sid, 2025 SECCLASS_FILE, FILE__ENTRYPOINT, &ad); 2026 if (rc) 2027 return rc; 2028 2029 /* Check for shared state */ 2030 if (bprm->unsafe & LSM_UNSAFE_SHARE) { 2031 rc = avc_has_perm(old_tsec->sid, new_tsec->sid, 2032 SECCLASS_PROCESS, PROCESS__SHARE, 2033 NULL); 2034 if (rc) 2035 return -EPERM; 2036 } 2037 2038 /* Make sure that anyone attempting to ptrace over a task that 2039 * changes its SID has the appropriate permit */ 2040 if (bprm->unsafe & 2041 (LSM_UNSAFE_PTRACE | LSM_UNSAFE_PTRACE_CAP)) { 2042 struct task_struct *tracer; 2043 struct task_security_struct *sec; 2044 u32 ptsid = 0; 2045 2046 rcu_read_lock(); 2047 tracer = ptrace_parent(current); 2048 if (likely(tracer != NULL)) { 2049 sec = __task_cred(tracer)->security; 2050 ptsid = sec->sid; 2051 } 2052 rcu_read_unlock(); 2053 2054 if (ptsid != 0) { 2055 rc = avc_has_perm(ptsid, new_tsec->sid, 2056 SECCLASS_PROCESS, 2057 PROCESS__PTRACE, NULL); 2058 if (rc) 2059 return -EPERM; 2060 } 2061 } 2062 2063 /* Clear any possibly unsafe personality bits on exec: */ 2064 bprm->per_clear |= PER_CLEAR_ON_SETID; 2065 } 2066 2067 return 0; 2068 } 2069 2070 static int selinux_bprm_secureexec(struct linux_binprm *bprm) 2071 { 2072 const struct task_security_struct *tsec = current_security(); 2073 u32 sid, osid; 2074 int atsecure = 0; 2075 2076 sid = tsec->sid; 2077 osid = tsec->osid; 2078 2079 if (osid != sid) { 2080 /* Enable secure mode for SIDs transitions unless 2081 the noatsecure permission is granted between 2082 the two SIDs, i.e. ahp returns 0. */ 2083 atsecure = avc_has_perm(osid, sid, 2084 SECCLASS_PROCESS, 2085 PROCESS__NOATSECURE, NULL); 2086 } 2087 2088 return (atsecure || cap_bprm_secureexec(bprm)); 2089 } 2090 2091 static int match_file(const void *p, struct file *file, unsigned fd) 2092 { 2093 return file_has_perm(p, file, file_to_av(file)) ? fd + 1 : 0; 2094 } 2095 2096 /* Derived from fs/exec.c:flush_old_files. */ 2097 static inline void flush_unauthorized_files(const struct cred *cred, 2098 struct files_struct *files) 2099 { 2100 struct file *file, *devnull = NULL; 2101 struct tty_struct *tty; 2102 int drop_tty = 0; 2103 unsigned n; 2104 2105 tty = get_current_tty(); 2106 if (tty) { 2107 spin_lock(&tty_files_lock); 2108 if (!list_empty(&tty->tty_files)) { 2109 struct tty_file_private *file_priv; 2110 2111 /* Revalidate access to controlling tty. 2112 Use path_has_perm on the tty path directly rather 2113 than using file_has_perm, as this particular open 2114 file may belong to another process and we are only 2115 interested in the inode-based check here. */ 2116 file_priv = list_first_entry(&tty->tty_files, 2117 struct tty_file_private, list); 2118 file = file_priv->file; 2119 if (path_has_perm(cred, &file->f_path, FILE__READ | FILE__WRITE)) 2120 drop_tty = 1; 2121 } 2122 spin_unlock(&tty_files_lock); 2123 tty_kref_put(tty); 2124 } 2125 /* Reset controlling tty. */ 2126 if (drop_tty) 2127 no_tty(); 2128 2129 /* Revalidate access to inherited open files. */ 2130 n = iterate_fd(files, 0, match_file, cred); 2131 if (!n) /* none found? */ 2132 return; 2133 2134 devnull = dentry_open(&selinux_null, O_RDWR, cred); 2135 if (IS_ERR(devnull)) 2136 devnull = NULL; 2137 /* replace all the matching ones with this */ 2138 do { 2139 replace_fd(n - 1, devnull, 0); 2140 } while ((n = iterate_fd(files, n, match_file, cred)) != 0); 2141 if (devnull) 2142 fput(devnull); 2143 } 2144 2145 /* 2146 * Prepare a process for imminent new credential changes due to exec 2147 */ 2148 static void selinux_bprm_committing_creds(struct linux_binprm *bprm) 2149 { 2150 struct task_security_struct *new_tsec; 2151 struct rlimit *rlim, *initrlim; 2152 int rc, i; 2153 2154 new_tsec = bprm->cred->security; 2155 if (new_tsec->sid == new_tsec->osid) 2156 return; 2157 2158 /* Close files for which the new task SID is not authorized. */ 2159 flush_unauthorized_files(bprm->cred, current->files); 2160 2161 /* Always clear parent death signal on SID transitions. */ 2162 current->pdeath_signal = 0; 2163 2164 /* Check whether the new SID can inherit resource limits from the old 2165 * SID. If not, reset all soft limits to the lower of the current 2166 * task's hard limit and the init task's soft limit. 2167 * 2168 * Note that the setting of hard limits (even to lower them) can be 2169 * controlled by the setrlimit check. The inclusion of the init task's 2170 * soft limit into the computation is to avoid resetting soft limits 2171 * higher than the default soft limit for cases where the default is 2172 * lower than the hard limit, e.g. RLIMIT_CORE or RLIMIT_STACK. 2173 */ 2174 rc = avc_has_perm(new_tsec->osid, new_tsec->sid, SECCLASS_PROCESS, 2175 PROCESS__RLIMITINH, NULL); 2176 if (rc) { 2177 /* protect against do_prlimit() */ 2178 task_lock(current); 2179 for (i = 0; i < RLIM_NLIMITS; i++) { 2180 rlim = current->signal->rlim + i; 2181 initrlim = init_task.signal->rlim + i; 2182 rlim->rlim_cur = min(rlim->rlim_max, initrlim->rlim_cur); 2183 } 2184 task_unlock(current); 2185 update_rlimit_cpu(current, rlimit(RLIMIT_CPU)); 2186 } 2187 } 2188 2189 /* 2190 * Clean up the process immediately after the installation of new credentials 2191 * due to exec 2192 */ 2193 static void selinux_bprm_committed_creds(struct linux_binprm *bprm) 2194 { 2195 const struct task_security_struct *tsec = current_security(); 2196 struct itimerval itimer; 2197 u32 osid, sid; 2198 int rc, i; 2199 2200 osid = tsec->osid; 2201 sid = tsec->sid; 2202 2203 if (sid == osid) 2204 return; 2205 2206 /* Check whether the new SID can inherit signal state from the old SID. 2207 * If not, clear itimers to avoid subsequent signal generation and 2208 * flush and unblock signals. 2209 * 2210 * This must occur _after_ the task SID has been updated so that any 2211 * kill done after the flush will be checked against the new SID. 2212 */ 2213 rc = avc_has_perm(osid, sid, SECCLASS_PROCESS, PROCESS__SIGINH, NULL); 2214 if (rc) { 2215 memset(&itimer, 0, sizeof itimer); 2216 for (i = 0; i < 3; i++) 2217 do_setitimer(i, &itimer, NULL); 2218 spin_lock_irq(¤t->sighand->siglock); 2219 if (!(current->signal->flags & SIGNAL_GROUP_EXIT)) { 2220 __flush_signals(current); 2221 flush_signal_handlers(current, 1); 2222 sigemptyset(¤t->blocked); 2223 } 2224 spin_unlock_irq(¤t->sighand->siglock); 2225 } 2226 2227 /* Wake up the parent if it is waiting so that it can recheck 2228 * wait permission to the new task SID. */ 2229 read_lock(&tasklist_lock); 2230 __wake_up_parent(current, current->real_parent); 2231 read_unlock(&tasklist_lock); 2232 } 2233 2234 /* superblock security operations */ 2235 2236 static int selinux_sb_alloc_security(struct super_block *sb) 2237 { 2238 return superblock_alloc_security(sb); 2239 } 2240 2241 static void selinux_sb_free_security(struct super_block *sb) 2242 { 2243 superblock_free_security(sb); 2244 } 2245 2246 static inline int match_prefix(char *prefix, int plen, char *option, int olen) 2247 { 2248 if (plen > olen) 2249 return 0; 2250 2251 return !memcmp(prefix, option, plen); 2252 } 2253 2254 static inline int selinux_option(char *option, int len) 2255 { 2256 return (match_prefix(CONTEXT_STR, sizeof(CONTEXT_STR)-1, option, len) || 2257 match_prefix(FSCONTEXT_STR, sizeof(FSCONTEXT_STR)-1, option, len) || 2258 match_prefix(DEFCONTEXT_STR, sizeof(DEFCONTEXT_STR)-1, option, len) || 2259 match_prefix(ROOTCONTEXT_STR, sizeof(ROOTCONTEXT_STR)-1, option, len) || 2260 match_prefix(LABELSUPP_STR, sizeof(LABELSUPP_STR)-1, option, len)); 2261 } 2262 2263 static inline void take_option(char **to, char *from, int *first, int len) 2264 { 2265 if (!*first) { 2266 **to = ','; 2267 *to += 1; 2268 } else 2269 *first = 0; 2270 memcpy(*to, from, len); 2271 *to += len; 2272 } 2273 2274 static inline void take_selinux_option(char **to, char *from, int *first, 2275 int len) 2276 { 2277 int current_size = 0; 2278 2279 if (!*first) { 2280 **to = '|'; 2281 *to += 1; 2282 } else 2283 *first = 0; 2284 2285 while (current_size < len) { 2286 if (*from != '"') { 2287 **to = *from; 2288 *to += 1; 2289 } 2290 from += 1; 2291 current_size += 1; 2292 } 2293 } 2294 2295 static int selinux_sb_copy_data(char *orig, char *copy) 2296 { 2297 int fnosec, fsec, rc = 0; 2298 char *in_save, *in_curr, *in_end; 2299 char *sec_curr, *nosec_save, *nosec; 2300 int open_quote = 0; 2301 2302 in_curr = orig; 2303 sec_curr = copy; 2304 2305 nosec = (char *)get_zeroed_page(GFP_KERNEL); 2306 if (!nosec) { 2307 rc = -ENOMEM; 2308 goto out; 2309 } 2310 2311 nosec_save = nosec; 2312 fnosec = fsec = 1; 2313 in_save = in_end = orig; 2314 2315 do { 2316 if (*in_end == '"') 2317 open_quote = !open_quote; 2318 if ((*in_end == ',' && open_quote == 0) || 2319 *in_end == '\0') { 2320 int len = in_end - in_curr; 2321 2322 if (selinux_option(in_curr, len)) 2323 take_selinux_option(&sec_curr, in_curr, &fsec, len); 2324 else 2325 take_option(&nosec, in_curr, &fnosec, len); 2326 2327 in_curr = in_end + 1; 2328 } 2329 } while (*in_end++); 2330 2331 strcpy(in_save, nosec_save); 2332 free_page((unsigned long)nosec_save); 2333 out: 2334 return rc; 2335 } 2336 2337 static int selinux_sb_remount(struct super_block *sb, void *data) 2338 { 2339 int rc, i, *flags; 2340 struct security_mnt_opts opts; 2341 char *secdata, **mount_options; 2342 struct superblock_security_struct *sbsec = sb->s_security; 2343 2344 if (!(sbsec->flags & SE_SBINITIALIZED)) 2345 return 0; 2346 2347 if (!data) 2348 return 0; 2349 2350 if (sb->s_type->fs_flags & FS_BINARY_MOUNTDATA) 2351 return 0; 2352 2353 security_init_mnt_opts(&opts); 2354 secdata = alloc_secdata(); 2355 if (!secdata) 2356 return -ENOMEM; 2357 rc = selinux_sb_copy_data(data, secdata); 2358 if (rc) 2359 goto out_free_secdata; 2360 2361 rc = selinux_parse_opts_str(secdata, &opts); 2362 if (rc) 2363 goto out_free_secdata; 2364 2365 mount_options = opts.mnt_opts; 2366 flags = opts.mnt_opts_flags; 2367 2368 for (i = 0; i < opts.num_mnt_opts; i++) { 2369 u32 sid; 2370 size_t len; 2371 2372 if (flags[i] == SE_SBLABELSUPP) 2373 continue; 2374 len = strlen(mount_options[i]); 2375 rc = security_context_to_sid(mount_options[i], len, &sid); 2376 if (rc) { 2377 printk(KERN_WARNING "SELinux: security_context_to_sid" 2378 "(%s) failed for (dev %s, type %s) errno=%d\n", 2379 mount_options[i], sb->s_id, sb->s_type->name, rc); 2380 goto out_free_opts; 2381 } 2382 rc = -EINVAL; 2383 switch (flags[i]) { 2384 case FSCONTEXT_MNT: 2385 if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid, sid)) 2386 goto out_bad_option; 2387 break; 2388 case CONTEXT_MNT: 2389 if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid, sid)) 2390 goto out_bad_option; 2391 break; 2392 case ROOTCONTEXT_MNT: { 2393 struct inode_security_struct *root_isec; 2394 root_isec = sb->s_root->d_inode->i_security; 2395 2396 if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid, sid)) 2397 goto out_bad_option; 2398 break; 2399 } 2400 case DEFCONTEXT_MNT: 2401 if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid, sid)) 2402 goto out_bad_option; 2403 break; 2404 default: 2405 goto out_free_opts; 2406 } 2407 } 2408 2409 rc = 0; 2410 out_free_opts: 2411 security_free_mnt_opts(&opts); 2412 out_free_secdata: 2413 free_secdata(secdata); 2414 return rc; 2415 out_bad_option: 2416 printk(KERN_WARNING "SELinux: unable to change security options " 2417 "during remount (dev %s, type=%s)\n", sb->s_id, 2418 sb->s_type->name); 2419 goto out_free_opts; 2420 } 2421 2422 static int selinux_sb_kern_mount(struct super_block *sb, int flags, void *data) 2423 { 2424 const struct cred *cred = current_cred(); 2425 struct common_audit_data ad; 2426 int rc; 2427 2428 rc = superblock_doinit(sb, data); 2429 if (rc) 2430 return rc; 2431 2432 /* Allow all mounts performed by the kernel */ 2433 if (flags & MS_KERNMOUNT) 2434 return 0; 2435 2436 ad.type = LSM_AUDIT_DATA_DENTRY; 2437 ad.u.dentry = sb->s_root; 2438 return superblock_has_perm(cred, sb, FILESYSTEM__MOUNT, &ad); 2439 } 2440 2441 static int selinux_sb_statfs(struct dentry *dentry) 2442 { 2443 const struct cred *cred = current_cred(); 2444 struct common_audit_data ad; 2445 2446 ad.type = LSM_AUDIT_DATA_DENTRY; 2447 ad.u.dentry = dentry->d_sb->s_root; 2448 return superblock_has_perm(cred, dentry->d_sb, FILESYSTEM__GETATTR, &ad); 2449 } 2450 2451 static int selinux_mount(const char *dev_name, 2452 struct path *path, 2453 const char *type, 2454 unsigned long flags, 2455 void *data) 2456 { 2457 const struct cred *cred = current_cred(); 2458 2459 if (flags & MS_REMOUNT) 2460 return superblock_has_perm(cred, path->dentry->d_sb, 2461 FILESYSTEM__REMOUNT, NULL); 2462 else 2463 return path_has_perm(cred, path, FILE__MOUNTON); 2464 } 2465 2466 static int selinux_umount(struct vfsmount *mnt, int flags) 2467 { 2468 const struct cred *cred = current_cred(); 2469 2470 return superblock_has_perm(cred, mnt->mnt_sb, 2471 FILESYSTEM__UNMOUNT, NULL); 2472 } 2473 2474 /* inode security operations */ 2475 2476 static int selinux_inode_alloc_security(struct inode *inode) 2477 { 2478 return inode_alloc_security(inode); 2479 } 2480 2481 static void selinux_inode_free_security(struct inode *inode) 2482 { 2483 inode_free_security(inode); 2484 } 2485 2486 static int selinux_inode_init_security(struct inode *inode, struct inode *dir, 2487 const struct qstr *qstr, char **name, 2488 void **value, size_t *len) 2489 { 2490 const struct task_security_struct *tsec = current_security(); 2491 struct inode_security_struct *dsec; 2492 struct superblock_security_struct *sbsec; 2493 u32 sid, newsid, clen; 2494 int rc; 2495 char *namep = NULL, *context; 2496 2497 dsec = dir->i_security; 2498 sbsec = dir->i_sb->s_security; 2499 2500 sid = tsec->sid; 2501 newsid = tsec->create_sid; 2502 2503 if ((sbsec->flags & SE_SBINITIALIZED) && 2504 (sbsec->behavior == SECURITY_FS_USE_MNTPOINT)) 2505 newsid = sbsec->mntpoint_sid; 2506 else if (!newsid || !(sbsec->flags & SE_SBLABELSUPP)) { 2507 rc = security_transition_sid(sid, dsec->sid, 2508 inode_mode_to_security_class(inode->i_mode), 2509 qstr, &newsid); 2510 if (rc) { 2511 printk(KERN_WARNING "%s: " 2512 "security_transition_sid failed, rc=%d (dev=%s " 2513 "ino=%ld)\n", 2514 __func__, 2515 -rc, inode->i_sb->s_id, inode->i_ino); 2516 return rc; 2517 } 2518 } 2519 2520 /* Possibly defer initialization to selinux_complete_init. */ 2521 if (sbsec->flags & SE_SBINITIALIZED) { 2522 struct inode_security_struct *isec = inode->i_security; 2523 isec->sclass = inode_mode_to_security_class(inode->i_mode); 2524 isec->sid = newsid; 2525 isec->initialized = 1; 2526 } 2527 2528 if (!ss_initialized || !(sbsec->flags & SE_SBLABELSUPP)) 2529 return -EOPNOTSUPP; 2530 2531 if (name) { 2532 namep = kstrdup(XATTR_SELINUX_SUFFIX, GFP_NOFS); 2533 if (!namep) 2534 return -ENOMEM; 2535 *name = namep; 2536 } 2537 2538 if (value && len) { 2539 rc = security_sid_to_context_force(newsid, &context, &clen); 2540 if (rc) { 2541 kfree(namep); 2542 return rc; 2543 } 2544 *value = context; 2545 *len = clen; 2546 } 2547 2548 return 0; 2549 } 2550 2551 static int selinux_inode_create(struct inode *dir, struct dentry *dentry, umode_t mode) 2552 { 2553 return may_create(dir, dentry, SECCLASS_FILE); 2554 } 2555 2556 static int selinux_inode_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry) 2557 { 2558 return may_link(dir, old_dentry, MAY_LINK); 2559 } 2560 2561 static int selinux_inode_unlink(struct inode *dir, struct dentry *dentry) 2562 { 2563 return may_link(dir, dentry, MAY_UNLINK); 2564 } 2565 2566 static int selinux_inode_symlink(struct inode *dir, struct dentry *dentry, const char *name) 2567 { 2568 return may_create(dir, dentry, SECCLASS_LNK_FILE); 2569 } 2570 2571 static int selinux_inode_mkdir(struct inode *dir, struct dentry *dentry, umode_t mask) 2572 { 2573 return may_create(dir, dentry, SECCLASS_DIR); 2574 } 2575 2576 static int selinux_inode_rmdir(struct inode *dir, struct dentry *dentry) 2577 { 2578 return may_link(dir, dentry, MAY_RMDIR); 2579 } 2580 2581 static int selinux_inode_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev) 2582 { 2583 return may_create(dir, dentry, inode_mode_to_security_class(mode)); 2584 } 2585 2586 static int selinux_inode_rename(struct inode *old_inode, struct dentry *old_dentry, 2587 struct inode *new_inode, struct dentry *new_dentry) 2588 { 2589 return may_rename(old_inode, old_dentry, new_inode, new_dentry); 2590 } 2591 2592 static int selinux_inode_readlink(struct dentry *dentry) 2593 { 2594 const struct cred *cred = current_cred(); 2595 2596 return dentry_has_perm(cred, dentry, FILE__READ); 2597 } 2598 2599 static int selinux_inode_follow_link(struct dentry *dentry, struct nameidata *nameidata) 2600 { 2601 const struct cred *cred = current_cred(); 2602 2603 return dentry_has_perm(cred, dentry, FILE__READ); 2604 } 2605 2606 static noinline int audit_inode_permission(struct inode *inode, 2607 u32 perms, u32 audited, u32 denied, 2608 unsigned flags) 2609 { 2610 struct common_audit_data ad; 2611 struct inode_security_struct *isec = inode->i_security; 2612 int rc; 2613 2614 ad.type = LSM_AUDIT_DATA_INODE; 2615 ad.u.inode = inode; 2616 2617 rc = slow_avc_audit(current_sid(), isec->sid, isec->sclass, perms, 2618 audited, denied, &ad, flags); 2619 if (rc) 2620 return rc; 2621 return 0; 2622 } 2623 2624 static int selinux_inode_permission(struct inode *inode, int mask) 2625 { 2626 const struct cred *cred = current_cred(); 2627 u32 perms; 2628 bool from_access; 2629 unsigned flags = mask & MAY_NOT_BLOCK; 2630 struct inode_security_struct *isec; 2631 u32 sid; 2632 struct av_decision avd; 2633 int rc, rc2; 2634 u32 audited, denied; 2635 2636 from_access = mask & MAY_ACCESS; 2637 mask &= (MAY_READ|MAY_WRITE|MAY_EXEC|MAY_APPEND); 2638 2639 /* No permission to check. Existence test. */ 2640 if (!mask) 2641 return 0; 2642 2643 validate_creds(cred); 2644 2645 if (unlikely(IS_PRIVATE(inode))) 2646 return 0; 2647 2648 perms = file_mask_to_av(inode->i_mode, mask); 2649 2650 sid = cred_sid(cred); 2651 isec = inode->i_security; 2652 2653 rc = avc_has_perm_noaudit(sid, isec->sid, isec->sclass, perms, 0, &avd); 2654 audited = avc_audit_required(perms, &avd, rc, 2655 from_access ? FILE__AUDIT_ACCESS : 0, 2656 &denied); 2657 if (likely(!audited)) 2658 return rc; 2659 2660 rc2 = audit_inode_permission(inode, perms, audited, denied, flags); 2661 if (rc2) 2662 return rc2; 2663 return rc; 2664 } 2665 2666 static int selinux_inode_setattr(struct dentry *dentry, struct iattr *iattr) 2667 { 2668 const struct cred *cred = current_cred(); 2669 unsigned int ia_valid = iattr->ia_valid; 2670 __u32 av = FILE__WRITE; 2671 2672 /* ATTR_FORCE is just used for ATTR_KILL_S[UG]ID. */ 2673 if (ia_valid & ATTR_FORCE) { 2674 ia_valid &= ~(ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_MODE | 2675 ATTR_FORCE); 2676 if (!ia_valid) 2677 return 0; 2678 } 2679 2680 if (ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID | 2681 ATTR_ATIME_SET | ATTR_MTIME_SET | ATTR_TIMES_SET)) 2682 return dentry_has_perm(cred, dentry, FILE__SETATTR); 2683 2684 if (selinux_policycap_openperm && (ia_valid & ATTR_SIZE)) 2685 av |= FILE__OPEN; 2686 2687 return dentry_has_perm(cred, dentry, av); 2688 } 2689 2690 static int selinux_inode_getattr(struct vfsmount *mnt, struct dentry *dentry) 2691 { 2692 const struct cred *cred = current_cred(); 2693 struct path path; 2694 2695 path.dentry = dentry; 2696 path.mnt = mnt; 2697 2698 return path_has_perm(cred, &path, FILE__GETATTR); 2699 } 2700 2701 static int selinux_inode_setotherxattr(struct dentry *dentry, const char *name) 2702 { 2703 const struct cred *cred = current_cred(); 2704 2705 if (!strncmp(name, XATTR_SECURITY_PREFIX, 2706 sizeof XATTR_SECURITY_PREFIX - 1)) { 2707 if (!strcmp(name, XATTR_NAME_CAPS)) { 2708 if (!capable(CAP_SETFCAP)) 2709 return -EPERM; 2710 } else if (!capable(CAP_SYS_ADMIN)) { 2711 /* A different attribute in the security namespace. 2712 Restrict to administrator. */ 2713 return -EPERM; 2714 } 2715 } 2716 2717 /* Not an attribute we recognize, so just check the 2718 ordinary setattr permission. */ 2719 return dentry_has_perm(cred, dentry, FILE__SETATTR); 2720 } 2721 2722 static int selinux_inode_setxattr(struct dentry *dentry, const char *name, 2723 const void *value, size_t size, int flags) 2724 { 2725 struct inode *inode = dentry->d_inode; 2726 struct inode_security_struct *isec = inode->i_security; 2727 struct superblock_security_struct *sbsec; 2728 struct common_audit_data ad; 2729 u32 newsid, sid = current_sid(); 2730 int rc = 0; 2731 2732 if (strcmp(name, XATTR_NAME_SELINUX)) 2733 return selinux_inode_setotherxattr(dentry, name); 2734 2735 sbsec = inode->i_sb->s_security; 2736 if (!(sbsec->flags & SE_SBLABELSUPP)) 2737 return -EOPNOTSUPP; 2738 2739 if (!inode_owner_or_capable(inode)) 2740 return -EPERM; 2741 2742 ad.type = LSM_AUDIT_DATA_DENTRY; 2743 ad.u.dentry = dentry; 2744 2745 rc = avc_has_perm(sid, isec->sid, isec->sclass, 2746 FILE__RELABELFROM, &ad); 2747 if (rc) 2748 return rc; 2749 2750 rc = security_context_to_sid(value, size, &newsid); 2751 if (rc == -EINVAL) { 2752 if (!capable(CAP_MAC_ADMIN)) { 2753 struct audit_buffer *ab; 2754 size_t audit_size; 2755 const char *str; 2756 2757 /* We strip a nul only if it is at the end, otherwise the 2758 * context contains a nul and we should audit that */ 2759 if (value) { 2760 str = value; 2761 if (str[size - 1] == '\0') 2762 audit_size = size - 1; 2763 else 2764 audit_size = size; 2765 } else { 2766 str = ""; 2767 audit_size = 0; 2768 } 2769 ab = audit_log_start(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR); 2770 audit_log_format(ab, "op=setxattr invalid_context="); 2771 audit_log_n_untrustedstring(ab, value, audit_size); 2772 audit_log_end(ab); 2773 2774 return rc; 2775 } 2776 rc = security_context_to_sid_force(value, size, &newsid); 2777 } 2778 if (rc) 2779 return rc; 2780 2781 rc = avc_has_perm(sid, newsid, isec->sclass, 2782 FILE__RELABELTO, &ad); 2783 if (rc) 2784 return rc; 2785 2786 rc = security_validate_transition(isec->sid, newsid, sid, 2787 isec->sclass); 2788 if (rc) 2789 return rc; 2790 2791 return avc_has_perm(newsid, 2792 sbsec->sid, 2793 SECCLASS_FILESYSTEM, 2794 FILESYSTEM__ASSOCIATE, 2795 &ad); 2796 } 2797 2798 static void selinux_inode_post_setxattr(struct dentry *dentry, const char *name, 2799 const void *value, size_t size, 2800 int flags) 2801 { 2802 struct inode *inode = dentry->d_inode; 2803 struct inode_security_struct *isec = inode->i_security; 2804 u32 newsid; 2805 int rc; 2806 2807 if (strcmp(name, XATTR_NAME_SELINUX)) { 2808 /* Not an attribute we recognize, so nothing to do. */ 2809 return; 2810 } 2811 2812 rc = security_context_to_sid_force(value, size, &newsid); 2813 if (rc) { 2814 printk(KERN_ERR "SELinux: unable to map context to SID" 2815 "for (%s, %lu), rc=%d\n", 2816 inode->i_sb->s_id, inode->i_ino, -rc); 2817 return; 2818 } 2819 2820 isec->sid = newsid; 2821 return; 2822 } 2823 2824 static int selinux_inode_getxattr(struct dentry *dentry, const char *name) 2825 { 2826 const struct cred *cred = current_cred(); 2827 2828 return dentry_has_perm(cred, dentry, FILE__GETATTR); 2829 } 2830 2831 static int selinux_inode_listxattr(struct dentry *dentry) 2832 { 2833 const struct cred *cred = current_cred(); 2834 2835 return dentry_has_perm(cred, dentry, FILE__GETATTR); 2836 } 2837 2838 static int selinux_inode_removexattr(struct dentry *dentry, const char *name) 2839 { 2840 if (strcmp(name, XATTR_NAME_SELINUX)) 2841 return selinux_inode_setotherxattr(dentry, name); 2842 2843 /* No one is allowed to remove a SELinux security label. 2844 You can change the label, but all data must be labeled. */ 2845 return -EACCES; 2846 } 2847 2848 /* 2849 * Copy the inode security context value to the user. 2850 * 2851 * Permission check is handled by selinux_inode_getxattr hook. 2852 */ 2853 static int selinux_inode_getsecurity(const struct inode *inode, const char *name, void **buffer, bool alloc) 2854 { 2855 u32 size; 2856 int error; 2857 char *context = NULL; 2858 struct inode_security_struct *isec = inode->i_security; 2859 2860 if (strcmp(name, XATTR_SELINUX_SUFFIX)) 2861 return -EOPNOTSUPP; 2862 2863 /* 2864 * If the caller has CAP_MAC_ADMIN, then get the raw context 2865 * value even if it is not defined by current policy; otherwise, 2866 * use the in-core value under current policy. 2867 * Use the non-auditing forms of the permission checks since 2868 * getxattr may be called by unprivileged processes commonly 2869 * and lack of permission just means that we fall back to the 2870 * in-core context value, not a denial. 2871 */ 2872 error = selinux_capable(current_cred(), &init_user_ns, CAP_MAC_ADMIN, 2873 SECURITY_CAP_NOAUDIT); 2874 if (!error) 2875 error = security_sid_to_context_force(isec->sid, &context, 2876 &size); 2877 else 2878 error = security_sid_to_context(isec->sid, &context, &size); 2879 if (error) 2880 return error; 2881 error = size; 2882 if (alloc) { 2883 *buffer = context; 2884 goto out_nofree; 2885 } 2886 kfree(context); 2887 out_nofree: 2888 return error; 2889 } 2890 2891 static int selinux_inode_setsecurity(struct inode *inode, const char *name, 2892 const void *value, size_t size, int flags) 2893 { 2894 struct inode_security_struct *isec = inode->i_security; 2895 u32 newsid; 2896 int rc; 2897 2898 if (strcmp(name, XATTR_SELINUX_SUFFIX)) 2899 return -EOPNOTSUPP; 2900 2901 if (!value || !size) 2902 return -EACCES; 2903 2904 rc = security_context_to_sid((void *)value, size, &newsid); 2905 if (rc) 2906 return rc; 2907 2908 isec->sid = newsid; 2909 isec->initialized = 1; 2910 return 0; 2911 } 2912 2913 static int selinux_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size) 2914 { 2915 const int len = sizeof(XATTR_NAME_SELINUX); 2916 if (buffer && len <= buffer_size) 2917 memcpy(buffer, XATTR_NAME_SELINUX, len); 2918 return len; 2919 } 2920 2921 static void selinux_inode_getsecid(const struct inode *inode, u32 *secid) 2922 { 2923 struct inode_security_struct *isec = inode->i_security; 2924 *secid = isec->sid; 2925 } 2926 2927 /* file security operations */ 2928 2929 static int selinux_revalidate_file_permission(struct file *file, int mask) 2930 { 2931 const struct cred *cred = current_cred(); 2932 struct inode *inode = file->f_path.dentry->d_inode; 2933 2934 /* file_mask_to_av won't add FILE__WRITE if MAY_APPEND is set */ 2935 if ((file->f_flags & O_APPEND) && (mask & MAY_WRITE)) 2936 mask |= MAY_APPEND; 2937 2938 return file_has_perm(cred, file, 2939 file_mask_to_av(inode->i_mode, mask)); 2940 } 2941 2942 static int selinux_file_permission(struct file *file, int mask) 2943 { 2944 struct inode *inode = file->f_path.dentry->d_inode; 2945 struct file_security_struct *fsec = file->f_security; 2946 struct inode_security_struct *isec = inode->i_security; 2947 u32 sid = current_sid(); 2948 2949 if (!mask) 2950 /* No permission to check. Existence test. */ 2951 return 0; 2952 2953 if (sid == fsec->sid && fsec->isid == isec->sid && 2954 fsec->pseqno == avc_policy_seqno()) 2955 /* No change since file_open check. */ 2956 return 0; 2957 2958 return selinux_revalidate_file_permission(file, mask); 2959 } 2960 2961 static int selinux_file_alloc_security(struct file *file) 2962 { 2963 return file_alloc_security(file); 2964 } 2965 2966 static void selinux_file_free_security(struct file *file) 2967 { 2968 file_free_security(file); 2969 } 2970 2971 static int selinux_file_ioctl(struct file *file, unsigned int cmd, 2972 unsigned long arg) 2973 { 2974 const struct cred *cred = current_cred(); 2975 int error = 0; 2976 2977 switch (cmd) { 2978 case FIONREAD: 2979 /* fall through */ 2980 case FIBMAP: 2981 /* fall through */ 2982 case FIGETBSZ: 2983 /* fall through */ 2984 case FS_IOC_GETFLAGS: 2985 /* fall through */ 2986 case FS_IOC_GETVERSION: 2987 error = file_has_perm(cred, file, FILE__GETATTR); 2988 break; 2989 2990 case FS_IOC_SETFLAGS: 2991 /* fall through */ 2992 case FS_IOC_SETVERSION: 2993 error = file_has_perm(cred, file, FILE__SETATTR); 2994 break; 2995 2996 /* sys_ioctl() checks */ 2997 case FIONBIO: 2998 /* fall through */ 2999 case FIOASYNC: 3000 error = file_has_perm(cred, file, 0); 3001 break; 3002 3003 case KDSKBENT: 3004 case KDSKBSENT: 3005 error = cred_has_capability(cred, CAP_SYS_TTY_CONFIG, 3006 SECURITY_CAP_AUDIT); 3007 break; 3008 3009 /* default case assumes that the command will go 3010 * to the file's ioctl() function. 3011 */ 3012 default: 3013 error = file_has_perm(cred, file, FILE__IOCTL); 3014 } 3015 return error; 3016 } 3017 3018 static int default_noexec; 3019 3020 static int file_map_prot_check(struct file *file, unsigned long prot, int shared) 3021 { 3022 const struct cred *cred = current_cred(); 3023 int rc = 0; 3024 3025 if (default_noexec && 3026 (prot & PROT_EXEC) && (!file || (!shared && (prot & PROT_WRITE)))) { 3027 /* 3028 * We are making executable an anonymous mapping or a 3029 * private file mapping that will also be writable. 3030 * This has an additional check. 3031 */ 3032 rc = cred_has_perm(cred, cred, PROCESS__EXECMEM); 3033 if (rc) 3034 goto error; 3035 } 3036 3037 if (file) { 3038 /* read access is always possible with a mapping */ 3039 u32 av = FILE__READ; 3040 3041 /* write access only matters if the mapping is shared */ 3042 if (shared && (prot & PROT_WRITE)) 3043 av |= FILE__WRITE; 3044 3045 if (prot & PROT_EXEC) 3046 av |= FILE__EXECUTE; 3047 3048 return file_has_perm(cred, file, av); 3049 } 3050 3051 error: 3052 return rc; 3053 } 3054 3055 static int selinux_mmap_addr(unsigned long addr) 3056 { 3057 int rc = 0; 3058 u32 sid = current_sid(); 3059 3060 /* 3061 * notice that we are intentionally putting the SELinux check before 3062 * the secondary cap_file_mmap check. This is such a likely attempt 3063 * at bad behaviour/exploit that we always want to get the AVC, even 3064 * if DAC would have also denied the operation. 3065 */ 3066 if (addr < CONFIG_LSM_MMAP_MIN_ADDR) { 3067 rc = avc_has_perm(sid, sid, SECCLASS_MEMPROTECT, 3068 MEMPROTECT__MMAP_ZERO, NULL); 3069 if (rc) 3070 return rc; 3071 } 3072 3073 /* do DAC check on address space usage */ 3074 return cap_mmap_addr(addr); 3075 } 3076 3077 static int selinux_mmap_file(struct file *file, unsigned long reqprot, 3078 unsigned long prot, unsigned long flags) 3079 { 3080 if (selinux_checkreqprot) 3081 prot = reqprot; 3082 3083 return file_map_prot_check(file, prot, 3084 (flags & MAP_TYPE) == MAP_SHARED); 3085 } 3086 3087 static int selinux_file_mprotect(struct vm_area_struct *vma, 3088 unsigned long reqprot, 3089 unsigned long prot) 3090 { 3091 const struct cred *cred = current_cred(); 3092 3093 if (selinux_checkreqprot) 3094 prot = reqprot; 3095 3096 if (default_noexec && 3097 (prot & PROT_EXEC) && !(vma->vm_flags & VM_EXEC)) { 3098 int rc = 0; 3099 if (vma->vm_start >= vma->vm_mm->start_brk && 3100 vma->vm_end <= vma->vm_mm->brk) { 3101 rc = cred_has_perm(cred, cred, PROCESS__EXECHEAP); 3102 } else if (!vma->vm_file && 3103 vma->vm_start <= vma->vm_mm->start_stack && 3104 vma->vm_end >= vma->vm_mm->start_stack) { 3105 rc = current_has_perm(current, PROCESS__EXECSTACK); 3106 } else if (vma->vm_file && vma->anon_vma) { 3107 /* 3108 * We are making executable a file mapping that has 3109 * had some COW done. Since pages might have been 3110 * written, check ability to execute the possibly 3111 * modified content. This typically should only 3112 * occur for text relocations. 3113 */ 3114 rc = file_has_perm(cred, vma->vm_file, FILE__EXECMOD); 3115 } 3116 if (rc) 3117 return rc; 3118 } 3119 3120 return file_map_prot_check(vma->vm_file, prot, vma->vm_flags&VM_SHARED); 3121 } 3122 3123 static int selinux_file_lock(struct file *file, unsigned int cmd) 3124 { 3125 const struct cred *cred = current_cred(); 3126 3127 return file_has_perm(cred, file, FILE__LOCK); 3128 } 3129 3130 static int selinux_file_fcntl(struct file *file, unsigned int cmd, 3131 unsigned long arg) 3132 { 3133 const struct cred *cred = current_cred(); 3134 int err = 0; 3135 3136 switch (cmd) { 3137 case F_SETFL: 3138 if (!file->f_path.dentry || !file->f_path.dentry->d_inode) { 3139 err = -EINVAL; 3140 break; 3141 } 3142 3143 if ((file->f_flags & O_APPEND) && !(arg & O_APPEND)) { 3144 err = file_has_perm(cred, file, FILE__WRITE); 3145 break; 3146 } 3147 /* fall through */ 3148 case F_SETOWN: 3149 case F_SETSIG: 3150 case F_GETFL: 3151 case F_GETOWN: 3152 case F_GETSIG: 3153 case F_GETOWNER_UIDS: 3154 /* Just check FD__USE permission */ 3155 err = file_has_perm(cred, file, 0); 3156 break; 3157 case F_GETLK: 3158 case F_SETLK: 3159 case F_SETLKW: 3160 #if BITS_PER_LONG == 32 3161 case F_GETLK64: 3162 case F_SETLK64: 3163 case F_SETLKW64: 3164 #endif 3165 if (!file->f_path.dentry || !file->f_path.dentry->d_inode) { 3166 err = -EINVAL; 3167 break; 3168 } 3169 err = file_has_perm(cred, file, FILE__LOCK); 3170 break; 3171 } 3172 3173 return err; 3174 } 3175 3176 static int selinux_file_set_fowner(struct file *file) 3177 { 3178 struct file_security_struct *fsec; 3179 3180 fsec = file->f_security; 3181 fsec->fown_sid = current_sid(); 3182 3183 return 0; 3184 } 3185 3186 static int selinux_file_send_sigiotask(struct task_struct *tsk, 3187 struct fown_struct *fown, int signum) 3188 { 3189 struct file *file; 3190 u32 sid = task_sid(tsk); 3191 u32 perm; 3192 struct file_security_struct *fsec; 3193 3194 /* struct fown_struct is never outside the context of a struct file */ 3195 file = container_of(fown, struct file, f_owner); 3196 3197 fsec = file->f_security; 3198 3199 if (!signum) 3200 perm = signal_to_av(SIGIO); /* as per send_sigio_to_task */ 3201 else 3202 perm = signal_to_av(signum); 3203 3204 return avc_has_perm(fsec->fown_sid, sid, 3205 SECCLASS_PROCESS, perm, NULL); 3206 } 3207 3208 static int selinux_file_receive(struct file *file) 3209 { 3210 const struct cred *cred = current_cred(); 3211 3212 return file_has_perm(cred, file, file_to_av(file)); 3213 } 3214 3215 static int selinux_file_open(struct file *file, const struct cred *cred) 3216 { 3217 struct file_security_struct *fsec; 3218 struct inode_security_struct *isec; 3219 3220 fsec = file->f_security; 3221 isec = file->f_path.dentry->d_inode->i_security; 3222 /* 3223 * Save inode label and policy sequence number 3224 * at open-time so that selinux_file_permission 3225 * can determine whether revalidation is necessary. 3226 * Task label is already saved in the file security 3227 * struct as its SID. 3228 */ 3229 fsec->isid = isec->sid; 3230 fsec->pseqno = avc_policy_seqno(); 3231 /* 3232 * Since the inode label or policy seqno may have changed 3233 * between the selinux_inode_permission check and the saving 3234 * of state above, recheck that access is still permitted. 3235 * Otherwise, access might never be revalidated against the 3236 * new inode label or new policy. 3237 * This check is not redundant - do not remove. 3238 */ 3239 return path_has_perm(cred, &file->f_path, open_file_to_av(file)); 3240 } 3241 3242 /* task security operations */ 3243 3244 static int selinux_task_create(unsigned long clone_flags) 3245 { 3246 return current_has_perm(current, PROCESS__FORK); 3247 } 3248 3249 /* 3250 * allocate the SELinux part of blank credentials 3251 */ 3252 static int selinux_cred_alloc_blank(struct cred *cred, gfp_t gfp) 3253 { 3254 struct task_security_struct *tsec; 3255 3256 tsec = kzalloc(sizeof(struct task_security_struct), gfp); 3257 if (!tsec) 3258 return -ENOMEM; 3259 3260 cred->security = tsec; 3261 return 0; 3262 } 3263 3264 /* 3265 * detach and free the LSM part of a set of credentials 3266 */ 3267 static void selinux_cred_free(struct cred *cred) 3268 { 3269 struct task_security_struct *tsec = cred->security; 3270 3271 /* 3272 * cred->security == NULL if security_cred_alloc_blank() or 3273 * security_prepare_creds() returned an error. 3274 */ 3275 BUG_ON(cred->security && (unsigned long) cred->security < PAGE_SIZE); 3276 cred->security = (void *) 0x7UL; 3277 kfree(tsec); 3278 } 3279 3280 /* 3281 * prepare a new set of credentials for modification 3282 */ 3283 static int selinux_cred_prepare(struct cred *new, const struct cred *old, 3284 gfp_t gfp) 3285 { 3286 const struct task_security_struct *old_tsec; 3287 struct task_security_struct *tsec; 3288 3289 old_tsec = old->security; 3290 3291 tsec = kmemdup(old_tsec, sizeof(struct task_security_struct), gfp); 3292 if (!tsec) 3293 return -ENOMEM; 3294 3295 new->security = tsec; 3296 return 0; 3297 } 3298 3299 /* 3300 * transfer the SELinux data to a blank set of creds 3301 */ 3302 static void selinux_cred_transfer(struct cred *new, const struct cred *old) 3303 { 3304 const struct task_security_struct *old_tsec = old->security; 3305 struct task_security_struct *tsec = new->security; 3306 3307 *tsec = *old_tsec; 3308 } 3309 3310 /* 3311 * set the security data for a kernel service 3312 * - all the creation contexts are set to unlabelled 3313 */ 3314 static int selinux_kernel_act_as(struct cred *new, u32 secid) 3315 { 3316 struct task_security_struct *tsec = new->security; 3317 u32 sid = current_sid(); 3318 int ret; 3319 3320 ret = avc_has_perm(sid, secid, 3321 SECCLASS_KERNEL_SERVICE, 3322 KERNEL_SERVICE__USE_AS_OVERRIDE, 3323 NULL); 3324 if (ret == 0) { 3325 tsec->sid = secid; 3326 tsec->create_sid = 0; 3327 tsec->keycreate_sid = 0; 3328 tsec->sockcreate_sid = 0; 3329 } 3330 return ret; 3331 } 3332 3333 /* 3334 * set the file creation context in a security record to the same as the 3335 * objective context of the specified inode 3336 */ 3337 static int selinux_kernel_create_files_as(struct cred *new, struct inode *inode) 3338 { 3339 struct inode_security_struct *isec = inode->i_security; 3340 struct task_security_struct *tsec = new->security; 3341 u32 sid = current_sid(); 3342 int ret; 3343 3344 ret = avc_has_perm(sid, isec->sid, 3345 SECCLASS_KERNEL_SERVICE, 3346 KERNEL_SERVICE__CREATE_FILES_AS, 3347 NULL); 3348 3349 if (ret == 0) 3350 tsec->create_sid = isec->sid; 3351 return ret; 3352 } 3353 3354 static int selinux_kernel_module_request(char *kmod_name) 3355 { 3356 u32 sid; 3357 struct common_audit_data ad; 3358 3359 sid = task_sid(current); 3360 3361 ad.type = LSM_AUDIT_DATA_KMOD; 3362 ad.u.kmod_name = kmod_name; 3363 3364 return avc_has_perm(sid, SECINITSID_KERNEL, SECCLASS_SYSTEM, 3365 SYSTEM__MODULE_REQUEST, &ad); 3366 } 3367 3368 static int selinux_task_setpgid(struct task_struct *p, pid_t pgid) 3369 { 3370 return current_has_perm(p, PROCESS__SETPGID); 3371 } 3372 3373 static int selinux_task_getpgid(struct task_struct *p) 3374 { 3375 return current_has_perm(p, PROCESS__GETPGID); 3376 } 3377 3378 static int selinux_task_getsid(struct task_struct *p) 3379 { 3380 return current_has_perm(p, PROCESS__GETSESSION); 3381 } 3382 3383 static void selinux_task_getsecid(struct task_struct *p, u32 *secid) 3384 { 3385 *secid = task_sid(p); 3386 } 3387 3388 static int selinux_task_setnice(struct task_struct *p, int nice) 3389 { 3390 int rc; 3391 3392 rc = cap_task_setnice(p, nice); 3393 if (rc) 3394 return rc; 3395 3396 return current_has_perm(p, PROCESS__SETSCHED); 3397 } 3398 3399 static int selinux_task_setioprio(struct task_struct *p, int ioprio) 3400 { 3401 int rc; 3402 3403 rc = cap_task_setioprio(p, ioprio); 3404 if (rc) 3405 return rc; 3406 3407 return current_has_perm(p, PROCESS__SETSCHED); 3408 } 3409 3410 static int selinux_task_getioprio(struct task_struct *p) 3411 { 3412 return current_has_perm(p, PROCESS__GETSCHED); 3413 } 3414 3415 static int selinux_task_setrlimit(struct task_struct *p, unsigned int resource, 3416 struct rlimit *new_rlim) 3417 { 3418 struct rlimit *old_rlim = p->signal->rlim + resource; 3419 3420 /* Control the ability to change the hard limit (whether 3421 lowering or raising it), so that the hard limit can 3422 later be used as a safe reset point for the soft limit 3423 upon context transitions. See selinux_bprm_committing_creds. */ 3424 if (old_rlim->rlim_max != new_rlim->rlim_max) 3425 return current_has_perm(p, PROCESS__SETRLIMIT); 3426 3427 return 0; 3428 } 3429 3430 static int selinux_task_setscheduler(struct task_struct *p) 3431 { 3432 int rc; 3433 3434 rc = cap_task_setscheduler(p); 3435 if (rc) 3436 return rc; 3437 3438 return current_has_perm(p, PROCESS__SETSCHED); 3439 } 3440 3441 static int selinux_task_getscheduler(struct task_struct *p) 3442 { 3443 return current_has_perm(p, PROCESS__GETSCHED); 3444 } 3445 3446 static int selinux_task_movememory(struct task_struct *p) 3447 { 3448 return current_has_perm(p, PROCESS__SETSCHED); 3449 } 3450 3451 static int selinux_task_kill(struct task_struct *p, struct siginfo *info, 3452 int sig, u32 secid) 3453 { 3454 u32 perm; 3455 int rc; 3456 3457 if (!sig) 3458 perm = PROCESS__SIGNULL; /* null signal; existence test */ 3459 else 3460 perm = signal_to_av(sig); 3461 if (secid) 3462 rc = avc_has_perm(secid, task_sid(p), 3463 SECCLASS_PROCESS, perm, NULL); 3464 else 3465 rc = current_has_perm(p, perm); 3466 return rc; 3467 } 3468 3469 static int selinux_task_wait(struct task_struct *p) 3470 { 3471 return task_has_perm(p, current, PROCESS__SIGCHLD); 3472 } 3473 3474 static void selinux_task_to_inode(struct task_struct *p, 3475 struct inode *inode) 3476 { 3477 struct inode_security_struct *isec = inode->i_security; 3478 u32 sid = task_sid(p); 3479 3480 isec->sid = sid; 3481 isec->initialized = 1; 3482 } 3483 3484 /* Returns error only if unable to parse addresses */ 3485 static int selinux_parse_skb_ipv4(struct sk_buff *skb, 3486 struct common_audit_data *ad, u8 *proto) 3487 { 3488 int offset, ihlen, ret = -EINVAL; 3489 struct iphdr _iph, *ih; 3490 3491 offset = skb_network_offset(skb); 3492 ih = skb_header_pointer(skb, offset, sizeof(_iph), &_iph); 3493 if (ih == NULL) 3494 goto out; 3495 3496 ihlen = ih->ihl * 4; 3497 if (ihlen < sizeof(_iph)) 3498 goto out; 3499 3500 ad->u.net->v4info.saddr = ih->saddr; 3501 ad->u.net->v4info.daddr = ih->daddr; 3502 ret = 0; 3503 3504 if (proto) 3505 *proto = ih->protocol; 3506 3507 switch (ih->protocol) { 3508 case IPPROTO_TCP: { 3509 struct tcphdr _tcph, *th; 3510 3511 if (ntohs(ih->frag_off) & IP_OFFSET) 3512 break; 3513 3514 offset += ihlen; 3515 th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph); 3516 if (th == NULL) 3517 break; 3518 3519 ad->u.net->sport = th->source; 3520 ad->u.net->dport = th->dest; 3521 break; 3522 } 3523 3524 case IPPROTO_UDP: { 3525 struct udphdr _udph, *uh; 3526 3527 if (ntohs(ih->frag_off) & IP_OFFSET) 3528 break; 3529 3530 offset += ihlen; 3531 uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph); 3532 if (uh == NULL) 3533 break; 3534 3535 ad->u.net->sport = uh->source; 3536 ad->u.net->dport = uh->dest; 3537 break; 3538 } 3539 3540 case IPPROTO_DCCP: { 3541 struct dccp_hdr _dccph, *dh; 3542 3543 if (ntohs(ih->frag_off) & IP_OFFSET) 3544 break; 3545 3546 offset += ihlen; 3547 dh = skb_header_pointer(skb, offset, sizeof(_dccph), &_dccph); 3548 if (dh == NULL) 3549 break; 3550 3551 ad->u.net->sport = dh->dccph_sport; 3552 ad->u.net->dport = dh->dccph_dport; 3553 break; 3554 } 3555 3556 default: 3557 break; 3558 } 3559 out: 3560 return ret; 3561 } 3562 3563 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) 3564 3565 /* Returns error only if unable to parse addresses */ 3566 static int selinux_parse_skb_ipv6(struct sk_buff *skb, 3567 struct common_audit_data *ad, u8 *proto) 3568 { 3569 u8 nexthdr; 3570 int ret = -EINVAL, offset; 3571 struct ipv6hdr _ipv6h, *ip6; 3572 __be16 frag_off; 3573 3574 offset = skb_network_offset(skb); 3575 ip6 = skb_header_pointer(skb, offset, sizeof(_ipv6h), &_ipv6h); 3576 if (ip6 == NULL) 3577 goto out; 3578 3579 ad->u.net->v6info.saddr = ip6->saddr; 3580 ad->u.net->v6info.daddr = ip6->daddr; 3581 ret = 0; 3582 3583 nexthdr = ip6->nexthdr; 3584 offset += sizeof(_ipv6h); 3585 offset = ipv6_skip_exthdr(skb, offset, &nexthdr, &frag_off); 3586 if (offset < 0) 3587 goto out; 3588 3589 if (proto) 3590 *proto = nexthdr; 3591 3592 switch (nexthdr) { 3593 case IPPROTO_TCP: { 3594 struct tcphdr _tcph, *th; 3595 3596 th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph); 3597 if (th == NULL) 3598 break; 3599 3600 ad->u.net->sport = th->source; 3601 ad->u.net->dport = th->dest; 3602 break; 3603 } 3604 3605 case IPPROTO_UDP: { 3606 struct udphdr _udph, *uh; 3607 3608 uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph); 3609 if (uh == NULL) 3610 break; 3611 3612 ad->u.net->sport = uh->source; 3613 ad->u.net->dport = uh->dest; 3614 break; 3615 } 3616 3617 case IPPROTO_DCCP: { 3618 struct dccp_hdr _dccph, *dh; 3619 3620 dh = skb_header_pointer(skb, offset, sizeof(_dccph), &_dccph); 3621 if (dh == NULL) 3622 break; 3623 3624 ad->u.net->sport = dh->dccph_sport; 3625 ad->u.net->dport = dh->dccph_dport; 3626 break; 3627 } 3628 3629 /* includes fragments */ 3630 default: 3631 break; 3632 } 3633 out: 3634 return ret; 3635 } 3636 3637 #endif /* IPV6 */ 3638 3639 static int selinux_parse_skb(struct sk_buff *skb, struct common_audit_data *ad, 3640 char **_addrp, int src, u8 *proto) 3641 { 3642 char *addrp; 3643 int ret; 3644 3645 switch (ad->u.net->family) { 3646 case PF_INET: 3647 ret = selinux_parse_skb_ipv4(skb, ad, proto); 3648 if (ret) 3649 goto parse_error; 3650 addrp = (char *)(src ? &ad->u.net->v4info.saddr : 3651 &ad->u.net->v4info.daddr); 3652 goto okay; 3653 3654 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) 3655 case PF_INET6: 3656 ret = selinux_parse_skb_ipv6(skb, ad, proto); 3657 if (ret) 3658 goto parse_error; 3659 addrp = (char *)(src ? &ad->u.net->v6info.saddr : 3660 &ad->u.net->v6info.daddr); 3661 goto okay; 3662 #endif /* IPV6 */ 3663 default: 3664 addrp = NULL; 3665 goto okay; 3666 } 3667 3668 parse_error: 3669 printk(KERN_WARNING 3670 "SELinux: failure in selinux_parse_skb()," 3671 " unable to parse packet\n"); 3672 return ret; 3673 3674 okay: 3675 if (_addrp) 3676 *_addrp = addrp; 3677 return 0; 3678 } 3679 3680 /** 3681 * selinux_skb_peerlbl_sid - Determine the peer label of a packet 3682 * @skb: the packet 3683 * @family: protocol family 3684 * @sid: the packet's peer label SID 3685 * 3686 * Description: 3687 * Check the various different forms of network peer labeling and determine 3688 * the peer label/SID for the packet; most of the magic actually occurs in 3689 * the security server function security_net_peersid_cmp(). The function 3690 * returns zero if the value in @sid is valid (although it may be SECSID_NULL) 3691 * or -EACCES if @sid is invalid due to inconsistencies with the different 3692 * peer labels. 3693 * 3694 */ 3695 static int selinux_skb_peerlbl_sid(struct sk_buff *skb, u16 family, u32 *sid) 3696 { 3697 int err; 3698 u32 xfrm_sid; 3699 u32 nlbl_sid; 3700 u32 nlbl_type; 3701 3702 selinux_skb_xfrm_sid(skb, &xfrm_sid); 3703 selinux_netlbl_skbuff_getsid(skb, family, &nlbl_type, &nlbl_sid); 3704 3705 err = security_net_peersid_resolve(nlbl_sid, nlbl_type, xfrm_sid, sid); 3706 if (unlikely(err)) { 3707 printk(KERN_WARNING 3708 "SELinux: failure in selinux_skb_peerlbl_sid()," 3709 " unable to determine packet's peer label\n"); 3710 return -EACCES; 3711 } 3712 3713 return 0; 3714 } 3715 3716 /* socket security operations */ 3717 3718 static int socket_sockcreate_sid(const struct task_security_struct *tsec, 3719 u16 secclass, u32 *socksid) 3720 { 3721 if (tsec->sockcreate_sid > SECSID_NULL) { 3722 *socksid = tsec->sockcreate_sid; 3723 return 0; 3724 } 3725 3726 return security_transition_sid(tsec->sid, tsec->sid, secclass, NULL, 3727 socksid); 3728 } 3729 3730 static int sock_has_perm(struct task_struct *task, struct sock *sk, u32 perms) 3731 { 3732 struct sk_security_struct *sksec = sk->sk_security; 3733 struct common_audit_data ad; 3734 struct lsm_network_audit net = {0,}; 3735 u32 tsid = task_sid(task); 3736 3737 if (sksec->sid == SECINITSID_KERNEL) 3738 return 0; 3739 3740 ad.type = LSM_AUDIT_DATA_NET; 3741 ad.u.net = &net; 3742 ad.u.net->sk = sk; 3743 3744 return avc_has_perm(tsid, sksec->sid, sksec->sclass, perms, &ad); 3745 } 3746 3747 static int selinux_socket_create(int family, int type, 3748 int protocol, int kern) 3749 { 3750 const struct task_security_struct *tsec = current_security(); 3751 u32 newsid; 3752 u16 secclass; 3753 int rc; 3754 3755 if (kern) 3756 return 0; 3757 3758 secclass = socket_type_to_security_class(family, type, protocol); 3759 rc = socket_sockcreate_sid(tsec, secclass, &newsid); 3760 if (rc) 3761 return rc; 3762 3763 return avc_has_perm(tsec->sid, newsid, secclass, SOCKET__CREATE, NULL); 3764 } 3765 3766 static int selinux_socket_post_create(struct socket *sock, int family, 3767 int type, int protocol, int kern) 3768 { 3769 const struct task_security_struct *tsec = current_security(); 3770 struct inode_security_struct *isec = SOCK_INODE(sock)->i_security; 3771 struct sk_security_struct *sksec; 3772 int err = 0; 3773 3774 isec->sclass = socket_type_to_security_class(family, type, protocol); 3775 3776 if (kern) 3777 isec->sid = SECINITSID_KERNEL; 3778 else { 3779 err = socket_sockcreate_sid(tsec, isec->sclass, &(isec->sid)); 3780 if (err) 3781 return err; 3782 } 3783 3784 isec->initialized = 1; 3785 3786 if (sock->sk) { 3787 sksec = sock->sk->sk_security; 3788 sksec->sid = isec->sid; 3789 sksec->sclass = isec->sclass; 3790 err = selinux_netlbl_socket_post_create(sock->sk, family); 3791 } 3792 3793 return err; 3794 } 3795 3796 /* Range of port numbers used to automatically bind. 3797 Need to determine whether we should perform a name_bind 3798 permission check between the socket and the port number. */ 3799 3800 static int selinux_socket_bind(struct socket *sock, struct sockaddr *address, int addrlen) 3801 { 3802 struct sock *sk = sock->sk; 3803 u16 family; 3804 int err; 3805 3806 err = sock_has_perm(current, sk, SOCKET__BIND); 3807 if (err) 3808 goto out; 3809 3810 /* 3811 * If PF_INET or PF_INET6, check name_bind permission for the port. 3812 * Multiple address binding for SCTP is not supported yet: we just 3813 * check the first address now. 3814 */ 3815 family = sk->sk_family; 3816 if (family == PF_INET || family == PF_INET6) { 3817 char *addrp; 3818 struct sk_security_struct *sksec = sk->sk_security; 3819 struct common_audit_data ad; 3820 struct lsm_network_audit net = {0,}; 3821 struct sockaddr_in *addr4 = NULL; 3822 struct sockaddr_in6 *addr6 = NULL; 3823 unsigned short snum; 3824 u32 sid, node_perm; 3825 3826 if (family == PF_INET) { 3827 addr4 = (struct sockaddr_in *)address; 3828 snum = ntohs(addr4->sin_port); 3829 addrp = (char *)&addr4->sin_addr.s_addr; 3830 } else { 3831 addr6 = (struct sockaddr_in6 *)address; 3832 snum = ntohs(addr6->sin6_port); 3833 addrp = (char *)&addr6->sin6_addr.s6_addr; 3834 } 3835 3836 if (snum) { 3837 int low, high; 3838 3839 inet_get_local_port_range(&low, &high); 3840 3841 if (snum < max(PROT_SOCK, low) || snum > high) { 3842 err = sel_netport_sid(sk->sk_protocol, 3843 snum, &sid); 3844 if (err) 3845 goto out; 3846 ad.type = LSM_AUDIT_DATA_NET; 3847 ad.u.net = &net; 3848 ad.u.net->sport = htons(snum); 3849 ad.u.net->family = family; 3850 err = avc_has_perm(sksec->sid, sid, 3851 sksec->sclass, 3852 SOCKET__NAME_BIND, &ad); 3853 if (err) 3854 goto out; 3855 } 3856 } 3857 3858 switch (sksec->sclass) { 3859 case SECCLASS_TCP_SOCKET: 3860 node_perm = TCP_SOCKET__NODE_BIND; 3861 break; 3862 3863 case SECCLASS_UDP_SOCKET: 3864 node_perm = UDP_SOCKET__NODE_BIND; 3865 break; 3866 3867 case SECCLASS_DCCP_SOCKET: 3868 node_perm = DCCP_SOCKET__NODE_BIND; 3869 break; 3870 3871 default: 3872 node_perm = RAWIP_SOCKET__NODE_BIND; 3873 break; 3874 } 3875 3876 err = sel_netnode_sid(addrp, family, &sid); 3877 if (err) 3878 goto out; 3879 3880 ad.type = LSM_AUDIT_DATA_NET; 3881 ad.u.net = &net; 3882 ad.u.net->sport = htons(snum); 3883 ad.u.net->family = family; 3884 3885 if (family == PF_INET) 3886 ad.u.net->v4info.saddr = addr4->sin_addr.s_addr; 3887 else 3888 ad.u.net->v6info.saddr = addr6->sin6_addr; 3889 3890 err = avc_has_perm(sksec->sid, sid, 3891 sksec->sclass, node_perm, &ad); 3892 if (err) 3893 goto out; 3894 } 3895 out: 3896 return err; 3897 } 3898 3899 static int selinux_socket_connect(struct socket *sock, struct sockaddr *address, int addrlen) 3900 { 3901 struct sock *sk = sock->sk; 3902 struct sk_security_struct *sksec = sk->sk_security; 3903 int err; 3904 3905 err = sock_has_perm(current, sk, SOCKET__CONNECT); 3906 if (err) 3907 return err; 3908 3909 /* 3910 * If a TCP or DCCP socket, check name_connect permission for the port. 3911 */ 3912 if (sksec->sclass == SECCLASS_TCP_SOCKET || 3913 sksec->sclass == SECCLASS_DCCP_SOCKET) { 3914 struct common_audit_data ad; 3915 struct lsm_network_audit net = {0,}; 3916 struct sockaddr_in *addr4 = NULL; 3917 struct sockaddr_in6 *addr6 = NULL; 3918 unsigned short snum; 3919 u32 sid, perm; 3920 3921 if (sk->sk_family == PF_INET) { 3922 addr4 = (struct sockaddr_in *)address; 3923 if (addrlen < sizeof(struct sockaddr_in)) 3924 return -EINVAL; 3925 snum = ntohs(addr4->sin_port); 3926 } else { 3927 addr6 = (struct sockaddr_in6 *)address; 3928 if (addrlen < SIN6_LEN_RFC2133) 3929 return -EINVAL; 3930 snum = ntohs(addr6->sin6_port); 3931 } 3932 3933 err = sel_netport_sid(sk->sk_protocol, snum, &sid); 3934 if (err) 3935 goto out; 3936 3937 perm = (sksec->sclass == SECCLASS_TCP_SOCKET) ? 3938 TCP_SOCKET__NAME_CONNECT : DCCP_SOCKET__NAME_CONNECT; 3939 3940 ad.type = LSM_AUDIT_DATA_NET; 3941 ad.u.net = &net; 3942 ad.u.net->dport = htons(snum); 3943 ad.u.net->family = sk->sk_family; 3944 err = avc_has_perm(sksec->sid, sid, sksec->sclass, perm, &ad); 3945 if (err) 3946 goto out; 3947 } 3948 3949 err = selinux_netlbl_socket_connect(sk, address); 3950 3951 out: 3952 return err; 3953 } 3954 3955 static int selinux_socket_listen(struct socket *sock, int backlog) 3956 { 3957 return sock_has_perm(current, sock->sk, SOCKET__LISTEN); 3958 } 3959 3960 static int selinux_socket_accept(struct socket *sock, struct socket *newsock) 3961 { 3962 int err; 3963 struct inode_security_struct *isec; 3964 struct inode_security_struct *newisec; 3965 3966 err = sock_has_perm(current, sock->sk, SOCKET__ACCEPT); 3967 if (err) 3968 return err; 3969 3970 newisec = SOCK_INODE(newsock)->i_security; 3971 3972 isec = SOCK_INODE(sock)->i_security; 3973 newisec->sclass = isec->sclass; 3974 newisec->sid = isec->sid; 3975 newisec->initialized = 1; 3976 3977 return 0; 3978 } 3979 3980 static int selinux_socket_sendmsg(struct socket *sock, struct msghdr *msg, 3981 int size) 3982 { 3983 return sock_has_perm(current, sock->sk, SOCKET__WRITE); 3984 } 3985 3986 static int selinux_socket_recvmsg(struct socket *sock, struct msghdr *msg, 3987 int size, int flags) 3988 { 3989 return sock_has_perm(current, sock->sk, SOCKET__READ); 3990 } 3991 3992 static int selinux_socket_getsockname(struct socket *sock) 3993 { 3994 return sock_has_perm(current, sock->sk, SOCKET__GETATTR); 3995 } 3996 3997 static int selinux_socket_getpeername(struct socket *sock) 3998 { 3999 return sock_has_perm(current, sock->sk, SOCKET__GETATTR); 4000 } 4001 4002 static int selinux_socket_setsockopt(struct socket *sock, int level, int optname) 4003 { 4004 int err; 4005 4006 err = sock_has_perm(current, sock->sk, SOCKET__SETOPT); 4007 if (err) 4008 return err; 4009 4010 return selinux_netlbl_socket_setsockopt(sock, level, optname); 4011 } 4012 4013 static int selinux_socket_getsockopt(struct socket *sock, int level, 4014 int optname) 4015 { 4016 return sock_has_perm(current, sock->sk, SOCKET__GETOPT); 4017 } 4018 4019 static int selinux_socket_shutdown(struct socket *sock, int how) 4020 { 4021 return sock_has_perm(current, sock->sk, SOCKET__SHUTDOWN); 4022 } 4023 4024 static int selinux_socket_unix_stream_connect(struct sock *sock, 4025 struct sock *other, 4026 struct sock *newsk) 4027 { 4028 struct sk_security_struct *sksec_sock = sock->sk_security; 4029 struct sk_security_struct *sksec_other = other->sk_security; 4030 struct sk_security_struct *sksec_new = newsk->sk_security; 4031 struct common_audit_data ad; 4032 struct lsm_network_audit net = {0,}; 4033 int err; 4034 4035 ad.type = LSM_AUDIT_DATA_NET; 4036 ad.u.net = &net; 4037 ad.u.net->sk = other; 4038 4039 err = avc_has_perm(sksec_sock->sid, sksec_other->sid, 4040 sksec_other->sclass, 4041 UNIX_STREAM_SOCKET__CONNECTTO, &ad); 4042 if (err) 4043 return err; 4044 4045 /* server child socket */ 4046 sksec_new->peer_sid = sksec_sock->sid; 4047 err = security_sid_mls_copy(sksec_other->sid, sksec_sock->sid, 4048 &sksec_new->sid); 4049 if (err) 4050 return err; 4051 4052 /* connecting socket */ 4053 sksec_sock->peer_sid = sksec_new->sid; 4054 4055 return 0; 4056 } 4057 4058 static int selinux_socket_unix_may_send(struct socket *sock, 4059 struct socket *other) 4060 { 4061 struct sk_security_struct *ssec = sock->sk->sk_security; 4062 struct sk_security_struct *osec = other->sk->sk_security; 4063 struct common_audit_data ad; 4064 struct lsm_network_audit net = {0,}; 4065 4066 ad.type = LSM_AUDIT_DATA_NET; 4067 ad.u.net = &net; 4068 ad.u.net->sk = other->sk; 4069 4070 return avc_has_perm(ssec->sid, osec->sid, osec->sclass, SOCKET__SENDTO, 4071 &ad); 4072 } 4073 4074 static int selinux_inet_sys_rcv_skb(int ifindex, char *addrp, u16 family, 4075 u32 peer_sid, 4076 struct common_audit_data *ad) 4077 { 4078 int err; 4079 u32 if_sid; 4080 u32 node_sid; 4081 4082 err = sel_netif_sid(ifindex, &if_sid); 4083 if (err) 4084 return err; 4085 err = avc_has_perm(peer_sid, if_sid, 4086 SECCLASS_NETIF, NETIF__INGRESS, ad); 4087 if (err) 4088 return err; 4089 4090 err = sel_netnode_sid(addrp, family, &node_sid); 4091 if (err) 4092 return err; 4093 return avc_has_perm(peer_sid, node_sid, 4094 SECCLASS_NODE, NODE__RECVFROM, ad); 4095 } 4096 4097 static int selinux_sock_rcv_skb_compat(struct sock *sk, struct sk_buff *skb, 4098 u16 family) 4099 { 4100 int err = 0; 4101 struct sk_security_struct *sksec = sk->sk_security; 4102 u32 sk_sid = sksec->sid; 4103 struct common_audit_data ad; 4104 struct lsm_network_audit net = {0,}; 4105 char *addrp; 4106 4107 ad.type = LSM_AUDIT_DATA_NET; 4108 ad.u.net = &net; 4109 ad.u.net->netif = skb->skb_iif; 4110 ad.u.net->family = family; 4111 err = selinux_parse_skb(skb, &ad, &addrp, 1, NULL); 4112 if (err) 4113 return err; 4114 4115 if (selinux_secmark_enabled()) { 4116 err = avc_has_perm(sk_sid, skb->secmark, SECCLASS_PACKET, 4117 PACKET__RECV, &ad); 4118 if (err) 4119 return err; 4120 } 4121 4122 err = selinux_netlbl_sock_rcv_skb(sksec, skb, family, &ad); 4123 if (err) 4124 return err; 4125 err = selinux_xfrm_sock_rcv_skb(sksec->sid, skb, &ad); 4126 4127 return err; 4128 } 4129 4130 static int selinux_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb) 4131 { 4132 int err; 4133 struct sk_security_struct *sksec = sk->sk_security; 4134 u16 family = sk->sk_family; 4135 u32 sk_sid = sksec->sid; 4136 struct common_audit_data ad; 4137 struct lsm_network_audit net = {0,}; 4138 char *addrp; 4139 u8 secmark_active; 4140 u8 peerlbl_active; 4141 4142 if (family != PF_INET && family != PF_INET6) 4143 return 0; 4144 4145 /* Handle mapped IPv4 packets arriving via IPv6 sockets */ 4146 if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP)) 4147 family = PF_INET; 4148 4149 /* If any sort of compatibility mode is enabled then handoff processing 4150 * to the selinux_sock_rcv_skb_compat() function to deal with the 4151 * special handling. We do this in an attempt to keep this function 4152 * as fast and as clean as possible. */ 4153 if (!selinux_policycap_netpeer) 4154 return selinux_sock_rcv_skb_compat(sk, skb, family); 4155 4156 secmark_active = selinux_secmark_enabled(); 4157 peerlbl_active = netlbl_enabled() || selinux_xfrm_enabled(); 4158 if (!secmark_active && !peerlbl_active) 4159 return 0; 4160 4161 ad.type = LSM_AUDIT_DATA_NET; 4162 ad.u.net = &net; 4163 ad.u.net->netif = skb->skb_iif; 4164 ad.u.net->family = family; 4165 err = selinux_parse_skb(skb, &ad, &addrp, 1, NULL); 4166 if (err) 4167 return err; 4168 4169 if (peerlbl_active) { 4170 u32 peer_sid; 4171 4172 err = selinux_skb_peerlbl_sid(skb, family, &peer_sid); 4173 if (err) 4174 return err; 4175 err = selinux_inet_sys_rcv_skb(skb->skb_iif, addrp, family, 4176 peer_sid, &ad); 4177 if (err) { 4178 selinux_netlbl_err(skb, err, 0); 4179 return err; 4180 } 4181 err = avc_has_perm(sk_sid, peer_sid, SECCLASS_PEER, 4182 PEER__RECV, &ad); 4183 if (err) 4184 selinux_netlbl_err(skb, err, 0); 4185 } 4186 4187 if (secmark_active) { 4188 err = avc_has_perm(sk_sid, skb->secmark, SECCLASS_PACKET, 4189 PACKET__RECV, &ad); 4190 if (err) 4191 return err; 4192 } 4193 4194 return err; 4195 } 4196 4197 static int selinux_socket_getpeersec_stream(struct socket *sock, char __user *optval, 4198 int __user *optlen, unsigned len) 4199 { 4200 int err = 0; 4201 char *scontext; 4202 u32 scontext_len; 4203 struct sk_security_struct *sksec = sock->sk->sk_security; 4204 u32 peer_sid = SECSID_NULL; 4205 4206 if (sksec->sclass == SECCLASS_UNIX_STREAM_SOCKET || 4207 sksec->sclass == SECCLASS_TCP_SOCKET) 4208 peer_sid = sksec->peer_sid; 4209 if (peer_sid == SECSID_NULL) 4210 return -ENOPROTOOPT; 4211 4212 err = security_sid_to_context(peer_sid, &scontext, &scontext_len); 4213 if (err) 4214 return err; 4215 4216 if (scontext_len > len) { 4217 err = -ERANGE; 4218 goto out_len; 4219 } 4220 4221 if (copy_to_user(optval, scontext, scontext_len)) 4222 err = -EFAULT; 4223 4224 out_len: 4225 if (put_user(scontext_len, optlen)) 4226 err = -EFAULT; 4227 kfree(scontext); 4228 return err; 4229 } 4230 4231 static int selinux_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb, u32 *secid) 4232 { 4233 u32 peer_secid = SECSID_NULL; 4234 u16 family; 4235 4236 if (skb && skb->protocol == htons(ETH_P_IP)) 4237 family = PF_INET; 4238 else if (skb && skb->protocol == htons(ETH_P_IPV6)) 4239 family = PF_INET6; 4240 else if (sock) 4241 family = sock->sk->sk_family; 4242 else 4243 goto out; 4244 4245 if (sock && family == PF_UNIX) 4246 selinux_inode_getsecid(SOCK_INODE(sock), &peer_secid); 4247 else if (skb) 4248 selinux_skb_peerlbl_sid(skb, family, &peer_secid); 4249 4250 out: 4251 *secid = peer_secid; 4252 if (peer_secid == SECSID_NULL) 4253 return -EINVAL; 4254 return 0; 4255 } 4256 4257 static int selinux_sk_alloc_security(struct sock *sk, int family, gfp_t priority) 4258 { 4259 struct sk_security_struct *sksec; 4260 4261 sksec = kzalloc(sizeof(*sksec), priority); 4262 if (!sksec) 4263 return -ENOMEM; 4264 4265 sksec->peer_sid = SECINITSID_UNLABELED; 4266 sksec->sid = SECINITSID_UNLABELED; 4267 selinux_netlbl_sk_security_reset(sksec); 4268 sk->sk_security = sksec; 4269 4270 return 0; 4271 } 4272 4273 static void selinux_sk_free_security(struct sock *sk) 4274 { 4275 struct sk_security_struct *sksec = sk->sk_security; 4276 4277 sk->sk_security = NULL; 4278 selinux_netlbl_sk_security_free(sksec); 4279 kfree(sksec); 4280 } 4281 4282 static void selinux_sk_clone_security(const struct sock *sk, struct sock *newsk) 4283 { 4284 struct sk_security_struct *sksec = sk->sk_security; 4285 struct sk_security_struct *newsksec = newsk->sk_security; 4286 4287 newsksec->sid = sksec->sid; 4288 newsksec->peer_sid = sksec->peer_sid; 4289 newsksec->sclass = sksec->sclass; 4290 4291 selinux_netlbl_sk_security_reset(newsksec); 4292 } 4293 4294 static void selinux_sk_getsecid(struct sock *sk, u32 *secid) 4295 { 4296 if (!sk) 4297 *secid = SECINITSID_ANY_SOCKET; 4298 else { 4299 struct sk_security_struct *sksec = sk->sk_security; 4300 4301 *secid = sksec->sid; 4302 } 4303 } 4304 4305 static void selinux_sock_graft(struct sock *sk, struct socket *parent) 4306 { 4307 struct inode_security_struct *isec = SOCK_INODE(parent)->i_security; 4308 struct sk_security_struct *sksec = sk->sk_security; 4309 4310 if (sk->sk_family == PF_INET || sk->sk_family == PF_INET6 || 4311 sk->sk_family == PF_UNIX) 4312 isec->sid = sksec->sid; 4313 sksec->sclass = isec->sclass; 4314 } 4315 4316 static int selinux_inet_conn_request(struct sock *sk, struct sk_buff *skb, 4317 struct request_sock *req) 4318 { 4319 struct sk_security_struct *sksec = sk->sk_security; 4320 int err; 4321 u16 family = sk->sk_family; 4322 u32 newsid; 4323 u32 peersid; 4324 4325 /* handle mapped IPv4 packets arriving via IPv6 sockets */ 4326 if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP)) 4327 family = PF_INET; 4328 4329 err = selinux_skb_peerlbl_sid(skb, family, &peersid); 4330 if (err) 4331 return err; 4332 if (peersid == SECSID_NULL) { 4333 req->secid = sksec->sid; 4334 req->peer_secid = SECSID_NULL; 4335 } else { 4336 err = security_sid_mls_copy(sksec->sid, peersid, &newsid); 4337 if (err) 4338 return err; 4339 req->secid = newsid; 4340 req->peer_secid = peersid; 4341 } 4342 4343 return selinux_netlbl_inet_conn_request(req, family); 4344 } 4345 4346 static void selinux_inet_csk_clone(struct sock *newsk, 4347 const struct request_sock *req) 4348 { 4349 struct sk_security_struct *newsksec = newsk->sk_security; 4350 4351 newsksec->sid = req->secid; 4352 newsksec->peer_sid = req->peer_secid; 4353 /* NOTE: Ideally, we should also get the isec->sid for the 4354 new socket in sync, but we don't have the isec available yet. 4355 So we will wait until sock_graft to do it, by which 4356 time it will have been created and available. */ 4357 4358 /* We don't need to take any sort of lock here as we are the only 4359 * thread with access to newsksec */ 4360 selinux_netlbl_inet_csk_clone(newsk, req->rsk_ops->family); 4361 } 4362 4363 static void selinux_inet_conn_established(struct sock *sk, struct sk_buff *skb) 4364 { 4365 u16 family = sk->sk_family; 4366 struct sk_security_struct *sksec = sk->sk_security; 4367 4368 /* handle mapped IPv4 packets arriving via IPv6 sockets */ 4369 if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP)) 4370 family = PF_INET; 4371 4372 selinux_skb_peerlbl_sid(skb, family, &sksec->peer_sid); 4373 } 4374 4375 static int selinux_secmark_relabel_packet(u32 sid) 4376 { 4377 const struct task_security_struct *__tsec; 4378 u32 tsid; 4379 4380 __tsec = current_security(); 4381 tsid = __tsec->sid; 4382 4383 return avc_has_perm(tsid, sid, SECCLASS_PACKET, PACKET__RELABELTO, NULL); 4384 } 4385 4386 static void selinux_secmark_refcount_inc(void) 4387 { 4388 atomic_inc(&selinux_secmark_refcount); 4389 } 4390 4391 static void selinux_secmark_refcount_dec(void) 4392 { 4393 atomic_dec(&selinux_secmark_refcount); 4394 } 4395 4396 static void selinux_req_classify_flow(const struct request_sock *req, 4397 struct flowi *fl) 4398 { 4399 fl->flowi_secid = req->secid; 4400 } 4401 4402 static int selinux_tun_dev_alloc_security(void **security) 4403 { 4404 struct tun_security_struct *tunsec; 4405 4406 tunsec = kzalloc(sizeof(*tunsec), GFP_KERNEL); 4407 if (!tunsec) 4408 return -ENOMEM; 4409 tunsec->sid = current_sid(); 4410 4411 *security = tunsec; 4412 return 0; 4413 } 4414 4415 static void selinux_tun_dev_free_security(void *security) 4416 { 4417 kfree(security); 4418 } 4419 4420 static int selinux_tun_dev_create(void) 4421 { 4422 u32 sid = current_sid(); 4423 4424 /* we aren't taking into account the "sockcreate" SID since the socket 4425 * that is being created here is not a socket in the traditional sense, 4426 * instead it is a private sock, accessible only to the kernel, and 4427 * representing a wide range of network traffic spanning multiple 4428 * connections unlike traditional sockets - check the TUN driver to 4429 * get a better understanding of why this socket is special */ 4430 4431 return avc_has_perm(sid, sid, SECCLASS_TUN_SOCKET, TUN_SOCKET__CREATE, 4432 NULL); 4433 } 4434 4435 static int selinux_tun_dev_attach_queue(void *security) 4436 { 4437 struct tun_security_struct *tunsec = security; 4438 4439 return avc_has_perm(current_sid(), tunsec->sid, SECCLASS_TUN_SOCKET, 4440 TUN_SOCKET__ATTACH_QUEUE, NULL); 4441 } 4442 4443 static int selinux_tun_dev_attach(struct sock *sk, void *security) 4444 { 4445 struct tun_security_struct *tunsec = security; 4446 struct sk_security_struct *sksec = sk->sk_security; 4447 4448 /* we don't currently perform any NetLabel based labeling here and it 4449 * isn't clear that we would want to do so anyway; while we could apply 4450 * labeling without the support of the TUN user the resulting labeled 4451 * traffic from the other end of the connection would almost certainly 4452 * cause confusion to the TUN user that had no idea network labeling 4453 * protocols were being used */ 4454 4455 sksec->sid = tunsec->sid; 4456 sksec->sclass = SECCLASS_TUN_SOCKET; 4457 4458 return 0; 4459 } 4460 4461 static int selinux_tun_dev_open(void *security) 4462 { 4463 struct tun_security_struct *tunsec = security; 4464 u32 sid = current_sid(); 4465 int err; 4466 4467 err = avc_has_perm(sid, tunsec->sid, SECCLASS_TUN_SOCKET, 4468 TUN_SOCKET__RELABELFROM, NULL); 4469 if (err) 4470 return err; 4471 err = avc_has_perm(sid, sid, SECCLASS_TUN_SOCKET, 4472 TUN_SOCKET__RELABELTO, NULL); 4473 if (err) 4474 return err; 4475 tunsec->sid = sid; 4476 4477 return 0; 4478 } 4479 4480 static int selinux_nlmsg_perm(struct sock *sk, struct sk_buff *skb) 4481 { 4482 int err = 0; 4483 u32 perm; 4484 struct nlmsghdr *nlh; 4485 struct sk_security_struct *sksec = sk->sk_security; 4486 4487 if (skb->len < NLMSG_SPACE(0)) { 4488 err = -EINVAL; 4489 goto out; 4490 } 4491 nlh = nlmsg_hdr(skb); 4492 4493 err = selinux_nlmsg_lookup(sksec->sclass, nlh->nlmsg_type, &perm); 4494 if (err) { 4495 if (err == -EINVAL) { 4496 audit_log(current->audit_context, GFP_KERNEL, AUDIT_SELINUX_ERR, 4497 "SELinux: unrecognized netlink message" 4498 " type=%hu for sclass=%hu\n", 4499 nlh->nlmsg_type, sksec->sclass); 4500 if (!selinux_enforcing || security_get_allow_unknown()) 4501 err = 0; 4502 } 4503 4504 /* Ignore */ 4505 if (err == -ENOENT) 4506 err = 0; 4507 goto out; 4508 } 4509 4510 err = sock_has_perm(current, sk, perm); 4511 out: 4512 return err; 4513 } 4514 4515 #ifdef CONFIG_NETFILTER 4516 4517 static unsigned int selinux_ip_forward(struct sk_buff *skb, int ifindex, 4518 u16 family) 4519 { 4520 int err; 4521 char *addrp; 4522 u32 peer_sid; 4523 struct common_audit_data ad; 4524 struct lsm_network_audit net = {0,}; 4525 u8 secmark_active; 4526 u8 netlbl_active; 4527 u8 peerlbl_active; 4528 4529 if (!selinux_policycap_netpeer) 4530 return NF_ACCEPT; 4531 4532 secmark_active = selinux_secmark_enabled(); 4533 netlbl_active = netlbl_enabled(); 4534 peerlbl_active = netlbl_active || selinux_xfrm_enabled(); 4535 if (!secmark_active && !peerlbl_active) 4536 return NF_ACCEPT; 4537 4538 if (selinux_skb_peerlbl_sid(skb, family, &peer_sid) != 0) 4539 return NF_DROP; 4540 4541 ad.type = LSM_AUDIT_DATA_NET; 4542 ad.u.net = &net; 4543 ad.u.net->netif = ifindex; 4544 ad.u.net->family = family; 4545 if (selinux_parse_skb(skb, &ad, &addrp, 1, NULL) != 0) 4546 return NF_DROP; 4547 4548 if (peerlbl_active) { 4549 err = selinux_inet_sys_rcv_skb(ifindex, addrp, family, 4550 peer_sid, &ad); 4551 if (err) { 4552 selinux_netlbl_err(skb, err, 1); 4553 return NF_DROP; 4554 } 4555 } 4556 4557 if (secmark_active) 4558 if (avc_has_perm(peer_sid, skb->secmark, 4559 SECCLASS_PACKET, PACKET__FORWARD_IN, &ad)) 4560 return NF_DROP; 4561 4562 if (netlbl_active) 4563 /* we do this in the FORWARD path and not the POST_ROUTING 4564 * path because we want to make sure we apply the necessary 4565 * labeling before IPsec is applied so we can leverage AH 4566 * protection */ 4567 if (selinux_netlbl_skbuff_setsid(skb, family, peer_sid) != 0) 4568 return NF_DROP; 4569 4570 return NF_ACCEPT; 4571 } 4572 4573 static unsigned int selinux_ipv4_forward(unsigned int hooknum, 4574 struct sk_buff *skb, 4575 const struct net_device *in, 4576 const struct net_device *out, 4577 int (*okfn)(struct sk_buff *)) 4578 { 4579 return selinux_ip_forward(skb, in->ifindex, PF_INET); 4580 } 4581 4582 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) 4583 static unsigned int selinux_ipv6_forward(unsigned int hooknum, 4584 struct sk_buff *skb, 4585 const struct net_device *in, 4586 const struct net_device *out, 4587 int (*okfn)(struct sk_buff *)) 4588 { 4589 return selinux_ip_forward(skb, in->ifindex, PF_INET6); 4590 } 4591 #endif /* IPV6 */ 4592 4593 static unsigned int selinux_ip_output(struct sk_buff *skb, 4594 u16 family) 4595 { 4596 u32 sid; 4597 4598 if (!netlbl_enabled()) 4599 return NF_ACCEPT; 4600 4601 /* we do this in the LOCAL_OUT path and not the POST_ROUTING path 4602 * because we want to make sure we apply the necessary labeling 4603 * before IPsec is applied so we can leverage AH protection */ 4604 if (skb->sk) { 4605 struct sk_security_struct *sksec = skb->sk->sk_security; 4606 sid = sksec->sid; 4607 } else 4608 sid = SECINITSID_KERNEL; 4609 if (selinux_netlbl_skbuff_setsid(skb, family, sid) != 0) 4610 return NF_DROP; 4611 4612 return NF_ACCEPT; 4613 } 4614 4615 static unsigned int selinux_ipv4_output(unsigned int hooknum, 4616 struct sk_buff *skb, 4617 const struct net_device *in, 4618 const struct net_device *out, 4619 int (*okfn)(struct sk_buff *)) 4620 { 4621 return selinux_ip_output(skb, PF_INET); 4622 } 4623 4624 static unsigned int selinux_ip_postroute_compat(struct sk_buff *skb, 4625 int ifindex, 4626 u16 family) 4627 { 4628 struct sock *sk = skb->sk; 4629 struct sk_security_struct *sksec; 4630 struct common_audit_data ad; 4631 struct lsm_network_audit net = {0,}; 4632 char *addrp; 4633 u8 proto; 4634 4635 if (sk == NULL) 4636 return NF_ACCEPT; 4637 sksec = sk->sk_security; 4638 4639 ad.type = LSM_AUDIT_DATA_NET; 4640 ad.u.net = &net; 4641 ad.u.net->netif = ifindex; 4642 ad.u.net->family = family; 4643 if (selinux_parse_skb(skb, &ad, &addrp, 0, &proto)) 4644 return NF_DROP; 4645 4646 if (selinux_secmark_enabled()) 4647 if (avc_has_perm(sksec->sid, skb->secmark, 4648 SECCLASS_PACKET, PACKET__SEND, &ad)) 4649 return NF_DROP_ERR(-ECONNREFUSED); 4650 4651 if (selinux_xfrm_postroute_last(sksec->sid, skb, &ad, proto)) 4652 return NF_DROP_ERR(-ECONNREFUSED); 4653 4654 return NF_ACCEPT; 4655 } 4656 4657 static unsigned int selinux_ip_postroute(struct sk_buff *skb, int ifindex, 4658 u16 family) 4659 { 4660 u32 secmark_perm; 4661 u32 peer_sid; 4662 struct sock *sk; 4663 struct common_audit_data ad; 4664 struct lsm_network_audit net = {0,}; 4665 char *addrp; 4666 u8 secmark_active; 4667 u8 peerlbl_active; 4668 4669 /* If any sort of compatibility mode is enabled then handoff processing 4670 * to the selinux_ip_postroute_compat() function to deal with the 4671 * special handling. We do this in an attempt to keep this function 4672 * as fast and as clean as possible. */ 4673 if (!selinux_policycap_netpeer) 4674 return selinux_ip_postroute_compat(skb, ifindex, family); 4675 #ifdef CONFIG_XFRM 4676 /* If skb->dst->xfrm is non-NULL then the packet is undergoing an IPsec 4677 * packet transformation so allow the packet to pass without any checks 4678 * since we'll have another chance to perform access control checks 4679 * when the packet is on it's final way out. 4680 * NOTE: there appear to be some IPv6 multicast cases where skb->dst 4681 * is NULL, in this case go ahead and apply access control. */ 4682 if (skb_dst(skb) != NULL && skb_dst(skb)->xfrm != NULL) 4683 return NF_ACCEPT; 4684 #endif 4685 secmark_active = selinux_secmark_enabled(); 4686 peerlbl_active = netlbl_enabled() || selinux_xfrm_enabled(); 4687 if (!secmark_active && !peerlbl_active) 4688 return NF_ACCEPT; 4689 4690 /* if the packet is being forwarded then get the peer label from the 4691 * packet itself; otherwise check to see if it is from a local 4692 * application or the kernel, if from an application get the peer label 4693 * from the sending socket, otherwise use the kernel's sid */ 4694 sk = skb->sk; 4695 if (sk == NULL) { 4696 if (skb->skb_iif) { 4697 secmark_perm = PACKET__FORWARD_OUT; 4698 if (selinux_skb_peerlbl_sid(skb, family, &peer_sid)) 4699 return NF_DROP; 4700 } else { 4701 secmark_perm = PACKET__SEND; 4702 peer_sid = SECINITSID_KERNEL; 4703 } 4704 } else { 4705 struct sk_security_struct *sksec = sk->sk_security; 4706 peer_sid = sksec->sid; 4707 secmark_perm = PACKET__SEND; 4708 } 4709 4710 ad.type = LSM_AUDIT_DATA_NET; 4711 ad.u.net = &net; 4712 ad.u.net->netif = ifindex; 4713 ad.u.net->family = family; 4714 if (selinux_parse_skb(skb, &ad, &addrp, 0, NULL)) 4715 return NF_DROP; 4716 4717 if (secmark_active) 4718 if (avc_has_perm(peer_sid, skb->secmark, 4719 SECCLASS_PACKET, secmark_perm, &ad)) 4720 return NF_DROP_ERR(-ECONNREFUSED); 4721 4722 if (peerlbl_active) { 4723 u32 if_sid; 4724 u32 node_sid; 4725 4726 if (sel_netif_sid(ifindex, &if_sid)) 4727 return NF_DROP; 4728 if (avc_has_perm(peer_sid, if_sid, 4729 SECCLASS_NETIF, NETIF__EGRESS, &ad)) 4730 return NF_DROP_ERR(-ECONNREFUSED); 4731 4732 if (sel_netnode_sid(addrp, family, &node_sid)) 4733 return NF_DROP; 4734 if (avc_has_perm(peer_sid, node_sid, 4735 SECCLASS_NODE, NODE__SENDTO, &ad)) 4736 return NF_DROP_ERR(-ECONNREFUSED); 4737 } 4738 4739 return NF_ACCEPT; 4740 } 4741 4742 static unsigned int selinux_ipv4_postroute(unsigned int hooknum, 4743 struct sk_buff *skb, 4744 const struct net_device *in, 4745 const struct net_device *out, 4746 int (*okfn)(struct sk_buff *)) 4747 { 4748 return selinux_ip_postroute(skb, out->ifindex, PF_INET); 4749 } 4750 4751 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) 4752 static unsigned int selinux_ipv6_postroute(unsigned int hooknum, 4753 struct sk_buff *skb, 4754 const struct net_device *in, 4755 const struct net_device *out, 4756 int (*okfn)(struct sk_buff *)) 4757 { 4758 return selinux_ip_postroute(skb, out->ifindex, PF_INET6); 4759 } 4760 #endif /* IPV6 */ 4761 4762 #endif /* CONFIG_NETFILTER */ 4763 4764 static int selinux_netlink_send(struct sock *sk, struct sk_buff *skb) 4765 { 4766 int err; 4767 4768 err = cap_netlink_send(sk, skb); 4769 if (err) 4770 return err; 4771 4772 return selinux_nlmsg_perm(sk, skb); 4773 } 4774 4775 static int ipc_alloc_security(struct task_struct *task, 4776 struct kern_ipc_perm *perm, 4777 u16 sclass) 4778 { 4779 struct ipc_security_struct *isec; 4780 u32 sid; 4781 4782 isec = kzalloc(sizeof(struct ipc_security_struct), GFP_KERNEL); 4783 if (!isec) 4784 return -ENOMEM; 4785 4786 sid = task_sid(task); 4787 isec->sclass = sclass; 4788 isec->sid = sid; 4789 perm->security = isec; 4790 4791 return 0; 4792 } 4793 4794 static void ipc_free_security(struct kern_ipc_perm *perm) 4795 { 4796 struct ipc_security_struct *isec = perm->security; 4797 perm->security = NULL; 4798 kfree(isec); 4799 } 4800 4801 static int msg_msg_alloc_security(struct msg_msg *msg) 4802 { 4803 struct msg_security_struct *msec; 4804 4805 msec = kzalloc(sizeof(struct msg_security_struct), GFP_KERNEL); 4806 if (!msec) 4807 return -ENOMEM; 4808 4809 msec->sid = SECINITSID_UNLABELED; 4810 msg->security = msec; 4811 4812 return 0; 4813 } 4814 4815 static void msg_msg_free_security(struct msg_msg *msg) 4816 { 4817 struct msg_security_struct *msec = msg->security; 4818 4819 msg->security = NULL; 4820 kfree(msec); 4821 } 4822 4823 static int ipc_has_perm(struct kern_ipc_perm *ipc_perms, 4824 u32 perms) 4825 { 4826 struct ipc_security_struct *isec; 4827 struct common_audit_data ad; 4828 u32 sid = current_sid(); 4829 4830 isec = ipc_perms->security; 4831 4832 ad.type = LSM_AUDIT_DATA_IPC; 4833 ad.u.ipc_id = ipc_perms->key; 4834 4835 return avc_has_perm(sid, isec->sid, isec->sclass, perms, &ad); 4836 } 4837 4838 static int selinux_msg_msg_alloc_security(struct msg_msg *msg) 4839 { 4840 return msg_msg_alloc_security(msg); 4841 } 4842 4843 static void selinux_msg_msg_free_security(struct msg_msg *msg) 4844 { 4845 msg_msg_free_security(msg); 4846 } 4847 4848 /* message queue security operations */ 4849 static int selinux_msg_queue_alloc_security(struct msg_queue *msq) 4850 { 4851 struct ipc_security_struct *isec; 4852 struct common_audit_data ad; 4853 u32 sid = current_sid(); 4854 int rc; 4855 4856 rc = ipc_alloc_security(current, &msq->q_perm, SECCLASS_MSGQ); 4857 if (rc) 4858 return rc; 4859 4860 isec = msq->q_perm.security; 4861 4862 ad.type = LSM_AUDIT_DATA_IPC; 4863 ad.u.ipc_id = msq->q_perm.key; 4864 4865 rc = avc_has_perm(sid, isec->sid, SECCLASS_MSGQ, 4866 MSGQ__CREATE, &ad); 4867 if (rc) { 4868 ipc_free_security(&msq->q_perm); 4869 return rc; 4870 } 4871 return 0; 4872 } 4873 4874 static void selinux_msg_queue_free_security(struct msg_queue *msq) 4875 { 4876 ipc_free_security(&msq->q_perm); 4877 } 4878 4879 static int selinux_msg_queue_associate(struct msg_queue *msq, int msqflg) 4880 { 4881 struct ipc_security_struct *isec; 4882 struct common_audit_data ad; 4883 u32 sid = current_sid(); 4884 4885 isec = msq->q_perm.security; 4886 4887 ad.type = LSM_AUDIT_DATA_IPC; 4888 ad.u.ipc_id = msq->q_perm.key; 4889 4890 return avc_has_perm(sid, isec->sid, SECCLASS_MSGQ, 4891 MSGQ__ASSOCIATE, &ad); 4892 } 4893 4894 static int selinux_msg_queue_msgctl(struct msg_queue *msq, int cmd) 4895 { 4896 int err; 4897 int perms; 4898 4899 switch (cmd) { 4900 case IPC_INFO: 4901 case MSG_INFO: 4902 /* No specific object, just general system-wide information. */ 4903 return task_has_system(current, SYSTEM__IPC_INFO); 4904 case IPC_STAT: 4905 case MSG_STAT: 4906 perms = MSGQ__GETATTR | MSGQ__ASSOCIATE; 4907 break; 4908 case IPC_SET: 4909 perms = MSGQ__SETATTR; 4910 break; 4911 case IPC_RMID: 4912 perms = MSGQ__DESTROY; 4913 break; 4914 default: 4915 return 0; 4916 } 4917 4918 err = ipc_has_perm(&msq->q_perm, perms); 4919 return err; 4920 } 4921 4922 static int selinux_msg_queue_msgsnd(struct msg_queue *msq, struct msg_msg *msg, int msqflg) 4923 { 4924 struct ipc_security_struct *isec; 4925 struct msg_security_struct *msec; 4926 struct common_audit_data ad; 4927 u32 sid = current_sid(); 4928 int rc; 4929 4930 isec = msq->q_perm.security; 4931 msec = msg->security; 4932 4933 /* 4934 * First time through, need to assign label to the message 4935 */ 4936 if (msec->sid == SECINITSID_UNLABELED) { 4937 /* 4938 * Compute new sid based on current process and 4939 * message queue this message will be stored in 4940 */ 4941 rc = security_transition_sid(sid, isec->sid, SECCLASS_MSG, 4942 NULL, &msec->sid); 4943 if (rc) 4944 return rc; 4945 } 4946 4947 ad.type = LSM_AUDIT_DATA_IPC; 4948 ad.u.ipc_id = msq->q_perm.key; 4949 4950 /* Can this process write to the queue? */ 4951 rc = avc_has_perm(sid, isec->sid, SECCLASS_MSGQ, 4952 MSGQ__WRITE, &ad); 4953 if (!rc) 4954 /* Can this process send the message */ 4955 rc = avc_has_perm(sid, msec->sid, SECCLASS_MSG, 4956 MSG__SEND, &ad); 4957 if (!rc) 4958 /* Can the message be put in the queue? */ 4959 rc = avc_has_perm(msec->sid, isec->sid, SECCLASS_MSGQ, 4960 MSGQ__ENQUEUE, &ad); 4961 4962 return rc; 4963 } 4964 4965 static int selinux_msg_queue_msgrcv(struct msg_queue *msq, struct msg_msg *msg, 4966 struct task_struct *target, 4967 long type, int mode) 4968 { 4969 struct ipc_security_struct *isec; 4970 struct msg_security_struct *msec; 4971 struct common_audit_data ad; 4972 u32 sid = task_sid(target); 4973 int rc; 4974 4975 isec = msq->q_perm.security; 4976 msec = msg->security; 4977 4978 ad.type = LSM_AUDIT_DATA_IPC; 4979 ad.u.ipc_id = msq->q_perm.key; 4980 4981 rc = avc_has_perm(sid, isec->sid, 4982 SECCLASS_MSGQ, MSGQ__READ, &ad); 4983 if (!rc) 4984 rc = avc_has_perm(sid, msec->sid, 4985 SECCLASS_MSG, MSG__RECEIVE, &ad); 4986 return rc; 4987 } 4988 4989 /* Shared Memory security operations */ 4990 static int selinux_shm_alloc_security(struct shmid_kernel *shp) 4991 { 4992 struct ipc_security_struct *isec; 4993 struct common_audit_data ad; 4994 u32 sid = current_sid(); 4995 int rc; 4996 4997 rc = ipc_alloc_security(current, &shp->shm_perm, SECCLASS_SHM); 4998 if (rc) 4999 return rc; 5000 5001 isec = shp->shm_perm.security; 5002 5003 ad.type = LSM_AUDIT_DATA_IPC; 5004 ad.u.ipc_id = shp->shm_perm.key; 5005 5006 rc = avc_has_perm(sid, isec->sid, SECCLASS_SHM, 5007 SHM__CREATE, &ad); 5008 if (rc) { 5009 ipc_free_security(&shp->shm_perm); 5010 return rc; 5011 } 5012 return 0; 5013 } 5014 5015 static void selinux_shm_free_security(struct shmid_kernel *shp) 5016 { 5017 ipc_free_security(&shp->shm_perm); 5018 } 5019 5020 static int selinux_shm_associate(struct shmid_kernel *shp, int shmflg) 5021 { 5022 struct ipc_security_struct *isec; 5023 struct common_audit_data ad; 5024 u32 sid = current_sid(); 5025 5026 isec = shp->shm_perm.security; 5027 5028 ad.type = LSM_AUDIT_DATA_IPC; 5029 ad.u.ipc_id = shp->shm_perm.key; 5030 5031 return avc_has_perm(sid, isec->sid, SECCLASS_SHM, 5032 SHM__ASSOCIATE, &ad); 5033 } 5034 5035 /* Note, at this point, shp is locked down */ 5036 static int selinux_shm_shmctl(struct shmid_kernel *shp, int cmd) 5037 { 5038 int perms; 5039 int err; 5040 5041 switch (cmd) { 5042 case IPC_INFO: 5043 case SHM_INFO: 5044 /* No specific object, just general system-wide information. */ 5045 return task_has_system(current, SYSTEM__IPC_INFO); 5046 case IPC_STAT: 5047 case SHM_STAT: 5048 perms = SHM__GETATTR | SHM__ASSOCIATE; 5049 break; 5050 case IPC_SET: 5051 perms = SHM__SETATTR; 5052 break; 5053 case SHM_LOCK: 5054 case SHM_UNLOCK: 5055 perms = SHM__LOCK; 5056 break; 5057 case IPC_RMID: 5058 perms = SHM__DESTROY; 5059 break; 5060 default: 5061 return 0; 5062 } 5063 5064 err = ipc_has_perm(&shp->shm_perm, perms); 5065 return err; 5066 } 5067 5068 static int selinux_shm_shmat(struct shmid_kernel *shp, 5069 char __user *shmaddr, int shmflg) 5070 { 5071 u32 perms; 5072 5073 if (shmflg & SHM_RDONLY) 5074 perms = SHM__READ; 5075 else 5076 perms = SHM__READ | SHM__WRITE; 5077 5078 return ipc_has_perm(&shp->shm_perm, perms); 5079 } 5080 5081 /* Semaphore security operations */ 5082 static int selinux_sem_alloc_security(struct sem_array *sma) 5083 { 5084 struct ipc_security_struct *isec; 5085 struct common_audit_data ad; 5086 u32 sid = current_sid(); 5087 int rc; 5088 5089 rc = ipc_alloc_security(current, &sma->sem_perm, SECCLASS_SEM); 5090 if (rc) 5091 return rc; 5092 5093 isec = sma->sem_perm.security; 5094 5095 ad.type = LSM_AUDIT_DATA_IPC; 5096 ad.u.ipc_id = sma->sem_perm.key; 5097 5098 rc = avc_has_perm(sid, isec->sid, SECCLASS_SEM, 5099 SEM__CREATE, &ad); 5100 if (rc) { 5101 ipc_free_security(&sma->sem_perm); 5102 return rc; 5103 } 5104 return 0; 5105 } 5106 5107 static void selinux_sem_free_security(struct sem_array *sma) 5108 { 5109 ipc_free_security(&sma->sem_perm); 5110 } 5111 5112 static int selinux_sem_associate(struct sem_array *sma, int semflg) 5113 { 5114 struct ipc_security_struct *isec; 5115 struct common_audit_data ad; 5116 u32 sid = current_sid(); 5117 5118 isec = sma->sem_perm.security; 5119 5120 ad.type = LSM_AUDIT_DATA_IPC; 5121 ad.u.ipc_id = sma->sem_perm.key; 5122 5123 return avc_has_perm(sid, isec->sid, SECCLASS_SEM, 5124 SEM__ASSOCIATE, &ad); 5125 } 5126 5127 /* Note, at this point, sma is locked down */ 5128 static int selinux_sem_semctl(struct sem_array *sma, int cmd) 5129 { 5130 int err; 5131 u32 perms; 5132 5133 switch (cmd) { 5134 case IPC_INFO: 5135 case SEM_INFO: 5136 /* No specific object, just general system-wide information. */ 5137 return task_has_system(current, SYSTEM__IPC_INFO); 5138 case GETPID: 5139 case GETNCNT: 5140 case GETZCNT: 5141 perms = SEM__GETATTR; 5142 break; 5143 case GETVAL: 5144 case GETALL: 5145 perms = SEM__READ; 5146 break; 5147 case SETVAL: 5148 case SETALL: 5149 perms = SEM__WRITE; 5150 break; 5151 case IPC_RMID: 5152 perms = SEM__DESTROY; 5153 break; 5154 case IPC_SET: 5155 perms = SEM__SETATTR; 5156 break; 5157 case IPC_STAT: 5158 case SEM_STAT: 5159 perms = SEM__GETATTR | SEM__ASSOCIATE; 5160 break; 5161 default: 5162 return 0; 5163 } 5164 5165 err = ipc_has_perm(&sma->sem_perm, perms); 5166 return err; 5167 } 5168 5169 static int selinux_sem_semop(struct sem_array *sma, 5170 struct sembuf *sops, unsigned nsops, int alter) 5171 { 5172 u32 perms; 5173 5174 if (alter) 5175 perms = SEM__READ | SEM__WRITE; 5176 else 5177 perms = SEM__READ; 5178 5179 return ipc_has_perm(&sma->sem_perm, perms); 5180 } 5181 5182 static int selinux_ipc_permission(struct kern_ipc_perm *ipcp, short flag) 5183 { 5184 u32 av = 0; 5185 5186 av = 0; 5187 if (flag & S_IRUGO) 5188 av |= IPC__UNIX_READ; 5189 if (flag & S_IWUGO) 5190 av |= IPC__UNIX_WRITE; 5191 5192 if (av == 0) 5193 return 0; 5194 5195 return ipc_has_perm(ipcp, av); 5196 } 5197 5198 static void selinux_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid) 5199 { 5200 struct ipc_security_struct *isec = ipcp->security; 5201 *secid = isec->sid; 5202 } 5203 5204 static void selinux_d_instantiate(struct dentry *dentry, struct inode *inode) 5205 { 5206 if (inode) 5207 inode_doinit_with_dentry(inode, dentry); 5208 } 5209 5210 static int selinux_getprocattr(struct task_struct *p, 5211 char *name, char **value) 5212 { 5213 const struct task_security_struct *__tsec; 5214 u32 sid; 5215 int error; 5216 unsigned len; 5217 5218 if (current != p) { 5219 error = current_has_perm(p, PROCESS__GETATTR); 5220 if (error) 5221 return error; 5222 } 5223 5224 rcu_read_lock(); 5225 __tsec = __task_cred(p)->security; 5226 5227 if (!strcmp(name, "current")) 5228 sid = __tsec->sid; 5229 else if (!strcmp(name, "prev")) 5230 sid = __tsec->osid; 5231 else if (!strcmp(name, "exec")) 5232 sid = __tsec->exec_sid; 5233 else if (!strcmp(name, "fscreate")) 5234 sid = __tsec->create_sid; 5235 else if (!strcmp(name, "keycreate")) 5236 sid = __tsec->keycreate_sid; 5237 else if (!strcmp(name, "sockcreate")) 5238 sid = __tsec->sockcreate_sid; 5239 else 5240 goto invalid; 5241 rcu_read_unlock(); 5242 5243 if (!sid) 5244 return 0; 5245 5246 error = security_sid_to_context(sid, value, &len); 5247 if (error) 5248 return error; 5249 return len; 5250 5251 invalid: 5252 rcu_read_unlock(); 5253 return -EINVAL; 5254 } 5255 5256 static int selinux_setprocattr(struct task_struct *p, 5257 char *name, void *value, size_t size) 5258 { 5259 struct task_security_struct *tsec; 5260 struct task_struct *tracer; 5261 struct cred *new; 5262 u32 sid = 0, ptsid; 5263 int error; 5264 char *str = value; 5265 5266 if (current != p) { 5267 /* SELinux only allows a process to change its own 5268 security attributes. */ 5269 return -EACCES; 5270 } 5271 5272 /* 5273 * Basic control over ability to set these attributes at all. 5274 * current == p, but we'll pass them separately in case the 5275 * above restriction is ever removed. 5276 */ 5277 if (!strcmp(name, "exec")) 5278 error = current_has_perm(p, PROCESS__SETEXEC); 5279 else if (!strcmp(name, "fscreate")) 5280 error = current_has_perm(p, PROCESS__SETFSCREATE); 5281 else if (!strcmp(name, "keycreate")) 5282 error = current_has_perm(p, PROCESS__SETKEYCREATE); 5283 else if (!strcmp(name, "sockcreate")) 5284 error = current_has_perm(p, PROCESS__SETSOCKCREATE); 5285 else if (!strcmp(name, "current")) 5286 error = current_has_perm(p, PROCESS__SETCURRENT); 5287 else 5288 error = -EINVAL; 5289 if (error) 5290 return error; 5291 5292 /* Obtain a SID for the context, if one was specified. */ 5293 if (size && str[1] && str[1] != '\n') { 5294 if (str[size-1] == '\n') { 5295 str[size-1] = 0; 5296 size--; 5297 } 5298 error = security_context_to_sid(value, size, &sid); 5299 if (error == -EINVAL && !strcmp(name, "fscreate")) { 5300 if (!capable(CAP_MAC_ADMIN)) { 5301 struct audit_buffer *ab; 5302 size_t audit_size; 5303 5304 /* We strip a nul only if it is at the end, otherwise the 5305 * context contains a nul and we should audit that */ 5306 if (str[size - 1] == '\0') 5307 audit_size = size - 1; 5308 else 5309 audit_size = size; 5310 ab = audit_log_start(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR); 5311 audit_log_format(ab, "op=fscreate invalid_context="); 5312 audit_log_n_untrustedstring(ab, value, audit_size); 5313 audit_log_end(ab); 5314 5315 return error; 5316 } 5317 error = security_context_to_sid_force(value, size, 5318 &sid); 5319 } 5320 if (error) 5321 return error; 5322 } 5323 5324 new = prepare_creds(); 5325 if (!new) 5326 return -ENOMEM; 5327 5328 /* Permission checking based on the specified context is 5329 performed during the actual operation (execve, 5330 open/mkdir/...), when we know the full context of the 5331 operation. See selinux_bprm_set_creds for the execve 5332 checks and may_create for the file creation checks. The 5333 operation will then fail if the context is not permitted. */ 5334 tsec = new->security; 5335 if (!strcmp(name, "exec")) { 5336 tsec->exec_sid = sid; 5337 } else if (!strcmp(name, "fscreate")) { 5338 tsec->create_sid = sid; 5339 } else if (!strcmp(name, "keycreate")) { 5340 error = may_create_key(sid, p); 5341 if (error) 5342 goto abort_change; 5343 tsec->keycreate_sid = sid; 5344 } else if (!strcmp(name, "sockcreate")) { 5345 tsec->sockcreate_sid = sid; 5346 } else if (!strcmp(name, "current")) { 5347 error = -EINVAL; 5348 if (sid == 0) 5349 goto abort_change; 5350 5351 /* Only allow single threaded processes to change context */ 5352 error = -EPERM; 5353 if (!current_is_single_threaded()) { 5354 error = security_bounded_transition(tsec->sid, sid); 5355 if (error) 5356 goto abort_change; 5357 } 5358 5359 /* Check permissions for the transition. */ 5360 error = avc_has_perm(tsec->sid, sid, SECCLASS_PROCESS, 5361 PROCESS__DYNTRANSITION, NULL); 5362 if (error) 5363 goto abort_change; 5364 5365 /* Check for ptracing, and update the task SID if ok. 5366 Otherwise, leave SID unchanged and fail. */ 5367 ptsid = 0; 5368 task_lock(p); 5369 tracer = ptrace_parent(p); 5370 if (tracer) 5371 ptsid = task_sid(tracer); 5372 task_unlock(p); 5373 5374 if (tracer) { 5375 error = avc_has_perm(ptsid, sid, SECCLASS_PROCESS, 5376 PROCESS__PTRACE, NULL); 5377 if (error) 5378 goto abort_change; 5379 } 5380 5381 tsec->sid = sid; 5382 } else { 5383 error = -EINVAL; 5384 goto abort_change; 5385 } 5386 5387 commit_creds(new); 5388 return size; 5389 5390 abort_change: 5391 abort_creds(new); 5392 return error; 5393 } 5394 5395 static int selinux_secid_to_secctx(u32 secid, char **secdata, u32 *seclen) 5396 { 5397 return security_sid_to_context(secid, secdata, seclen); 5398 } 5399 5400 static int selinux_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid) 5401 { 5402 return security_context_to_sid(secdata, seclen, secid); 5403 } 5404 5405 static void selinux_release_secctx(char *secdata, u32 seclen) 5406 { 5407 kfree(secdata); 5408 } 5409 5410 /* 5411 * called with inode->i_mutex locked 5412 */ 5413 static int selinux_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen) 5414 { 5415 return selinux_inode_setsecurity(inode, XATTR_SELINUX_SUFFIX, ctx, ctxlen, 0); 5416 } 5417 5418 /* 5419 * called with inode->i_mutex locked 5420 */ 5421 static int selinux_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen) 5422 { 5423 return __vfs_setxattr_noperm(dentry, XATTR_NAME_SELINUX, ctx, ctxlen, 0); 5424 } 5425 5426 static int selinux_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen) 5427 { 5428 int len = 0; 5429 len = selinux_inode_getsecurity(inode, XATTR_SELINUX_SUFFIX, 5430 ctx, true); 5431 if (len < 0) 5432 return len; 5433 *ctxlen = len; 5434 return 0; 5435 } 5436 #ifdef CONFIG_KEYS 5437 5438 static int selinux_key_alloc(struct key *k, const struct cred *cred, 5439 unsigned long flags) 5440 { 5441 const struct task_security_struct *tsec; 5442 struct key_security_struct *ksec; 5443 5444 ksec = kzalloc(sizeof(struct key_security_struct), GFP_KERNEL); 5445 if (!ksec) 5446 return -ENOMEM; 5447 5448 tsec = cred->security; 5449 if (tsec->keycreate_sid) 5450 ksec->sid = tsec->keycreate_sid; 5451 else 5452 ksec->sid = tsec->sid; 5453 5454 k->security = ksec; 5455 return 0; 5456 } 5457 5458 static void selinux_key_free(struct key *k) 5459 { 5460 struct key_security_struct *ksec = k->security; 5461 5462 k->security = NULL; 5463 kfree(ksec); 5464 } 5465 5466 static int selinux_key_permission(key_ref_t key_ref, 5467 const struct cred *cred, 5468 key_perm_t perm) 5469 { 5470 struct key *key; 5471 struct key_security_struct *ksec; 5472 u32 sid; 5473 5474 /* if no specific permissions are requested, we skip the 5475 permission check. No serious, additional covert channels 5476 appear to be created. */ 5477 if (perm == 0) 5478 return 0; 5479 5480 sid = cred_sid(cred); 5481 5482 key = key_ref_to_ptr(key_ref); 5483 ksec = key->security; 5484 5485 return avc_has_perm(sid, ksec->sid, SECCLASS_KEY, perm, NULL); 5486 } 5487 5488 static int selinux_key_getsecurity(struct key *key, char **_buffer) 5489 { 5490 struct key_security_struct *ksec = key->security; 5491 char *context = NULL; 5492 unsigned len; 5493 int rc; 5494 5495 rc = security_sid_to_context(ksec->sid, &context, &len); 5496 if (!rc) 5497 rc = len; 5498 *_buffer = context; 5499 return rc; 5500 } 5501 5502 #endif 5503 5504 static struct security_operations selinux_ops = { 5505 .name = "selinux", 5506 5507 .ptrace_access_check = selinux_ptrace_access_check, 5508 .ptrace_traceme = selinux_ptrace_traceme, 5509 .capget = selinux_capget, 5510 .capset = selinux_capset, 5511 .capable = selinux_capable, 5512 .quotactl = selinux_quotactl, 5513 .quota_on = selinux_quota_on, 5514 .syslog = selinux_syslog, 5515 .vm_enough_memory = selinux_vm_enough_memory, 5516 5517 .netlink_send = selinux_netlink_send, 5518 5519 .bprm_set_creds = selinux_bprm_set_creds, 5520 .bprm_committing_creds = selinux_bprm_committing_creds, 5521 .bprm_committed_creds = selinux_bprm_committed_creds, 5522 .bprm_secureexec = selinux_bprm_secureexec, 5523 5524 .sb_alloc_security = selinux_sb_alloc_security, 5525 .sb_free_security = selinux_sb_free_security, 5526 .sb_copy_data = selinux_sb_copy_data, 5527 .sb_remount = selinux_sb_remount, 5528 .sb_kern_mount = selinux_sb_kern_mount, 5529 .sb_show_options = selinux_sb_show_options, 5530 .sb_statfs = selinux_sb_statfs, 5531 .sb_mount = selinux_mount, 5532 .sb_umount = selinux_umount, 5533 .sb_set_mnt_opts = selinux_set_mnt_opts, 5534 .sb_clone_mnt_opts = selinux_sb_clone_mnt_opts, 5535 .sb_parse_opts_str = selinux_parse_opts_str, 5536 5537 5538 .inode_alloc_security = selinux_inode_alloc_security, 5539 .inode_free_security = selinux_inode_free_security, 5540 .inode_init_security = selinux_inode_init_security, 5541 .inode_create = selinux_inode_create, 5542 .inode_link = selinux_inode_link, 5543 .inode_unlink = selinux_inode_unlink, 5544 .inode_symlink = selinux_inode_symlink, 5545 .inode_mkdir = selinux_inode_mkdir, 5546 .inode_rmdir = selinux_inode_rmdir, 5547 .inode_mknod = selinux_inode_mknod, 5548 .inode_rename = selinux_inode_rename, 5549 .inode_readlink = selinux_inode_readlink, 5550 .inode_follow_link = selinux_inode_follow_link, 5551 .inode_permission = selinux_inode_permission, 5552 .inode_setattr = selinux_inode_setattr, 5553 .inode_getattr = selinux_inode_getattr, 5554 .inode_setxattr = selinux_inode_setxattr, 5555 .inode_post_setxattr = selinux_inode_post_setxattr, 5556 .inode_getxattr = selinux_inode_getxattr, 5557 .inode_listxattr = selinux_inode_listxattr, 5558 .inode_removexattr = selinux_inode_removexattr, 5559 .inode_getsecurity = selinux_inode_getsecurity, 5560 .inode_setsecurity = selinux_inode_setsecurity, 5561 .inode_listsecurity = selinux_inode_listsecurity, 5562 .inode_getsecid = selinux_inode_getsecid, 5563 5564 .file_permission = selinux_file_permission, 5565 .file_alloc_security = selinux_file_alloc_security, 5566 .file_free_security = selinux_file_free_security, 5567 .file_ioctl = selinux_file_ioctl, 5568 .mmap_file = selinux_mmap_file, 5569 .mmap_addr = selinux_mmap_addr, 5570 .file_mprotect = selinux_file_mprotect, 5571 .file_lock = selinux_file_lock, 5572 .file_fcntl = selinux_file_fcntl, 5573 .file_set_fowner = selinux_file_set_fowner, 5574 .file_send_sigiotask = selinux_file_send_sigiotask, 5575 .file_receive = selinux_file_receive, 5576 5577 .file_open = selinux_file_open, 5578 5579 .task_create = selinux_task_create, 5580 .cred_alloc_blank = selinux_cred_alloc_blank, 5581 .cred_free = selinux_cred_free, 5582 .cred_prepare = selinux_cred_prepare, 5583 .cred_transfer = selinux_cred_transfer, 5584 .kernel_act_as = selinux_kernel_act_as, 5585 .kernel_create_files_as = selinux_kernel_create_files_as, 5586 .kernel_module_request = selinux_kernel_module_request, 5587 .task_setpgid = selinux_task_setpgid, 5588 .task_getpgid = selinux_task_getpgid, 5589 .task_getsid = selinux_task_getsid, 5590 .task_getsecid = selinux_task_getsecid, 5591 .task_setnice = selinux_task_setnice, 5592 .task_setioprio = selinux_task_setioprio, 5593 .task_getioprio = selinux_task_getioprio, 5594 .task_setrlimit = selinux_task_setrlimit, 5595 .task_setscheduler = selinux_task_setscheduler, 5596 .task_getscheduler = selinux_task_getscheduler, 5597 .task_movememory = selinux_task_movememory, 5598 .task_kill = selinux_task_kill, 5599 .task_wait = selinux_task_wait, 5600 .task_to_inode = selinux_task_to_inode, 5601 5602 .ipc_permission = selinux_ipc_permission, 5603 .ipc_getsecid = selinux_ipc_getsecid, 5604 5605 .msg_msg_alloc_security = selinux_msg_msg_alloc_security, 5606 .msg_msg_free_security = selinux_msg_msg_free_security, 5607 5608 .msg_queue_alloc_security = selinux_msg_queue_alloc_security, 5609 .msg_queue_free_security = selinux_msg_queue_free_security, 5610 .msg_queue_associate = selinux_msg_queue_associate, 5611 .msg_queue_msgctl = selinux_msg_queue_msgctl, 5612 .msg_queue_msgsnd = selinux_msg_queue_msgsnd, 5613 .msg_queue_msgrcv = selinux_msg_queue_msgrcv, 5614 5615 .shm_alloc_security = selinux_shm_alloc_security, 5616 .shm_free_security = selinux_shm_free_security, 5617 .shm_associate = selinux_shm_associate, 5618 .shm_shmctl = selinux_shm_shmctl, 5619 .shm_shmat = selinux_shm_shmat, 5620 5621 .sem_alloc_security = selinux_sem_alloc_security, 5622 .sem_free_security = selinux_sem_free_security, 5623 .sem_associate = selinux_sem_associate, 5624 .sem_semctl = selinux_sem_semctl, 5625 .sem_semop = selinux_sem_semop, 5626 5627 .d_instantiate = selinux_d_instantiate, 5628 5629 .getprocattr = selinux_getprocattr, 5630 .setprocattr = selinux_setprocattr, 5631 5632 .secid_to_secctx = selinux_secid_to_secctx, 5633 .secctx_to_secid = selinux_secctx_to_secid, 5634 .release_secctx = selinux_release_secctx, 5635 .inode_notifysecctx = selinux_inode_notifysecctx, 5636 .inode_setsecctx = selinux_inode_setsecctx, 5637 .inode_getsecctx = selinux_inode_getsecctx, 5638 5639 .unix_stream_connect = selinux_socket_unix_stream_connect, 5640 .unix_may_send = selinux_socket_unix_may_send, 5641 5642 .socket_create = selinux_socket_create, 5643 .socket_post_create = selinux_socket_post_create, 5644 .socket_bind = selinux_socket_bind, 5645 .socket_connect = selinux_socket_connect, 5646 .socket_listen = selinux_socket_listen, 5647 .socket_accept = selinux_socket_accept, 5648 .socket_sendmsg = selinux_socket_sendmsg, 5649 .socket_recvmsg = selinux_socket_recvmsg, 5650 .socket_getsockname = selinux_socket_getsockname, 5651 .socket_getpeername = selinux_socket_getpeername, 5652 .socket_getsockopt = selinux_socket_getsockopt, 5653 .socket_setsockopt = selinux_socket_setsockopt, 5654 .socket_shutdown = selinux_socket_shutdown, 5655 .socket_sock_rcv_skb = selinux_socket_sock_rcv_skb, 5656 .socket_getpeersec_stream = selinux_socket_getpeersec_stream, 5657 .socket_getpeersec_dgram = selinux_socket_getpeersec_dgram, 5658 .sk_alloc_security = selinux_sk_alloc_security, 5659 .sk_free_security = selinux_sk_free_security, 5660 .sk_clone_security = selinux_sk_clone_security, 5661 .sk_getsecid = selinux_sk_getsecid, 5662 .sock_graft = selinux_sock_graft, 5663 .inet_conn_request = selinux_inet_conn_request, 5664 .inet_csk_clone = selinux_inet_csk_clone, 5665 .inet_conn_established = selinux_inet_conn_established, 5666 .secmark_relabel_packet = selinux_secmark_relabel_packet, 5667 .secmark_refcount_inc = selinux_secmark_refcount_inc, 5668 .secmark_refcount_dec = selinux_secmark_refcount_dec, 5669 .req_classify_flow = selinux_req_classify_flow, 5670 .tun_dev_alloc_security = selinux_tun_dev_alloc_security, 5671 .tun_dev_free_security = selinux_tun_dev_free_security, 5672 .tun_dev_create = selinux_tun_dev_create, 5673 .tun_dev_attach_queue = selinux_tun_dev_attach_queue, 5674 .tun_dev_attach = selinux_tun_dev_attach, 5675 .tun_dev_open = selinux_tun_dev_open, 5676 5677 #ifdef CONFIG_SECURITY_NETWORK_XFRM 5678 .xfrm_policy_alloc_security = selinux_xfrm_policy_alloc, 5679 .xfrm_policy_clone_security = selinux_xfrm_policy_clone, 5680 .xfrm_policy_free_security = selinux_xfrm_policy_free, 5681 .xfrm_policy_delete_security = selinux_xfrm_policy_delete, 5682 .xfrm_state_alloc_security = selinux_xfrm_state_alloc, 5683 .xfrm_state_free_security = selinux_xfrm_state_free, 5684 .xfrm_state_delete_security = selinux_xfrm_state_delete, 5685 .xfrm_policy_lookup = selinux_xfrm_policy_lookup, 5686 .xfrm_state_pol_flow_match = selinux_xfrm_state_pol_flow_match, 5687 .xfrm_decode_session = selinux_xfrm_decode_session, 5688 #endif 5689 5690 #ifdef CONFIG_KEYS 5691 .key_alloc = selinux_key_alloc, 5692 .key_free = selinux_key_free, 5693 .key_permission = selinux_key_permission, 5694 .key_getsecurity = selinux_key_getsecurity, 5695 #endif 5696 5697 #ifdef CONFIG_AUDIT 5698 .audit_rule_init = selinux_audit_rule_init, 5699 .audit_rule_known = selinux_audit_rule_known, 5700 .audit_rule_match = selinux_audit_rule_match, 5701 .audit_rule_free = selinux_audit_rule_free, 5702 #endif 5703 }; 5704 5705 static __init int selinux_init(void) 5706 { 5707 if (!security_module_enable(&selinux_ops)) { 5708 selinux_enabled = 0; 5709 return 0; 5710 } 5711 5712 if (!selinux_enabled) { 5713 printk(KERN_INFO "SELinux: Disabled at boot.\n"); 5714 return 0; 5715 } 5716 5717 printk(KERN_INFO "SELinux: Initializing.\n"); 5718 5719 /* Set the security state for the initial task. */ 5720 cred_init_security(); 5721 5722 default_noexec = !(VM_DATA_DEFAULT_FLAGS & VM_EXEC); 5723 5724 sel_inode_cache = kmem_cache_create("selinux_inode_security", 5725 sizeof(struct inode_security_struct), 5726 0, SLAB_PANIC, NULL); 5727 avc_init(); 5728 5729 if (register_security(&selinux_ops)) 5730 panic("SELinux: Unable to register with kernel.\n"); 5731 5732 if (selinux_enforcing) 5733 printk(KERN_DEBUG "SELinux: Starting in enforcing mode\n"); 5734 else 5735 printk(KERN_DEBUG "SELinux: Starting in permissive mode\n"); 5736 5737 return 0; 5738 } 5739 5740 static void delayed_superblock_init(struct super_block *sb, void *unused) 5741 { 5742 superblock_doinit(sb, NULL); 5743 } 5744 5745 void selinux_complete_init(void) 5746 { 5747 printk(KERN_DEBUG "SELinux: Completing initialization.\n"); 5748 5749 /* Set up any superblocks initialized prior to the policy load. */ 5750 printk(KERN_DEBUG "SELinux: Setting up existing superblocks.\n"); 5751 iterate_supers(delayed_superblock_init, NULL); 5752 } 5753 5754 /* SELinux requires early initialization in order to label 5755 all processes and objects when they are created. */ 5756 security_initcall(selinux_init); 5757 5758 #if defined(CONFIG_NETFILTER) 5759 5760 static struct nf_hook_ops selinux_ipv4_ops[] = { 5761 { 5762 .hook = selinux_ipv4_postroute, 5763 .owner = THIS_MODULE, 5764 .pf = NFPROTO_IPV4, 5765 .hooknum = NF_INET_POST_ROUTING, 5766 .priority = NF_IP_PRI_SELINUX_LAST, 5767 }, 5768 { 5769 .hook = selinux_ipv4_forward, 5770 .owner = THIS_MODULE, 5771 .pf = NFPROTO_IPV4, 5772 .hooknum = NF_INET_FORWARD, 5773 .priority = NF_IP_PRI_SELINUX_FIRST, 5774 }, 5775 { 5776 .hook = selinux_ipv4_output, 5777 .owner = THIS_MODULE, 5778 .pf = NFPROTO_IPV4, 5779 .hooknum = NF_INET_LOCAL_OUT, 5780 .priority = NF_IP_PRI_SELINUX_FIRST, 5781 } 5782 }; 5783 5784 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) 5785 5786 static struct nf_hook_ops selinux_ipv6_ops[] = { 5787 { 5788 .hook = selinux_ipv6_postroute, 5789 .owner = THIS_MODULE, 5790 .pf = NFPROTO_IPV6, 5791 .hooknum = NF_INET_POST_ROUTING, 5792 .priority = NF_IP6_PRI_SELINUX_LAST, 5793 }, 5794 { 5795 .hook = selinux_ipv6_forward, 5796 .owner = THIS_MODULE, 5797 .pf = NFPROTO_IPV6, 5798 .hooknum = NF_INET_FORWARD, 5799 .priority = NF_IP6_PRI_SELINUX_FIRST, 5800 } 5801 }; 5802 5803 #endif /* IPV6 */ 5804 5805 static int __init selinux_nf_ip_init(void) 5806 { 5807 int err = 0; 5808 5809 if (!selinux_enabled) 5810 goto out; 5811 5812 printk(KERN_DEBUG "SELinux: Registering netfilter hooks\n"); 5813 5814 err = nf_register_hooks(selinux_ipv4_ops, ARRAY_SIZE(selinux_ipv4_ops)); 5815 if (err) 5816 panic("SELinux: nf_register_hooks for IPv4: error %d\n", err); 5817 5818 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) 5819 err = nf_register_hooks(selinux_ipv6_ops, ARRAY_SIZE(selinux_ipv6_ops)); 5820 if (err) 5821 panic("SELinux: nf_register_hooks for IPv6: error %d\n", err); 5822 #endif /* IPV6 */ 5823 5824 out: 5825 return err; 5826 } 5827 5828 __initcall(selinux_nf_ip_init); 5829 5830 #ifdef CONFIG_SECURITY_SELINUX_DISABLE 5831 static void selinux_nf_ip_exit(void) 5832 { 5833 printk(KERN_DEBUG "SELinux: Unregistering netfilter hooks\n"); 5834 5835 nf_unregister_hooks(selinux_ipv4_ops, ARRAY_SIZE(selinux_ipv4_ops)); 5836 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) 5837 nf_unregister_hooks(selinux_ipv6_ops, ARRAY_SIZE(selinux_ipv6_ops)); 5838 #endif /* IPV6 */ 5839 } 5840 #endif 5841 5842 #else /* CONFIG_NETFILTER */ 5843 5844 #ifdef CONFIG_SECURITY_SELINUX_DISABLE 5845 #define selinux_nf_ip_exit() 5846 #endif 5847 5848 #endif /* CONFIG_NETFILTER */ 5849 5850 #ifdef CONFIG_SECURITY_SELINUX_DISABLE 5851 static int selinux_disabled; 5852 5853 int selinux_disable(void) 5854 { 5855 if (ss_initialized) { 5856 /* Not permitted after initial policy load. */ 5857 return -EINVAL; 5858 } 5859 5860 if (selinux_disabled) { 5861 /* Only do this once. */ 5862 return -EINVAL; 5863 } 5864 5865 printk(KERN_INFO "SELinux: Disabled at runtime.\n"); 5866 5867 selinux_disabled = 1; 5868 selinux_enabled = 0; 5869 5870 reset_security_ops(); 5871 5872 /* Try to destroy the avc node cache */ 5873 avc_disable(); 5874 5875 /* Unregister netfilter hooks. */ 5876 selinux_nf_ip_exit(); 5877 5878 /* Unregister selinuxfs. */ 5879 exit_sel_fs(); 5880 5881 return 0; 5882 } 5883 #endif 5884