1 /* 2 * Simplified MAC Kernel (smack) security module 3 * 4 * This file contains the smack hook function implementations. 5 * 6 * Authors: 7 * Casey Schaufler <casey@schaufler-ca.com> 8 * Jarkko Sakkinen <jarkko.sakkinen@intel.com> 9 * 10 * Copyright (C) 2007 Casey Schaufler <casey@schaufler-ca.com> 11 * Copyright (C) 2009 Hewlett-Packard Development Company, L.P. 12 * Paul Moore <paul@paul-moore.com> 13 * Copyright (C) 2010 Nokia Corporation 14 * Copyright (C) 2011 Intel Corporation. 15 * 16 * This program is free software; you can redistribute it and/or modify 17 * it under the terms of the GNU General Public License version 2, 18 * as published by the Free Software Foundation. 19 */ 20 21 #include <linux/xattr.h> 22 #include <linux/pagemap.h> 23 #include <linux/mount.h> 24 #include <linux/stat.h> 25 #include <linux/kd.h> 26 #include <asm/ioctls.h> 27 #include <linux/ip.h> 28 #include <linux/tcp.h> 29 #include <linux/udp.h> 30 #include <linux/slab.h> 31 #include <linux/mutex.h> 32 #include <linux/pipe_fs_i.h> 33 #include <net/cipso_ipv4.h> 34 #include <linux/audit.h> 35 #include <linux/magic.h> 36 #include <linux/dcache.h> 37 #include <linux/personality.h> 38 #include <linux/msg.h> 39 #include <linux/shm.h> 40 #include <linux/binfmts.h> 41 #include "smack.h" 42 43 #define task_security(task) (task_cred_xxx((task), security)) 44 45 #define TRANS_TRUE "TRUE" 46 #define TRANS_TRUE_SIZE 4 47 48 /** 49 * smk_fetch - Fetch the smack label from a file. 50 * @ip: a pointer to the inode 51 * @dp: a pointer to the dentry 52 * 53 * Returns a pointer to the master list entry for the Smack label 54 * or NULL if there was no label to fetch. 55 */ 56 static char *smk_fetch(const char *name, struct inode *ip, struct dentry *dp) 57 { 58 int rc; 59 char *buffer; 60 char *result = NULL; 61 62 if (ip->i_op->getxattr == NULL) 63 return NULL; 64 65 buffer = kzalloc(SMK_LONGLABEL, GFP_KERNEL); 66 if (buffer == NULL) 67 return NULL; 68 69 rc = ip->i_op->getxattr(dp, name, buffer, SMK_LONGLABEL); 70 if (rc > 0) 71 result = smk_import(buffer, rc); 72 73 kfree(buffer); 74 75 return result; 76 } 77 78 /** 79 * new_inode_smack - allocate an inode security blob 80 * @smack: a pointer to the Smack label to use in the blob 81 * 82 * Returns the new blob or NULL if there's no memory available 83 */ 84 struct inode_smack *new_inode_smack(char *smack) 85 { 86 struct inode_smack *isp; 87 88 isp = kzalloc(sizeof(struct inode_smack), GFP_NOFS); 89 if (isp == NULL) 90 return NULL; 91 92 isp->smk_inode = smack; 93 isp->smk_flags = 0; 94 mutex_init(&isp->smk_lock); 95 96 return isp; 97 } 98 99 /** 100 * new_task_smack - allocate a task security blob 101 * @smack: a pointer to the Smack label to use in the blob 102 * 103 * Returns the new blob or NULL if there's no memory available 104 */ 105 static struct task_smack *new_task_smack(char *task, char *forked, gfp_t gfp) 106 { 107 struct task_smack *tsp; 108 109 tsp = kzalloc(sizeof(struct task_smack), gfp); 110 if (tsp == NULL) 111 return NULL; 112 113 tsp->smk_task = task; 114 tsp->smk_forked = forked; 115 INIT_LIST_HEAD(&tsp->smk_rules); 116 mutex_init(&tsp->smk_rules_lock); 117 118 return tsp; 119 } 120 121 /** 122 * smk_copy_rules - copy a rule set 123 * @nhead - new rules header pointer 124 * @ohead - old rules header pointer 125 * 126 * Returns 0 on success, -ENOMEM on error 127 */ 128 static int smk_copy_rules(struct list_head *nhead, struct list_head *ohead, 129 gfp_t gfp) 130 { 131 struct smack_rule *nrp; 132 struct smack_rule *orp; 133 int rc = 0; 134 135 INIT_LIST_HEAD(nhead); 136 137 list_for_each_entry_rcu(orp, ohead, list) { 138 nrp = kzalloc(sizeof(struct smack_rule), gfp); 139 if (nrp == NULL) { 140 rc = -ENOMEM; 141 break; 142 } 143 *nrp = *orp; 144 list_add_rcu(&nrp->list, nhead); 145 } 146 return rc; 147 } 148 149 /* 150 * LSM hooks. 151 * We he, that is fun! 152 */ 153 154 /** 155 * smack_ptrace_access_check - Smack approval on PTRACE_ATTACH 156 * @ctp: child task pointer 157 * @mode: ptrace attachment mode 158 * 159 * Returns 0 if access is OK, an error code otherwise 160 * 161 * Do the capability checks, and require read and write. 162 */ 163 static int smack_ptrace_access_check(struct task_struct *ctp, unsigned int mode) 164 { 165 int rc; 166 struct smk_audit_info ad; 167 char *tsp; 168 169 rc = cap_ptrace_access_check(ctp, mode); 170 if (rc != 0) 171 return rc; 172 173 tsp = smk_of_task(task_security(ctp)); 174 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK); 175 smk_ad_setfield_u_tsk(&ad, ctp); 176 177 rc = smk_curacc(tsp, MAY_READWRITE, &ad); 178 return rc; 179 } 180 181 /** 182 * smack_ptrace_traceme - Smack approval on PTRACE_TRACEME 183 * @ptp: parent task pointer 184 * 185 * Returns 0 if access is OK, an error code otherwise 186 * 187 * Do the capability checks, and require read and write. 188 */ 189 static int smack_ptrace_traceme(struct task_struct *ptp) 190 { 191 int rc; 192 struct smk_audit_info ad; 193 char *tsp; 194 195 rc = cap_ptrace_traceme(ptp); 196 if (rc != 0) 197 return rc; 198 199 tsp = smk_of_task(task_security(ptp)); 200 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK); 201 smk_ad_setfield_u_tsk(&ad, ptp); 202 203 rc = smk_curacc(tsp, MAY_READWRITE, &ad); 204 return rc; 205 } 206 207 /** 208 * smack_syslog - Smack approval on syslog 209 * @type: message type 210 * 211 * Require that the task has the floor label 212 * 213 * Returns 0 on success, error code otherwise. 214 */ 215 static int smack_syslog(int typefrom_file) 216 { 217 int rc = 0; 218 char *sp = smk_of_current(); 219 220 if (smack_privileged(CAP_MAC_OVERRIDE)) 221 return 0; 222 223 if (sp != smack_known_floor.smk_known) 224 rc = -EACCES; 225 226 return rc; 227 } 228 229 230 /* 231 * Superblock Hooks. 232 */ 233 234 /** 235 * smack_sb_alloc_security - allocate a superblock blob 236 * @sb: the superblock getting the blob 237 * 238 * Returns 0 on success or -ENOMEM on error. 239 */ 240 static int smack_sb_alloc_security(struct super_block *sb) 241 { 242 struct superblock_smack *sbsp; 243 244 sbsp = kzalloc(sizeof(struct superblock_smack), GFP_KERNEL); 245 246 if (sbsp == NULL) 247 return -ENOMEM; 248 249 sbsp->smk_root = smack_known_floor.smk_known; 250 sbsp->smk_default = smack_known_floor.smk_known; 251 sbsp->smk_floor = smack_known_floor.smk_known; 252 sbsp->smk_hat = smack_known_hat.smk_known; 253 sbsp->smk_initialized = 0; 254 255 sb->s_security = sbsp; 256 257 return 0; 258 } 259 260 /** 261 * smack_sb_free_security - free a superblock blob 262 * @sb: the superblock getting the blob 263 * 264 */ 265 static void smack_sb_free_security(struct super_block *sb) 266 { 267 kfree(sb->s_security); 268 sb->s_security = NULL; 269 } 270 271 /** 272 * smack_sb_copy_data - copy mount options data for processing 273 * @orig: where to start 274 * @smackopts: mount options string 275 * 276 * Returns 0 on success or -ENOMEM on error. 277 * 278 * Copy the Smack specific mount options out of the mount 279 * options list. 280 */ 281 static int smack_sb_copy_data(char *orig, char *smackopts) 282 { 283 char *cp, *commap, *otheropts, *dp; 284 285 otheropts = (char *)get_zeroed_page(GFP_KERNEL); 286 if (otheropts == NULL) 287 return -ENOMEM; 288 289 for (cp = orig, commap = orig; commap != NULL; cp = commap + 1) { 290 if (strstr(cp, SMK_FSDEFAULT) == cp) 291 dp = smackopts; 292 else if (strstr(cp, SMK_FSFLOOR) == cp) 293 dp = smackopts; 294 else if (strstr(cp, SMK_FSHAT) == cp) 295 dp = smackopts; 296 else if (strstr(cp, SMK_FSROOT) == cp) 297 dp = smackopts; 298 else 299 dp = otheropts; 300 301 commap = strchr(cp, ','); 302 if (commap != NULL) 303 *commap = '\0'; 304 305 if (*dp != '\0') 306 strcat(dp, ","); 307 strcat(dp, cp); 308 } 309 310 strcpy(orig, otheropts); 311 free_page((unsigned long)otheropts); 312 313 return 0; 314 } 315 316 /** 317 * smack_sb_kern_mount - Smack specific mount processing 318 * @sb: the file system superblock 319 * @flags: the mount flags 320 * @data: the smack mount options 321 * 322 * Returns 0 on success, an error code on failure 323 */ 324 static int smack_sb_kern_mount(struct super_block *sb, int flags, void *data) 325 { 326 struct dentry *root = sb->s_root; 327 struct inode *inode = root->d_inode; 328 struct superblock_smack *sp = sb->s_security; 329 struct inode_smack *isp; 330 char *op; 331 char *commap; 332 char *nsp; 333 334 if (sp->smk_initialized != 0) 335 return 0; 336 337 sp->smk_initialized = 1; 338 339 for (op = data; op != NULL; op = commap) { 340 commap = strchr(op, ','); 341 if (commap != NULL) 342 *commap++ = '\0'; 343 344 if (strncmp(op, SMK_FSHAT, strlen(SMK_FSHAT)) == 0) { 345 op += strlen(SMK_FSHAT); 346 nsp = smk_import(op, 0); 347 if (nsp != NULL) 348 sp->smk_hat = nsp; 349 } else if (strncmp(op, SMK_FSFLOOR, strlen(SMK_FSFLOOR)) == 0) { 350 op += strlen(SMK_FSFLOOR); 351 nsp = smk_import(op, 0); 352 if (nsp != NULL) 353 sp->smk_floor = nsp; 354 } else if (strncmp(op, SMK_FSDEFAULT, 355 strlen(SMK_FSDEFAULT)) == 0) { 356 op += strlen(SMK_FSDEFAULT); 357 nsp = smk_import(op, 0); 358 if (nsp != NULL) 359 sp->smk_default = nsp; 360 } else if (strncmp(op, SMK_FSROOT, strlen(SMK_FSROOT)) == 0) { 361 op += strlen(SMK_FSROOT); 362 nsp = smk_import(op, 0); 363 if (nsp != NULL) 364 sp->smk_root = nsp; 365 } 366 } 367 368 /* 369 * Initialize the root inode. 370 */ 371 isp = inode->i_security; 372 if (isp == NULL) 373 inode->i_security = new_inode_smack(sp->smk_root); 374 else 375 isp->smk_inode = sp->smk_root; 376 377 return 0; 378 } 379 380 /** 381 * smack_sb_statfs - Smack check on statfs 382 * @dentry: identifies the file system in question 383 * 384 * Returns 0 if current can read the floor of the filesystem, 385 * and error code otherwise 386 */ 387 static int smack_sb_statfs(struct dentry *dentry) 388 { 389 struct superblock_smack *sbp = dentry->d_sb->s_security; 390 int rc; 391 struct smk_audit_info ad; 392 393 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); 394 smk_ad_setfield_u_fs_path_dentry(&ad, dentry); 395 396 rc = smk_curacc(sbp->smk_floor, MAY_READ, &ad); 397 return rc; 398 } 399 400 /** 401 * smack_sb_mount - Smack check for mounting 402 * @dev_name: unused 403 * @path: mount point 404 * @type: unused 405 * @flags: unused 406 * @data: unused 407 * 408 * Returns 0 if current can write the floor of the filesystem 409 * being mounted on, an error code otherwise. 410 */ 411 static int smack_sb_mount(const char *dev_name, struct path *path, 412 const char *type, unsigned long flags, void *data) 413 { 414 struct superblock_smack *sbp = path->dentry->d_sb->s_security; 415 struct smk_audit_info ad; 416 417 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH); 418 smk_ad_setfield_u_fs_path(&ad, *path); 419 420 return smk_curacc(sbp->smk_floor, MAY_WRITE, &ad); 421 } 422 423 /** 424 * smack_sb_umount - Smack check for unmounting 425 * @mnt: file system to unmount 426 * @flags: unused 427 * 428 * Returns 0 if current can write the floor of the filesystem 429 * being unmounted, an error code otherwise. 430 */ 431 static int smack_sb_umount(struct vfsmount *mnt, int flags) 432 { 433 struct superblock_smack *sbp; 434 struct smk_audit_info ad; 435 struct path path; 436 437 path.dentry = mnt->mnt_root; 438 path.mnt = mnt; 439 440 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH); 441 smk_ad_setfield_u_fs_path(&ad, path); 442 443 sbp = path.dentry->d_sb->s_security; 444 return smk_curacc(sbp->smk_floor, MAY_WRITE, &ad); 445 } 446 447 /* 448 * BPRM hooks 449 */ 450 451 /** 452 * smack_bprm_set_creds - set creds for exec 453 * @bprm: the exec information 454 * 455 * Returns 0 if it gets a blob, -ENOMEM otherwise 456 */ 457 static int smack_bprm_set_creds(struct linux_binprm *bprm) 458 { 459 struct inode *inode = file_inode(bprm->file); 460 struct task_smack *bsp = bprm->cred->security; 461 struct inode_smack *isp; 462 int rc; 463 464 rc = cap_bprm_set_creds(bprm); 465 if (rc != 0) 466 return rc; 467 468 if (bprm->cred_prepared) 469 return 0; 470 471 isp = inode->i_security; 472 if (isp->smk_task == NULL || isp->smk_task == bsp->smk_task) 473 return 0; 474 475 if (bprm->unsafe) 476 return -EPERM; 477 478 bsp->smk_task = isp->smk_task; 479 bprm->per_clear |= PER_CLEAR_ON_SETID; 480 481 return 0; 482 } 483 484 /** 485 * smack_bprm_committing_creds - Prepare to install the new credentials 486 * from bprm. 487 * 488 * @bprm: binprm for exec 489 */ 490 static void smack_bprm_committing_creds(struct linux_binprm *bprm) 491 { 492 struct task_smack *bsp = bprm->cred->security; 493 494 if (bsp->smk_task != bsp->smk_forked) 495 current->pdeath_signal = 0; 496 } 497 498 /** 499 * smack_bprm_secureexec - Return the decision to use secureexec. 500 * @bprm: binprm for exec 501 * 502 * Returns 0 on success. 503 */ 504 static int smack_bprm_secureexec(struct linux_binprm *bprm) 505 { 506 struct task_smack *tsp = current_security(); 507 int ret = cap_bprm_secureexec(bprm); 508 509 if (!ret && (tsp->smk_task != tsp->smk_forked)) 510 ret = 1; 511 512 return ret; 513 } 514 515 /* 516 * Inode hooks 517 */ 518 519 /** 520 * smack_inode_alloc_security - allocate an inode blob 521 * @inode: the inode in need of a blob 522 * 523 * Returns 0 if it gets a blob, -ENOMEM otherwise 524 */ 525 static int smack_inode_alloc_security(struct inode *inode) 526 { 527 inode->i_security = new_inode_smack(smk_of_current()); 528 if (inode->i_security == NULL) 529 return -ENOMEM; 530 return 0; 531 } 532 533 /** 534 * smack_inode_free_security - free an inode blob 535 * @inode: the inode with a blob 536 * 537 * Clears the blob pointer in inode 538 */ 539 static void smack_inode_free_security(struct inode *inode) 540 { 541 kfree(inode->i_security); 542 inode->i_security = NULL; 543 } 544 545 /** 546 * smack_inode_init_security - copy out the smack from an inode 547 * @inode: the inode 548 * @dir: unused 549 * @qstr: unused 550 * @name: where to put the attribute name 551 * @value: where to put the attribute value 552 * @len: where to put the length of the attribute 553 * 554 * Returns 0 if it all works out, -ENOMEM if there's no memory 555 */ 556 static int smack_inode_init_security(struct inode *inode, struct inode *dir, 557 const struct qstr *qstr, char **name, 558 void **value, size_t *len) 559 { 560 struct smack_known *skp; 561 struct inode_smack *issp = inode->i_security; 562 char *csp = smk_of_current(); 563 char *isp = smk_of_inode(inode); 564 char *dsp = smk_of_inode(dir); 565 int may; 566 567 if (name) { 568 *name = kstrdup(XATTR_SMACK_SUFFIX, GFP_NOFS); 569 if (*name == NULL) 570 return -ENOMEM; 571 } 572 573 if (value) { 574 skp = smk_find_entry(csp); 575 rcu_read_lock(); 576 may = smk_access_entry(csp, dsp, &skp->smk_rules); 577 rcu_read_unlock(); 578 579 /* 580 * If the access rule allows transmutation and 581 * the directory requests transmutation then 582 * by all means transmute. 583 * Mark the inode as changed. 584 */ 585 if (may > 0 && ((may & MAY_TRANSMUTE) != 0) && 586 smk_inode_transmutable(dir)) { 587 isp = dsp; 588 issp->smk_flags |= SMK_INODE_CHANGED; 589 } 590 591 *value = kstrdup(isp, GFP_NOFS); 592 if (*value == NULL) 593 return -ENOMEM; 594 } 595 596 if (len) 597 *len = strlen(isp) + 1; 598 599 return 0; 600 } 601 602 /** 603 * smack_inode_link - Smack check on link 604 * @old_dentry: the existing object 605 * @dir: unused 606 * @new_dentry: the new object 607 * 608 * Returns 0 if access is permitted, an error code otherwise 609 */ 610 static int smack_inode_link(struct dentry *old_dentry, struct inode *dir, 611 struct dentry *new_dentry) 612 { 613 char *isp; 614 struct smk_audit_info ad; 615 int rc; 616 617 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); 618 smk_ad_setfield_u_fs_path_dentry(&ad, old_dentry); 619 620 isp = smk_of_inode(old_dentry->d_inode); 621 rc = smk_curacc(isp, MAY_WRITE, &ad); 622 623 if (rc == 0 && new_dentry->d_inode != NULL) { 624 isp = smk_of_inode(new_dentry->d_inode); 625 smk_ad_setfield_u_fs_path_dentry(&ad, new_dentry); 626 rc = smk_curacc(isp, MAY_WRITE, &ad); 627 } 628 629 return rc; 630 } 631 632 /** 633 * smack_inode_unlink - Smack check on inode deletion 634 * @dir: containing directory object 635 * @dentry: file to unlink 636 * 637 * Returns 0 if current can write the containing directory 638 * and the object, error code otherwise 639 */ 640 static int smack_inode_unlink(struct inode *dir, struct dentry *dentry) 641 { 642 struct inode *ip = dentry->d_inode; 643 struct smk_audit_info ad; 644 int rc; 645 646 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); 647 smk_ad_setfield_u_fs_path_dentry(&ad, dentry); 648 649 /* 650 * You need write access to the thing you're unlinking 651 */ 652 rc = smk_curacc(smk_of_inode(ip), MAY_WRITE, &ad); 653 if (rc == 0) { 654 /* 655 * You also need write access to the containing directory 656 */ 657 smk_ad_setfield_u_fs_path_dentry(&ad, NULL); 658 smk_ad_setfield_u_fs_inode(&ad, dir); 659 rc = smk_curacc(smk_of_inode(dir), MAY_WRITE, &ad); 660 } 661 return rc; 662 } 663 664 /** 665 * smack_inode_rmdir - Smack check on directory deletion 666 * @dir: containing directory object 667 * @dentry: directory to unlink 668 * 669 * Returns 0 if current can write the containing directory 670 * and the directory, error code otherwise 671 */ 672 static int smack_inode_rmdir(struct inode *dir, struct dentry *dentry) 673 { 674 struct smk_audit_info ad; 675 int rc; 676 677 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); 678 smk_ad_setfield_u_fs_path_dentry(&ad, dentry); 679 680 /* 681 * You need write access to the thing you're removing 682 */ 683 rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE, &ad); 684 if (rc == 0) { 685 /* 686 * You also need write access to the containing directory 687 */ 688 smk_ad_setfield_u_fs_path_dentry(&ad, NULL); 689 smk_ad_setfield_u_fs_inode(&ad, dir); 690 rc = smk_curacc(smk_of_inode(dir), MAY_WRITE, &ad); 691 } 692 693 return rc; 694 } 695 696 /** 697 * smack_inode_rename - Smack check on rename 698 * @old_inode: the old directory 699 * @old_dentry: unused 700 * @new_inode: the new directory 701 * @new_dentry: unused 702 * 703 * Read and write access is required on both the old and 704 * new directories. 705 * 706 * Returns 0 if access is permitted, an error code otherwise 707 */ 708 static int smack_inode_rename(struct inode *old_inode, 709 struct dentry *old_dentry, 710 struct inode *new_inode, 711 struct dentry *new_dentry) 712 { 713 int rc; 714 char *isp; 715 struct smk_audit_info ad; 716 717 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); 718 smk_ad_setfield_u_fs_path_dentry(&ad, old_dentry); 719 720 isp = smk_of_inode(old_dentry->d_inode); 721 rc = smk_curacc(isp, MAY_READWRITE, &ad); 722 723 if (rc == 0 && new_dentry->d_inode != NULL) { 724 isp = smk_of_inode(new_dentry->d_inode); 725 smk_ad_setfield_u_fs_path_dentry(&ad, new_dentry); 726 rc = smk_curacc(isp, MAY_READWRITE, &ad); 727 } 728 return rc; 729 } 730 731 /** 732 * smack_inode_permission - Smack version of permission() 733 * @inode: the inode in question 734 * @mask: the access requested 735 * 736 * This is the important Smack hook. 737 * 738 * Returns 0 if access is permitted, -EACCES otherwise 739 */ 740 static int smack_inode_permission(struct inode *inode, int mask) 741 { 742 struct smk_audit_info ad; 743 int no_block = mask & MAY_NOT_BLOCK; 744 745 mask &= (MAY_READ|MAY_WRITE|MAY_EXEC|MAY_APPEND); 746 /* 747 * No permission to check. Existence test. Yup, it's there. 748 */ 749 if (mask == 0) 750 return 0; 751 752 /* May be droppable after audit */ 753 if (no_block) 754 return -ECHILD; 755 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_INODE); 756 smk_ad_setfield_u_fs_inode(&ad, inode); 757 return smk_curacc(smk_of_inode(inode), mask, &ad); 758 } 759 760 /** 761 * smack_inode_setattr - Smack check for setting attributes 762 * @dentry: the object 763 * @iattr: for the force flag 764 * 765 * Returns 0 if access is permitted, an error code otherwise 766 */ 767 static int smack_inode_setattr(struct dentry *dentry, struct iattr *iattr) 768 { 769 struct smk_audit_info ad; 770 /* 771 * Need to allow for clearing the setuid bit. 772 */ 773 if (iattr->ia_valid & ATTR_FORCE) 774 return 0; 775 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); 776 smk_ad_setfield_u_fs_path_dentry(&ad, dentry); 777 778 return smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE, &ad); 779 } 780 781 /** 782 * smack_inode_getattr - Smack check for getting attributes 783 * @mnt: unused 784 * @dentry: the object 785 * 786 * Returns 0 if access is permitted, an error code otherwise 787 */ 788 static int smack_inode_getattr(struct vfsmount *mnt, struct dentry *dentry) 789 { 790 struct smk_audit_info ad; 791 struct path path; 792 793 path.dentry = dentry; 794 path.mnt = mnt; 795 796 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH); 797 smk_ad_setfield_u_fs_path(&ad, path); 798 return smk_curacc(smk_of_inode(dentry->d_inode), MAY_READ, &ad); 799 } 800 801 /** 802 * smack_inode_setxattr - Smack check for setting xattrs 803 * @dentry: the object 804 * @name: name of the attribute 805 * @value: unused 806 * @size: unused 807 * @flags: unused 808 * 809 * This protects the Smack attribute explicitly. 810 * 811 * Returns 0 if access is permitted, an error code otherwise 812 */ 813 static int smack_inode_setxattr(struct dentry *dentry, const char *name, 814 const void *value, size_t size, int flags) 815 { 816 struct smk_audit_info ad; 817 int rc = 0; 818 819 if (strcmp(name, XATTR_NAME_SMACK) == 0 || 820 strcmp(name, XATTR_NAME_SMACKIPIN) == 0 || 821 strcmp(name, XATTR_NAME_SMACKIPOUT) == 0 || 822 strcmp(name, XATTR_NAME_SMACKEXEC) == 0 || 823 strcmp(name, XATTR_NAME_SMACKMMAP) == 0) { 824 if (!smack_privileged(CAP_MAC_ADMIN)) 825 rc = -EPERM; 826 /* 827 * check label validity here so import wont fail on 828 * post_setxattr 829 */ 830 if (size == 0 || size >= SMK_LONGLABEL || 831 smk_import(value, size) == NULL) 832 rc = -EINVAL; 833 } else if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0) { 834 if (!smack_privileged(CAP_MAC_ADMIN)) 835 rc = -EPERM; 836 if (size != TRANS_TRUE_SIZE || 837 strncmp(value, TRANS_TRUE, TRANS_TRUE_SIZE) != 0) 838 rc = -EINVAL; 839 } else 840 rc = cap_inode_setxattr(dentry, name, value, size, flags); 841 842 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); 843 smk_ad_setfield_u_fs_path_dentry(&ad, dentry); 844 845 if (rc == 0) 846 rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE, &ad); 847 848 return rc; 849 } 850 851 /** 852 * smack_inode_post_setxattr - Apply the Smack update approved above 853 * @dentry: object 854 * @name: attribute name 855 * @value: attribute value 856 * @size: attribute size 857 * @flags: unused 858 * 859 * Set the pointer in the inode blob to the entry found 860 * in the master label list. 861 */ 862 static void smack_inode_post_setxattr(struct dentry *dentry, const char *name, 863 const void *value, size_t size, int flags) 864 { 865 char *nsp; 866 struct inode_smack *isp = dentry->d_inode->i_security; 867 868 if (strcmp(name, XATTR_NAME_SMACK) == 0) { 869 nsp = smk_import(value, size); 870 if (nsp != NULL) 871 isp->smk_inode = nsp; 872 else 873 isp->smk_inode = smack_known_invalid.smk_known; 874 } else if (strcmp(name, XATTR_NAME_SMACKEXEC) == 0) { 875 nsp = smk_import(value, size); 876 if (nsp != NULL) 877 isp->smk_task = nsp; 878 else 879 isp->smk_task = smack_known_invalid.smk_known; 880 } else if (strcmp(name, XATTR_NAME_SMACKMMAP) == 0) { 881 nsp = smk_import(value, size); 882 if (nsp != NULL) 883 isp->smk_mmap = nsp; 884 else 885 isp->smk_mmap = smack_known_invalid.smk_known; 886 } else if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0) 887 isp->smk_flags |= SMK_INODE_TRANSMUTE; 888 889 return; 890 } 891 892 /** 893 * smack_inode_getxattr - Smack check on getxattr 894 * @dentry: the object 895 * @name: unused 896 * 897 * Returns 0 if access is permitted, an error code otherwise 898 */ 899 static int smack_inode_getxattr(struct dentry *dentry, const char *name) 900 { 901 struct smk_audit_info ad; 902 903 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); 904 smk_ad_setfield_u_fs_path_dentry(&ad, dentry); 905 906 return smk_curacc(smk_of_inode(dentry->d_inode), MAY_READ, &ad); 907 } 908 909 /** 910 * smack_inode_removexattr - Smack check on removexattr 911 * @dentry: the object 912 * @name: name of the attribute 913 * 914 * Removing the Smack attribute requires CAP_MAC_ADMIN 915 * 916 * Returns 0 if access is permitted, an error code otherwise 917 */ 918 static int smack_inode_removexattr(struct dentry *dentry, const char *name) 919 { 920 struct inode_smack *isp; 921 struct smk_audit_info ad; 922 int rc = 0; 923 924 if (strcmp(name, XATTR_NAME_SMACK) == 0 || 925 strcmp(name, XATTR_NAME_SMACKIPIN) == 0 || 926 strcmp(name, XATTR_NAME_SMACKIPOUT) == 0 || 927 strcmp(name, XATTR_NAME_SMACKEXEC) == 0 || 928 strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0 || 929 strcmp(name, XATTR_NAME_SMACKMMAP)) { 930 if (!smack_privileged(CAP_MAC_ADMIN)) 931 rc = -EPERM; 932 } else 933 rc = cap_inode_removexattr(dentry, name); 934 935 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); 936 smk_ad_setfield_u_fs_path_dentry(&ad, dentry); 937 if (rc == 0) 938 rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE, &ad); 939 940 if (rc == 0) { 941 isp = dentry->d_inode->i_security; 942 isp->smk_task = NULL; 943 isp->smk_mmap = NULL; 944 } 945 946 return rc; 947 } 948 949 /** 950 * smack_inode_getsecurity - get smack xattrs 951 * @inode: the object 952 * @name: attribute name 953 * @buffer: where to put the result 954 * @alloc: unused 955 * 956 * Returns the size of the attribute or an error code 957 */ 958 static int smack_inode_getsecurity(const struct inode *inode, 959 const char *name, void **buffer, 960 bool alloc) 961 { 962 struct socket_smack *ssp; 963 struct socket *sock; 964 struct super_block *sbp; 965 struct inode *ip = (struct inode *)inode; 966 char *isp; 967 int ilen; 968 int rc = 0; 969 970 if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) { 971 isp = smk_of_inode(inode); 972 ilen = strlen(isp) + 1; 973 *buffer = isp; 974 return ilen; 975 } 976 977 /* 978 * The rest of the Smack xattrs are only on sockets. 979 */ 980 sbp = ip->i_sb; 981 if (sbp->s_magic != SOCKFS_MAGIC) 982 return -EOPNOTSUPP; 983 984 sock = SOCKET_I(ip); 985 if (sock == NULL || sock->sk == NULL) 986 return -EOPNOTSUPP; 987 988 ssp = sock->sk->sk_security; 989 990 if (strcmp(name, XATTR_SMACK_IPIN) == 0) 991 isp = ssp->smk_in; 992 else if (strcmp(name, XATTR_SMACK_IPOUT) == 0) 993 isp = ssp->smk_out; 994 else 995 return -EOPNOTSUPP; 996 997 ilen = strlen(isp) + 1; 998 if (rc == 0) { 999 *buffer = isp; 1000 rc = ilen; 1001 } 1002 1003 return rc; 1004 } 1005 1006 1007 /** 1008 * smack_inode_listsecurity - list the Smack attributes 1009 * @inode: the object 1010 * @buffer: where they go 1011 * @buffer_size: size of buffer 1012 * 1013 * Returns 0 on success, -EINVAL otherwise 1014 */ 1015 static int smack_inode_listsecurity(struct inode *inode, char *buffer, 1016 size_t buffer_size) 1017 { 1018 int len = strlen(XATTR_NAME_SMACK); 1019 1020 if (buffer != NULL && len <= buffer_size) { 1021 memcpy(buffer, XATTR_NAME_SMACK, len); 1022 return len; 1023 } 1024 return -EINVAL; 1025 } 1026 1027 /** 1028 * smack_inode_getsecid - Extract inode's security id 1029 * @inode: inode to extract the info from 1030 * @secid: where result will be saved 1031 */ 1032 static void smack_inode_getsecid(const struct inode *inode, u32 *secid) 1033 { 1034 struct inode_smack *isp = inode->i_security; 1035 1036 *secid = smack_to_secid(isp->smk_inode); 1037 } 1038 1039 /* 1040 * File Hooks 1041 */ 1042 1043 /** 1044 * smack_file_permission - Smack check on file operations 1045 * @file: unused 1046 * @mask: unused 1047 * 1048 * Returns 0 1049 * 1050 * Should access checks be done on each read or write? 1051 * UNICOS and SELinux say yes. 1052 * Trusted Solaris, Trusted Irix, and just about everyone else says no. 1053 * 1054 * I'll say no for now. Smack does not do the frequent 1055 * label changing that SELinux does. 1056 */ 1057 static int smack_file_permission(struct file *file, int mask) 1058 { 1059 return 0; 1060 } 1061 1062 /** 1063 * smack_file_alloc_security - assign a file security blob 1064 * @file: the object 1065 * 1066 * The security blob for a file is a pointer to the master 1067 * label list, so no allocation is done. 1068 * 1069 * Returns 0 1070 */ 1071 static int smack_file_alloc_security(struct file *file) 1072 { 1073 file->f_security = smk_of_current(); 1074 return 0; 1075 } 1076 1077 /** 1078 * smack_file_free_security - clear a file security blob 1079 * @file: the object 1080 * 1081 * The security blob for a file is a pointer to the master 1082 * label list, so no memory is freed. 1083 */ 1084 static void smack_file_free_security(struct file *file) 1085 { 1086 file->f_security = NULL; 1087 } 1088 1089 /** 1090 * smack_file_ioctl - Smack check on ioctls 1091 * @file: the object 1092 * @cmd: what to do 1093 * @arg: unused 1094 * 1095 * Relies heavily on the correct use of the ioctl command conventions. 1096 * 1097 * Returns 0 if allowed, error code otherwise 1098 */ 1099 static int smack_file_ioctl(struct file *file, unsigned int cmd, 1100 unsigned long arg) 1101 { 1102 int rc = 0; 1103 struct smk_audit_info ad; 1104 1105 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH); 1106 smk_ad_setfield_u_fs_path(&ad, file->f_path); 1107 1108 if (_IOC_DIR(cmd) & _IOC_WRITE) 1109 rc = smk_curacc(file->f_security, MAY_WRITE, &ad); 1110 1111 if (rc == 0 && (_IOC_DIR(cmd) & _IOC_READ)) 1112 rc = smk_curacc(file->f_security, MAY_READ, &ad); 1113 1114 return rc; 1115 } 1116 1117 /** 1118 * smack_file_lock - Smack check on file locking 1119 * @file: the object 1120 * @cmd: unused 1121 * 1122 * Returns 0 if current has write access, error code otherwise 1123 */ 1124 static int smack_file_lock(struct file *file, unsigned int cmd) 1125 { 1126 struct smk_audit_info ad; 1127 1128 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH); 1129 smk_ad_setfield_u_fs_path(&ad, file->f_path); 1130 return smk_curacc(file->f_security, MAY_WRITE, &ad); 1131 } 1132 1133 /** 1134 * smack_file_fcntl - Smack check on fcntl 1135 * @file: the object 1136 * @cmd: what action to check 1137 * @arg: unused 1138 * 1139 * Generally these operations are harmless. 1140 * File locking operations present an obvious mechanism 1141 * for passing information, so they require write access. 1142 * 1143 * Returns 0 if current has access, error code otherwise 1144 */ 1145 static int smack_file_fcntl(struct file *file, unsigned int cmd, 1146 unsigned long arg) 1147 { 1148 struct smk_audit_info ad; 1149 int rc = 0; 1150 1151 1152 switch (cmd) { 1153 case F_GETLK: 1154 case F_SETLK: 1155 case F_SETLKW: 1156 case F_SETOWN: 1157 case F_SETSIG: 1158 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH); 1159 smk_ad_setfield_u_fs_path(&ad, file->f_path); 1160 rc = smk_curacc(file->f_security, MAY_WRITE, &ad); 1161 break; 1162 default: 1163 break; 1164 } 1165 1166 return rc; 1167 } 1168 1169 /** 1170 * smack_mmap_file : 1171 * Check permissions for a mmap operation. The @file may be NULL, e.g. 1172 * if mapping anonymous memory. 1173 * @file contains the file structure for file to map (may be NULL). 1174 * @reqprot contains the protection requested by the application. 1175 * @prot contains the protection that will be applied by the kernel. 1176 * @flags contains the operational flags. 1177 * Return 0 if permission is granted. 1178 */ 1179 static int smack_mmap_file(struct file *file, 1180 unsigned long reqprot, unsigned long prot, 1181 unsigned long flags) 1182 { 1183 struct smack_known *skp; 1184 struct smack_rule *srp; 1185 struct task_smack *tsp; 1186 char *sp; 1187 char *msmack; 1188 char *osmack; 1189 struct inode_smack *isp; 1190 int may; 1191 int mmay; 1192 int tmay; 1193 int rc; 1194 1195 if (file == NULL) 1196 return 0; 1197 1198 isp = file_inode(file)->i_security; 1199 if (isp->smk_mmap == NULL) 1200 return 0; 1201 msmack = isp->smk_mmap; 1202 1203 tsp = current_security(); 1204 sp = smk_of_current(); 1205 skp = smk_find_entry(sp); 1206 rc = 0; 1207 1208 rcu_read_lock(); 1209 /* 1210 * For each Smack rule associated with the subject 1211 * label verify that the SMACK64MMAP also has access 1212 * to that rule's object label. 1213 */ 1214 list_for_each_entry_rcu(srp, &skp->smk_rules, list) { 1215 osmack = srp->smk_object; 1216 /* 1217 * Matching labels always allows access. 1218 */ 1219 if (msmack == osmack) 1220 continue; 1221 /* 1222 * If there is a matching local rule take 1223 * that into account as well. 1224 */ 1225 may = smk_access_entry(srp->smk_subject, osmack, 1226 &tsp->smk_rules); 1227 if (may == -ENOENT) 1228 may = srp->smk_access; 1229 else 1230 may &= srp->smk_access; 1231 /* 1232 * If may is zero the SMACK64MMAP subject can't 1233 * possibly have less access. 1234 */ 1235 if (may == 0) 1236 continue; 1237 1238 /* 1239 * Fetch the global list entry. 1240 * If there isn't one a SMACK64MMAP subject 1241 * can't have as much access as current. 1242 */ 1243 skp = smk_find_entry(msmack); 1244 mmay = smk_access_entry(msmack, osmack, &skp->smk_rules); 1245 if (mmay == -ENOENT) { 1246 rc = -EACCES; 1247 break; 1248 } 1249 /* 1250 * If there is a local entry it modifies the 1251 * potential access, too. 1252 */ 1253 tmay = smk_access_entry(msmack, osmack, &tsp->smk_rules); 1254 if (tmay != -ENOENT) 1255 mmay &= tmay; 1256 1257 /* 1258 * If there is any access available to current that is 1259 * not available to a SMACK64MMAP subject 1260 * deny access. 1261 */ 1262 if ((may | mmay) != mmay) { 1263 rc = -EACCES; 1264 break; 1265 } 1266 } 1267 1268 rcu_read_unlock(); 1269 1270 return rc; 1271 } 1272 1273 /** 1274 * smack_file_set_fowner - set the file security blob value 1275 * @file: object in question 1276 * 1277 * Returns 0 1278 * Further research may be required on this one. 1279 */ 1280 static int smack_file_set_fowner(struct file *file) 1281 { 1282 file->f_security = smk_of_current(); 1283 return 0; 1284 } 1285 1286 /** 1287 * smack_file_send_sigiotask - Smack on sigio 1288 * @tsk: The target task 1289 * @fown: the object the signal come from 1290 * @signum: unused 1291 * 1292 * Allow a privileged task to get signals even if it shouldn't 1293 * 1294 * Returns 0 if a subject with the object's smack could 1295 * write to the task, an error code otherwise. 1296 */ 1297 static int smack_file_send_sigiotask(struct task_struct *tsk, 1298 struct fown_struct *fown, int signum) 1299 { 1300 struct file *file; 1301 int rc; 1302 char *tsp = smk_of_task(tsk->cred->security); 1303 struct smk_audit_info ad; 1304 1305 /* 1306 * struct fown_struct is never outside the context of a struct file 1307 */ 1308 file = container_of(fown, struct file, f_owner); 1309 1310 /* we don't log here as rc can be overriden */ 1311 rc = smk_access(file->f_security, tsp, MAY_WRITE, NULL); 1312 if (rc != 0 && has_capability(tsk, CAP_MAC_OVERRIDE)) 1313 rc = 0; 1314 1315 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK); 1316 smk_ad_setfield_u_tsk(&ad, tsk); 1317 smack_log(file->f_security, tsp, MAY_WRITE, rc, &ad); 1318 return rc; 1319 } 1320 1321 /** 1322 * smack_file_receive - Smack file receive check 1323 * @file: the object 1324 * 1325 * Returns 0 if current has access, error code otherwise 1326 */ 1327 static int smack_file_receive(struct file *file) 1328 { 1329 int may = 0; 1330 struct smk_audit_info ad; 1331 1332 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK); 1333 smk_ad_setfield_u_fs_path(&ad, file->f_path); 1334 /* 1335 * This code relies on bitmasks. 1336 */ 1337 if (file->f_mode & FMODE_READ) 1338 may = MAY_READ; 1339 if (file->f_mode & FMODE_WRITE) 1340 may |= MAY_WRITE; 1341 1342 return smk_curacc(file->f_security, may, &ad); 1343 } 1344 1345 /** 1346 * smack_file_open - Smack dentry open processing 1347 * @file: the object 1348 * @cred: unused 1349 * 1350 * Set the security blob in the file structure. 1351 * 1352 * Returns 0 1353 */ 1354 static int smack_file_open(struct file *file, const struct cred *cred) 1355 { 1356 struct inode_smack *isp = file_inode(file)->i_security; 1357 1358 file->f_security = isp->smk_inode; 1359 1360 return 0; 1361 } 1362 1363 /* 1364 * Task hooks 1365 */ 1366 1367 /** 1368 * smack_cred_alloc_blank - "allocate" blank task-level security credentials 1369 * @new: the new credentials 1370 * @gfp: the atomicity of any memory allocations 1371 * 1372 * Prepare a blank set of credentials for modification. This must allocate all 1373 * the memory the LSM module might require such that cred_transfer() can 1374 * complete without error. 1375 */ 1376 static int smack_cred_alloc_blank(struct cred *cred, gfp_t gfp) 1377 { 1378 struct task_smack *tsp; 1379 1380 tsp = new_task_smack(NULL, NULL, gfp); 1381 if (tsp == NULL) 1382 return -ENOMEM; 1383 1384 cred->security = tsp; 1385 1386 return 0; 1387 } 1388 1389 1390 /** 1391 * smack_cred_free - "free" task-level security credentials 1392 * @cred: the credentials in question 1393 * 1394 */ 1395 static void smack_cred_free(struct cred *cred) 1396 { 1397 struct task_smack *tsp = cred->security; 1398 struct smack_rule *rp; 1399 struct list_head *l; 1400 struct list_head *n; 1401 1402 if (tsp == NULL) 1403 return; 1404 cred->security = NULL; 1405 1406 list_for_each_safe(l, n, &tsp->smk_rules) { 1407 rp = list_entry(l, struct smack_rule, list); 1408 list_del(&rp->list); 1409 kfree(rp); 1410 } 1411 kfree(tsp); 1412 } 1413 1414 /** 1415 * smack_cred_prepare - prepare new set of credentials for modification 1416 * @new: the new credentials 1417 * @old: the original credentials 1418 * @gfp: the atomicity of any memory allocations 1419 * 1420 * Prepare a new set of credentials for modification. 1421 */ 1422 static int smack_cred_prepare(struct cred *new, const struct cred *old, 1423 gfp_t gfp) 1424 { 1425 struct task_smack *old_tsp = old->security; 1426 struct task_smack *new_tsp; 1427 int rc; 1428 1429 new_tsp = new_task_smack(old_tsp->smk_task, old_tsp->smk_task, gfp); 1430 if (new_tsp == NULL) 1431 return -ENOMEM; 1432 1433 rc = smk_copy_rules(&new_tsp->smk_rules, &old_tsp->smk_rules, gfp); 1434 if (rc != 0) 1435 return rc; 1436 1437 new->security = new_tsp; 1438 return 0; 1439 } 1440 1441 /** 1442 * smack_cred_transfer - Transfer the old credentials to the new credentials 1443 * @new: the new credentials 1444 * @old: the original credentials 1445 * 1446 * Fill in a set of blank credentials from another set of credentials. 1447 */ 1448 static void smack_cred_transfer(struct cred *new, const struct cred *old) 1449 { 1450 struct task_smack *old_tsp = old->security; 1451 struct task_smack *new_tsp = new->security; 1452 1453 new_tsp->smk_task = old_tsp->smk_task; 1454 new_tsp->smk_forked = old_tsp->smk_task; 1455 mutex_init(&new_tsp->smk_rules_lock); 1456 INIT_LIST_HEAD(&new_tsp->smk_rules); 1457 1458 1459 /* cbs copy rule list */ 1460 } 1461 1462 /** 1463 * smack_kernel_act_as - Set the subjective context in a set of credentials 1464 * @new: points to the set of credentials to be modified. 1465 * @secid: specifies the security ID to be set 1466 * 1467 * Set the security data for a kernel service. 1468 */ 1469 static int smack_kernel_act_as(struct cred *new, u32 secid) 1470 { 1471 struct task_smack *new_tsp = new->security; 1472 char *smack = smack_from_secid(secid); 1473 1474 if (smack == NULL) 1475 return -EINVAL; 1476 1477 new_tsp->smk_task = smack; 1478 return 0; 1479 } 1480 1481 /** 1482 * smack_kernel_create_files_as - Set the file creation label in a set of creds 1483 * @new: points to the set of credentials to be modified 1484 * @inode: points to the inode to use as a reference 1485 * 1486 * Set the file creation context in a set of credentials to the same 1487 * as the objective context of the specified inode 1488 */ 1489 static int smack_kernel_create_files_as(struct cred *new, 1490 struct inode *inode) 1491 { 1492 struct inode_smack *isp = inode->i_security; 1493 struct task_smack *tsp = new->security; 1494 1495 tsp->smk_forked = isp->smk_inode; 1496 tsp->smk_task = isp->smk_inode; 1497 return 0; 1498 } 1499 1500 /** 1501 * smk_curacc_on_task - helper to log task related access 1502 * @p: the task object 1503 * @access: the access requested 1504 * @caller: name of the calling function for audit 1505 * 1506 * Return 0 if access is permitted 1507 */ 1508 static int smk_curacc_on_task(struct task_struct *p, int access, 1509 const char *caller) 1510 { 1511 struct smk_audit_info ad; 1512 1513 smk_ad_init(&ad, caller, LSM_AUDIT_DATA_TASK); 1514 smk_ad_setfield_u_tsk(&ad, p); 1515 return smk_curacc(smk_of_task(task_security(p)), access, &ad); 1516 } 1517 1518 /** 1519 * smack_task_setpgid - Smack check on setting pgid 1520 * @p: the task object 1521 * @pgid: unused 1522 * 1523 * Return 0 if write access is permitted 1524 */ 1525 static int smack_task_setpgid(struct task_struct *p, pid_t pgid) 1526 { 1527 return smk_curacc_on_task(p, MAY_WRITE, __func__); 1528 } 1529 1530 /** 1531 * smack_task_getpgid - Smack access check for getpgid 1532 * @p: the object task 1533 * 1534 * Returns 0 if current can read the object task, error code otherwise 1535 */ 1536 static int smack_task_getpgid(struct task_struct *p) 1537 { 1538 return smk_curacc_on_task(p, MAY_READ, __func__); 1539 } 1540 1541 /** 1542 * smack_task_getsid - Smack access check for getsid 1543 * @p: the object task 1544 * 1545 * Returns 0 if current can read the object task, error code otherwise 1546 */ 1547 static int smack_task_getsid(struct task_struct *p) 1548 { 1549 return smk_curacc_on_task(p, MAY_READ, __func__); 1550 } 1551 1552 /** 1553 * smack_task_getsecid - get the secid of the task 1554 * @p: the object task 1555 * @secid: where to put the result 1556 * 1557 * Sets the secid to contain a u32 version of the smack label. 1558 */ 1559 static void smack_task_getsecid(struct task_struct *p, u32 *secid) 1560 { 1561 *secid = smack_to_secid(smk_of_task(task_security(p))); 1562 } 1563 1564 /** 1565 * smack_task_setnice - Smack check on setting nice 1566 * @p: the task object 1567 * @nice: unused 1568 * 1569 * Return 0 if write access is permitted 1570 */ 1571 static int smack_task_setnice(struct task_struct *p, int nice) 1572 { 1573 int rc; 1574 1575 rc = cap_task_setnice(p, nice); 1576 if (rc == 0) 1577 rc = smk_curacc_on_task(p, MAY_WRITE, __func__); 1578 return rc; 1579 } 1580 1581 /** 1582 * smack_task_setioprio - Smack check on setting ioprio 1583 * @p: the task object 1584 * @ioprio: unused 1585 * 1586 * Return 0 if write access is permitted 1587 */ 1588 static int smack_task_setioprio(struct task_struct *p, int ioprio) 1589 { 1590 int rc; 1591 1592 rc = cap_task_setioprio(p, ioprio); 1593 if (rc == 0) 1594 rc = smk_curacc_on_task(p, MAY_WRITE, __func__); 1595 return rc; 1596 } 1597 1598 /** 1599 * smack_task_getioprio - Smack check on reading ioprio 1600 * @p: the task object 1601 * 1602 * Return 0 if read access is permitted 1603 */ 1604 static int smack_task_getioprio(struct task_struct *p) 1605 { 1606 return smk_curacc_on_task(p, MAY_READ, __func__); 1607 } 1608 1609 /** 1610 * smack_task_setscheduler - Smack check on setting scheduler 1611 * @p: the task object 1612 * @policy: unused 1613 * @lp: unused 1614 * 1615 * Return 0 if read access is permitted 1616 */ 1617 static int smack_task_setscheduler(struct task_struct *p) 1618 { 1619 int rc; 1620 1621 rc = cap_task_setscheduler(p); 1622 if (rc == 0) 1623 rc = smk_curacc_on_task(p, MAY_WRITE, __func__); 1624 return rc; 1625 } 1626 1627 /** 1628 * smack_task_getscheduler - Smack check on reading scheduler 1629 * @p: the task object 1630 * 1631 * Return 0 if read access is permitted 1632 */ 1633 static int smack_task_getscheduler(struct task_struct *p) 1634 { 1635 return smk_curacc_on_task(p, MAY_READ, __func__); 1636 } 1637 1638 /** 1639 * smack_task_movememory - Smack check on moving memory 1640 * @p: the task object 1641 * 1642 * Return 0 if write access is permitted 1643 */ 1644 static int smack_task_movememory(struct task_struct *p) 1645 { 1646 return smk_curacc_on_task(p, MAY_WRITE, __func__); 1647 } 1648 1649 /** 1650 * smack_task_kill - Smack check on signal delivery 1651 * @p: the task object 1652 * @info: unused 1653 * @sig: unused 1654 * @secid: identifies the smack to use in lieu of current's 1655 * 1656 * Return 0 if write access is permitted 1657 * 1658 * The secid behavior is an artifact of an SELinux hack 1659 * in the USB code. Someday it may go away. 1660 */ 1661 static int smack_task_kill(struct task_struct *p, struct siginfo *info, 1662 int sig, u32 secid) 1663 { 1664 struct smk_audit_info ad; 1665 1666 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK); 1667 smk_ad_setfield_u_tsk(&ad, p); 1668 /* 1669 * Sending a signal requires that the sender 1670 * can write the receiver. 1671 */ 1672 if (secid == 0) 1673 return smk_curacc(smk_of_task(task_security(p)), MAY_WRITE, 1674 &ad); 1675 /* 1676 * If the secid isn't 0 we're dealing with some USB IO 1677 * specific behavior. This is not clean. For one thing 1678 * we can't take privilege into account. 1679 */ 1680 return smk_access(smack_from_secid(secid), 1681 smk_of_task(task_security(p)), MAY_WRITE, &ad); 1682 } 1683 1684 /** 1685 * smack_task_wait - Smack access check for waiting 1686 * @p: task to wait for 1687 * 1688 * Returns 0 1689 */ 1690 static int smack_task_wait(struct task_struct *p) 1691 { 1692 /* 1693 * Allow the operation to succeed. 1694 * Zombies are bad. 1695 * In userless environments (e.g. phones) programs 1696 * get marked with SMACK64EXEC and even if the parent 1697 * and child shouldn't be talking the parent still 1698 * may expect to know when the child exits. 1699 */ 1700 return 0; 1701 } 1702 1703 /** 1704 * smack_task_to_inode - copy task smack into the inode blob 1705 * @p: task to copy from 1706 * @inode: inode to copy to 1707 * 1708 * Sets the smack pointer in the inode security blob 1709 */ 1710 static void smack_task_to_inode(struct task_struct *p, struct inode *inode) 1711 { 1712 struct inode_smack *isp = inode->i_security; 1713 isp->smk_inode = smk_of_task(task_security(p)); 1714 } 1715 1716 /* 1717 * Socket hooks. 1718 */ 1719 1720 /** 1721 * smack_sk_alloc_security - Allocate a socket blob 1722 * @sk: the socket 1723 * @family: unused 1724 * @gfp_flags: memory allocation flags 1725 * 1726 * Assign Smack pointers to current 1727 * 1728 * Returns 0 on success, -ENOMEM is there's no memory 1729 */ 1730 static int smack_sk_alloc_security(struct sock *sk, int family, gfp_t gfp_flags) 1731 { 1732 char *csp = smk_of_current(); 1733 struct socket_smack *ssp; 1734 1735 ssp = kzalloc(sizeof(struct socket_smack), gfp_flags); 1736 if (ssp == NULL) 1737 return -ENOMEM; 1738 1739 ssp->smk_in = csp; 1740 ssp->smk_out = csp; 1741 ssp->smk_packet = NULL; 1742 1743 sk->sk_security = ssp; 1744 1745 return 0; 1746 } 1747 1748 /** 1749 * smack_sk_free_security - Free a socket blob 1750 * @sk: the socket 1751 * 1752 * Clears the blob pointer 1753 */ 1754 static void smack_sk_free_security(struct sock *sk) 1755 { 1756 kfree(sk->sk_security); 1757 } 1758 1759 /** 1760 * smack_host_label - check host based restrictions 1761 * @sip: the object end 1762 * 1763 * looks for host based access restrictions 1764 * 1765 * This version will only be appropriate for really small sets of single label 1766 * hosts. The caller is responsible for ensuring that the RCU read lock is 1767 * taken before calling this function. 1768 * 1769 * Returns the label of the far end or NULL if it's not special. 1770 */ 1771 static char *smack_host_label(struct sockaddr_in *sip) 1772 { 1773 struct smk_netlbladdr *snp; 1774 struct in_addr *siap = &sip->sin_addr; 1775 1776 if (siap->s_addr == 0) 1777 return NULL; 1778 1779 list_for_each_entry_rcu(snp, &smk_netlbladdr_list, list) 1780 /* 1781 * we break after finding the first match because 1782 * the list is sorted from longest to shortest mask 1783 * so we have found the most specific match 1784 */ 1785 if ((&snp->smk_host.sin_addr)->s_addr == 1786 (siap->s_addr & (&snp->smk_mask)->s_addr)) { 1787 /* we have found the special CIPSO option */ 1788 if (snp->smk_label == smack_cipso_option) 1789 return NULL; 1790 return snp->smk_label; 1791 } 1792 1793 return NULL; 1794 } 1795 1796 /** 1797 * smack_netlabel - Set the secattr on a socket 1798 * @sk: the socket 1799 * @labeled: socket label scheme 1800 * 1801 * Convert the outbound smack value (smk_out) to a 1802 * secattr and attach it to the socket. 1803 * 1804 * Returns 0 on success or an error code 1805 */ 1806 static int smack_netlabel(struct sock *sk, int labeled) 1807 { 1808 struct smack_known *skp; 1809 struct socket_smack *ssp = sk->sk_security; 1810 int rc = 0; 1811 1812 /* 1813 * Usually the netlabel code will handle changing the 1814 * packet labeling based on the label. 1815 * The case of a single label host is different, because 1816 * a single label host should never get a labeled packet 1817 * even though the label is usually associated with a packet 1818 * label. 1819 */ 1820 local_bh_disable(); 1821 bh_lock_sock_nested(sk); 1822 1823 if (ssp->smk_out == smack_net_ambient || 1824 labeled == SMACK_UNLABELED_SOCKET) 1825 netlbl_sock_delattr(sk); 1826 else { 1827 skp = smk_find_entry(ssp->smk_out); 1828 rc = netlbl_sock_setattr(sk, sk->sk_family, &skp->smk_netlabel); 1829 } 1830 1831 bh_unlock_sock(sk); 1832 local_bh_enable(); 1833 1834 return rc; 1835 } 1836 1837 /** 1838 * smack_netlbel_send - Set the secattr on a socket and perform access checks 1839 * @sk: the socket 1840 * @sap: the destination address 1841 * 1842 * Set the correct secattr for the given socket based on the destination 1843 * address and perform any outbound access checks needed. 1844 * 1845 * Returns 0 on success or an error code. 1846 * 1847 */ 1848 static int smack_netlabel_send(struct sock *sk, struct sockaddr_in *sap) 1849 { 1850 int rc; 1851 int sk_lbl; 1852 char *hostsp; 1853 struct socket_smack *ssp = sk->sk_security; 1854 struct smk_audit_info ad; 1855 1856 rcu_read_lock(); 1857 hostsp = smack_host_label(sap); 1858 if (hostsp != NULL) { 1859 #ifdef CONFIG_AUDIT 1860 struct lsm_network_audit net; 1861 1862 smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net); 1863 ad.a.u.net->family = sap->sin_family; 1864 ad.a.u.net->dport = sap->sin_port; 1865 ad.a.u.net->v4info.daddr = sap->sin_addr.s_addr; 1866 #endif 1867 sk_lbl = SMACK_UNLABELED_SOCKET; 1868 rc = smk_access(ssp->smk_out, hostsp, MAY_WRITE, &ad); 1869 } else { 1870 sk_lbl = SMACK_CIPSO_SOCKET; 1871 rc = 0; 1872 } 1873 rcu_read_unlock(); 1874 if (rc != 0) 1875 return rc; 1876 1877 return smack_netlabel(sk, sk_lbl); 1878 } 1879 1880 /** 1881 * smack_inode_setsecurity - set smack xattrs 1882 * @inode: the object 1883 * @name: attribute name 1884 * @value: attribute value 1885 * @size: size of the attribute 1886 * @flags: unused 1887 * 1888 * Sets the named attribute in the appropriate blob 1889 * 1890 * Returns 0 on success, or an error code 1891 */ 1892 static int smack_inode_setsecurity(struct inode *inode, const char *name, 1893 const void *value, size_t size, int flags) 1894 { 1895 char *sp; 1896 struct inode_smack *nsp = inode->i_security; 1897 struct socket_smack *ssp; 1898 struct socket *sock; 1899 int rc = 0; 1900 1901 if (value == NULL || size > SMK_LONGLABEL || size == 0) 1902 return -EACCES; 1903 1904 sp = smk_import(value, size); 1905 if (sp == NULL) 1906 return -EINVAL; 1907 1908 if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) { 1909 nsp->smk_inode = sp; 1910 nsp->smk_flags |= SMK_INODE_INSTANT; 1911 return 0; 1912 } 1913 /* 1914 * The rest of the Smack xattrs are only on sockets. 1915 */ 1916 if (inode->i_sb->s_magic != SOCKFS_MAGIC) 1917 return -EOPNOTSUPP; 1918 1919 sock = SOCKET_I(inode); 1920 if (sock == NULL || sock->sk == NULL) 1921 return -EOPNOTSUPP; 1922 1923 ssp = sock->sk->sk_security; 1924 1925 if (strcmp(name, XATTR_SMACK_IPIN) == 0) 1926 ssp->smk_in = sp; 1927 else if (strcmp(name, XATTR_SMACK_IPOUT) == 0) { 1928 ssp->smk_out = sp; 1929 if (sock->sk->sk_family != PF_UNIX) { 1930 rc = smack_netlabel(sock->sk, SMACK_CIPSO_SOCKET); 1931 if (rc != 0) 1932 printk(KERN_WARNING 1933 "Smack: \"%s\" netlbl error %d.\n", 1934 __func__, -rc); 1935 } 1936 } else 1937 return -EOPNOTSUPP; 1938 1939 return 0; 1940 } 1941 1942 /** 1943 * smack_socket_post_create - finish socket setup 1944 * @sock: the socket 1945 * @family: protocol family 1946 * @type: unused 1947 * @protocol: unused 1948 * @kern: unused 1949 * 1950 * Sets the netlabel information on the socket 1951 * 1952 * Returns 0 on success, and error code otherwise 1953 */ 1954 static int smack_socket_post_create(struct socket *sock, int family, 1955 int type, int protocol, int kern) 1956 { 1957 if (family != PF_INET || sock->sk == NULL) 1958 return 0; 1959 /* 1960 * Set the outbound netlbl. 1961 */ 1962 return smack_netlabel(sock->sk, SMACK_CIPSO_SOCKET); 1963 } 1964 1965 /** 1966 * smack_socket_connect - connect access check 1967 * @sock: the socket 1968 * @sap: the other end 1969 * @addrlen: size of sap 1970 * 1971 * Verifies that a connection may be possible 1972 * 1973 * Returns 0 on success, and error code otherwise 1974 */ 1975 static int smack_socket_connect(struct socket *sock, struct sockaddr *sap, 1976 int addrlen) 1977 { 1978 if (sock->sk == NULL || sock->sk->sk_family != PF_INET) 1979 return 0; 1980 if (addrlen < sizeof(struct sockaddr_in)) 1981 return -EINVAL; 1982 1983 return smack_netlabel_send(sock->sk, (struct sockaddr_in *)sap); 1984 } 1985 1986 /** 1987 * smack_flags_to_may - convert S_ to MAY_ values 1988 * @flags: the S_ value 1989 * 1990 * Returns the equivalent MAY_ value 1991 */ 1992 static int smack_flags_to_may(int flags) 1993 { 1994 int may = 0; 1995 1996 if (flags & S_IRUGO) 1997 may |= MAY_READ; 1998 if (flags & S_IWUGO) 1999 may |= MAY_WRITE; 2000 if (flags & S_IXUGO) 2001 may |= MAY_EXEC; 2002 2003 return may; 2004 } 2005 2006 /** 2007 * smack_msg_msg_alloc_security - Set the security blob for msg_msg 2008 * @msg: the object 2009 * 2010 * Returns 0 2011 */ 2012 static int smack_msg_msg_alloc_security(struct msg_msg *msg) 2013 { 2014 msg->security = smk_of_current(); 2015 return 0; 2016 } 2017 2018 /** 2019 * smack_msg_msg_free_security - Clear the security blob for msg_msg 2020 * @msg: the object 2021 * 2022 * Clears the blob pointer 2023 */ 2024 static void smack_msg_msg_free_security(struct msg_msg *msg) 2025 { 2026 msg->security = NULL; 2027 } 2028 2029 /** 2030 * smack_of_shm - the smack pointer for the shm 2031 * @shp: the object 2032 * 2033 * Returns a pointer to the smack value 2034 */ 2035 static char *smack_of_shm(struct shmid_kernel *shp) 2036 { 2037 return (char *)shp->shm_perm.security; 2038 } 2039 2040 /** 2041 * smack_shm_alloc_security - Set the security blob for shm 2042 * @shp: the object 2043 * 2044 * Returns 0 2045 */ 2046 static int smack_shm_alloc_security(struct shmid_kernel *shp) 2047 { 2048 struct kern_ipc_perm *isp = &shp->shm_perm; 2049 2050 isp->security = smk_of_current(); 2051 return 0; 2052 } 2053 2054 /** 2055 * smack_shm_free_security - Clear the security blob for shm 2056 * @shp: the object 2057 * 2058 * Clears the blob pointer 2059 */ 2060 static void smack_shm_free_security(struct shmid_kernel *shp) 2061 { 2062 struct kern_ipc_perm *isp = &shp->shm_perm; 2063 2064 isp->security = NULL; 2065 } 2066 2067 /** 2068 * smk_curacc_shm : check if current has access on shm 2069 * @shp : the object 2070 * @access : access requested 2071 * 2072 * Returns 0 if current has the requested access, error code otherwise 2073 */ 2074 static int smk_curacc_shm(struct shmid_kernel *shp, int access) 2075 { 2076 char *ssp = smack_of_shm(shp); 2077 struct smk_audit_info ad; 2078 2079 #ifdef CONFIG_AUDIT 2080 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC); 2081 ad.a.u.ipc_id = shp->shm_perm.id; 2082 #endif 2083 return smk_curacc(ssp, access, &ad); 2084 } 2085 2086 /** 2087 * smack_shm_associate - Smack access check for shm 2088 * @shp: the object 2089 * @shmflg: access requested 2090 * 2091 * Returns 0 if current has the requested access, error code otherwise 2092 */ 2093 static int smack_shm_associate(struct shmid_kernel *shp, int shmflg) 2094 { 2095 int may; 2096 2097 may = smack_flags_to_may(shmflg); 2098 return smk_curacc_shm(shp, may); 2099 } 2100 2101 /** 2102 * smack_shm_shmctl - Smack access check for shm 2103 * @shp: the object 2104 * @cmd: what it wants to do 2105 * 2106 * Returns 0 if current has the requested access, error code otherwise 2107 */ 2108 static int smack_shm_shmctl(struct shmid_kernel *shp, int cmd) 2109 { 2110 int may; 2111 2112 switch (cmd) { 2113 case IPC_STAT: 2114 case SHM_STAT: 2115 may = MAY_READ; 2116 break; 2117 case IPC_SET: 2118 case SHM_LOCK: 2119 case SHM_UNLOCK: 2120 case IPC_RMID: 2121 may = MAY_READWRITE; 2122 break; 2123 case IPC_INFO: 2124 case SHM_INFO: 2125 /* 2126 * System level information. 2127 */ 2128 return 0; 2129 default: 2130 return -EINVAL; 2131 } 2132 return smk_curacc_shm(shp, may); 2133 } 2134 2135 /** 2136 * smack_shm_shmat - Smack access for shmat 2137 * @shp: the object 2138 * @shmaddr: unused 2139 * @shmflg: access requested 2140 * 2141 * Returns 0 if current has the requested access, error code otherwise 2142 */ 2143 static int smack_shm_shmat(struct shmid_kernel *shp, char __user *shmaddr, 2144 int shmflg) 2145 { 2146 int may; 2147 2148 may = smack_flags_to_may(shmflg); 2149 return smk_curacc_shm(shp, may); 2150 } 2151 2152 /** 2153 * smack_of_sem - the smack pointer for the sem 2154 * @sma: the object 2155 * 2156 * Returns a pointer to the smack value 2157 */ 2158 static char *smack_of_sem(struct sem_array *sma) 2159 { 2160 return (char *)sma->sem_perm.security; 2161 } 2162 2163 /** 2164 * smack_sem_alloc_security - Set the security blob for sem 2165 * @sma: the object 2166 * 2167 * Returns 0 2168 */ 2169 static int smack_sem_alloc_security(struct sem_array *sma) 2170 { 2171 struct kern_ipc_perm *isp = &sma->sem_perm; 2172 2173 isp->security = smk_of_current(); 2174 return 0; 2175 } 2176 2177 /** 2178 * smack_sem_free_security - Clear the security blob for sem 2179 * @sma: the object 2180 * 2181 * Clears the blob pointer 2182 */ 2183 static void smack_sem_free_security(struct sem_array *sma) 2184 { 2185 struct kern_ipc_perm *isp = &sma->sem_perm; 2186 2187 isp->security = NULL; 2188 } 2189 2190 /** 2191 * smk_curacc_sem : check if current has access on sem 2192 * @sma : the object 2193 * @access : access requested 2194 * 2195 * Returns 0 if current has the requested access, error code otherwise 2196 */ 2197 static int smk_curacc_sem(struct sem_array *sma, int access) 2198 { 2199 char *ssp = smack_of_sem(sma); 2200 struct smk_audit_info ad; 2201 2202 #ifdef CONFIG_AUDIT 2203 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC); 2204 ad.a.u.ipc_id = sma->sem_perm.id; 2205 #endif 2206 return smk_curacc(ssp, access, &ad); 2207 } 2208 2209 /** 2210 * smack_sem_associate - Smack access check for sem 2211 * @sma: the object 2212 * @semflg: access requested 2213 * 2214 * Returns 0 if current has the requested access, error code otherwise 2215 */ 2216 static int smack_sem_associate(struct sem_array *sma, int semflg) 2217 { 2218 int may; 2219 2220 may = smack_flags_to_may(semflg); 2221 return smk_curacc_sem(sma, may); 2222 } 2223 2224 /** 2225 * smack_sem_shmctl - Smack access check for sem 2226 * @sma: the object 2227 * @cmd: what it wants to do 2228 * 2229 * Returns 0 if current has the requested access, error code otherwise 2230 */ 2231 static int smack_sem_semctl(struct sem_array *sma, int cmd) 2232 { 2233 int may; 2234 2235 switch (cmd) { 2236 case GETPID: 2237 case GETNCNT: 2238 case GETZCNT: 2239 case GETVAL: 2240 case GETALL: 2241 case IPC_STAT: 2242 case SEM_STAT: 2243 may = MAY_READ; 2244 break; 2245 case SETVAL: 2246 case SETALL: 2247 case IPC_RMID: 2248 case IPC_SET: 2249 may = MAY_READWRITE; 2250 break; 2251 case IPC_INFO: 2252 case SEM_INFO: 2253 /* 2254 * System level information 2255 */ 2256 return 0; 2257 default: 2258 return -EINVAL; 2259 } 2260 2261 return smk_curacc_sem(sma, may); 2262 } 2263 2264 /** 2265 * smack_sem_semop - Smack checks of semaphore operations 2266 * @sma: the object 2267 * @sops: unused 2268 * @nsops: unused 2269 * @alter: unused 2270 * 2271 * Treated as read and write in all cases. 2272 * 2273 * Returns 0 if access is allowed, error code otherwise 2274 */ 2275 static int smack_sem_semop(struct sem_array *sma, struct sembuf *sops, 2276 unsigned nsops, int alter) 2277 { 2278 return smk_curacc_sem(sma, MAY_READWRITE); 2279 } 2280 2281 /** 2282 * smack_msg_alloc_security - Set the security blob for msg 2283 * @msq: the object 2284 * 2285 * Returns 0 2286 */ 2287 static int smack_msg_queue_alloc_security(struct msg_queue *msq) 2288 { 2289 struct kern_ipc_perm *kisp = &msq->q_perm; 2290 2291 kisp->security = smk_of_current(); 2292 return 0; 2293 } 2294 2295 /** 2296 * smack_msg_free_security - Clear the security blob for msg 2297 * @msq: the object 2298 * 2299 * Clears the blob pointer 2300 */ 2301 static void smack_msg_queue_free_security(struct msg_queue *msq) 2302 { 2303 struct kern_ipc_perm *kisp = &msq->q_perm; 2304 2305 kisp->security = NULL; 2306 } 2307 2308 /** 2309 * smack_of_msq - the smack pointer for the msq 2310 * @msq: the object 2311 * 2312 * Returns a pointer to the smack value 2313 */ 2314 static char *smack_of_msq(struct msg_queue *msq) 2315 { 2316 return (char *)msq->q_perm.security; 2317 } 2318 2319 /** 2320 * smk_curacc_msq : helper to check if current has access on msq 2321 * @msq : the msq 2322 * @access : access requested 2323 * 2324 * return 0 if current has access, error otherwise 2325 */ 2326 static int smk_curacc_msq(struct msg_queue *msq, int access) 2327 { 2328 char *msp = smack_of_msq(msq); 2329 struct smk_audit_info ad; 2330 2331 #ifdef CONFIG_AUDIT 2332 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC); 2333 ad.a.u.ipc_id = msq->q_perm.id; 2334 #endif 2335 return smk_curacc(msp, access, &ad); 2336 } 2337 2338 /** 2339 * smack_msg_queue_associate - Smack access check for msg_queue 2340 * @msq: the object 2341 * @msqflg: access requested 2342 * 2343 * Returns 0 if current has the requested access, error code otherwise 2344 */ 2345 static int smack_msg_queue_associate(struct msg_queue *msq, int msqflg) 2346 { 2347 int may; 2348 2349 may = smack_flags_to_may(msqflg); 2350 return smk_curacc_msq(msq, may); 2351 } 2352 2353 /** 2354 * smack_msg_queue_msgctl - Smack access check for msg_queue 2355 * @msq: the object 2356 * @cmd: what it wants to do 2357 * 2358 * Returns 0 if current has the requested access, error code otherwise 2359 */ 2360 static int smack_msg_queue_msgctl(struct msg_queue *msq, int cmd) 2361 { 2362 int may; 2363 2364 switch (cmd) { 2365 case IPC_STAT: 2366 case MSG_STAT: 2367 may = MAY_READ; 2368 break; 2369 case IPC_SET: 2370 case IPC_RMID: 2371 may = MAY_READWRITE; 2372 break; 2373 case IPC_INFO: 2374 case MSG_INFO: 2375 /* 2376 * System level information 2377 */ 2378 return 0; 2379 default: 2380 return -EINVAL; 2381 } 2382 2383 return smk_curacc_msq(msq, may); 2384 } 2385 2386 /** 2387 * smack_msg_queue_msgsnd - Smack access check for msg_queue 2388 * @msq: the object 2389 * @msg: unused 2390 * @msqflg: access requested 2391 * 2392 * Returns 0 if current has the requested access, error code otherwise 2393 */ 2394 static int smack_msg_queue_msgsnd(struct msg_queue *msq, struct msg_msg *msg, 2395 int msqflg) 2396 { 2397 int may; 2398 2399 may = smack_flags_to_may(msqflg); 2400 return smk_curacc_msq(msq, may); 2401 } 2402 2403 /** 2404 * smack_msg_queue_msgsnd - Smack access check for msg_queue 2405 * @msq: the object 2406 * @msg: unused 2407 * @target: unused 2408 * @type: unused 2409 * @mode: unused 2410 * 2411 * Returns 0 if current has read and write access, error code otherwise 2412 */ 2413 static int smack_msg_queue_msgrcv(struct msg_queue *msq, struct msg_msg *msg, 2414 struct task_struct *target, long type, int mode) 2415 { 2416 return smk_curacc_msq(msq, MAY_READWRITE); 2417 } 2418 2419 /** 2420 * smack_ipc_permission - Smack access for ipc_permission() 2421 * @ipp: the object permissions 2422 * @flag: access requested 2423 * 2424 * Returns 0 if current has read and write access, error code otherwise 2425 */ 2426 static int smack_ipc_permission(struct kern_ipc_perm *ipp, short flag) 2427 { 2428 char *isp = ipp->security; 2429 int may = smack_flags_to_may(flag); 2430 struct smk_audit_info ad; 2431 2432 #ifdef CONFIG_AUDIT 2433 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC); 2434 ad.a.u.ipc_id = ipp->id; 2435 #endif 2436 return smk_curacc(isp, may, &ad); 2437 } 2438 2439 /** 2440 * smack_ipc_getsecid - Extract smack security id 2441 * @ipp: the object permissions 2442 * @secid: where result will be saved 2443 */ 2444 static void smack_ipc_getsecid(struct kern_ipc_perm *ipp, u32 *secid) 2445 { 2446 char *smack = ipp->security; 2447 2448 *secid = smack_to_secid(smack); 2449 } 2450 2451 /** 2452 * smack_d_instantiate - Make sure the blob is correct on an inode 2453 * @opt_dentry: dentry where inode will be attached 2454 * @inode: the object 2455 * 2456 * Set the inode's security blob if it hasn't been done already. 2457 */ 2458 static void smack_d_instantiate(struct dentry *opt_dentry, struct inode *inode) 2459 { 2460 struct super_block *sbp; 2461 struct superblock_smack *sbsp; 2462 struct inode_smack *isp; 2463 char *csp = smk_of_current(); 2464 char *fetched; 2465 char *final; 2466 char trattr[TRANS_TRUE_SIZE]; 2467 int transflag = 0; 2468 int rc; 2469 struct dentry *dp; 2470 2471 if (inode == NULL) 2472 return; 2473 2474 isp = inode->i_security; 2475 2476 mutex_lock(&isp->smk_lock); 2477 /* 2478 * If the inode is already instantiated 2479 * take the quick way out 2480 */ 2481 if (isp->smk_flags & SMK_INODE_INSTANT) 2482 goto unlockandout; 2483 2484 sbp = inode->i_sb; 2485 sbsp = sbp->s_security; 2486 /* 2487 * We're going to use the superblock default label 2488 * if there's no label on the file. 2489 */ 2490 final = sbsp->smk_default; 2491 2492 /* 2493 * If this is the root inode the superblock 2494 * may be in the process of initialization. 2495 * If that is the case use the root value out 2496 * of the superblock. 2497 */ 2498 if (opt_dentry->d_parent == opt_dentry) { 2499 isp->smk_inode = sbsp->smk_root; 2500 isp->smk_flags |= SMK_INODE_INSTANT; 2501 goto unlockandout; 2502 } 2503 2504 /* 2505 * This is pretty hackish. 2506 * Casey says that we shouldn't have to do 2507 * file system specific code, but it does help 2508 * with keeping it simple. 2509 */ 2510 switch (sbp->s_magic) { 2511 case SMACK_MAGIC: 2512 /* 2513 * Casey says that it's a little embarrassing 2514 * that the smack file system doesn't do 2515 * extended attributes. 2516 */ 2517 final = smack_known_star.smk_known; 2518 break; 2519 case PIPEFS_MAGIC: 2520 /* 2521 * Casey says pipes are easy (?) 2522 */ 2523 final = smack_known_star.smk_known; 2524 break; 2525 case DEVPTS_SUPER_MAGIC: 2526 /* 2527 * devpts seems content with the label of the task. 2528 * Programs that change smack have to treat the 2529 * pty with respect. 2530 */ 2531 final = csp; 2532 break; 2533 case SOCKFS_MAGIC: 2534 /* 2535 * Socket access is controlled by the socket 2536 * structures associated with the task involved. 2537 */ 2538 final = smack_known_star.smk_known; 2539 break; 2540 case PROC_SUPER_MAGIC: 2541 /* 2542 * Casey says procfs appears not to care. 2543 * The superblock default suffices. 2544 */ 2545 break; 2546 case TMPFS_MAGIC: 2547 /* 2548 * Device labels should come from the filesystem, 2549 * but watch out, because they're volitile, 2550 * getting recreated on every reboot. 2551 */ 2552 final = smack_known_star.smk_known; 2553 /* 2554 * No break. 2555 * 2556 * If a smack value has been set we want to use it, 2557 * but since tmpfs isn't giving us the opportunity 2558 * to set mount options simulate setting the 2559 * superblock default. 2560 */ 2561 default: 2562 /* 2563 * This isn't an understood special case. 2564 * Get the value from the xattr. 2565 */ 2566 2567 /* 2568 * UNIX domain sockets use lower level socket data. 2569 */ 2570 if (S_ISSOCK(inode->i_mode)) { 2571 final = smack_known_star.smk_known; 2572 break; 2573 } 2574 /* 2575 * No xattr support means, alas, no SMACK label. 2576 * Use the aforeapplied default. 2577 * It would be curious if the label of the task 2578 * does not match that assigned. 2579 */ 2580 if (inode->i_op->getxattr == NULL) 2581 break; 2582 /* 2583 * Get the dentry for xattr. 2584 */ 2585 dp = dget(opt_dentry); 2586 fetched = smk_fetch(XATTR_NAME_SMACK, inode, dp); 2587 if (fetched != NULL) 2588 final = fetched; 2589 2590 /* 2591 * Transmuting directory 2592 */ 2593 if (S_ISDIR(inode->i_mode)) { 2594 /* 2595 * If this is a new directory and the label was 2596 * transmuted when the inode was initialized 2597 * set the transmute attribute on the directory 2598 * and mark the inode. 2599 * 2600 * If there is a transmute attribute on the 2601 * directory mark the inode. 2602 */ 2603 if (isp->smk_flags & SMK_INODE_CHANGED) { 2604 isp->smk_flags &= ~SMK_INODE_CHANGED; 2605 rc = inode->i_op->setxattr(dp, 2606 XATTR_NAME_SMACKTRANSMUTE, 2607 TRANS_TRUE, TRANS_TRUE_SIZE, 2608 0); 2609 } else { 2610 rc = inode->i_op->getxattr(dp, 2611 XATTR_NAME_SMACKTRANSMUTE, trattr, 2612 TRANS_TRUE_SIZE); 2613 if (rc >= 0 && strncmp(trattr, TRANS_TRUE, 2614 TRANS_TRUE_SIZE) != 0) 2615 rc = -EINVAL; 2616 } 2617 if (rc >= 0) 2618 transflag = SMK_INODE_TRANSMUTE; 2619 } 2620 isp->smk_task = smk_fetch(XATTR_NAME_SMACKEXEC, inode, dp); 2621 isp->smk_mmap = smk_fetch(XATTR_NAME_SMACKMMAP, inode, dp); 2622 2623 dput(dp); 2624 break; 2625 } 2626 2627 if (final == NULL) 2628 isp->smk_inode = csp; 2629 else 2630 isp->smk_inode = final; 2631 2632 isp->smk_flags |= (SMK_INODE_INSTANT | transflag); 2633 2634 unlockandout: 2635 mutex_unlock(&isp->smk_lock); 2636 return; 2637 } 2638 2639 /** 2640 * smack_getprocattr - Smack process attribute access 2641 * @p: the object task 2642 * @name: the name of the attribute in /proc/.../attr 2643 * @value: where to put the result 2644 * 2645 * Places a copy of the task Smack into value 2646 * 2647 * Returns the length of the smack label or an error code 2648 */ 2649 static int smack_getprocattr(struct task_struct *p, char *name, char **value) 2650 { 2651 char *cp; 2652 int slen; 2653 2654 if (strcmp(name, "current") != 0) 2655 return -EINVAL; 2656 2657 cp = kstrdup(smk_of_task(task_security(p)), GFP_KERNEL); 2658 if (cp == NULL) 2659 return -ENOMEM; 2660 2661 slen = strlen(cp); 2662 *value = cp; 2663 return slen; 2664 } 2665 2666 /** 2667 * smack_setprocattr - Smack process attribute setting 2668 * @p: the object task 2669 * @name: the name of the attribute in /proc/.../attr 2670 * @value: the value to set 2671 * @size: the size of the value 2672 * 2673 * Sets the Smack value of the task. Only setting self 2674 * is permitted and only with privilege 2675 * 2676 * Returns the length of the smack label or an error code 2677 */ 2678 static int smack_setprocattr(struct task_struct *p, char *name, 2679 void *value, size_t size) 2680 { 2681 struct task_smack *tsp; 2682 struct cred *new; 2683 char *newsmack; 2684 2685 /* 2686 * Changing another process' Smack value is too dangerous 2687 * and supports no sane use case. 2688 */ 2689 if (p != current) 2690 return -EPERM; 2691 2692 if (!smack_privileged(CAP_MAC_ADMIN)) 2693 return -EPERM; 2694 2695 if (value == NULL || size == 0 || size >= SMK_LONGLABEL) 2696 return -EINVAL; 2697 2698 if (strcmp(name, "current") != 0) 2699 return -EINVAL; 2700 2701 newsmack = smk_import(value, size); 2702 if (newsmack == NULL) 2703 return -EINVAL; 2704 2705 /* 2706 * No process is ever allowed the web ("@") label. 2707 */ 2708 if (newsmack == smack_known_web.smk_known) 2709 return -EPERM; 2710 2711 new = prepare_creds(); 2712 if (new == NULL) 2713 return -ENOMEM; 2714 2715 tsp = new->security; 2716 tsp->smk_task = newsmack; 2717 2718 commit_creds(new); 2719 return size; 2720 } 2721 2722 /** 2723 * smack_unix_stream_connect - Smack access on UDS 2724 * @sock: one sock 2725 * @other: the other sock 2726 * @newsk: unused 2727 * 2728 * Return 0 if a subject with the smack of sock could access 2729 * an object with the smack of other, otherwise an error code 2730 */ 2731 static int smack_unix_stream_connect(struct sock *sock, 2732 struct sock *other, struct sock *newsk) 2733 { 2734 struct socket_smack *ssp = sock->sk_security; 2735 struct socket_smack *osp = other->sk_security; 2736 struct socket_smack *nsp = newsk->sk_security; 2737 struct smk_audit_info ad; 2738 int rc = 0; 2739 2740 #ifdef CONFIG_AUDIT 2741 struct lsm_network_audit net; 2742 2743 smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net); 2744 smk_ad_setfield_u_net_sk(&ad, other); 2745 #endif 2746 2747 if (!smack_privileged(CAP_MAC_OVERRIDE)) 2748 rc = smk_access(ssp->smk_out, osp->smk_in, MAY_WRITE, &ad); 2749 2750 /* 2751 * Cross reference the peer labels for SO_PEERSEC. 2752 */ 2753 if (rc == 0) { 2754 nsp->smk_packet = ssp->smk_out; 2755 ssp->smk_packet = osp->smk_out; 2756 } 2757 2758 return rc; 2759 } 2760 2761 /** 2762 * smack_unix_may_send - Smack access on UDS 2763 * @sock: one socket 2764 * @other: the other socket 2765 * 2766 * Return 0 if a subject with the smack of sock could access 2767 * an object with the smack of other, otherwise an error code 2768 */ 2769 static int smack_unix_may_send(struct socket *sock, struct socket *other) 2770 { 2771 struct socket_smack *ssp = sock->sk->sk_security; 2772 struct socket_smack *osp = other->sk->sk_security; 2773 struct smk_audit_info ad; 2774 int rc = 0; 2775 2776 #ifdef CONFIG_AUDIT 2777 struct lsm_network_audit net; 2778 2779 smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net); 2780 smk_ad_setfield_u_net_sk(&ad, other->sk); 2781 #endif 2782 2783 if (!smack_privileged(CAP_MAC_OVERRIDE)) 2784 rc = smk_access(ssp->smk_out, osp->smk_in, MAY_WRITE, &ad); 2785 2786 return rc; 2787 } 2788 2789 /** 2790 * smack_socket_sendmsg - Smack check based on destination host 2791 * @sock: the socket 2792 * @msg: the message 2793 * @size: the size of the message 2794 * 2795 * Return 0 if the current subject can write to the destination 2796 * host. This is only a question if the destination is a single 2797 * label host. 2798 */ 2799 static int smack_socket_sendmsg(struct socket *sock, struct msghdr *msg, 2800 int size) 2801 { 2802 struct sockaddr_in *sip = (struct sockaddr_in *) msg->msg_name; 2803 2804 /* 2805 * Perfectly reasonable for this to be NULL 2806 */ 2807 if (sip == NULL || sip->sin_family != AF_INET) 2808 return 0; 2809 2810 return smack_netlabel_send(sock->sk, sip); 2811 } 2812 2813 /** 2814 * smack_from_secattr - Convert a netlabel attr.mls.lvl/attr.mls.cat pair to smack 2815 * @sap: netlabel secattr 2816 * @ssp: socket security information 2817 * 2818 * Returns a pointer to a Smack label found on the label list. 2819 */ 2820 static char *smack_from_secattr(struct netlbl_lsm_secattr *sap, 2821 struct socket_smack *ssp) 2822 { 2823 struct smack_known *kp; 2824 char *sp; 2825 int found = 0; 2826 2827 if ((sap->flags & NETLBL_SECATTR_MLS_LVL) != 0) { 2828 /* 2829 * Looks like a CIPSO packet. 2830 * If there are flags but no level netlabel isn't 2831 * behaving the way we expect it to. 2832 * 2833 * Look it up in the label table 2834 * Without guidance regarding the smack value 2835 * for the packet fall back on the network 2836 * ambient value. 2837 */ 2838 rcu_read_lock(); 2839 list_for_each_entry(kp, &smack_known_list, list) { 2840 if (sap->attr.mls.lvl != kp->smk_netlabel.attr.mls.lvl) 2841 continue; 2842 if (memcmp(sap->attr.mls.cat, 2843 kp->smk_netlabel.attr.mls.cat, 2844 SMK_CIPSOLEN) != 0) 2845 continue; 2846 found = 1; 2847 break; 2848 } 2849 rcu_read_unlock(); 2850 2851 if (found) 2852 return kp->smk_known; 2853 2854 if (ssp != NULL && ssp->smk_in == smack_known_star.smk_known) 2855 return smack_known_web.smk_known; 2856 return smack_known_star.smk_known; 2857 } 2858 if ((sap->flags & NETLBL_SECATTR_SECID) != 0) { 2859 /* 2860 * Looks like a fallback, which gives us a secid. 2861 */ 2862 sp = smack_from_secid(sap->attr.secid); 2863 /* 2864 * This has got to be a bug because it is 2865 * impossible to specify a fallback without 2866 * specifying the label, which will ensure 2867 * it has a secid, and the only way to get a 2868 * secid is from a fallback. 2869 */ 2870 BUG_ON(sp == NULL); 2871 return sp; 2872 } 2873 /* 2874 * Without guidance regarding the smack value 2875 * for the packet fall back on the network 2876 * ambient value. 2877 */ 2878 return smack_net_ambient; 2879 } 2880 2881 /** 2882 * smack_socket_sock_rcv_skb - Smack packet delivery access check 2883 * @sk: socket 2884 * @skb: packet 2885 * 2886 * Returns 0 if the packet should be delivered, an error code otherwise 2887 */ 2888 static int smack_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb) 2889 { 2890 struct netlbl_lsm_secattr secattr; 2891 struct socket_smack *ssp = sk->sk_security; 2892 char *csp; 2893 int rc; 2894 struct smk_audit_info ad; 2895 #ifdef CONFIG_AUDIT 2896 struct lsm_network_audit net; 2897 #endif 2898 if (sk->sk_family != PF_INET && sk->sk_family != PF_INET6) 2899 return 0; 2900 2901 /* 2902 * Translate what netlabel gave us. 2903 */ 2904 netlbl_secattr_init(&secattr); 2905 2906 rc = netlbl_skbuff_getattr(skb, sk->sk_family, &secattr); 2907 if (rc == 0) 2908 csp = smack_from_secattr(&secattr, ssp); 2909 else 2910 csp = smack_net_ambient; 2911 2912 netlbl_secattr_destroy(&secattr); 2913 2914 #ifdef CONFIG_AUDIT 2915 smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net); 2916 ad.a.u.net->family = sk->sk_family; 2917 ad.a.u.net->netif = skb->skb_iif; 2918 ipv4_skb_to_auditdata(skb, &ad.a, NULL); 2919 #endif 2920 /* 2921 * Receiving a packet requires that the other end 2922 * be able to write here. Read access is not required. 2923 * This is the simplist possible security model 2924 * for networking. 2925 */ 2926 rc = smk_access(csp, ssp->smk_in, MAY_WRITE, &ad); 2927 if (rc != 0) 2928 netlbl_skbuff_err(skb, rc, 0); 2929 return rc; 2930 } 2931 2932 /** 2933 * smack_socket_getpeersec_stream - pull in packet label 2934 * @sock: the socket 2935 * @optval: user's destination 2936 * @optlen: size thereof 2937 * @len: max thereof 2938 * 2939 * returns zero on success, an error code otherwise 2940 */ 2941 static int smack_socket_getpeersec_stream(struct socket *sock, 2942 char __user *optval, 2943 int __user *optlen, unsigned len) 2944 { 2945 struct socket_smack *ssp; 2946 char *rcp = ""; 2947 int slen = 1; 2948 int rc = 0; 2949 2950 ssp = sock->sk->sk_security; 2951 if (ssp->smk_packet != NULL) { 2952 rcp = ssp->smk_packet; 2953 slen = strlen(rcp) + 1; 2954 } 2955 2956 if (slen > len) 2957 rc = -ERANGE; 2958 else if (copy_to_user(optval, rcp, slen) != 0) 2959 rc = -EFAULT; 2960 2961 if (put_user(slen, optlen) != 0) 2962 rc = -EFAULT; 2963 2964 return rc; 2965 } 2966 2967 2968 /** 2969 * smack_socket_getpeersec_dgram - pull in packet label 2970 * @sock: the peer socket 2971 * @skb: packet data 2972 * @secid: pointer to where to put the secid of the packet 2973 * 2974 * Sets the netlabel socket state on sk from parent 2975 */ 2976 static int smack_socket_getpeersec_dgram(struct socket *sock, 2977 struct sk_buff *skb, u32 *secid) 2978 2979 { 2980 struct netlbl_lsm_secattr secattr; 2981 struct socket_smack *ssp = NULL; 2982 char *sp; 2983 int family = PF_UNSPEC; 2984 u32 s = 0; /* 0 is the invalid secid */ 2985 int rc; 2986 2987 if (skb != NULL) { 2988 if (skb->protocol == htons(ETH_P_IP)) 2989 family = PF_INET; 2990 else if (skb->protocol == htons(ETH_P_IPV6)) 2991 family = PF_INET6; 2992 } 2993 if (family == PF_UNSPEC && sock != NULL) 2994 family = sock->sk->sk_family; 2995 2996 if (family == PF_UNIX) { 2997 ssp = sock->sk->sk_security; 2998 s = smack_to_secid(ssp->smk_out); 2999 } else if (family == PF_INET || family == PF_INET6) { 3000 /* 3001 * Translate what netlabel gave us. 3002 */ 3003 if (sock != NULL && sock->sk != NULL) 3004 ssp = sock->sk->sk_security; 3005 netlbl_secattr_init(&secattr); 3006 rc = netlbl_skbuff_getattr(skb, family, &secattr); 3007 if (rc == 0) { 3008 sp = smack_from_secattr(&secattr, ssp); 3009 s = smack_to_secid(sp); 3010 } 3011 netlbl_secattr_destroy(&secattr); 3012 } 3013 *secid = s; 3014 if (s == 0) 3015 return -EINVAL; 3016 return 0; 3017 } 3018 3019 /** 3020 * smack_sock_graft - Initialize a newly created socket with an existing sock 3021 * @sk: child sock 3022 * @parent: parent socket 3023 * 3024 * Set the smk_{in,out} state of an existing sock based on the process that 3025 * is creating the new socket. 3026 */ 3027 static void smack_sock_graft(struct sock *sk, struct socket *parent) 3028 { 3029 struct socket_smack *ssp; 3030 3031 if (sk == NULL || 3032 (sk->sk_family != PF_INET && sk->sk_family != PF_INET6)) 3033 return; 3034 3035 ssp = sk->sk_security; 3036 ssp->smk_in = ssp->smk_out = smk_of_current(); 3037 /* cssp->smk_packet is already set in smack_inet_csk_clone() */ 3038 } 3039 3040 /** 3041 * smack_inet_conn_request - Smack access check on connect 3042 * @sk: socket involved 3043 * @skb: packet 3044 * @req: unused 3045 * 3046 * Returns 0 if a task with the packet label could write to 3047 * the socket, otherwise an error code 3048 */ 3049 static int smack_inet_conn_request(struct sock *sk, struct sk_buff *skb, 3050 struct request_sock *req) 3051 { 3052 u16 family = sk->sk_family; 3053 struct smack_known *skp; 3054 struct socket_smack *ssp = sk->sk_security; 3055 struct netlbl_lsm_secattr secattr; 3056 struct sockaddr_in addr; 3057 struct iphdr *hdr; 3058 char *sp; 3059 char *hsp; 3060 int rc; 3061 struct smk_audit_info ad; 3062 #ifdef CONFIG_AUDIT 3063 struct lsm_network_audit net; 3064 #endif 3065 3066 /* handle mapped IPv4 packets arriving via IPv6 sockets */ 3067 if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP)) 3068 family = PF_INET; 3069 3070 netlbl_secattr_init(&secattr); 3071 rc = netlbl_skbuff_getattr(skb, family, &secattr); 3072 if (rc == 0) 3073 sp = smack_from_secattr(&secattr, ssp); 3074 else 3075 sp = smack_known_huh.smk_known; 3076 netlbl_secattr_destroy(&secattr); 3077 3078 #ifdef CONFIG_AUDIT 3079 smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net); 3080 ad.a.u.net->family = family; 3081 ad.a.u.net->netif = skb->skb_iif; 3082 ipv4_skb_to_auditdata(skb, &ad.a, NULL); 3083 #endif 3084 /* 3085 * Receiving a packet requires that the other end be able to write 3086 * here. Read access is not required. 3087 */ 3088 rc = smk_access(sp, ssp->smk_in, MAY_WRITE, &ad); 3089 if (rc != 0) 3090 return rc; 3091 3092 /* 3093 * Save the peer's label in the request_sock so we can later setup 3094 * smk_packet in the child socket so that SO_PEERCRED can report it. 3095 */ 3096 req->peer_secid = smack_to_secid(sp); 3097 3098 /* 3099 * We need to decide if we want to label the incoming connection here 3100 * if we do we only need to label the request_sock and the stack will 3101 * propagate the wire-label to the sock when it is created. 3102 */ 3103 hdr = ip_hdr(skb); 3104 addr.sin_addr.s_addr = hdr->saddr; 3105 rcu_read_lock(); 3106 hsp = smack_host_label(&addr); 3107 rcu_read_unlock(); 3108 3109 if (hsp == NULL) { 3110 skp = smk_find_entry(sp); 3111 rc = netlbl_req_setattr(req, &skp->smk_netlabel); 3112 } else 3113 netlbl_req_delattr(req); 3114 3115 return rc; 3116 } 3117 3118 /** 3119 * smack_inet_csk_clone - Copy the connection information to the new socket 3120 * @sk: the new socket 3121 * @req: the connection's request_sock 3122 * 3123 * Transfer the connection's peer label to the newly created socket. 3124 */ 3125 static void smack_inet_csk_clone(struct sock *sk, 3126 const struct request_sock *req) 3127 { 3128 struct socket_smack *ssp = sk->sk_security; 3129 3130 if (req->peer_secid != 0) 3131 ssp->smk_packet = smack_from_secid(req->peer_secid); 3132 else 3133 ssp->smk_packet = NULL; 3134 } 3135 3136 /* 3137 * Key management security hooks 3138 * 3139 * Casey has not tested key support very heavily. 3140 * The permission check is most likely too restrictive. 3141 * If you care about keys please have a look. 3142 */ 3143 #ifdef CONFIG_KEYS 3144 3145 /** 3146 * smack_key_alloc - Set the key security blob 3147 * @key: object 3148 * @cred: the credentials to use 3149 * @flags: unused 3150 * 3151 * No allocation required 3152 * 3153 * Returns 0 3154 */ 3155 static int smack_key_alloc(struct key *key, const struct cred *cred, 3156 unsigned long flags) 3157 { 3158 key->security = smk_of_task(cred->security); 3159 return 0; 3160 } 3161 3162 /** 3163 * smack_key_free - Clear the key security blob 3164 * @key: the object 3165 * 3166 * Clear the blob pointer 3167 */ 3168 static void smack_key_free(struct key *key) 3169 { 3170 key->security = NULL; 3171 } 3172 3173 /* 3174 * smack_key_permission - Smack access on a key 3175 * @key_ref: gets to the object 3176 * @cred: the credentials to use 3177 * @perm: unused 3178 * 3179 * Return 0 if the task has read and write to the object, 3180 * an error code otherwise 3181 */ 3182 static int smack_key_permission(key_ref_t key_ref, 3183 const struct cred *cred, key_perm_t perm) 3184 { 3185 struct key *keyp; 3186 struct smk_audit_info ad; 3187 char *tsp = smk_of_task(cred->security); 3188 3189 keyp = key_ref_to_ptr(key_ref); 3190 if (keyp == NULL) 3191 return -EINVAL; 3192 /* 3193 * If the key hasn't been initialized give it access so that 3194 * it may do so. 3195 */ 3196 if (keyp->security == NULL) 3197 return 0; 3198 /* 3199 * This should not occur 3200 */ 3201 if (tsp == NULL) 3202 return -EACCES; 3203 #ifdef CONFIG_AUDIT 3204 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_KEY); 3205 ad.a.u.key_struct.key = keyp->serial; 3206 ad.a.u.key_struct.key_desc = keyp->description; 3207 #endif 3208 return smk_access(tsp, keyp->security, 3209 MAY_READWRITE, &ad); 3210 } 3211 #endif /* CONFIG_KEYS */ 3212 3213 /* 3214 * Smack Audit hooks 3215 * 3216 * Audit requires a unique representation of each Smack specific 3217 * rule. This unique representation is used to distinguish the 3218 * object to be audited from remaining kernel objects and also 3219 * works as a glue between the audit hooks. 3220 * 3221 * Since repository entries are added but never deleted, we'll use 3222 * the smack_known label address related to the given audit rule as 3223 * the needed unique representation. This also better fits the smack 3224 * model where nearly everything is a label. 3225 */ 3226 #ifdef CONFIG_AUDIT 3227 3228 /** 3229 * smack_audit_rule_init - Initialize a smack audit rule 3230 * @field: audit rule fields given from user-space (audit.h) 3231 * @op: required testing operator (=, !=, >, <, ...) 3232 * @rulestr: smack label to be audited 3233 * @vrule: pointer to save our own audit rule representation 3234 * 3235 * Prepare to audit cases where (@field @op @rulestr) is true. 3236 * The label to be audited is created if necessay. 3237 */ 3238 static int smack_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule) 3239 { 3240 char **rule = (char **)vrule; 3241 *rule = NULL; 3242 3243 if (field != AUDIT_SUBJ_USER && field != AUDIT_OBJ_USER) 3244 return -EINVAL; 3245 3246 if (op != Audit_equal && op != Audit_not_equal) 3247 return -EINVAL; 3248 3249 *rule = smk_import(rulestr, 0); 3250 3251 return 0; 3252 } 3253 3254 /** 3255 * smack_audit_rule_known - Distinguish Smack audit rules 3256 * @krule: rule of interest, in Audit kernel representation format 3257 * 3258 * This is used to filter Smack rules from remaining Audit ones. 3259 * If it's proved that this rule belongs to us, the 3260 * audit_rule_match hook will be called to do the final judgement. 3261 */ 3262 static int smack_audit_rule_known(struct audit_krule *krule) 3263 { 3264 struct audit_field *f; 3265 int i; 3266 3267 for (i = 0; i < krule->field_count; i++) { 3268 f = &krule->fields[i]; 3269 3270 if (f->type == AUDIT_SUBJ_USER || f->type == AUDIT_OBJ_USER) 3271 return 1; 3272 } 3273 3274 return 0; 3275 } 3276 3277 /** 3278 * smack_audit_rule_match - Audit given object ? 3279 * @secid: security id for identifying the object to test 3280 * @field: audit rule flags given from user-space 3281 * @op: required testing operator 3282 * @vrule: smack internal rule presentation 3283 * @actx: audit context associated with the check 3284 * 3285 * The core Audit hook. It's used to take the decision of 3286 * whether to audit or not to audit a given object. 3287 */ 3288 static int smack_audit_rule_match(u32 secid, u32 field, u32 op, void *vrule, 3289 struct audit_context *actx) 3290 { 3291 char *smack; 3292 char *rule = vrule; 3293 3294 if (!rule) { 3295 audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR, 3296 "Smack: missing rule\n"); 3297 return -ENOENT; 3298 } 3299 3300 if (field != AUDIT_SUBJ_USER && field != AUDIT_OBJ_USER) 3301 return 0; 3302 3303 smack = smack_from_secid(secid); 3304 3305 /* 3306 * No need to do string comparisons. If a match occurs, 3307 * both pointers will point to the same smack_known 3308 * label. 3309 */ 3310 if (op == Audit_equal) 3311 return (rule == smack); 3312 if (op == Audit_not_equal) 3313 return (rule != smack); 3314 3315 return 0; 3316 } 3317 3318 /** 3319 * smack_audit_rule_free - free smack rule representation 3320 * @vrule: rule to be freed. 3321 * 3322 * No memory was allocated. 3323 */ 3324 static void smack_audit_rule_free(void *vrule) 3325 { 3326 /* No-op */ 3327 } 3328 3329 #endif /* CONFIG_AUDIT */ 3330 3331 /** 3332 * smack_secid_to_secctx - return the smack label for a secid 3333 * @secid: incoming integer 3334 * @secdata: destination 3335 * @seclen: how long it is 3336 * 3337 * Exists for networking code. 3338 */ 3339 static int smack_secid_to_secctx(u32 secid, char **secdata, u32 *seclen) 3340 { 3341 char *sp = smack_from_secid(secid); 3342 3343 if (secdata) 3344 *secdata = sp; 3345 *seclen = strlen(sp); 3346 return 0; 3347 } 3348 3349 /** 3350 * smack_secctx_to_secid - return the secid for a smack label 3351 * @secdata: smack label 3352 * @seclen: how long result is 3353 * @secid: outgoing integer 3354 * 3355 * Exists for audit and networking code. 3356 */ 3357 static int smack_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid) 3358 { 3359 *secid = smack_to_secid(secdata); 3360 return 0; 3361 } 3362 3363 /** 3364 * smack_release_secctx - don't do anything. 3365 * @secdata: unused 3366 * @seclen: unused 3367 * 3368 * Exists to make sure nothing gets done, and properly 3369 */ 3370 static void smack_release_secctx(char *secdata, u32 seclen) 3371 { 3372 } 3373 3374 static int smack_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen) 3375 { 3376 return smack_inode_setsecurity(inode, XATTR_SMACK_SUFFIX, ctx, ctxlen, 0); 3377 } 3378 3379 static int smack_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen) 3380 { 3381 return __vfs_setxattr_noperm(dentry, XATTR_NAME_SMACK, ctx, ctxlen, 0); 3382 } 3383 3384 static int smack_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen) 3385 { 3386 int len = 0; 3387 len = smack_inode_getsecurity(inode, XATTR_SMACK_SUFFIX, ctx, true); 3388 3389 if (len < 0) 3390 return len; 3391 *ctxlen = len; 3392 return 0; 3393 } 3394 3395 struct security_operations smack_ops = { 3396 .name = "smack", 3397 3398 .ptrace_access_check = smack_ptrace_access_check, 3399 .ptrace_traceme = smack_ptrace_traceme, 3400 .syslog = smack_syslog, 3401 3402 .sb_alloc_security = smack_sb_alloc_security, 3403 .sb_free_security = smack_sb_free_security, 3404 .sb_copy_data = smack_sb_copy_data, 3405 .sb_kern_mount = smack_sb_kern_mount, 3406 .sb_statfs = smack_sb_statfs, 3407 .sb_mount = smack_sb_mount, 3408 .sb_umount = smack_sb_umount, 3409 3410 .bprm_set_creds = smack_bprm_set_creds, 3411 .bprm_committing_creds = smack_bprm_committing_creds, 3412 .bprm_secureexec = smack_bprm_secureexec, 3413 3414 .inode_alloc_security = smack_inode_alloc_security, 3415 .inode_free_security = smack_inode_free_security, 3416 .inode_init_security = smack_inode_init_security, 3417 .inode_link = smack_inode_link, 3418 .inode_unlink = smack_inode_unlink, 3419 .inode_rmdir = smack_inode_rmdir, 3420 .inode_rename = smack_inode_rename, 3421 .inode_permission = smack_inode_permission, 3422 .inode_setattr = smack_inode_setattr, 3423 .inode_getattr = smack_inode_getattr, 3424 .inode_setxattr = smack_inode_setxattr, 3425 .inode_post_setxattr = smack_inode_post_setxattr, 3426 .inode_getxattr = smack_inode_getxattr, 3427 .inode_removexattr = smack_inode_removexattr, 3428 .inode_getsecurity = smack_inode_getsecurity, 3429 .inode_setsecurity = smack_inode_setsecurity, 3430 .inode_listsecurity = smack_inode_listsecurity, 3431 .inode_getsecid = smack_inode_getsecid, 3432 3433 .file_permission = smack_file_permission, 3434 .file_alloc_security = smack_file_alloc_security, 3435 .file_free_security = smack_file_free_security, 3436 .file_ioctl = smack_file_ioctl, 3437 .file_lock = smack_file_lock, 3438 .file_fcntl = smack_file_fcntl, 3439 .mmap_file = smack_mmap_file, 3440 .mmap_addr = cap_mmap_addr, 3441 .file_set_fowner = smack_file_set_fowner, 3442 .file_send_sigiotask = smack_file_send_sigiotask, 3443 .file_receive = smack_file_receive, 3444 3445 .file_open = smack_file_open, 3446 3447 .cred_alloc_blank = smack_cred_alloc_blank, 3448 .cred_free = smack_cred_free, 3449 .cred_prepare = smack_cred_prepare, 3450 .cred_transfer = smack_cred_transfer, 3451 .kernel_act_as = smack_kernel_act_as, 3452 .kernel_create_files_as = smack_kernel_create_files_as, 3453 .task_setpgid = smack_task_setpgid, 3454 .task_getpgid = smack_task_getpgid, 3455 .task_getsid = smack_task_getsid, 3456 .task_getsecid = smack_task_getsecid, 3457 .task_setnice = smack_task_setnice, 3458 .task_setioprio = smack_task_setioprio, 3459 .task_getioprio = smack_task_getioprio, 3460 .task_setscheduler = smack_task_setscheduler, 3461 .task_getscheduler = smack_task_getscheduler, 3462 .task_movememory = smack_task_movememory, 3463 .task_kill = smack_task_kill, 3464 .task_wait = smack_task_wait, 3465 .task_to_inode = smack_task_to_inode, 3466 3467 .ipc_permission = smack_ipc_permission, 3468 .ipc_getsecid = smack_ipc_getsecid, 3469 3470 .msg_msg_alloc_security = smack_msg_msg_alloc_security, 3471 .msg_msg_free_security = smack_msg_msg_free_security, 3472 3473 .msg_queue_alloc_security = smack_msg_queue_alloc_security, 3474 .msg_queue_free_security = smack_msg_queue_free_security, 3475 .msg_queue_associate = smack_msg_queue_associate, 3476 .msg_queue_msgctl = smack_msg_queue_msgctl, 3477 .msg_queue_msgsnd = smack_msg_queue_msgsnd, 3478 .msg_queue_msgrcv = smack_msg_queue_msgrcv, 3479 3480 .shm_alloc_security = smack_shm_alloc_security, 3481 .shm_free_security = smack_shm_free_security, 3482 .shm_associate = smack_shm_associate, 3483 .shm_shmctl = smack_shm_shmctl, 3484 .shm_shmat = smack_shm_shmat, 3485 3486 .sem_alloc_security = smack_sem_alloc_security, 3487 .sem_free_security = smack_sem_free_security, 3488 .sem_associate = smack_sem_associate, 3489 .sem_semctl = smack_sem_semctl, 3490 .sem_semop = smack_sem_semop, 3491 3492 .d_instantiate = smack_d_instantiate, 3493 3494 .getprocattr = smack_getprocattr, 3495 .setprocattr = smack_setprocattr, 3496 3497 .unix_stream_connect = smack_unix_stream_connect, 3498 .unix_may_send = smack_unix_may_send, 3499 3500 .socket_post_create = smack_socket_post_create, 3501 .socket_connect = smack_socket_connect, 3502 .socket_sendmsg = smack_socket_sendmsg, 3503 .socket_sock_rcv_skb = smack_socket_sock_rcv_skb, 3504 .socket_getpeersec_stream = smack_socket_getpeersec_stream, 3505 .socket_getpeersec_dgram = smack_socket_getpeersec_dgram, 3506 .sk_alloc_security = smack_sk_alloc_security, 3507 .sk_free_security = smack_sk_free_security, 3508 .sock_graft = smack_sock_graft, 3509 .inet_conn_request = smack_inet_conn_request, 3510 .inet_csk_clone = smack_inet_csk_clone, 3511 3512 /* key management security hooks */ 3513 #ifdef CONFIG_KEYS 3514 .key_alloc = smack_key_alloc, 3515 .key_free = smack_key_free, 3516 .key_permission = smack_key_permission, 3517 #endif /* CONFIG_KEYS */ 3518 3519 /* Audit hooks */ 3520 #ifdef CONFIG_AUDIT 3521 .audit_rule_init = smack_audit_rule_init, 3522 .audit_rule_known = smack_audit_rule_known, 3523 .audit_rule_match = smack_audit_rule_match, 3524 .audit_rule_free = smack_audit_rule_free, 3525 #endif /* CONFIG_AUDIT */ 3526 3527 .secid_to_secctx = smack_secid_to_secctx, 3528 .secctx_to_secid = smack_secctx_to_secid, 3529 .release_secctx = smack_release_secctx, 3530 .inode_notifysecctx = smack_inode_notifysecctx, 3531 .inode_setsecctx = smack_inode_setsecctx, 3532 .inode_getsecctx = smack_inode_getsecctx, 3533 }; 3534 3535 3536 static __init void init_smack_known_list(void) 3537 { 3538 /* 3539 * Initialize rule list locks 3540 */ 3541 mutex_init(&smack_known_huh.smk_rules_lock); 3542 mutex_init(&smack_known_hat.smk_rules_lock); 3543 mutex_init(&smack_known_floor.smk_rules_lock); 3544 mutex_init(&smack_known_star.smk_rules_lock); 3545 mutex_init(&smack_known_invalid.smk_rules_lock); 3546 mutex_init(&smack_known_web.smk_rules_lock); 3547 /* 3548 * Initialize rule lists 3549 */ 3550 INIT_LIST_HEAD(&smack_known_huh.smk_rules); 3551 INIT_LIST_HEAD(&smack_known_hat.smk_rules); 3552 INIT_LIST_HEAD(&smack_known_star.smk_rules); 3553 INIT_LIST_HEAD(&smack_known_floor.smk_rules); 3554 INIT_LIST_HEAD(&smack_known_invalid.smk_rules); 3555 INIT_LIST_HEAD(&smack_known_web.smk_rules); 3556 /* 3557 * Create the known labels list 3558 */ 3559 list_add(&smack_known_huh.list, &smack_known_list); 3560 list_add(&smack_known_hat.list, &smack_known_list); 3561 list_add(&smack_known_star.list, &smack_known_list); 3562 list_add(&smack_known_floor.list, &smack_known_list); 3563 list_add(&smack_known_invalid.list, &smack_known_list); 3564 list_add(&smack_known_web.list, &smack_known_list); 3565 } 3566 3567 /** 3568 * smack_init - initialize the smack system 3569 * 3570 * Returns 0 3571 */ 3572 static __init int smack_init(void) 3573 { 3574 struct cred *cred; 3575 struct task_smack *tsp; 3576 3577 if (!security_module_enable(&smack_ops)) 3578 return 0; 3579 3580 tsp = new_task_smack(smack_known_floor.smk_known, 3581 smack_known_floor.smk_known, GFP_KERNEL); 3582 if (tsp == NULL) 3583 return -ENOMEM; 3584 3585 printk(KERN_INFO "Smack: Initializing.\n"); 3586 3587 /* 3588 * Set the security state for the initial task. 3589 */ 3590 cred = (struct cred *) current->cred; 3591 cred->security = tsp; 3592 3593 /* initialize the smack_known_list */ 3594 init_smack_known_list(); 3595 3596 /* 3597 * Register with LSM 3598 */ 3599 if (register_security(&smack_ops)) 3600 panic("smack: Unable to register with kernel.\n"); 3601 3602 return 0; 3603 } 3604 3605 /* 3606 * Smack requires early initialization in order to label 3607 * all processes and objects when they are created. 3608 */ 3609 security_initcall(smack_init); 3610