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 = bprm->file->f_path.dentry->d_inode; 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 struct dentry *dp; 1191 int may; 1192 int mmay; 1193 int tmay; 1194 int rc; 1195 1196 if (file == NULL || file->f_dentry == NULL) 1197 return 0; 1198 1199 dp = file->f_dentry; 1200 1201 if (dp->d_inode == NULL) 1202 return 0; 1203 1204 isp = dp->d_inode->i_security; 1205 if (isp->smk_mmap == NULL) 1206 return 0; 1207 msmack = isp->smk_mmap; 1208 1209 tsp = current_security(); 1210 sp = smk_of_current(); 1211 skp = smk_find_entry(sp); 1212 rc = 0; 1213 1214 rcu_read_lock(); 1215 /* 1216 * For each Smack rule associated with the subject 1217 * label verify that the SMACK64MMAP also has access 1218 * to that rule's object label. 1219 */ 1220 list_for_each_entry_rcu(srp, &skp->smk_rules, list) { 1221 osmack = srp->smk_object; 1222 /* 1223 * Matching labels always allows access. 1224 */ 1225 if (msmack == osmack) 1226 continue; 1227 /* 1228 * If there is a matching local rule take 1229 * that into account as well. 1230 */ 1231 may = smk_access_entry(srp->smk_subject, osmack, 1232 &tsp->smk_rules); 1233 if (may == -ENOENT) 1234 may = srp->smk_access; 1235 else 1236 may &= srp->smk_access; 1237 /* 1238 * If may is zero the SMACK64MMAP subject can't 1239 * possibly have less access. 1240 */ 1241 if (may == 0) 1242 continue; 1243 1244 /* 1245 * Fetch the global list entry. 1246 * If there isn't one a SMACK64MMAP subject 1247 * can't have as much access as current. 1248 */ 1249 skp = smk_find_entry(msmack); 1250 mmay = smk_access_entry(msmack, osmack, &skp->smk_rules); 1251 if (mmay == -ENOENT) { 1252 rc = -EACCES; 1253 break; 1254 } 1255 /* 1256 * If there is a local entry it modifies the 1257 * potential access, too. 1258 */ 1259 tmay = smk_access_entry(msmack, osmack, &tsp->smk_rules); 1260 if (tmay != -ENOENT) 1261 mmay &= tmay; 1262 1263 /* 1264 * If there is any access available to current that is 1265 * not available to a SMACK64MMAP subject 1266 * deny access. 1267 */ 1268 if ((may | mmay) != mmay) { 1269 rc = -EACCES; 1270 break; 1271 } 1272 } 1273 1274 rcu_read_unlock(); 1275 1276 return rc; 1277 } 1278 1279 /** 1280 * smack_file_set_fowner - set the file security blob value 1281 * @file: object in question 1282 * 1283 * Returns 0 1284 * Further research may be required on this one. 1285 */ 1286 static int smack_file_set_fowner(struct file *file) 1287 { 1288 file->f_security = smk_of_current(); 1289 return 0; 1290 } 1291 1292 /** 1293 * smack_file_send_sigiotask - Smack on sigio 1294 * @tsk: The target task 1295 * @fown: the object the signal come from 1296 * @signum: unused 1297 * 1298 * Allow a privileged task to get signals even if it shouldn't 1299 * 1300 * Returns 0 if a subject with the object's smack could 1301 * write to the task, an error code otherwise. 1302 */ 1303 static int smack_file_send_sigiotask(struct task_struct *tsk, 1304 struct fown_struct *fown, int signum) 1305 { 1306 struct file *file; 1307 int rc; 1308 char *tsp = smk_of_task(tsk->cred->security); 1309 struct smk_audit_info ad; 1310 1311 /* 1312 * struct fown_struct is never outside the context of a struct file 1313 */ 1314 file = container_of(fown, struct file, f_owner); 1315 1316 /* we don't log here as rc can be overriden */ 1317 rc = smk_access(file->f_security, tsp, MAY_WRITE, NULL); 1318 if (rc != 0 && has_capability(tsk, CAP_MAC_OVERRIDE)) 1319 rc = 0; 1320 1321 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK); 1322 smk_ad_setfield_u_tsk(&ad, tsk); 1323 smack_log(file->f_security, tsp, MAY_WRITE, rc, &ad); 1324 return rc; 1325 } 1326 1327 /** 1328 * smack_file_receive - Smack file receive check 1329 * @file: the object 1330 * 1331 * Returns 0 if current has access, error code otherwise 1332 */ 1333 static int smack_file_receive(struct file *file) 1334 { 1335 int may = 0; 1336 struct smk_audit_info ad; 1337 1338 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK); 1339 smk_ad_setfield_u_fs_path(&ad, file->f_path); 1340 /* 1341 * This code relies on bitmasks. 1342 */ 1343 if (file->f_mode & FMODE_READ) 1344 may = MAY_READ; 1345 if (file->f_mode & FMODE_WRITE) 1346 may |= MAY_WRITE; 1347 1348 return smk_curacc(file->f_security, may, &ad); 1349 } 1350 1351 /** 1352 * smack_file_open - Smack dentry open processing 1353 * @file: the object 1354 * @cred: unused 1355 * 1356 * Set the security blob in the file structure. 1357 * 1358 * Returns 0 1359 */ 1360 static int smack_file_open(struct file *file, const struct cred *cred) 1361 { 1362 struct inode_smack *isp = file->f_path.dentry->d_inode->i_security; 1363 1364 file->f_security = isp->smk_inode; 1365 1366 return 0; 1367 } 1368 1369 /* 1370 * Task hooks 1371 */ 1372 1373 /** 1374 * smack_cred_alloc_blank - "allocate" blank task-level security credentials 1375 * @new: the new credentials 1376 * @gfp: the atomicity of any memory allocations 1377 * 1378 * Prepare a blank set of credentials for modification. This must allocate all 1379 * the memory the LSM module might require such that cred_transfer() can 1380 * complete without error. 1381 */ 1382 static int smack_cred_alloc_blank(struct cred *cred, gfp_t gfp) 1383 { 1384 struct task_smack *tsp; 1385 1386 tsp = new_task_smack(NULL, NULL, gfp); 1387 if (tsp == NULL) 1388 return -ENOMEM; 1389 1390 cred->security = tsp; 1391 1392 return 0; 1393 } 1394 1395 1396 /** 1397 * smack_cred_free - "free" task-level security credentials 1398 * @cred: the credentials in question 1399 * 1400 */ 1401 static void smack_cred_free(struct cred *cred) 1402 { 1403 struct task_smack *tsp = cred->security; 1404 struct smack_rule *rp; 1405 struct list_head *l; 1406 struct list_head *n; 1407 1408 if (tsp == NULL) 1409 return; 1410 cred->security = NULL; 1411 1412 list_for_each_safe(l, n, &tsp->smk_rules) { 1413 rp = list_entry(l, struct smack_rule, list); 1414 list_del(&rp->list); 1415 kfree(rp); 1416 } 1417 kfree(tsp); 1418 } 1419 1420 /** 1421 * smack_cred_prepare - prepare new set of credentials for modification 1422 * @new: the new credentials 1423 * @old: the original credentials 1424 * @gfp: the atomicity of any memory allocations 1425 * 1426 * Prepare a new set of credentials for modification. 1427 */ 1428 static int smack_cred_prepare(struct cred *new, const struct cred *old, 1429 gfp_t gfp) 1430 { 1431 struct task_smack *old_tsp = old->security; 1432 struct task_smack *new_tsp; 1433 int rc; 1434 1435 new_tsp = new_task_smack(old_tsp->smk_task, old_tsp->smk_task, gfp); 1436 if (new_tsp == NULL) 1437 return -ENOMEM; 1438 1439 rc = smk_copy_rules(&new_tsp->smk_rules, &old_tsp->smk_rules, gfp); 1440 if (rc != 0) 1441 return rc; 1442 1443 new->security = new_tsp; 1444 return 0; 1445 } 1446 1447 /** 1448 * smack_cred_transfer - Transfer the old credentials to the new credentials 1449 * @new: the new credentials 1450 * @old: the original credentials 1451 * 1452 * Fill in a set of blank credentials from another set of credentials. 1453 */ 1454 static void smack_cred_transfer(struct cred *new, const struct cred *old) 1455 { 1456 struct task_smack *old_tsp = old->security; 1457 struct task_smack *new_tsp = new->security; 1458 1459 new_tsp->smk_task = old_tsp->smk_task; 1460 new_tsp->smk_forked = old_tsp->smk_task; 1461 mutex_init(&new_tsp->smk_rules_lock); 1462 INIT_LIST_HEAD(&new_tsp->smk_rules); 1463 1464 1465 /* cbs copy rule list */ 1466 } 1467 1468 /** 1469 * smack_kernel_act_as - Set the subjective context in a set of credentials 1470 * @new: points to the set of credentials to be modified. 1471 * @secid: specifies the security ID to be set 1472 * 1473 * Set the security data for a kernel service. 1474 */ 1475 static int smack_kernel_act_as(struct cred *new, u32 secid) 1476 { 1477 struct task_smack *new_tsp = new->security; 1478 char *smack = smack_from_secid(secid); 1479 1480 if (smack == NULL) 1481 return -EINVAL; 1482 1483 new_tsp->smk_task = smack; 1484 return 0; 1485 } 1486 1487 /** 1488 * smack_kernel_create_files_as - Set the file creation label in a set of creds 1489 * @new: points to the set of credentials to be modified 1490 * @inode: points to the inode to use as a reference 1491 * 1492 * Set the file creation context in a set of credentials to the same 1493 * as the objective context of the specified inode 1494 */ 1495 static int smack_kernel_create_files_as(struct cred *new, 1496 struct inode *inode) 1497 { 1498 struct inode_smack *isp = inode->i_security; 1499 struct task_smack *tsp = new->security; 1500 1501 tsp->smk_forked = isp->smk_inode; 1502 tsp->smk_task = isp->smk_inode; 1503 return 0; 1504 } 1505 1506 /** 1507 * smk_curacc_on_task - helper to log task related access 1508 * @p: the task object 1509 * @access: the access requested 1510 * @caller: name of the calling function for audit 1511 * 1512 * Return 0 if access is permitted 1513 */ 1514 static int smk_curacc_on_task(struct task_struct *p, int access, 1515 const char *caller) 1516 { 1517 struct smk_audit_info ad; 1518 1519 smk_ad_init(&ad, caller, LSM_AUDIT_DATA_TASK); 1520 smk_ad_setfield_u_tsk(&ad, p); 1521 return smk_curacc(smk_of_task(task_security(p)), access, &ad); 1522 } 1523 1524 /** 1525 * smack_task_setpgid - Smack check on setting pgid 1526 * @p: the task object 1527 * @pgid: unused 1528 * 1529 * Return 0 if write access is permitted 1530 */ 1531 static int smack_task_setpgid(struct task_struct *p, pid_t pgid) 1532 { 1533 return smk_curacc_on_task(p, MAY_WRITE, __func__); 1534 } 1535 1536 /** 1537 * smack_task_getpgid - Smack access check for getpgid 1538 * @p: the object task 1539 * 1540 * Returns 0 if current can read the object task, error code otherwise 1541 */ 1542 static int smack_task_getpgid(struct task_struct *p) 1543 { 1544 return smk_curacc_on_task(p, MAY_READ, __func__); 1545 } 1546 1547 /** 1548 * smack_task_getsid - Smack access check for getsid 1549 * @p: the object task 1550 * 1551 * Returns 0 if current can read the object task, error code otherwise 1552 */ 1553 static int smack_task_getsid(struct task_struct *p) 1554 { 1555 return smk_curacc_on_task(p, MAY_READ, __func__); 1556 } 1557 1558 /** 1559 * smack_task_getsecid - get the secid of the task 1560 * @p: the object task 1561 * @secid: where to put the result 1562 * 1563 * Sets the secid to contain a u32 version of the smack label. 1564 */ 1565 static void smack_task_getsecid(struct task_struct *p, u32 *secid) 1566 { 1567 *secid = smack_to_secid(smk_of_task(task_security(p))); 1568 } 1569 1570 /** 1571 * smack_task_setnice - Smack check on setting nice 1572 * @p: the task object 1573 * @nice: unused 1574 * 1575 * Return 0 if write access is permitted 1576 */ 1577 static int smack_task_setnice(struct task_struct *p, int nice) 1578 { 1579 int rc; 1580 1581 rc = cap_task_setnice(p, nice); 1582 if (rc == 0) 1583 rc = smk_curacc_on_task(p, MAY_WRITE, __func__); 1584 return rc; 1585 } 1586 1587 /** 1588 * smack_task_setioprio - Smack check on setting ioprio 1589 * @p: the task object 1590 * @ioprio: unused 1591 * 1592 * Return 0 if write access is permitted 1593 */ 1594 static int smack_task_setioprio(struct task_struct *p, int ioprio) 1595 { 1596 int rc; 1597 1598 rc = cap_task_setioprio(p, ioprio); 1599 if (rc == 0) 1600 rc = smk_curacc_on_task(p, MAY_WRITE, __func__); 1601 return rc; 1602 } 1603 1604 /** 1605 * smack_task_getioprio - Smack check on reading ioprio 1606 * @p: the task object 1607 * 1608 * Return 0 if read access is permitted 1609 */ 1610 static int smack_task_getioprio(struct task_struct *p) 1611 { 1612 return smk_curacc_on_task(p, MAY_READ, __func__); 1613 } 1614 1615 /** 1616 * smack_task_setscheduler - Smack check on setting scheduler 1617 * @p: the task object 1618 * @policy: unused 1619 * @lp: unused 1620 * 1621 * Return 0 if read access is permitted 1622 */ 1623 static int smack_task_setscheduler(struct task_struct *p) 1624 { 1625 int rc; 1626 1627 rc = cap_task_setscheduler(p); 1628 if (rc == 0) 1629 rc = smk_curacc_on_task(p, MAY_WRITE, __func__); 1630 return rc; 1631 } 1632 1633 /** 1634 * smack_task_getscheduler - Smack check on reading scheduler 1635 * @p: the task object 1636 * 1637 * Return 0 if read access is permitted 1638 */ 1639 static int smack_task_getscheduler(struct task_struct *p) 1640 { 1641 return smk_curacc_on_task(p, MAY_READ, __func__); 1642 } 1643 1644 /** 1645 * smack_task_movememory - Smack check on moving memory 1646 * @p: the task object 1647 * 1648 * Return 0 if write access is permitted 1649 */ 1650 static int smack_task_movememory(struct task_struct *p) 1651 { 1652 return smk_curacc_on_task(p, MAY_WRITE, __func__); 1653 } 1654 1655 /** 1656 * smack_task_kill - Smack check on signal delivery 1657 * @p: the task object 1658 * @info: unused 1659 * @sig: unused 1660 * @secid: identifies the smack to use in lieu of current's 1661 * 1662 * Return 0 if write access is permitted 1663 * 1664 * The secid behavior is an artifact of an SELinux hack 1665 * in the USB code. Someday it may go away. 1666 */ 1667 static int smack_task_kill(struct task_struct *p, struct siginfo *info, 1668 int sig, u32 secid) 1669 { 1670 struct smk_audit_info ad; 1671 1672 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK); 1673 smk_ad_setfield_u_tsk(&ad, p); 1674 /* 1675 * Sending a signal requires that the sender 1676 * can write the receiver. 1677 */ 1678 if (secid == 0) 1679 return smk_curacc(smk_of_task(task_security(p)), MAY_WRITE, 1680 &ad); 1681 /* 1682 * If the secid isn't 0 we're dealing with some USB IO 1683 * specific behavior. This is not clean. For one thing 1684 * we can't take privilege into account. 1685 */ 1686 return smk_access(smack_from_secid(secid), 1687 smk_of_task(task_security(p)), MAY_WRITE, &ad); 1688 } 1689 1690 /** 1691 * smack_task_wait - Smack access check for waiting 1692 * @p: task to wait for 1693 * 1694 * Returns 0 1695 */ 1696 static int smack_task_wait(struct task_struct *p) 1697 { 1698 /* 1699 * Allow the operation to succeed. 1700 * Zombies are bad. 1701 * In userless environments (e.g. phones) programs 1702 * get marked with SMACK64EXEC and even if the parent 1703 * and child shouldn't be talking the parent still 1704 * may expect to know when the child exits. 1705 */ 1706 return 0; 1707 } 1708 1709 /** 1710 * smack_task_to_inode - copy task smack into the inode blob 1711 * @p: task to copy from 1712 * @inode: inode to copy to 1713 * 1714 * Sets the smack pointer in the inode security blob 1715 */ 1716 static void smack_task_to_inode(struct task_struct *p, struct inode *inode) 1717 { 1718 struct inode_smack *isp = inode->i_security; 1719 isp->smk_inode = smk_of_task(task_security(p)); 1720 } 1721 1722 /* 1723 * Socket hooks. 1724 */ 1725 1726 /** 1727 * smack_sk_alloc_security - Allocate a socket blob 1728 * @sk: the socket 1729 * @family: unused 1730 * @gfp_flags: memory allocation flags 1731 * 1732 * Assign Smack pointers to current 1733 * 1734 * Returns 0 on success, -ENOMEM is there's no memory 1735 */ 1736 static int smack_sk_alloc_security(struct sock *sk, int family, gfp_t gfp_flags) 1737 { 1738 char *csp = smk_of_current(); 1739 struct socket_smack *ssp; 1740 1741 ssp = kzalloc(sizeof(struct socket_smack), gfp_flags); 1742 if (ssp == NULL) 1743 return -ENOMEM; 1744 1745 ssp->smk_in = csp; 1746 ssp->smk_out = csp; 1747 ssp->smk_packet = NULL; 1748 1749 sk->sk_security = ssp; 1750 1751 return 0; 1752 } 1753 1754 /** 1755 * smack_sk_free_security - Free a socket blob 1756 * @sk: the socket 1757 * 1758 * Clears the blob pointer 1759 */ 1760 static void smack_sk_free_security(struct sock *sk) 1761 { 1762 kfree(sk->sk_security); 1763 } 1764 1765 /** 1766 * smack_host_label - check host based restrictions 1767 * @sip: the object end 1768 * 1769 * looks for host based access restrictions 1770 * 1771 * This version will only be appropriate for really small sets of single label 1772 * hosts. The caller is responsible for ensuring that the RCU read lock is 1773 * taken before calling this function. 1774 * 1775 * Returns the label of the far end or NULL if it's not special. 1776 */ 1777 static char *smack_host_label(struct sockaddr_in *sip) 1778 { 1779 struct smk_netlbladdr *snp; 1780 struct in_addr *siap = &sip->sin_addr; 1781 1782 if (siap->s_addr == 0) 1783 return NULL; 1784 1785 list_for_each_entry_rcu(snp, &smk_netlbladdr_list, list) 1786 /* 1787 * we break after finding the first match because 1788 * the list is sorted from longest to shortest mask 1789 * so we have found the most specific match 1790 */ 1791 if ((&snp->smk_host.sin_addr)->s_addr == 1792 (siap->s_addr & (&snp->smk_mask)->s_addr)) { 1793 /* we have found the special CIPSO option */ 1794 if (snp->smk_label == smack_cipso_option) 1795 return NULL; 1796 return snp->smk_label; 1797 } 1798 1799 return NULL; 1800 } 1801 1802 /** 1803 * smack_netlabel - Set the secattr on a socket 1804 * @sk: the socket 1805 * @labeled: socket label scheme 1806 * 1807 * Convert the outbound smack value (smk_out) to a 1808 * secattr and attach it to the socket. 1809 * 1810 * Returns 0 on success or an error code 1811 */ 1812 static int smack_netlabel(struct sock *sk, int labeled) 1813 { 1814 struct smack_known *skp; 1815 struct socket_smack *ssp = sk->sk_security; 1816 int rc = 0; 1817 1818 /* 1819 * Usually the netlabel code will handle changing the 1820 * packet labeling based on the label. 1821 * The case of a single label host is different, because 1822 * a single label host should never get a labeled packet 1823 * even though the label is usually associated with a packet 1824 * label. 1825 */ 1826 local_bh_disable(); 1827 bh_lock_sock_nested(sk); 1828 1829 if (ssp->smk_out == smack_net_ambient || 1830 labeled == SMACK_UNLABELED_SOCKET) 1831 netlbl_sock_delattr(sk); 1832 else { 1833 skp = smk_find_entry(ssp->smk_out); 1834 rc = netlbl_sock_setattr(sk, sk->sk_family, &skp->smk_netlabel); 1835 } 1836 1837 bh_unlock_sock(sk); 1838 local_bh_enable(); 1839 1840 return rc; 1841 } 1842 1843 /** 1844 * smack_netlbel_send - Set the secattr on a socket and perform access checks 1845 * @sk: the socket 1846 * @sap: the destination address 1847 * 1848 * Set the correct secattr for the given socket based on the destination 1849 * address and perform any outbound access checks needed. 1850 * 1851 * Returns 0 on success or an error code. 1852 * 1853 */ 1854 static int smack_netlabel_send(struct sock *sk, struct sockaddr_in *sap) 1855 { 1856 int rc; 1857 int sk_lbl; 1858 char *hostsp; 1859 struct socket_smack *ssp = sk->sk_security; 1860 struct smk_audit_info ad; 1861 1862 rcu_read_lock(); 1863 hostsp = smack_host_label(sap); 1864 if (hostsp != NULL) { 1865 #ifdef CONFIG_AUDIT 1866 struct lsm_network_audit net; 1867 1868 smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net); 1869 ad.a.u.net->family = sap->sin_family; 1870 ad.a.u.net->dport = sap->sin_port; 1871 ad.a.u.net->v4info.daddr = sap->sin_addr.s_addr; 1872 #endif 1873 sk_lbl = SMACK_UNLABELED_SOCKET; 1874 rc = smk_access(ssp->smk_out, hostsp, MAY_WRITE, &ad); 1875 } else { 1876 sk_lbl = SMACK_CIPSO_SOCKET; 1877 rc = 0; 1878 } 1879 rcu_read_unlock(); 1880 if (rc != 0) 1881 return rc; 1882 1883 return smack_netlabel(sk, sk_lbl); 1884 } 1885 1886 /** 1887 * smack_inode_setsecurity - set smack xattrs 1888 * @inode: the object 1889 * @name: attribute name 1890 * @value: attribute value 1891 * @size: size of the attribute 1892 * @flags: unused 1893 * 1894 * Sets the named attribute in the appropriate blob 1895 * 1896 * Returns 0 on success, or an error code 1897 */ 1898 static int smack_inode_setsecurity(struct inode *inode, const char *name, 1899 const void *value, size_t size, int flags) 1900 { 1901 char *sp; 1902 struct inode_smack *nsp = inode->i_security; 1903 struct socket_smack *ssp; 1904 struct socket *sock; 1905 int rc = 0; 1906 1907 if (value == NULL || size > SMK_LONGLABEL || size == 0) 1908 return -EACCES; 1909 1910 sp = smk_import(value, size); 1911 if (sp == NULL) 1912 return -EINVAL; 1913 1914 if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) { 1915 nsp->smk_inode = sp; 1916 nsp->smk_flags |= SMK_INODE_INSTANT; 1917 return 0; 1918 } 1919 /* 1920 * The rest of the Smack xattrs are only on sockets. 1921 */ 1922 if (inode->i_sb->s_magic != SOCKFS_MAGIC) 1923 return -EOPNOTSUPP; 1924 1925 sock = SOCKET_I(inode); 1926 if (sock == NULL || sock->sk == NULL) 1927 return -EOPNOTSUPP; 1928 1929 ssp = sock->sk->sk_security; 1930 1931 if (strcmp(name, XATTR_SMACK_IPIN) == 0) 1932 ssp->smk_in = sp; 1933 else if (strcmp(name, XATTR_SMACK_IPOUT) == 0) { 1934 ssp->smk_out = sp; 1935 if (sock->sk->sk_family != PF_UNIX) { 1936 rc = smack_netlabel(sock->sk, SMACK_CIPSO_SOCKET); 1937 if (rc != 0) 1938 printk(KERN_WARNING 1939 "Smack: \"%s\" netlbl error %d.\n", 1940 __func__, -rc); 1941 } 1942 } else 1943 return -EOPNOTSUPP; 1944 1945 return 0; 1946 } 1947 1948 /** 1949 * smack_socket_post_create - finish socket setup 1950 * @sock: the socket 1951 * @family: protocol family 1952 * @type: unused 1953 * @protocol: unused 1954 * @kern: unused 1955 * 1956 * Sets the netlabel information on the socket 1957 * 1958 * Returns 0 on success, and error code otherwise 1959 */ 1960 static int smack_socket_post_create(struct socket *sock, int family, 1961 int type, int protocol, int kern) 1962 { 1963 if (family != PF_INET || sock->sk == NULL) 1964 return 0; 1965 /* 1966 * Set the outbound netlbl. 1967 */ 1968 return smack_netlabel(sock->sk, SMACK_CIPSO_SOCKET); 1969 } 1970 1971 /** 1972 * smack_socket_connect - connect access check 1973 * @sock: the socket 1974 * @sap: the other end 1975 * @addrlen: size of sap 1976 * 1977 * Verifies that a connection may be possible 1978 * 1979 * Returns 0 on success, and error code otherwise 1980 */ 1981 static int smack_socket_connect(struct socket *sock, struct sockaddr *sap, 1982 int addrlen) 1983 { 1984 if (sock->sk == NULL || sock->sk->sk_family != PF_INET) 1985 return 0; 1986 if (addrlen < sizeof(struct sockaddr_in)) 1987 return -EINVAL; 1988 1989 return smack_netlabel_send(sock->sk, (struct sockaddr_in *)sap); 1990 } 1991 1992 /** 1993 * smack_flags_to_may - convert S_ to MAY_ values 1994 * @flags: the S_ value 1995 * 1996 * Returns the equivalent MAY_ value 1997 */ 1998 static int smack_flags_to_may(int flags) 1999 { 2000 int may = 0; 2001 2002 if (flags & S_IRUGO) 2003 may |= MAY_READ; 2004 if (flags & S_IWUGO) 2005 may |= MAY_WRITE; 2006 if (flags & S_IXUGO) 2007 may |= MAY_EXEC; 2008 2009 return may; 2010 } 2011 2012 /** 2013 * smack_msg_msg_alloc_security - Set the security blob for msg_msg 2014 * @msg: the object 2015 * 2016 * Returns 0 2017 */ 2018 static int smack_msg_msg_alloc_security(struct msg_msg *msg) 2019 { 2020 msg->security = smk_of_current(); 2021 return 0; 2022 } 2023 2024 /** 2025 * smack_msg_msg_free_security - Clear the security blob for msg_msg 2026 * @msg: the object 2027 * 2028 * Clears the blob pointer 2029 */ 2030 static void smack_msg_msg_free_security(struct msg_msg *msg) 2031 { 2032 msg->security = NULL; 2033 } 2034 2035 /** 2036 * smack_of_shm - the smack pointer for the shm 2037 * @shp: the object 2038 * 2039 * Returns a pointer to the smack value 2040 */ 2041 static char *smack_of_shm(struct shmid_kernel *shp) 2042 { 2043 return (char *)shp->shm_perm.security; 2044 } 2045 2046 /** 2047 * smack_shm_alloc_security - Set the security blob for shm 2048 * @shp: the object 2049 * 2050 * Returns 0 2051 */ 2052 static int smack_shm_alloc_security(struct shmid_kernel *shp) 2053 { 2054 struct kern_ipc_perm *isp = &shp->shm_perm; 2055 2056 isp->security = smk_of_current(); 2057 return 0; 2058 } 2059 2060 /** 2061 * smack_shm_free_security - Clear the security blob for shm 2062 * @shp: the object 2063 * 2064 * Clears the blob pointer 2065 */ 2066 static void smack_shm_free_security(struct shmid_kernel *shp) 2067 { 2068 struct kern_ipc_perm *isp = &shp->shm_perm; 2069 2070 isp->security = NULL; 2071 } 2072 2073 /** 2074 * smk_curacc_shm : check if current has access on shm 2075 * @shp : the object 2076 * @access : access requested 2077 * 2078 * Returns 0 if current has the requested access, error code otherwise 2079 */ 2080 static int smk_curacc_shm(struct shmid_kernel *shp, int access) 2081 { 2082 char *ssp = smack_of_shm(shp); 2083 struct smk_audit_info ad; 2084 2085 #ifdef CONFIG_AUDIT 2086 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC); 2087 ad.a.u.ipc_id = shp->shm_perm.id; 2088 #endif 2089 return smk_curacc(ssp, access, &ad); 2090 } 2091 2092 /** 2093 * smack_shm_associate - Smack access check for shm 2094 * @shp: the object 2095 * @shmflg: access requested 2096 * 2097 * Returns 0 if current has the requested access, error code otherwise 2098 */ 2099 static int smack_shm_associate(struct shmid_kernel *shp, int shmflg) 2100 { 2101 int may; 2102 2103 may = smack_flags_to_may(shmflg); 2104 return smk_curacc_shm(shp, may); 2105 } 2106 2107 /** 2108 * smack_shm_shmctl - Smack access check for shm 2109 * @shp: the object 2110 * @cmd: what it wants to do 2111 * 2112 * Returns 0 if current has the requested access, error code otherwise 2113 */ 2114 static int smack_shm_shmctl(struct shmid_kernel *shp, int cmd) 2115 { 2116 int may; 2117 2118 switch (cmd) { 2119 case IPC_STAT: 2120 case SHM_STAT: 2121 may = MAY_READ; 2122 break; 2123 case IPC_SET: 2124 case SHM_LOCK: 2125 case SHM_UNLOCK: 2126 case IPC_RMID: 2127 may = MAY_READWRITE; 2128 break; 2129 case IPC_INFO: 2130 case SHM_INFO: 2131 /* 2132 * System level information. 2133 */ 2134 return 0; 2135 default: 2136 return -EINVAL; 2137 } 2138 return smk_curacc_shm(shp, may); 2139 } 2140 2141 /** 2142 * smack_shm_shmat - Smack access for shmat 2143 * @shp: the object 2144 * @shmaddr: unused 2145 * @shmflg: access requested 2146 * 2147 * Returns 0 if current has the requested access, error code otherwise 2148 */ 2149 static int smack_shm_shmat(struct shmid_kernel *shp, char __user *shmaddr, 2150 int shmflg) 2151 { 2152 int may; 2153 2154 may = smack_flags_to_may(shmflg); 2155 return smk_curacc_shm(shp, may); 2156 } 2157 2158 /** 2159 * smack_of_sem - the smack pointer for the sem 2160 * @sma: the object 2161 * 2162 * Returns a pointer to the smack value 2163 */ 2164 static char *smack_of_sem(struct sem_array *sma) 2165 { 2166 return (char *)sma->sem_perm.security; 2167 } 2168 2169 /** 2170 * smack_sem_alloc_security - Set the security blob for sem 2171 * @sma: the object 2172 * 2173 * Returns 0 2174 */ 2175 static int smack_sem_alloc_security(struct sem_array *sma) 2176 { 2177 struct kern_ipc_perm *isp = &sma->sem_perm; 2178 2179 isp->security = smk_of_current(); 2180 return 0; 2181 } 2182 2183 /** 2184 * smack_sem_free_security - Clear the security blob for sem 2185 * @sma: the object 2186 * 2187 * Clears the blob pointer 2188 */ 2189 static void smack_sem_free_security(struct sem_array *sma) 2190 { 2191 struct kern_ipc_perm *isp = &sma->sem_perm; 2192 2193 isp->security = NULL; 2194 } 2195 2196 /** 2197 * smk_curacc_sem : check if current has access on sem 2198 * @sma : the object 2199 * @access : access requested 2200 * 2201 * Returns 0 if current has the requested access, error code otherwise 2202 */ 2203 static int smk_curacc_sem(struct sem_array *sma, int access) 2204 { 2205 char *ssp = smack_of_sem(sma); 2206 struct smk_audit_info ad; 2207 2208 #ifdef CONFIG_AUDIT 2209 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC); 2210 ad.a.u.ipc_id = sma->sem_perm.id; 2211 #endif 2212 return smk_curacc(ssp, access, &ad); 2213 } 2214 2215 /** 2216 * smack_sem_associate - Smack access check for sem 2217 * @sma: the object 2218 * @semflg: access requested 2219 * 2220 * Returns 0 if current has the requested access, error code otherwise 2221 */ 2222 static int smack_sem_associate(struct sem_array *sma, int semflg) 2223 { 2224 int may; 2225 2226 may = smack_flags_to_may(semflg); 2227 return smk_curacc_sem(sma, may); 2228 } 2229 2230 /** 2231 * smack_sem_shmctl - Smack access check for sem 2232 * @sma: the object 2233 * @cmd: what it wants to do 2234 * 2235 * Returns 0 if current has the requested access, error code otherwise 2236 */ 2237 static int smack_sem_semctl(struct sem_array *sma, int cmd) 2238 { 2239 int may; 2240 2241 switch (cmd) { 2242 case GETPID: 2243 case GETNCNT: 2244 case GETZCNT: 2245 case GETVAL: 2246 case GETALL: 2247 case IPC_STAT: 2248 case SEM_STAT: 2249 may = MAY_READ; 2250 break; 2251 case SETVAL: 2252 case SETALL: 2253 case IPC_RMID: 2254 case IPC_SET: 2255 may = MAY_READWRITE; 2256 break; 2257 case IPC_INFO: 2258 case SEM_INFO: 2259 /* 2260 * System level information 2261 */ 2262 return 0; 2263 default: 2264 return -EINVAL; 2265 } 2266 2267 return smk_curacc_sem(sma, may); 2268 } 2269 2270 /** 2271 * smack_sem_semop - Smack checks of semaphore operations 2272 * @sma: the object 2273 * @sops: unused 2274 * @nsops: unused 2275 * @alter: unused 2276 * 2277 * Treated as read and write in all cases. 2278 * 2279 * Returns 0 if access is allowed, error code otherwise 2280 */ 2281 static int smack_sem_semop(struct sem_array *sma, struct sembuf *sops, 2282 unsigned nsops, int alter) 2283 { 2284 return smk_curacc_sem(sma, MAY_READWRITE); 2285 } 2286 2287 /** 2288 * smack_msg_alloc_security - Set the security blob for msg 2289 * @msq: the object 2290 * 2291 * Returns 0 2292 */ 2293 static int smack_msg_queue_alloc_security(struct msg_queue *msq) 2294 { 2295 struct kern_ipc_perm *kisp = &msq->q_perm; 2296 2297 kisp->security = smk_of_current(); 2298 return 0; 2299 } 2300 2301 /** 2302 * smack_msg_free_security - Clear the security blob for msg 2303 * @msq: the object 2304 * 2305 * Clears the blob pointer 2306 */ 2307 static void smack_msg_queue_free_security(struct msg_queue *msq) 2308 { 2309 struct kern_ipc_perm *kisp = &msq->q_perm; 2310 2311 kisp->security = NULL; 2312 } 2313 2314 /** 2315 * smack_of_msq - the smack pointer for the msq 2316 * @msq: the object 2317 * 2318 * Returns a pointer to the smack value 2319 */ 2320 static char *smack_of_msq(struct msg_queue *msq) 2321 { 2322 return (char *)msq->q_perm.security; 2323 } 2324 2325 /** 2326 * smk_curacc_msq : helper to check if current has access on msq 2327 * @msq : the msq 2328 * @access : access requested 2329 * 2330 * return 0 if current has access, error otherwise 2331 */ 2332 static int smk_curacc_msq(struct msg_queue *msq, int access) 2333 { 2334 char *msp = smack_of_msq(msq); 2335 struct smk_audit_info ad; 2336 2337 #ifdef CONFIG_AUDIT 2338 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC); 2339 ad.a.u.ipc_id = msq->q_perm.id; 2340 #endif 2341 return smk_curacc(msp, access, &ad); 2342 } 2343 2344 /** 2345 * smack_msg_queue_associate - Smack access check for msg_queue 2346 * @msq: the object 2347 * @msqflg: access requested 2348 * 2349 * Returns 0 if current has the requested access, error code otherwise 2350 */ 2351 static int smack_msg_queue_associate(struct msg_queue *msq, int msqflg) 2352 { 2353 int may; 2354 2355 may = smack_flags_to_may(msqflg); 2356 return smk_curacc_msq(msq, may); 2357 } 2358 2359 /** 2360 * smack_msg_queue_msgctl - Smack access check for msg_queue 2361 * @msq: the object 2362 * @cmd: what it wants to do 2363 * 2364 * Returns 0 if current has the requested access, error code otherwise 2365 */ 2366 static int smack_msg_queue_msgctl(struct msg_queue *msq, int cmd) 2367 { 2368 int may; 2369 2370 switch (cmd) { 2371 case IPC_STAT: 2372 case MSG_STAT: 2373 may = MAY_READ; 2374 break; 2375 case IPC_SET: 2376 case IPC_RMID: 2377 may = MAY_READWRITE; 2378 break; 2379 case IPC_INFO: 2380 case MSG_INFO: 2381 /* 2382 * System level information 2383 */ 2384 return 0; 2385 default: 2386 return -EINVAL; 2387 } 2388 2389 return smk_curacc_msq(msq, may); 2390 } 2391 2392 /** 2393 * smack_msg_queue_msgsnd - Smack access check for msg_queue 2394 * @msq: the object 2395 * @msg: unused 2396 * @msqflg: access requested 2397 * 2398 * Returns 0 if current has the requested access, error code otherwise 2399 */ 2400 static int smack_msg_queue_msgsnd(struct msg_queue *msq, struct msg_msg *msg, 2401 int msqflg) 2402 { 2403 int may; 2404 2405 may = smack_flags_to_may(msqflg); 2406 return smk_curacc_msq(msq, may); 2407 } 2408 2409 /** 2410 * smack_msg_queue_msgsnd - Smack access check for msg_queue 2411 * @msq: the object 2412 * @msg: unused 2413 * @target: unused 2414 * @type: unused 2415 * @mode: unused 2416 * 2417 * Returns 0 if current has read and write access, error code otherwise 2418 */ 2419 static int smack_msg_queue_msgrcv(struct msg_queue *msq, struct msg_msg *msg, 2420 struct task_struct *target, long type, int mode) 2421 { 2422 return smk_curacc_msq(msq, MAY_READWRITE); 2423 } 2424 2425 /** 2426 * smack_ipc_permission - Smack access for ipc_permission() 2427 * @ipp: the object permissions 2428 * @flag: access requested 2429 * 2430 * Returns 0 if current has read and write access, error code otherwise 2431 */ 2432 static int smack_ipc_permission(struct kern_ipc_perm *ipp, short flag) 2433 { 2434 char *isp = ipp->security; 2435 int may = smack_flags_to_may(flag); 2436 struct smk_audit_info ad; 2437 2438 #ifdef CONFIG_AUDIT 2439 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC); 2440 ad.a.u.ipc_id = ipp->id; 2441 #endif 2442 return smk_curacc(isp, may, &ad); 2443 } 2444 2445 /** 2446 * smack_ipc_getsecid - Extract smack security id 2447 * @ipp: the object permissions 2448 * @secid: where result will be saved 2449 */ 2450 static void smack_ipc_getsecid(struct kern_ipc_perm *ipp, u32 *secid) 2451 { 2452 char *smack = ipp->security; 2453 2454 *secid = smack_to_secid(smack); 2455 } 2456 2457 /** 2458 * smack_d_instantiate - Make sure the blob is correct on an inode 2459 * @opt_dentry: dentry where inode will be attached 2460 * @inode: the object 2461 * 2462 * Set the inode's security blob if it hasn't been done already. 2463 */ 2464 static void smack_d_instantiate(struct dentry *opt_dentry, struct inode *inode) 2465 { 2466 struct super_block *sbp; 2467 struct superblock_smack *sbsp; 2468 struct inode_smack *isp; 2469 char *csp = smk_of_current(); 2470 char *fetched; 2471 char *final; 2472 char trattr[TRANS_TRUE_SIZE]; 2473 int transflag = 0; 2474 int rc; 2475 struct dentry *dp; 2476 2477 if (inode == NULL) 2478 return; 2479 2480 isp = inode->i_security; 2481 2482 mutex_lock(&isp->smk_lock); 2483 /* 2484 * If the inode is already instantiated 2485 * take the quick way out 2486 */ 2487 if (isp->smk_flags & SMK_INODE_INSTANT) 2488 goto unlockandout; 2489 2490 sbp = inode->i_sb; 2491 sbsp = sbp->s_security; 2492 /* 2493 * We're going to use the superblock default label 2494 * if there's no label on the file. 2495 */ 2496 final = sbsp->smk_default; 2497 2498 /* 2499 * If this is the root inode the superblock 2500 * may be in the process of initialization. 2501 * If that is the case use the root value out 2502 * of the superblock. 2503 */ 2504 if (opt_dentry->d_parent == opt_dentry) { 2505 isp->smk_inode = sbsp->smk_root; 2506 isp->smk_flags |= SMK_INODE_INSTANT; 2507 goto unlockandout; 2508 } 2509 2510 /* 2511 * This is pretty hackish. 2512 * Casey says that we shouldn't have to do 2513 * file system specific code, but it does help 2514 * with keeping it simple. 2515 */ 2516 switch (sbp->s_magic) { 2517 case SMACK_MAGIC: 2518 /* 2519 * Casey says that it's a little embarrassing 2520 * that the smack file system doesn't do 2521 * extended attributes. 2522 */ 2523 final = smack_known_star.smk_known; 2524 break; 2525 case PIPEFS_MAGIC: 2526 /* 2527 * Casey says pipes are easy (?) 2528 */ 2529 final = smack_known_star.smk_known; 2530 break; 2531 case DEVPTS_SUPER_MAGIC: 2532 /* 2533 * devpts seems content with the label of the task. 2534 * Programs that change smack have to treat the 2535 * pty with respect. 2536 */ 2537 final = csp; 2538 break; 2539 case SOCKFS_MAGIC: 2540 /* 2541 * Socket access is controlled by the socket 2542 * structures associated with the task involved. 2543 */ 2544 final = smack_known_star.smk_known; 2545 break; 2546 case PROC_SUPER_MAGIC: 2547 /* 2548 * Casey says procfs appears not to care. 2549 * The superblock default suffices. 2550 */ 2551 break; 2552 case TMPFS_MAGIC: 2553 /* 2554 * Device labels should come from the filesystem, 2555 * but watch out, because they're volitile, 2556 * getting recreated on every reboot. 2557 */ 2558 final = smack_known_star.smk_known; 2559 /* 2560 * No break. 2561 * 2562 * If a smack value has been set we want to use it, 2563 * but since tmpfs isn't giving us the opportunity 2564 * to set mount options simulate setting the 2565 * superblock default. 2566 */ 2567 default: 2568 /* 2569 * This isn't an understood special case. 2570 * Get the value from the xattr. 2571 */ 2572 2573 /* 2574 * UNIX domain sockets use lower level socket data. 2575 */ 2576 if (S_ISSOCK(inode->i_mode)) { 2577 final = smack_known_star.smk_known; 2578 break; 2579 } 2580 /* 2581 * No xattr support means, alas, no SMACK label. 2582 * Use the aforeapplied default. 2583 * It would be curious if the label of the task 2584 * does not match that assigned. 2585 */ 2586 if (inode->i_op->getxattr == NULL) 2587 break; 2588 /* 2589 * Get the dentry for xattr. 2590 */ 2591 dp = dget(opt_dentry); 2592 fetched = smk_fetch(XATTR_NAME_SMACK, inode, dp); 2593 if (fetched != NULL) 2594 final = fetched; 2595 2596 /* 2597 * Transmuting directory 2598 */ 2599 if (S_ISDIR(inode->i_mode)) { 2600 /* 2601 * If this is a new directory and the label was 2602 * transmuted when the inode was initialized 2603 * set the transmute attribute on the directory 2604 * and mark the inode. 2605 * 2606 * If there is a transmute attribute on the 2607 * directory mark the inode. 2608 */ 2609 if (isp->smk_flags & SMK_INODE_CHANGED) { 2610 isp->smk_flags &= ~SMK_INODE_CHANGED; 2611 rc = inode->i_op->setxattr(dp, 2612 XATTR_NAME_SMACKTRANSMUTE, 2613 TRANS_TRUE, TRANS_TRUE_SIZE, 2614 0); 2615 } else { 2616 rc = inode->i_op->getxattr(dp, 2617 XATTR_NAME_SMACKTRANSMUTE, trattr, 2618 TRANS_TRUE_SIZE); 2619 if (rc >= 0 && strncmp(trattr, TRANS_TRUE, 2620 TRANS_TRUE_SIZE) != 0) 2621 rc = -EINVAL; 2622 } 2623 if (rc >= 0) 2624 transflag = SMK_INODE_TRANSMUTE; 2625 } 2626 isp->smk_task = smk_fetch(XATTR_NAME_SMACKEXEC, inode, dp); 2627 isp->smk_mmap = smk_fetch(XATTR_NAME_SMACKMMAP, inode, dp); 2628 2629 dput(dp); 2630 break; 2631 } 2632 2633 if (final == NULL) 2634 isp->smk_inode = csp; 2635 else 2636 isp->smk_inode = final; 2637 2638 isp->smk_flags |= (SMK_INODE_INSTANT | transflag); 2639 2640 unlockandout: 2641 mutex_unlock(&isp->smk_lock); 2642 return; 2643 } 2644 2645 /** 2646 * smack_getprocattr - Smack process attribute access 2647 * @p: the object task 2648 * @name: the name of the attribute in /proc/.../attr 2649 * @value: where to put the result 2650 * 2651 * Places a copy of the task Smack into value 2652 * 2653 * Returns the length of the smack label or an error code 2654 */ 2655 static int smack_getprocattr(struct task_struct *p, char *name, char **value) 2656 { 2657 char *cp; 2658 int slen; 2659 2660 if (strcmp(name, "current") != 0) 2661 return -EINVAL; 2662 2663 cp = kstrdup(smk_of_task(task_security(p)), GFP_KERNEL); 2664 if (cp == NULL) 2665 return -ENOMEM; 2666 2667 slen = strlen(cp); 2668 *value = cp; 2669 return slen; 2670 } 2671 2672 /** 2673 * smack_setprocattr - Smack process attribute setting 2674 * @p: the object task 2675 * @name: the name of the attribute in /proc/.../attr 2676 * @value: the value to set 2677 * @size: the size of the value 2678 * 2679 * Sets the Smack value of the task. Only setting self 2680 * is permitted and only with privilege 2681 * 2682 * Returns the length of the smack label or an error code 2683 */ 2684 static int smack_setprocattr(struct task_struct *p, char *name, 2685 void *value, size_t size) 2686 { 2687 struct task_smack *tsp; 2688 struct cred *new; 2689 char *newsmack; 2690 2691 /* 2692 * Changing another process' Smack value is too dangerous 2693 * and supports no sane use case. 2694 */ 2695 if (p != current) 2696 return -EPERM; 2697 2698 if (!smack_privileged(CAP_MAC_ADMIN)) 2699 return -EPERM; 2700 2701 if (value == NULL || size == 0 || size >= SMK_LONGLABEL) 2702 return -EINVAL; 2703 2704 if (strcmp(name, "current") != 0) 2705 return -EINVAL; 2706 2707 newsmack = smk_import(value, size); 2708 if (newsmack == NULL) 2709 return -EINVAL; 2710 2711 /* 2712 * No process is ever allowed the web ("@") label. 2713 */ 2714 if (newsmack == smack_known_web.smk_known) 2715 return -EPERM; 2716 2717 new = prepare_creds(); 2718 if (new == NULL) 2719 return -ENOMEM; 2720 2721 tsp = new->security; 2722 tsp->smk_task = newsmack; 2723 2724 commit_creds(new); 2725 return size; 2726 } 2727 2728 /** 2729 * smack_unix_stream_connect - Smack access on UDS 2730 * @sock: one sock 2731 * @other: the other sock 2732 * @newsk: unused 2733 * 2734 * Return 0 if a subject with the smack of sock could access 2735 * an object with the smack of other, otherwise an error code 2736 */ 2737 static int smack_unix_stream_connect(struct sock *sock, 2738 struct sock *other, struct sock *newsk) 2739 { 2740 struct socket_smack *ssp = sock->sk_security; 2741 struct socket_smack *osp = other->sk_security; 2742 struct socket_smack *nsp = newsk->sk_security; 2743 struct smk_audit_info ad; 2744 int rc = 0; 2745 2746 #ifdef CONFIG_AUDIT 2747 struct lsm_network_audit net; 2748 2749 smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net); 2750 smk_ad_setfield_u_net_sk(&ad, other); 2751 #endif 2752 2753 if (!smack_privileged(CAP_MAC_OVERRIDE)) 2754 rc = smk_access(ssp->smk_out, osp->smk_in, MAY_WRITE, &ad); 2755 2756 /* 2757 * Cross reference the peer labels for SO_PEERSEC. 2758 */ 2759 if (rc == 0) { 2760 nsp->smk_packet = ssp->smk_out; 2761 ssp->smk_packet = osp->smk_out; 2762 } 2763 2764 return rc; 2765 } 2766 2767 /** 2768 * smack_unix_may_send - Smack access on UDS 2769 * @sock: one socket 2770 * @other: the other socket 2771 * 2772 * Return 0 if a subject with the smack of sock could access 2773 * an object with the smack of other, otherwise an error code 2774 */ 2775 static int smack_unix_may_send(struct socket *sock, struct socket *other) 2776 { 2777 struct socket_smack *ssp = sock->sk->sk_security; 2778 struct socket_smack *osp = other->sk->sk_security; 2779 struct smk_audit_info ad; 2780 int rc = 0; 2781 2782 #ifdef CONFIG_AUDIT 2783 struct lsm_network_audit net; 2784 2785 smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net); 2786 smk_ad_setfield_u_net_sk(&ad, other->sk); 2787 #endif 2788 2789 if (!smack_privileged(CAP_MAC_OVERRIDE)) 2790 rc = smk_access(ssp->smk_out, osp->smk_in, MAY_WRITE, &ad); 2791 2792 return rc; 2793 } 2794 2795 /** 2796 * smack_socket_sendmsg - Smack check based on destination host 2797 * @sock: the socket 2798 * @msg: the message 2799 * @size: the size of the message 2800 * 2801 * Return 0 if the current subject can write to the destination 2802 * host. This is only a question if the destination is a single 2803 * label host. 2804 */ 2805 static int smack_socket_sendmsg(struct socket *sock, struct msghdr *msg, 2806 int size) 2807 { 2808 struct sockaddr_in *sip = (struct sockaddr_in *) msg->msg_name; 2809 2810 /* 2811 * Perfectly reasonable for this to be NULL 2812 */ 2813 if (sip == NULL || sip->sin_family != AF_INET) 2814 return 0; 2815 2816 return smack_netlabel_send(sock->sk, sip); 2817 } 2818 2819 /** 2820 * smack_from_secattr - Convert a netlabel attr.mls.lvl/attr.mls.cat pair to smack 2821 * @sap: netlabel secattr 2822 * @ssp: socket security information 2823 * 2824 * Returns a pointer to a Smack label found on the label list. 2825 */ 2826 static char *smack_from_secattr(struct netlbl_lsm_secattr *sap, 2827 struct socket_smack *ssp) 2828 { 2829 struct smack_known *kp; 2830 char *sp; 2831 int found = 0; 2832 2833 if ((sap->flags & NETLBL_SECATTR_MLS_LVL) != 0) { 2834 /* 2835 * Looks like a CIPSO packet. 2836 * If there are flags but no level netlabel isn't 2837 * behaving the way we expect it to. 2838 * 2839 * Look it up in the label table 2840 * Without guidance regarding the smack value 2841 * for the packet fall back on the network 2842 * ambient value. 2843 */ 2844 rcu_read_lock(); 2845 list_for_each_entry(kp, &smack_known_list, list) { 2846 if (sap->attr.mls.lvl != kp->smk_netlabel.attr.mls.lvl) 2847 continue; 2848 if (memcmp(sap->attr.mls.cat, 2849 kp->smk_netlabel.attr.mls.cat, 2850 SMK_CIPSOLEN) != 0) 2851 continue; 2852 found = 1; 2853 break; 2854 } 2855 rcu_read_unlock(); 2856 2857 if (found) 2858 return kp->smk_known; 2859 2860 if (ssp != NULL && ssp->smk_in == smack_known_star.smk_known) 2861 return smack_known_web.smk_known; 2862 return smack_known_star.smk_known; 2863 } 2864 if ((sap->flags & NETLBL_SECATTR_SECID) != 0) { 2865 /* 2866 * Looks like a fallback, which gives us a secid. 2867 */ 2868 sp = smack_from_secid(sap->attr.secid); 2869 /* 2870 * This has got to be a bug because it is 2871 * impossible to specify a fallback without 2872 * specifying the label, which will ensure 2873 * it has a secid, and the only way to get a 2874 * secid is from a fallback. 2875 */ 2876 BUG_ON(sp == NULL); 2877 return sp; 2878 } 2879 /* 2880 * Without guidance regarding the smack value 2881 * for the packet fall back on the network 2882 * ambient value. 2883 */ 2884 return smack_net_ambient; 2885 } 2886 2887 /** 2888 * smack_socket_sock_rcv_skb - Smack packet delivery access check 2889 * @sk: socket 2890 * @skb: packet 2891 * 2892 * Returns 0 if the packet should be delivered, an error code otherwise 2893 */ 2894 static int smack_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb) 2895 { 2896 struct netlbl_lsm_secattr secattr; 2897 struct socket_smack *ssp = sk->sk_security; 2898 char *csp; 2899 int rc; 2900 struct smk_audit_info ad; 2901 #ifdef CONFIG_AUDIT 2902 struct lsm_network_audit net; 2903 #endif 2904 if (sk->sk_family != PF_INET && sk->sk_family != PF_INET6) 2905 return 0; 2906 2907 /* 2908 * Translate what netlabel gave us. 2909 */ 2910 netlbl_secattr_init(&secattr); 2911 2912 rc = netlbl_skbuff_getattr(skb, sk->sk_family, &secattr); 2913 if (rc == 0) 2914 csp = smack_from_secattr(&secattr, ssp); 2915 else 2916 csp = smack_net_ambient; 2917 2918 netlbl_secattr_destroy(&secattr); 2919 2920 #ifdef CONFIG_AUDIT 2921 smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net); 2922 ad.a.u.net->family = sk->sk_family; 2923 ad.a.u.net->netif = skb->skb_iif; 2924 ipv4_skb_to_auditdata(skb, &ad.a, NULL); 2925 #endif 2926 /* 2927 * Receiving a packet requires that the other end 2928 * be able to write here. Read access is not required. 2929 * This is the simplist possible security model 2930 * for networking. 2931 */ 2932 rc = smk_access(csp, ssp->smk_in, MAY_WRITE, &ad); 2933 if (rc != 0) 2934 netlbl_skbuff_err(skb, rc, 0); 2935 return rc; 2936 } 2937 2938 /** 2939 * smack_socket_getpeersec_stream - pull in packet label 2940 * @sock: the socket 2941 * @optval: user's destination 2942 * @optlen: size thereof 2943 * @len: max thereof 2944 * 2945 * returns zero on success, an error code otherwise 2946 */ 2947 static int smack_socket_getpeersec_stream(struct socket *sock, 2948 char __user *optval, 2949 int __user *optlen, unsigned len) 2950 { 2951 struct socket_smack *ssp; 2952 char *rcp = ""; 2953 int slen = 1; 2954 int rc = 0; 2955 2956 ssp = sock->sk->sk_security; 2957 if (ssp->smk_packet != NULL) { 2958 rcp = ssp->smk_packet; 2959 slen = strlen(rcp) + 1; 2960 } 2961 2962 if (slen > len) 2963 rc = -ERANGE; 2964 else if (copy_to_user(optval, rcp, slen) != 0) 2965 rc = -EFAULT; 2966 2967 if (put_user(slen, optlen) != 0) 2968 rc = -EFAULT; 2969 2970 return rc; 2971 } 2972 2973 2974 /** 2975 * smack_socket_getpeersec_dgram - pull in packet label 2976 * @sock: the peer socket 2977 * @skb: packet data 2978 * @secid: pointer to where to put the secid of the packet 2979 * 2980 * Sets the netlabel socket state on sk from parent 2981 */ 2982 static int smack_socket_getpeersec_dgram(struct socket *sock, 2983 struct sk_buff *skb, u32 *secid) 2984 2985 { 2986 struct netlbl_lsm_secattr secattr; 2987 struct socket_smack *ssp = NULL; 2988 char *sp; 2989 int family = PF_UNSPEC; 2990 u32 s = 0; /* 0 is the invalid secid */ 2991 int rc; 2992 2993 if (skb != NULL) { 2994 if (skb->protocol == htons(ETH_P_IP)) 2995 family = PF_INET; 2996 else if (skb->protocol == htons(ETH_P_IPV6)) 2997 family = PF_INET6; 2998 } 2999 if (family == PF_UNSPEC && sock != NULL) 3000 family = sock->sk->sk_family; 3001 3002 if (family == PF_UNIX) { 3003 ssp = sock->sk->sk_security; 3004 s = smack_to_secid(ssp->smk_out); 3005 } else if (family == PF_INET || family == PF_INET6) { 3006 /* 3007 * Translate what netlabel gave us. 3008 */ 3009 if (sock != NULL && sock->sk != NULL) 3010 ssp = sock->sk->sk_security; 3011 netlbl_secattr_init(&secattr); 3012 rc = netlbl_skbuff_getattr(skb, family, &secattr); 3013 if (rc == 0) { 3014 sp = smack_from_secattr(&secattr, ssp); 3015 s = smack_to_secid(sp); 3016 } 3017 netlbl_secattr_destroy(&secattr); 3018 } 3019 *secid = s; 3020 if (s == 0) 3021 return -EINVAL; 3022 return 0; 3023 } 3024 3025 /** 3026 * smack_sock_graft - Initialize a newly created socket with an existing sock 3027 * @sk: child sock 3028 * @parent: parent socket 3029 * 3030 * Set the smk_{in,out} state of an existing sock based on the process that 3031 * is creating the new socket. 3032 */ 3033 static void smack_sock_graft(struct sock *sk, struct socket *parent) 3034 { 3035 struct socket_smack *ssp; 3036 3037 if (sk == NULL || 3038 (sk->sk_family != PF_INET && sk->sk_family != PF_INET6)) 3039 return; 3040 3041 ssp = sk->sk_security; 3042 ssp->smk_in = ssp->smk_out = smk_of_current(); 3043 /* cssp->smk_packet is already set in smack_inet_csk_clone() */ 3044 } 3045 3046 /** 3047 * smack_inet_conn_request - Smack access check on connect 3048 * @sk: socket involved 3049 * @skb: packet 3050 * @req: unused 3051 * 3052 * Returns 0 if a task with the packet label could write to 3053 * the socket, otherwise an error code 3054 */ 3055 static int smack_inet_conn_request(struct sock *sk, struct sk_buff *skb, 3056 struct request_sock *req) 3057 { 3058 u16 family = sk->sk_family; 3059 struct smack_known *skp; 3060 struct socket_smack *ssp = sk->sk_security; 3061 struct netlbl_lsm_secattr secattr; 3062 struct sockaddr_in addr; 3063 struct iphdr *hdr; 3064 char *sp; 3065 char *hsp; 3066 int rc; 3067 struct smk_audit_info ad; 3068 #ifdef CONFIG_AUDIT 3069 struct lsm_network_audit net; 3070 #endif 3071 3072 /* handle mapped IPv4 packets arriving via IPv6 sockets */ 3073 if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP)) 3074 family = PF_INET; 3075 3076 netlbl_secattr_init(&secattr); 3077 rc = netlbl_skbuff_getattr(skb, family, &secattr); 3078 if (rc == 0) 3079 sp = smack_from_secattr(&secattr, ssp); 3080 else 3081 sp = smack_known_huh.smk_known; 3082 netlbl_secattr_destroy(&secattr); 3083 3084 #ifdef CONFIG_AUDIT 3085 smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net); 3086 ad.a.u.net->family = family; 3087 ad.a.u.net->netif = skb->skb_iif; 3088 ipv4_skb_to_auditdata(skb, &ad.a, NULL); 3089 #endif 3090 /* 3091 * Receiving a packet requires that the other end be able to write 3092 * here. Read access is not required. 3093 */ 3094 rc = smk_access(sp, ssp->smk_in, MAY_WRITE, &ad); 3095 if (rc != 0) 3096 return rc; 3097 3098 /* 3099 * Save the peer's label in the request_sock so we can later setup 3100 * smk_packet in the child socket so that SO_PEERCRED can report it. 3101 */ 3102 req->peer_secid = smack_to_secid(sp); 3103 3104 /* 3105 * We need to decide if we want to label the incoming connection here 3106 * if we do we only need to label the request_sock and the stack will 3107 * propagate the wire-label to the sock when it is created. 3108 */ 3109 hdr = ip_hdr(skb); 3110 addr.sin_addr.s_addr = hdr->saddr; 3111 rcu_read_lock(); 3112 hsp = smack_host_label(&addr); 3113 rcu_read_unlock(); 3114 3115 if (hsp == NULL) { 3116 skp = smk_find_entry(sp); 3117 rc = netlbl_req_setattr(req, &skp->smk_netlabel); 3118 } else 3119 netlbl_req_delattr(req); 3120 3121 return rc; 3122 } 3123 3124 /** 3125 * smack_inet_csk_clone - Copy the connection information to the new socket 3126 * @sk: the new socket 3127 * @req: the connection's request_sock 3128 * 3129 * Transfer the connection's peer label to the newly created socket. 3130 */ 3131 static void smack_inet_csk_clone(struct sock *sk, 3132 const struct request_sock *req) 3133 { 3134 struct socket_smack *ssp = sk->sk_security; 3135 3136 if (req->peer_secid != 0) 3137 ssp->smk_packet = smack_from_secid(req->peer_secid); 3138 else 3139 ssp->smk_packet = NULL; 3140 } 3141 3142 /* 3143 * Key management security hooks 3144 * 3145 * Casey has not tested key support very heavily. 3146 * The permission check is most likely too restrictive. 3147 * If you care about keys please have a look. 3148 */ 3149 #ifdef CONFIG_KEYS 3150 3151 /** 3152 * smack_key_alloc - Set the key security blob 3153 * @key: object 3154 * @cred: the credentials to use 3155 * @flags: unused 3156 * 3157 * No allocation required 3158 * 3159 * Returns 0 3160 */ 3161 static int smack_key_alloc(struct key *key, const struct cred *cred, 3162 unsigned long flags) 3163 { 3164 key->security = smk_of_task(cred->security); 3165 return 0; 3166 } 3167 3168 /** 3169 * smack_key_free - Clear the key security blob 3170 * @key: the object 3171 * 3172 * Clear the blob pointer 3173 */ 3174 static void smack_key_free(struct key *key) 3175 { 3176 key->security = NULL; 3177 } 3178 3179 /* 3180 * smack_key_permission - Smack access on a key 3181 * @key_ref: gets to the object 3182 * @cred: the credentials to use 3183 * @perm: unused 3184 * 3185 * Return 0 if the task has read and write to the object, 3186 * an error code otherwise 3187 */ 3188 static int smack_key_permission(key_ref_t key_ref, 3189 const struct cred *cred, key_perm_t perm) 3190 { 3191 struct key *keyp; 3192 struct smk_audit_info ad; 3193 char *tsp = smk_of_task(cred->security); 3194 3195 keyp = key_ref_to_ptr(key_ref); 3196 if (keyp == NULL) 3197 return -EINVAL; 3198 /* 3199 * If the key hasn't been initialized give it access so that 3200 * it may do so. 3201 */ 3202 if (keyp->security == NULL) 3203 return 0; 3204 /* 3205 * This should not occur 3206 */ 3207 if (tsp == NULL) 3208 return -EACCES; 3209 #ifdef CONFIG_AUDIT 3210 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_KEY); 3211 ad.a.u.key_struct.key = keyp->serial; 3212 ad.a.u.key_struct.key_desc = keyp->description; 3213 #endif 3214 return smk_access(tsp, keyp->security, 3215 MAY_READWRITE, &ad); 3216 } 3217 #endif /* CONFIG_KEYS */ 3218 3219 /* 3220 * Smack Audit hooks 3221 * 3222 * Audit requires a unique representation of each Smack specific 3223 * rule. This unique representation is used to distinguish the 3224 * object to be audited from remaining kernel objects and also 3225 * works as a glue between the audit hooks. 3226 * 3227 * Since repository entries are added but never deleted, we'll use 3228 * the smack_known label address related to the given audit rule as 3229 * the needed unique representation. This also better fits the smack 3230 * model where nearly everything is a label. 3231 */ 3232 #ifdef CONFIG_AUDIT 3233 3234 /** 3235 * smack_audit_rule_init - Initialize a smack audit rule 3236 * @field: audit rule fields given from user-space (audit.h) 3237 * @op: required testing operator (=, !=, >, <, ...) 3238 * @rulestr: smack label to be audited 3239 * @vrule: pointer to save our own audit rule representation 3240 * 3241 * Prepare to audit cases where (@field @op @rulestr) is true. 3242 * The label to be audited is created if necessay. 3243 */ 3244 static int smack_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule) 3245 { 3246 char **rule = (char **)vrule; 3247 *rule = NULL; 3248 3249 if (field != AUDIT_SUBJ_USER && field != AUDIT_OBJ_USER) 3250 return -EINVAL; 3251 3252 if (op != Audit_equal && op != Audit_not_equal) 3253 return -EINVAL; 3254 3255 *rule = smk_import(rulestr, 0); 3256 3257 return 0; 3258 } 3259 3260 /** 3261 * smack_audit_rule_known - Distinguish Smack audit rules 3262 * @krule: rule of interest, in Audit kernel representation format 3263 * 3264 * This is used to filter Smack rules from remaining Audit ones. 3265 * If it's proved that this rule belongs to us, the 3266 * audit_rule_match hook will be called to do the final judgement. 3267 */ 3268 static int smack_audit_rule_known(struct audit_krule *krule) 3269 { 3270 struct audit_field *f; 3271 int i; 3272 3273 for (i = 0; i < krule->field_count; i++) { 3274 f = &krule->fields[i]; 3275 3276 if (f->type == AUDIT_SUBJ_USER || f->type == AUDIT_OBJ_USER) 3277 return 1; 3278 } 3279 3280 return 0; 3281 } 3282 3283 /** 3284 * smack_audit_rule_match - Audit given object ? 3285 * @secid: security id for identifying the object to test 3286 * @field: audit rule flags given from user-space 3287 * @op: required testing operator 3288 * @vrule: smack internal rule presentation 3289 * @actx: audit context associated with the check 3290 * 3291 * The core Audit hook. It's used to take the decision of 3292 * whether to audit or not to audit a given object. 3293 */ 3294 static int smack_audit_rule_match(u32 secid, u32 field, u32 op, void *vrule, 3295 struct audit_context *actx) 3296 { 3297 char *smack; 3298 char *rule = vrule; 3299 3300 if (!rule) { 3301 audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR, 3302 "Smack: missing rule\n"); 3303 return -ENOENT; 3304 } 3305 3306 if (field != AUDIT_SUBJ_USER && field != AUDIT_OBJ_USER) 3307 return 0; 3308 3309 smack = smack_from_secid(secid); 3310 3311 /* 3312 * No need to do string comparisons. If a match occurs, 3313 * both pointers will point to the same smack_known 3314 * label. 3315 */ 3316 if (op == Audit_equal) 3317 return (rule == smack); 3318 if (op == Audit_not_equal) 3319 return (rule != smack); 3320 3321 return 0; 3322 } 3323 3324 /** 3325 * smack_audit_rule_free - free smack rule representation 3326 * @vrule: rule to be freed. 3327 * 3328 * No memory was allocated. 3329 */ 3330 static void smack_audit_rule_free(void *vrule) 3331 { 3332 /* No-op */ 3333 } 3334 3335 #endif /* CONFIG_AUDIT */ 3336 3337 /** 3338 * smack_secid_to_secctx - return the smack label for a secid 3339 * @secid: incoming integer 3340 * @secdata: destination 3341 * @seclen: how long it is 3342 * 3343 * Exists for networking code. 3344 */ 3345 static int smack_secid_to_secctx(u32 secid, char **secdata, u32 *seclen) 3346 { 3347 char *sp = smack_from_secid(secid); 3348 3349 if (secdata) 3350 *secdata = sp; 3351 *seclen = strlen(sp); 3352 return 0; 3353 } 3354 3355 /** 3356 * smack_secctx_to_secid - return the secid for a smack label 3357 * @secdata: smack label 3358 * @seclen: how long result is 3359 * @secid: outgoing integer 3360 * 3361 * Exists for audit and networking code. 3362 */ 3363 static int smack_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid) 3364 { 3365 *secid = smack_to_secid(secdata); 3366 return 0; 3367 } 3368 3369 /** 3370 * smack_release_secctx - don't do anything. 3371 * @secdata: unused 3372 * @seclen: unused 3373 * 3374 * Exists to make sure nothing gets done, and properly 3375 */ 3376 static void smack_release_secctx(char *secdata, u32 seclen) 3377 { 3378 } 3379 3380 static int smack_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen) 3381 { 3382 return smack_inode_setsecurity(inode, XATTR_SMACK_SUFFIX, ctx, ctxlen, 0); 3383 } 3384 3385 static int smack_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen) 3386 { 3387 return __vfs_setxattr_noperm(dentry, XATTR_NAME_SMACK, ctx, ctxlen, 0); 3388 } 3389 3390 static int smack_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen) 3391 { 3392 int len = 0; 3393 len = smack_inode_getsecurity(inode, XATTR_SMACK_SUFFIX, ctx, true); 3394 3395 if (len < 0) 3396 return len; 3397 *ctxlen = len; 3398 return 0; 3399 } 3400 3401 struct security_operations smack_ops = { 3402 .name = "smack", 3403 3404 .ptrace_access_check = smack_ptrace_access_check, 3405 .ptrace_traceme = smack_ptrace_traceme, 3406 .syslog = smack_syslog, 3407 3408 .sb_alloc_security = smack_sb_alloc_security, 3409 .sb_free_security = smack_sb_free_security, 3410 .sb_copy_data = smack_sb_copy_data, 3411 .sb_kern_mount = smack_sb_kern_mount, 3412 .sb_statfs = smack_sb_statfs, 3413 .sb_mount = smack_sb_mount, 3414 .sb_umount = smack_sb_umount, 3415 3416 .bprm_set_creds = smack_bprm_set_creds, 3417 .bprm_committing_creds = smack_bprm_committing_creds, 3418 .bprm_secureexec = smack_bprm_secureexec, 3419 3420 .inode_alloc_security = smack_inode_alloc_security, 3421 .inode_free_security = smack_inode_free_security, 3422 .inode_init_security = smack_inode_init_security, 3423 .inode_link = smack_inode_link, 3424 .inode_unlink = smack_inode_unlink, 3425 .inode_rmdir = smack_inode_rmdir, 3426 .inode_rename = smack_inode_rename, 3427 .inode_permission = smack_inode_permission, 3428 .inode_setattr = smack_inode_setattr, 3429 .inode_getattr = smack_inode_getattr, 3430 .inode_setxattr = smack_inode_setxattr, 3431 .inode_post_setxattr = smack_inode_post_setxattr, 3432 .inode_getxattr = smack_inode_getxattr, 3433 .inode_removexattr = smack_inode_removexattr, 3434 .inode_getsecurity = smack_inode_getsecurity, 3435 .inode_setsecurity = smack_inode_setsecurity, 3436 .inode_listsecurity = smack_inode_listsecurity, 3437 .inode_getsecid = smack_inode_getsecid, 3438 3439 .file_permission = smack_file_permission, 3440 .file_alloc_security = smack_file_alloc_security, 3441 .file_free_security = smack_file_free_security, 3442 .file_ioctl = smack_file_ioctl, 3443 .file_lock = smack_file_lock, 3444 .file_fcntl = smack_file_fcntl, 3445 .mmap_file = smack_mmap_file, 3446 .mmap_addr = cap_mmap_addr, 3447 .file_set_fowner = smack_file_set_fowner, 3448 .file_send_sigiotask = smack_file_send_sigiotask, 3449 .file_receive = smack_file_receive, 3450 3451 .file_open = smack_file_open, 3452 3453 .cred_alloc_blank = smack_cred_alloc_blank, 3454 .cred_free = smack_cred_free, 3455 .cred_prepare = smack_cred_prepare, 3456 .cred_transfer = smack_cred_transfer, 3457 .kernel_act_as = smack_kernel_act_as, 3458 .kernel_create_files_as = smack_kernel_create_files_as, 3459 .task_setpgid = smack_task_setpgid, 3460 .task_getpgid = smack_task_getpgid, 3461 .task_getsid = smack_task_getsid, 3462 .task_getsecid = smack_task_getsecid, 3463 .task_setnice = smack_task_setnice, 3464 .task_setioprio = smack_task_setioprio, 3465 .task_getioprio = smack_task_getioprio, 3466 .task_setscheduler = smack_task_setscheduler, 3467 .task_getscheduler = smack_task_getscheduler, 3468 .task_movememory = smack_task_movememory, 3469 .task_kill = smack_task_kill, 3470 .task_wait = smack_task_wait, 3471 .task_to_inode = smack_task_to_inode, 3472 3473 .ipc_permission = smack_ipc_permission, 3474 .ipc_getsecid = smack_ipc_getsecid, 3475 3476 .msg_msg_alloc_security = smack_msg_msg_alloc_security, 3477 .msg_msg_free_security = smack_msg_msg_free_security, 3478 3479 .msg_queue_alloc_security = smack_msg_queue_alloc_security, 3480 .msg_queue_free_security = smack_msg_queue_free_security, 3481 .msg_queue_associate = smack_msg_queue_associate, 3482 .msg_queue_msgctl = smack_msg_queue_msgctl, 3483 .msg_queue_msgsnd = smack_msg_queue_msgsnd, 3484 .msg_queue_msgrcv = smack_msg_queue_msgrcv, 3485 3486 .shm_alloc_security = smack_shm_alloc_security, 3487 .shm_free_security = smack_shm_free_security, 3488 .shm_associate = smack_shm_associate, 3489 .shm_shmctl = smack_shm_shmctl, 3490 .shm_shmat = smack_shm_shmat, 3491 3492 .sem_alloc_security = smack_sem_alloc_security, 3493 .sem_free_security = smack_sem_free_security, 3494 .sem_associate = smack_sem_associate, 3495 .sem_semctl = smack_sem_semctl, 3496 .sem_semop = smack_sem_semop, 3497 3498 .d_instantiate = smack_d_instantiate, 3499 3500 .getprocattr = smack_getprocattr, 3501 .setprocattr = smack_setprocattr, 3502 3503 .unix_stream_connect = smack_unix_stream_connect, 3504 .unix_may_send = smack_unix_may_send, 3505 3506 .socket_post_create = smack_socket_post_create, 3507 .socket_connect = smack_socket_connect, 3508 .socket_sendmsg = smack_socket_sendmsg, 3509 .socket_sock_rcv_skb = smack_socket_sock_rcv_skb, 3510 .socket_getpeersec_stream = smack_socket_getpeersec_stream, 3511 .socket_getpeersec_dgram = smack_socket_getpeersec_dgram, 3512 .sk_alloc_security = smack_sk_alloc_security, 3513 .sk_free_security = smack_sk_free_security, 3514 .sock_graft = smack_sock_graft, 3515 .inet_conn_request = smack_inet_conn_request, 3516 .inet_csk_clone = smack_inet_csk_clone, 3517 3518 /* key management security hooks */ 3519 #ifdef CONFIG_KEYS 3520 .key_alloc = smack_key_alloc, 3521 .key_free = smack_key_free, 3522 .key_permission = smack_key_permission, 3523 #endif /* CONFIG_KEYS */ 3524 3525 /* Audit hooks */ 3526 #ifdef CONFIG_AUDIT 3527 .audit_rule_init = smack_audit_rule_init, 3528 .audit_rule_known = smack_audit_rule_known, 3529 .audit_rule_match = smack_audit_rule_match, 3530 .audit_rule_free = smack_audit_rule_free, 3531 #endif /* CONFIG_AUDIT */ 3532 3533 .secid_to_secctx = smack_secid_to_secctx, 3534 .secctx_to_secid = smack_secctx_to_secid, 3535 .release_secctx = smack_release_secctx, 3536 .inode_notifysecctx = smack_inode_notifysecctx, 3537 .inode_setsecctx = smack_inode_setsecctx, 3538 .inode_getsecctx = smack_inode_getsecctx, 3539 }; 3540 3541 3542 static __init void init_smack_known_list(void) 3543 { 3544 /* 3545 * Initialize rule list locks 3546 */ 3547 mutex_init(&smack_known_huh.smk_rules_lock); 3548 mutex_init(&smack_known_hat.smk_rules_lock); 3549 mutex_init(&smack_known_floor.smk_rules_lock); 3550 mutex_init(&smack_known_star.smk_rules_lock); 3551 mutex_init(&smack_known_invalid.smk_rules_lock); 3552 mutex_init(&smack_known_web.smk_rules_lock); 3553 /* 3554 * Initialize rule lists 3555 */ 3556 INIT_LIST_HEAD(&smack_known_huh.smk_rules); 3557 INIT_LIST_HEAD(&smack_known_hat.smk_rules); 3558 INIT_LIST_HEAD(&smack_known_star.smk_rules); 3559 INIT_LIST_HEAD(&smack_known_floor.smk_rules); 3560 INIT_LIST_HEAD(&smack_known_invalid.smk_rules); 3561 INIT_LIST_HEAD(&smack_known_web.smk_rules); 3562 /* 3563 * Create the known labels list 3564 */ 3565 list_add(&smack_known_huh.list, &smack_known_list); 3566 list_add(&smack_known_hat.list, &smack_known_list); 3567 list_add(&smack_known_star.list, &smack_known_list); 3568 list_add(&smack_known_floor.list, &smack_known_list); 3569 list_add(&smack_known_invalid.list, &smack_known_list); 3570 list_add(&smack_known_web.list, &smack_known_list); 3571 } 3572 3573 /** 3574 * smack_init - initialize the smack system 3575 * 3576 * Returns 0 3577 */ 3578 static __init int smack_init(void) 3579 { 3580 struct cred *cred; 3581 struct task_smack *tsp; 3582 3583 if (!security_module_enable(&smack_ops)) 3584 return 0; 3585 3586 tsp = new_task_smack(smack_known_floor.smk_known, 3587 smack_known_floor.smk_known, GFP_KERNEL); 3588 if (tsp == NULL) 3589 return -ENOMEM; 3590 3591 printk(KERN_INFO "Smack: Initializing.\n"); 3592 3593 /* 3594 * Set the security state for the initial task. 3595 */ 3596 cred = (struct cred *) current->cred; 3597 cred->security = tsp; 3598 3599 /* initialize the smack_known_list */ 3600 init_smack_known_list(); 3601 3602 /* 3603 * Register with LSM 3604 */ 3605 if (register_security(&smack_ops)) 3606 panic("smack: Unable to register with kernel.\n"); 3607 3608 return 0; 3609 } 3610 3611 /* 3612 * Smack requires early initialization in order to label 3613 * all processes and objects when they are created. 3614 */ 3615 security_initcall(smack_init); 3616