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 <ext-jarkko.2.sakkinen@nokia.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 * 15 * This program is free software; you can redistribute it and/or modify 16 * it under the terms of the GNU General Public License version 2, 17 * as published by the Free Software Foundation. 18 */ 19 20 #include <linux/xattr.h> 21 #include <linux/pagemap.h> 22 #include <linux/mount.h> 23 #include <linux/stat.h> 24 #include <linux/kd.h> 25 #include <asm/ioctls.h> 26 #include <linux/ip.h> 27 #include <linux/tcp.h> 28 #include <linux/udp.h> 29 #include <linux/slab.h> 30 #include <linux/mutex.h> 31 #include <linux/pipe_fs_i.h> 32 #include <net/netlabel.h> 33 #include <net/cipso_ipv4.h> 34 #include <linux/audit.h> 35 #include <linux/magic.h> 36 #include <linux/dcache.h> 37 #include "smack.h" 38 39 #define task_security(task) (task_cred_xxx((task), security)) 40 41 #define TRANS_TRUE "TRUE" 42 #define TRANS_TRUE_SIZE 4 43 44 /** 45 * smk_fetch - Fetch the smack label from a file. 46 * @ip: a pointer to the inode 47 * @dp: a pointer to the dentry 48 * 49 * Returns a pointer to the master list entry for the Smack label 50 * or NULL if there was no label to fetch. 51 */ 52 static char *smk_fetch(const char *name, struct inode *ip, struct dentry *dp) 53 { 54 int rc; 55 char in[SMK_LABELLEN]; 56 57 if (ip->i_op->getxattr == NULL) 58 return NULL; 59 60 rc = ip->i_op->getxattr(dp, name, in, SMK_LABELLEN); 61 if (rc < 0) 62 return NULL; 63 64 return smk_import(in, rc); 65 } 66 67 /** 68 * new_inode_smack - allocate an inode security blob 69 * @smack: a pointer to the Smack label to use in the blob 70 * 71 * Returns the new blob or NULL if there's no memory available 72 */ 73 struct inode_smack *new_inode_smack(char *smack) 74 { 75 struct inode_smack *isp; 76 77 isp = kzalloc(sizeof(struct inode_smack), GFP_KERNEL); 78 if (isp == NULL) 79 return NULL; 80 81 isp->smk_inode = smack; 82 isp->smk_flags = 0; 83 mutex_init(&isp->smk_lock); 84 85 return isp; 86 } 87 88 /** 89 * new_task_smack - allocate a task security blob 90 * @smack: a pointer to the Smack label to use in the blob 91 * 92 * Returns the new blob or NULL if there's no memory available 93 */ 94 static struct task_smack *new_task_smack(char *task, char *forked, gfp_t gfp) 95 { 96 struct task_smack *tsp; 97 98 tsp = kzalloc(sizeof(struct task_smack), gfp); 99 if (tsp == NULL) 100 return NULL; 101 102 tsp->smk_task = task; 103 tsp->smk_forked = forked; 104 INIT_LIST_HEAD(&tsp->smk_rules); 105 mutex_init(&tsp->smk_rules_lock); 106 107 return tsp; 108 } 109 110 /** 111 * smk_copy_rules - copy a rule set 112 * @nhead - new rules header pointer 113 * @ohead - old rules header pointer 114 * 115 * Returns 0 on success, -ENOMEM on error 116 */ 117 static int smk_copy_rules(struct list_head *nhead, struct list_head *ohead, 118 gfp_t gfp) 119 { 120 struct smack_rule *nrp; 121 struct smack_rule *orp; 122 int rc = 0; 123 124 INIT_LIST_HEAD(nhead); 125 126 list_for_each_entry_rcu(orp, ohead, list) { 127 nrp = kzalloc(sizeof(struct smack_rule), gfp); 128 if (nrp == NULL) { 129 rc = -ENOMEM; 130 break; 131 } 132 *nrp = *orp; 133 list_add_rcu(&nrp->list, nhead); 134 } 135 return rc; 136 } 137 138 /* 139 * LSM hooks. 140 * We he, that is fun! 141 */ 142 143 /** 144 * smack_ptrace_access_check - Smack approval on PTRACE_ATTACH 145 * @ctp: child task pointer 146 * @mode: ptrace attachment mode 147 * 148 * Returns 0 if access is OK, an error code otherwise 149 * 150 * Do the capability checks, and require read and write. 151 */ 152 static int smack_ptrace_access_check(struct task_struct *ctp, unsigned int mode) 153 { 154 int rc; 155 struct smk_audit_info ad; 156 char *tsp; 157 158 rc = cap_ptrace_access_check(ctp, mode); 159 if (rc != 0) 160 return rc; 161 162 tsp = smk_of_task(task_security(ctp)); 163 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK); 164 smk_ad_setfield_u_tsk(&ad, ctp); 165 166 rc = smk_curacc(tsp, MAY_READWRITE, &ad); 167 return rc; 168 } 169 170 /** 171 * smack_ptrace_traceme - Smack approval on PTRACE_TRACEME 172 * @ptp: parent task pointer 173 * 174 * Returns 0 if access is OK, an error code otherwise 175 * 176 * Do the capability checks, and require read and write. 177 */ 178 static int smack_ptrace_traceme(struct task_struct *ptp) 179 { 180 int rc; 181 struct smk_audit_info ad; 182 char *tsp; 183 184 rc = cap_ptrace_traceme(ptp); 185 if (rc != 0) 186 return rc; 187 188 tsp = smk_of_task(task_security(ptp)); 189 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK); 190 smk_ad_setfield_u_tsk(&ad, ptp); 191 192 rc = smk_curacc(tsp, MAY_READWRITE, &ad); 193 return rc; 194 } 195 196 /** 197 * smack_syslog - Smack approval on syslog 198 * @type: message type 199 * 200 * Require that the task has the floor label 201 * 202 * Returns 0 on success, error code otherwise. 203 */ 204 static int smack_syslog(int typefrom_file) 205 { 206 int rc = 0; 207 char *sp = smk_of_current(); 208 209 if (capable(CAP_MAC_OVERRIDE)) 210 return 0; 211 212 if (sp != smack_known_floor.smk_known) 213 rc = -EACCES; 214 215 return rc; 216 } 217 218 219 /* 220 * Superblock Hooks. 221 */ 222 223 /** 224 * smack_sb_alloc_security - allocate a superblock blob 225 * @sb: the superblock getting the blob 226 * 227 * Returns 0 on success or -ENOMEM on error. 228 */ 229 static int smack_sb_alloc_security(struct super_block *sb) 230 { 231 struct superblock_smack *sbsp; 232 233 sbsp = kzalloc(sizeof(struct superblock_smack), GFP_KERNEL); 234 235 if (sbsp == NULL) 236 return -ENOMEM; 237 238 sbsp->smk_root = smack_known_floor.smk_known; 239 sbsp->smk_default = smack_known_floor.smk_known; 240 sbsp->smk_floor = smack_known_floor.smk_known; 241 sbsp->smk_hat = smack_known_hat.smk_known; 242 sbsp->smk_initialized = 0; 243 spin_lock_init(&sbsp->smk_sblock); 244 245 sb->s_security = sbsp; 246 247 return 0; 248 } 249 250 /** 251 * smack_sb_free_security - free a superblock blob 252 * @sb: the superblock getting the blob 253 * 254 */ 255 static void smack_sb_free_security(struct super_block *sb) 256 { 257 kfree(sb->s_security); 258 sb->s_security = NULL; 259 } 260 261 /** 262 * smack_sb_copy_data - copy mount options data for processing 263 * @orig: where to start 264 * @smackopts: mount options string 265 * 266 * Returns 0 on success or -ENOMEM on error. 267 * 268 * Copy the Smack specific mount options out of the mount 269 * options list. 270 */ 271 static int smack_sb_copy_data(char *orig, char *smackopts) 272 { 273 char *cp, *commap, *otheropts, *dp; 274 275 otheropts = (char *)get_zeroed_page(GFP_KERNEL); 276 if (otheropts == NULL) 277 return -ENOMEM; 278 279 for (cp = orig, commap = orig; commap != NULL; cp = commap + 1) { 280 if (strstr(cp, SMK_FSDEFAULT) == cp) 281 dp = smackopts; 282 else if (strstr(cp, SMK_FSFLOOR) == cp) 283 dp = smackopts; 284 else if (strstr(cp, SMK_FSHAT) == cp) 285 dp = smackopts; 286 else if (strstr(cp, SMK_FSROOT) == cp) 287 dp = smackopts; 288 else 289 dp = otheropts; 290 291 commap = strchr(cp, ','); 292 if (commap != NULL) 293 *commap = '\0'; 294 295 if (*dp != '\0') 296 strcat(dp, ","); 297 strcat(dp, cp); 298 } 299 300 strcpy(orig, otheropts); 301 free_page((unsigned long)otheropts); 302 303 return 0; 304 } 305 306 /** 307 * smack_sb_kern_mount - Smack specific mount processing 308 * @sb: the file system superblock 309 * @flags: the mount flags 310 * @data: the smack mount options 311 * 312 * Returns 0 on success, an error code on failure 313 */ 314 static int smack_sb_kern_mount(struct super_block *sb, int flags, void *data) 315 { 316 struct dentry *root = sb->s_root; 317 struct inode *inode = root->d_inode; 318 struct superblock_smack *sp = sb->s_security; 319 struct inode_smack *isp; 320 char *op; 321 char *commap; 322 char *nsp; 323 324 spin_lock(&sp->smk_sblock); 325 if (sp->smk_initialized != 0) { 326 spin_unlock(&sp->smk_sblock); 327 return 0; 328 } 329 sp->smk_initialized = 1; 330 spin_unlock(&sp->smk_sblock); 331 332 for (op = data; op != NULL; op = commap) { 333 commap = strchr(op, ','); 334 if (commap != NULL) 335 *commap++ = '\0'; 336 337 if (strncmp(op, SMK_FSHAT, strlen(SMK_FSHAT)) == 0) { 338 op += strlen(SMK_FSHAT); 339 nsp = smk_import(op, 0); 340 if (nsp != NULL) 341 sp->smk_hat = nsp; 342 } else if (strncmp(op, SMK_FSFLOOR, strlen(SMK_FSFLOOR)) == 0) { 343 op += strlen(SMK_FSFLOOR); 344 nsp = smk_import(op, 0); 345 if (nsp != NULL) 346 sp->smk_floor = nsp; 347 } else if (strncmp(op, SMK_FSDEFAULT, 348 strlen(SMK_FSDEFAULT)) == 0) { 349 op += strlen(SMK_FSDEFAULT); 350 nsp = smk_import(op, 0); 351 if (nsp != NULL) 352 sp->smk_default = nsp; 353 } else if (strncmp(op, SMK_FSROOT, strlen(SMK_FSROOT)) == 0) { 354 op += strlen(SMK_FSROOT); 355 nsp = smk_import(op, 0); 356 if (nsp != NULL) 357 sp->smk_root = nsp; 358 } 359 } 360 361 /* 362 * Initialize the root inode. 363 */ 364 isp = inode->i_security; 365 if (isp == NULL) 366 inode->i_security = new_inode_smack(sp->smk_root); 367 else 368 isp->smk_inode = sp->smk_root; 369 370 return 0; 371 } 372 373 /** 374 * smack_sb_statfs - Smack check on statfs 375 * @dentry: identifies the file system in question 376 * 377 * Returns 0 if current can read the floor of the filesystem, 378 * and error code otherwise 379 */ 380 static int smack_sb_statfs(struct dentry *dentry) 381 { 382 struct superblock_smack *sbp = dentry->d_sb->s_security; 383 int rc; 384 struct smk_audit_info ad; 385 386 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); 387 smk_ad_setfield_u_fs_path_dentry(&ad, dentry); 388 389 rc = smk_curacc(sbp->smk_floor, MAY_READ, &ad); 390 return rc; 391 } 392 393 /** 394 * smack_sb_mount - Smack check for mounting 395 * @dev_name: unused 396 * @path: mount point 397 * @type: unused 398 * @flags: unused 399 * @data: unused 400 * 401 * Returns 0 if current can write the floor of the filesystem 402 * being mounted on, an error code otherwise. 403 */ 404 static int smack_sb_mount(char *dev_name, struct path *path, 405 char *type, unsigned long flags, void *data) 406 { 407 struct superblock_smack *sbp = path->mnt->mnt_sb->s_security; 408 struct smk_audit_info ad; 409 410 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH); 411 smk_ad_setfield_u_fs_path(&ad, *path); 412 413 return smk_curacc(sbp->smk_floor, MAY_WRITE, &ad); 414 } 415 416 /** 417 * smack_sb_umount - Smack check for unmounting 418 * @mnt: file system to unmount 419 * @flags: unused 420 * 421 * Returns 0 if current can write the floor of the filesystem 422 * being unmounted, an error code otherwise. 423 */ 424 static int smack_sb_umount(struct vfsmount *mnt, int flags) 425 { 426 struct superblock_smack *sbp; 427 struct smk_audit_info ad; 428 struct path path; 429 430 path.dentry = mnt->mnt_root; 431 path.mnt = mnt; 432 433 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH); 434 smk_ad_setfield_u_fs_path(&ad, path); 435 436 sbp = mnt->mnt_sb->s_security; 437 return smk_curacc(sbp->smk_floor, MAY_WRITE, &ad); 438 } 439 440 /* 441 * BPRM hooks 442 */ 443 444 static int smack_bprm_set_creds(struct linux_binprm *bprm) 445 { 446 struct task_smack *tsp = bprm->cred->security; 447 struct inode_smack *isp; 448 struct dentry *dp; 449 int rc; 450 451 rc = cap_bprm_set_creds(bprm); 452 if (rc != 0) 453 return rc; 454 455 if (bprm->cred_prepared) 456 return 0; 457 458 if (bprm->file == NULL || bprm->file->f_dentry == NULL) 459 return 0; 460 461 dp = bprm->file->f_dentry; 462 463 if (dp->d_inode == NULL) 464 return 0; 465 466 isp = dp->d_inode->i_security; 467 468 if (isp->smk_task != NULL) 469 tsp->smk_task = isp->smk_task; 470 471 return 0; 472 } 473 474 /* 475 * Inode hooks 476 */ 477 478 /** 479 * smack_inode_alloc_security - allocate an inode blob 480 * @inode: the inode in need of a blob 481 * 482 * Returns 0 if it gets a blob, -ENOMEM otherwise 483 */ 484 static int smack_inode_alloc_security(struct inode *inode) 485 { 486 inode->i_security = new_inode_smack(smk_of_current()); 487 if (inode->i_security == NULL) 488 return -ENOMEM; 489 return 0; 490 } 491 492 /** 493 * smack_inode_free_security - free an inode blob 494 * @inode: the inode with a blob 495 * 496 * Clears the blob pointer in inode 497 */ 498 static void smack_inode_free_security(struct inode *inode) 499 { 500 kfree(inode->i_security); 501 inode->i_security = NULL; 502 } 503 504 /** 505 * smack_inode_init_security - copy out the smack from an inode 506 * @inode: the inode 507 * @dir: unused 508 * @qstr: unused 509 * @name: where to put the attribute name 510 * @value: where to put the attribute value 511 * @len: where to put the length of the attribute 512 * 513 * Returns 0 if it all works out, -ENOMEM if there's no memory 514 */ 515 static int smack_inode_init_security(struct inode *inode, struct inode *dir, 516 const struct qstr *qstr, char **name, 517 void **value, size_t *len) 518 { 519 char *isp = smk_of_inode(inode); 520 char *dsp = smk_of_inode(dir); 521 int may; 522 523 if (name) { 524 *name = kstrdup(XATTR_SMACK_SUFFIX, GFP_KERNEL); 525 if (*name == NULL) 526 return -ENOMEM; 527 } 528 529 if (value) { 530 rcu_read_lock(); 531 may = smk_access_entry(smk_of_current(), dsp, &smack_rule_list); 532 rcu_read_unlock(); 533 534 /* 535 * If the access rule allows transmutation and 536 * the directory requests transmutation then 537 * by all means transmute. 538 */ 539 if (may > 0 && ((may & MAY_TRANSMUTE) != 0) && 540 smk_inode_transmutable(dir)) 541 isp = dsp; 542 543 *value = kstrdup(isp, GFP_KERNEL); 544 if (*value == NULL) 545 return -ENOMEM; 546 } 547 548 if (len) 549 *len = strlen(isp) + 1; 550 551 return 0; 552 } 553 554 /** 555 * smack_inode_link - Smack check on link 556 * @old_dentry: the existing object 557 * @dir: unused 558 * @new_dentry: the new object 559 * 560 * Returns 0 if access is permitted, an error code otherwise 561 */ 562 static int smack_inode_link(struct dentry *old_dentry, struct inode *dir, 563 struct dentry *new_dentry) 564 { 565 char *isp; 566 struct smk_audit_info ad; 567 int rc; 568 569 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); 570 smk_ad_setfield_u_fs_path_dentry(&ad, old_dentry); 571 572 isp = smk_of_inode(old_dentry->d_inode); 573 rc = smk_curacc(isp, MAY_WRITE, &ad); 574 575 if (rc == 0 && new_dentry->d_inode != NULL) { 576 isp = smk_of_inode(new_dentry->d_inode); 577 smk_ad_setfield_u_fs_path_dentry(&ad, new_dentry); 578 rc = smk_curacc(isp, MAY_WRITE, &ad); 579 } 580 581 return rc; 582 } 583 584 /** 585 * smack_inode_unlink - Smack check on inode deletion 586 * @dir: containing directory object 587 * @dentry: file to unlink 588 * 589 * Returns 0 if current can write the containing directory 590 * and the object, error code otherwise 591 */ 592 static int smack_inode_unlink(struct inode *dir, struct dentry *dentry) 593 { 594 struct inode *ip = dentry->d_inode; 595 struct smk_audit_info ad; 596 int rc; 597 598 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); 599 smk_ad_setfield_u_fs_path_dentry(&ad, dentry); 600 601 /* 602 * You need write access to the thing you're unlinking 603 */ 604 rc = smk_curacc(smk_of_inode(ip), MAY_WRITE, &ad); 605 if (rc == 0) { 606 /* 607 * You also need write access to the containing directory 608 */ 609 smk_ad_setfield_u_fs_path_dentry(&ad, NULL); 610 smk_ad_setfield_u_fs_inode(&ad, dir); 611 rc = smk_curacc(smk_of_inode(dir), MAY_WRITE, &ad); 612 } 613 return rc; 614 } 615 616 /** 617 * smack_inode_rmdir - Smack check on directory deletion 618 * @dir: containing directory object 619 * @dentry: directory to unlink 620 * 621 * Returns 0 if current can write the containing directory 622 * and the directory, error code otherwise 623 */ 624 static int smack_inode_rmdir(struct inode *dir, struct dentry *dentry) 625 { 626 struct smk_audit_info ad; 627 int rc; 628 629 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); 630 smk_ad_setfield_u_fs_path_dentry(&ad, dentry); 631 632 /* 633 * You need write access to the thing you're removing 634 */ 635 rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE, &ad); 636 if (rc == 0) { 637 /* 638 * You also need write access to the containing directory 639 */ 640 smk_ad_setfield_u_fs_path_dentry(&ad, NULL); 641 smk_ad_setfield_u_fs_inode(&ad, dir); 642 rc = smk_curacc(smk_of_inode(dir), MAY_WRITE, &ad); 643 } 644 645 return rc; 646 } 647 648 /** 649 * smack_inode_rename - Smack check on rename 650 * @old_inode: the old directory 651 * @old_dentry: unused 652 * @new_inode: the new directory 653 * @new_dentry: unused 654 * 655 * Read and write access is required on both the old and 656 * new directories. 657 * 658 * Returns 0 if access is permitted, an error code otherwise 659 */ 660 static int smack_inode_rename(struct inode *old_inode, 661 struct dentry *old_dentry, 662 struct inode *new_inode, 663 struct dentry *new_dentry) 664 { 665 int rc; 666 char *isp; 667 struct smk_audit_info ad; 668 669 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); 670 smk_ad_setfield_u_fs_path_dentry(&ad, old_dentry); 671 672 isp = smk_of_inode(old_dentry->d_inode); 673 rc = smk_curacc(isp, MAY_READWRITE, &ad); 674 675 if (rc == 0 && new_dentry->d_inode != NULL) { 676 isp = smk_of_inode(new_dentry->d_inode); 677 smk_ad_setfield_u_fs_path_dentry(&ad, new_dentry); 678 rc = smk_curacc(isp, MAY_READWRITE, &ad); 679 } 680 return rc; 681 } 682 683 /** 684 * smack_inode_permission - Smack version of permission() 685 * @inode: the inode in question 686 * @mask: the access requested 687 * 688 * This is the important Smack hook. 689 * 690 * Returns 0 if access is permitted, -EACCES otherwise 691 */ 692 static int smack_inode_permission(struct inode *inode, int mask) 693 { 694 struct smk_audit_info ad; 695 int no_block = mask & MAY_NOT_BLOCK; 696 697 mask &= (MAY_READ|MAY_WRITE|MAY_EXEC|MAY_APPEND); 698 /* 699 * No permission to check. Existence test. Yup, it's there. 700 */ 701 if (mask == 0) 702 return 0; 703 704 /* May be droppable after audit */ 705 if (no_block) 706 return -ECHILD; 707 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_INODE); 708 smk_ad_setfield_u_fs_inode(&ad, inode); 709 return smk_curacc(smk_of_inode(inode), mask, &ad); 710 } 711 712 /** 713 * smack_inode_setattr - Smack check for setting attributes 714 * @dentry: the object 715 * @iattr: for the force flag 716 * 717 * Returns 0 if access is permitted, an error code otherwise 718 */ 719 static int smack_inode_setattr(struct dentry *dentry, struct iattr *iattr) 720 { 721 struct smk_audit_info ad; 722 /* 723 * Need to allow for clearing the setuid bit. 724 */ 725 if (iattr->ia_valid & ATTR_FORCE) 726 return 0; 727 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); 728 smk_ad_setfield_u_fs_path_dentry(&ad, dentry); 729 730 return smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE, &ad); 731 } 732 733 /** 734 * smack_inode_getattr - Smack check for getting attributes 735 * @mnt: unused 736 * @dentry: the object 737 * 738 * Returns 0 if access is permitted, an error code otherwise 739 */ 740 static int smack_inode_getattr(struct vfsmount *mnt, struct dentry *dentry) 741 { 742 struct smk_audit_info ad; 743 struct path path; 744 745 path.dentry = dentry; 746 path.mnt = mnt; 747 748 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH); 749 smk_ad_setfield_u_fs_path(&ad, path); 750 return smk_curacc(smk_of_inode(dentry->d_inode), MAY_READ, &ad); 751 } 752 753 /** 754 * smack_inode_setxattr - Smack check for setting xattrs 755 * @dentry: the object 756 * @name: name of the attribute 757 * @value: unused 758 * @size: unused 759 * @flags: unused 760 * 761 * This protects the Smack attribute explicitly. 762 * 763 * Returns 0 if access is permitted, an error code otherwise 764 */ 765 static int smack_inode_setxattr(struct dentry *dentry, const char *name, 766 const void *value, size_t size, int flags) 767 { 768 struct smk_audit_info ad; 769 int rc = 0; 770 771 if (strcmp(name, XATTR_NAME_SMACK) == 0 || 772 strcmp(name, XATTR_NAME_SMACKIPIN) == 0 || 773 strcmp(name, XATTR_NAME_SMACKIPOUT) == 0 || 774 strcmp(name, XATTR_NAME_SMACKEXEC) == 0 || 775 strcmp(name, XATTR_NAME_SMACKMMAP) == 0) { 776 if (!capable(CAP_MAC_ADMIN)) 777 rc = -EPERM; 778 /* 779 * check label validity here so import wont fail on 780 * post_setxattr 781 */ 782 if (size == 0 || size >= SMK_LABELLEN || 783 smk_import(value, size) == NULL) 784 rc = -EINVAL; 785 } else if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0) { 786 if (!capable(CAP_MAC_ADMIN)) 787 rc = -EPERM; 788 if (size != TRANS_TRUE_SIZE || 789 strncmp(value, TRANS_TRUE, TRANS_TRUE_SIZE) != 0) 790 rc = -EINVAL; 791 } else 792 rc = cap_inode_setxattr(dentry, name, value, size, flags); 793 794 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); 795 smk_ad_setfield_u_fs_path_dentry(&ad, dentry); 796 797 if (rc == 0) 798 rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE, &ad); 799 800 return rc; 801 } 802 803 /** 804 * smack_inode_post_setxattr - Apply the Smack update approved above 805 * @dentry: object 806 * @name: attribute name 807 * @value: attribute value 808 * @size: attribute size 809 * @flags: unused 810 * 811 * Set the pointer in the inode blob to the entry found 812 * in the master label list. 813 */ 814 static void smack_inode_post_setxattr(struct dentry *dentry, const char *name, 815 const void *value, size_t size, int flags) 816 { 817 char *nsp; 818 struct inode_smack *isp = dentry->d_inode->i_security; 819 820 if (strcmp(name, XATTR_NAME_SMACK) == 0) { 821 nsp = smk_import(value, size); 822 if (nsp != NULL) 823 isp->smk_inode = nsp; 824 else 825 isp->smk_inode = smack_known_invalid.smk_known; 826 } else if (strcmp(name, XATTR_NAME_SMACKEXEC) == 0) { 827 nsp = smk_import(value, size); 828 if (nsp != NULL) 829 isp->smk_task = nsp; 830 else 831 isp->smk_task = smack_known_invalid.smk_known; 832 } else if (strcmp(name, XATTR_NAME_SMACKMMAP) == 0) { 833 nsp = smk_import(value, size); 834 if (nsp != NULL) 835 isp->smk_mmap = nsp; 836 else 837 isp->smk_mmap = smack_known_invalid.smk_known; 838 } else if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0) 839 isp->smk_flags |= SMK_INODE_TRANSMUTE; 840 841 return; 842 } 843 844 /* 845 * smack_inode_getxattr - Smack check on getxattr 846 * @dentry: the object 847 * @name: unused 848 * 849 * Returns 0 if access is permitted, an error code otherwise 850 */ 851 static int smack_inode_getxattr(struct dentry *dentry, const char *name) 852 { 853 struct smk_audit_info ad; 854 855 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); 856 smk_ad_setfield_u_fs_path_dentry(&ad, dentry); 857 858 return smk_curacc(smk_of_inode(dentry->d_inode), MAY_READ, &ad); 859 } 860 861 /* 862 * smack_inode_removexattr - Smack check on removexattr 863 * @dentry: the object 864 * @name: name of the attribute 865 * 866 * Removing the Smack attribute requires CAP_MAC_ADMIN 867 * 868 * Returns 0 if access is permitted, an error code otherwise 869 */ 870 static int smack_inode_removexattr(struct dentry *dentry, const char *name) 871 { 872 struct inode_smack *isp; 873 struct smk_audit_info ad; 874 int rc = 0; 875 876 if (strcmp(name, XATTR_NAME_SMACK) == 0 || 877 strcmp(name, XATTR_NAME_SMACKIPIN) == 0 || 878 strcmp(name, XATTR_NAME_SMACKIPOUT) == 0 || 879 strcmp(name, XATTR_NAME_SMACKEXEC) == 0 || 880 strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0 || 881 strcmp(name, XATTR_NAME_SMACKMMAP)) { 882 if (!capable(CAP_MAC_ADMIN)) 883 rc = -EPERM; 884 } else 885 rc = cap_inode_removexattr(dentry, name); 886 887 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); 888 smk_ad_setfield_u_fs_path_dentry(&ad, dentry); 889 if (rc == 0) 890 rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE, &ad); 891 892 if (rc == 0) { 893 isp = dentry->d_inode->i_security; 894 isp->smk_task = NULL; 895 isp->smk_mmap = NULL; 896 } 897 898 return rc; 899 } 900 901 /** 902 * smack_inode_getsecurity - get smack xattrs 903 * @inode: the object 904 * @name: attribute name 905 * @buffer: where to put the result 906 * @alloc: unused 907 * 908 * Returns the size of the attribute or an error code 909 */ 910 static int smack_inode_getsecurity(const struct inode *inode, 911 const char *name, void **buffer, 912 bool alloc) 913 { 914 struct socket_smack *ssp; 915 struct socket *sock; 916 struct super_block *sbp; 917 struct inode *ip = (struct inode *)inode; 918 char *isp; 919 int ilen; 920 int rc = 0; 921 922 if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) { 923 isp = smk_of_inode(inode); 924 ilen = strlen(isp) + 1; 925 *buffer = isp; 926 return ilen; 927 } 928 929 /* 930 * The rest of the Smack xattrs are only on sockets. 931 */ 932 sbp = ip->i_sb; 933 if (sbp->s_magic != SOCKFS_MAGIC) 934 return -EOPNOTSUPP; 935 936 sock = SOCKET_I(ip); 937 if (sock == NULL || sock->sk == NULL) 938 return -EOPNOTSUPP; 939 940 ssp = sock->sk->sk_security; 941 942 if (strcmp(name, XATTR_SMACK_IPIN) == 0) 943 isp = ssp->smk_in; 944 else if (strcmp(name, XATTR_SMACK_IPOUT) == 0) 945 isp = ssp->smk_out; 946 else 947 return -EOPNOTSUPP; 948 949 ilen = strlen(isp) + 1; 950 if (rc == 0) { 951 *buffer = isp; 952 rc = ilen; 953 } 954 955 return rc; 956 } 957 958 959 /** 960 * smack_inode_listsecurity - list the Smack attributes 961 * @inode: the object 962 * @buffer: where they go 963 * @buffer_size: size of buffer 964 * 965 * Returns 0 on success, -EINVAL otherwise 966 */ 967 static int smack_inode_listsecurity(struct inode *inode, char *buffer, 968 size_t buffer_size) 969 { 970 int len = strlen(XATTR_NAME_SMACK); 971 972 if (buffer != NULL && len <= buffer_size) { 973 memcpy(buffer, XATTR_NAME_SMACK, len); 974 return len; 975 } 976 return -EINVAL; 977 } 978 979 /** 980 * smack_inode_getsecid - Extract inode's security id 981 * @inode: inode to extract the info from 982 * @secid: where result will be saved 983 */ 984 static void smack_inode_getsecid(const struct inode *inode, u32 *secid) 985 { 986 struct inode_smack *isp = inode->i_security; 987 988 *secid = smack_to_secid(isp->smk_inode); 989 } 990 991 /* 992 * File Hooks 993 */ 994 995 /** 996 * smack_file_permission - Smack check on file operations 997 * @file: unused 998 * @mask: unused 999 * 1000 * Returns 0 1001 * 1002 * Should access checks be done on each read or write? 1003 * UNICOS and SELinux say yes. 1004 * Trusted Solaris, Trusted Irix, and just about everyone else says no. 1005 * 1006 * I'll say no for now. Smack does not do the frequent 1007 * label changing that SELinux does. 1008 */ 1009 static int smack_file_permission(struct file *file, int mask) 1010 { 1011 return 0; 1012 } 1013 1014 /** 1015 * smack_file_alloc_security - assign a file security blob 1016 * @file: the object 1017 * 1018 * The security blob for a file is a pointer to the master 1019 * label list, so no allocation is done. 1020 * 1021 * Returns 0 1022 */ 1023 static int smack_file_alloc_security(struct file *file) 1024 { 1025 file->f_security = smk_of_current(); 1026 return 0; 1027 } 1028 1029 /** 1030 * smack_file_free_security - clear a file security blob 1031 * @file: the object 1032 * 1033 * The security blob for a file is a pointer to the master 1034 * label list, so no memory is freed. 1035 */ 1036 static void smack_file_free_security(struct file *file) 1037 { 1038 file->f_security = NULL; 1039 } 1040 1041 /** 1042 * smack_file_ioctl - Smack check on ioctls 1043 * @file: the object 1044 * @cmd: what to do 1045 * @arg: unused 1046 * 1047 * Relies heavily on the correct use of the ioctl command conventions. 1048 * 1049 * Returns 0 if allowed, error code otherwise 1050 */ 1051 static int smack_file_ioctl(struct file *file, unsigned int cmd, 1052 unsigned long arg) 1053 { 1054 int rc = 0; 1055 struct smk_audit_info ad; 1056 1057 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH); 1058 smk_ad_setfield_u_fs_path(&ad, file->f_path); 1059 1060 if (_IOC_DIR(cmd) & _IOC_WRITE) 1061 rc = smk_curacc(file->f_security, MAY_WRITE, &ad); 1062 1063 if (rc == 0 && (_IOC_DIR(cmd) & _IOC_READ)) 1064 rc = smk_curacc(file->f_security, MAY_READ, &ad); 1065 1066 return rc; 1067 } 1068 1069 /** 1070 * smack_file_lock - Smack check on file locking 1071 * @file: the object 1072 * @cmd: unused 1073 * 1074 * Returns 0 if current has write access, error code otherwise 1075 */ 1076 static int smack_file_lock(struct file *file, unsigned int cmd) 1077 { 1078 struct smk_audit_info ad; 1079 1080 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH); 1081 smk_ad_setfield_u_fs_path(&ad, file->f_path); 1082 return smk_curacc(file->f_security, MAY_WRITE, &ad); 1083 } 1084 1085 /** 1086 * smack_file_fcntl - Smack check on fcntl 1087 * @file: the object 1088 * @cmd: what action to check 1089 * @arg: unused 1090 * 1091 * Returns 0 if current has access, error code otherwise 1092 */ 1093 static int smack_file_fcntl(struct file *file, unsigned int cmd, 1094 unsigned long arg) 1095 { 1096 struct smk_audit_info ad; 1097 int rc; 1098 1099 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH); 1100 smk_ad_setfield_u_fs_path(&ad, file->f_path); 1101 1102 switch (cmd) { 1103 case F_DUPFD: 1104 case F_GETFD: 1105 case F_GETFL: 1106 case F_GETLK: 1107 case F_GETOWN: 1108 case F_GETSIG: 1109 rc = smk_curacc(file->f_security, MAY_READ, &ad); 1110 break; 1111 case F_SETFD: 1112 case F_SETFL: 1113 case F_SETLK: 1114 case F_SETLKW: 1115 case F_SETOWN: 1116 case F_SETSIG: 1117 rc = smk_curacc(file->f_security, MAY_WRITE, &ad); 1118 break; 1119 default: 1120 rc = smk_curacc(file->f_security, MAY_READWRITE, &ad); 1121 } 1122 1123 return rc; 1124 } 1125 1126 /** 1127 * smack_file_mmap : 1128 * Check permissions for a mmap operation. The @file may be NULL, e.g. 1129 * if mapping anonymous memory. 1130 * @file contains the file structure for file to map (may be NULL). 1131 * @reqprot contains the protection requested by the application. 1132 * @prot contains the protection that will be applied by the kernel. 1133 * @flags contains the operational flags. 1134 * Return 0 if permission is granted. 1135 */ 1136 static int smack_file_mmap(struct file *file, 1137 unsigned long reqprot, unsigned long prot, 1138 unsigned long flags, unsigned long addr, 1139 unsigned long addr_only) 1140 { 1141 struct smack_rule *srp; 1142 struct task_smack *tsp; 1143 char *sp; 1144 char *msmack; 1145 char *osmack; 1146 struct inode_smack *isp; 1147 struct dentry *dp; 1148 int may; 1149 int mmay; 1150 int tmay; 1151 int rc; 1152 1153 /* do DAC check on address space usage */ 1154 rc = cap_file_mmap(file, reqprot, prot, flags, addr, addr_only); 1155 if (rc || addr_only) 1156 return rc; 1157 1158 if (file == NULL || file->f_dentry == NULL) 1159 return 0; 1160 1161 dp = file->f_dentry; 1162 1163 if (dp->d_inode == NULL) 1164 return 0; 1165 1166 isp = dp->d_inode->i_security; 1167 if (isp->smk_mmap == NULL) 1168 return 0; 1169 msmack = isp->smk_mmap; 1170 1171 tsp = current_security(); 1172 sp = smk_of_current(); 1173 rc = 0; 1174 1175 rcu_read_lock(); 1176 /* 1177 * For each Smack rule associated with the subject 1178 * label verify that the SMACK64MMAP also has access 1179 * to that rule's object label. 1180 * 1181 * Because neither of the labels comes 1182 * from the networking code it is sufficient 1183 * to compare pointers. 1184 */ 1185 list_for_each_entry_rcu(srp, &smack_rule_list, list) { 1186 if (srp->smk_subject != sp) 1187 continue; 1188 1189 osmack = srp->smk_object; 1190 /* 1191 * Matching labels always allows access. 1192 */ 1193 if (msmack == osmack) 1194 continue; 1195 /* 1196 * If there is a matching local rule take 1197 * that into account as well. 1198 */ 1199 may = smk_access_entry(srp->smk_subject, osmack, 1200 &tsp->smk_rules); 1201 if (may == -ENOENT) 1202 may = srp->smk_access; 1203 else 1204 may &= srp->smk_access; 1205 /* 1206 * If may is zero the SMACK64MMAP subject can't 1207 * possibly have less access. 1208 */ 1209 if (may == 0) 1210 continue; 1211 1212 /* 1213 * Fetch the global list entry. 1214 * If there isn't one a SMACK64MMAP subject 1215 * can't have as much access as current. 1216 */ 1217 mmay = smk_access_entry(msmack, osmack, &smack_rule_list); 1218 if (mmay == -ENOENT) { 1219 rc = -EACCES; 1220 break; 1221 } 1222 /* 1223 * If there is a local entry it modifies the 1224 * potential access, too. 1225 */ 1226 tmay = smk_access_entry(msmack, osmack, &tsp->smk_rules); 1227 if (tmay != -ENOENT) 1228 mmay &= tmay; 1229 1230 /* 1231 * If there is any access available to current that is 1232 * not available to a SMACK64MMAP subject 1233 * deny access. 1234 */ 1235 if ((may | mmay) != mmay) { 1236 rc = -EACCES; 1237 break; 1238 } 1239 } 1240 1241 rcu_read_unlock(); 1242 1243 return rc; 1244 } 1245 1246 /** 1247 * smack_file_set_fowner - set the file security blob value 1248 * @file: object in question 1249 * 1250 * Returns 0 1251 * Further research may be required on this one. 1252 */ 1253 static int smack_file_set_fowner(struct file *file) 1254 { 1255 file->f_security = smk_of_current(); 1256 return 0; 1257 } 1258 1259 /** 1260 * smack_file_send_sigiotask - Smack on sigio 1261 * @tsk: The target task 1262 * @fown: the object the signal come from 1263 * @signum: unused 1264 * 1265 * Allow a privileged task to get signals even if it shouldn't 1266 * 1267 * Returns 0 if a subject with the object's smack could 1268 * write to the task, an error code otherwise. 1269 */ 1270 static int smack_file_send_sigiotask(struct task_struct *tsk, 1271 struct fown_struct *fown, int signum) 1272 { 1273 struct file *file; 1274 int rc; 1275 char *tsp = smk_of_task(tsk->cred->security); 1276 struct smk_audit_info ad; 1277 1278 /* 1279 * struct fown_struct is never outside the context of a struct file 1280 */ 1281 file = container_of(fown, struct file, f_owner); 1282 1283 /* we don't log here as rc can be overriden */ 1284 rc = smk_access(file->f_security, tsp, MAY_WRITE, NULL); 1285 if (rc != 0 && has_capability(tsk, CAP_MAC_OVERRIDE)) 1286 rc = 0; 1287 1288 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK); 1289 smk_ad_setfield_u_tsk(&ad, tsk); 1290 smack_log(file->f_security, tsp, MAY_WRITE, rc, &ad); 1291 return rc; 1292 } 1293 1294 /** 1295 * smack_file_receive - Smack file receive check 1296 * @file: the object 1297 * 1298 * Returns 0 if current has access, error code otherwise 1299 */ 1300 static int smack_file_receive(struct file *file) 1301 { 1302 int may = 0; 1303 struct smk_audit_info ad; 1304 1305 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK); 1306 smk_ad_setfield_u_fs_path(&ad, file->f_path); 1307 /* 1308 * This code relies on bitmasks. 1309 */ 1310 if (file->f_mode & FMODE_READ) 1311 may = MAY_READ; 1312 if (file->f_mode & FMODE_WRITE) 1313 may |= MAY_WRITE; 1314 1315 return smk_curacc(file->f_security, may, &ad); 1316 } 1317 1318 /* 1319 * Task hooks 1320 */ 1321 1322 /** 1323 * smack_cred_alloc_blank - "allocate" blank task-level security credentials 1324 * @new: the new credentials 1325 * @gfp: the atomicity of any memory allocations 1326 * 1327 * Prepare a blank set of credentials for modification. This must allocate all 1328 * the memory the LSM module might require such that cred_transfer() can 1329 * complete without error. 1330 */ 1331 static int smack_cred_alloc_blank(struct cred *cred, gfp_t gfp) 1332 { 1333 struct task_smack *tsp; 1334 1335 tsp = new_task_smack(NULL, NULL, gfp); 1336 if (tsp == NULL) 1337 return -ENOMEM; 1338 1339 cred->security = tsp; 1340 1341 return 0; 1342 } 1343 1344 1345 /** 1346 * smack_cred_free - "free" task-level security credentials 1347 * @cred: the credentials in question 1348 * 1349 */ 1350 static void smack_cred_free(struct cred *cred) 1351 { 1352 struct task_smack *tsp = cred->security; 1353 struct smack_rule *rp; 1354 struct list_head *l; 1355 struct list_head *n; 1356 1357 if (tsp == NULL) 1358 return; 1359 cred->security = NULL; 1360 1361 list_for_each_safe(l, n, &tsp->smk_rules) { 1362 rp = list_entry(l, struct smack_rule, list); 1363 list_del(&rp->list); 1364 kfree(rp); 1365 } 1366 kfree(tsp); 1367 } 1368 1369 /** 1370 * smack_cred_prepare - prepare new set of credentials for modification 1371 * @new: the new credentials 1372 * @old: the original credentials 1373 * @gfp: the atomicity of any memory allocations 1374 * 1375 * Prepare a new set of credentials for modification. 1376 */ 1377 static int smack_cred_prepare(struct cred *new, const struct cred *old, 1378 gfp_t gfp) 1379 { 1380 struct task_smack *old_tsp = old->security; 1381 struct task_smack *new_tsp; 1382 int rc; 1383 1384 new_tsp = new_task_smack(old_tsp->smk_task, old_tsp->smk_task, gfp); 1385 if (new_tsp == NULL) 1386 return -ENOMEM; 1387 1388 rc = smk_copy_rules(&new_tsp->smk_rules, &old_tsp->smk_rules, gfp); 1389 if (rc != 0) 1390 return rc; 1391 1392 new->security = new_tsp; 1393 return 0; 1394 } 1395 1396 /** 1397 * smack_cred_transfer - Transfer the old credentials to the new credentials 1398 * @new: the new credentials 1399 * @old: the original credentials 1400 * 1401 * Fill in a set of blank credentials from another set of credentials. 1402 */ 1403 static void smack_cred_transfer(struct cred *new, const struct cred *old) 1404 { 1405 struct task_smack *old_tsp = old->security; 1406 struct task_smack *new_tsp = new->security; 1407 1408 new_tsp->smk_task = old_tsp->smk_task; 1409 new_tsp->smk_forked = old_tsp->smk_task; 1410 mutex_init(&new_tsp->smk_rules_lock); 1411 INIT_LIST_HEAD(&new_tsp->smk_rules); 1412 1413 1414 /* cbs copy rule list */ 1415 } 1416 1417 /** 1418 * smack_kernel_act_as - Set the subjective context in a set of credentials 1419 * @new: points to the set of credentials to be modified. 1420 * @secid: specifies the security ID to be set 1421 * 1422 * Set the security data for a kernel service. 1423 */ 1424 static int smack_kernel_act_as(struct cred *new, u32 secid) 1425 { 1426 struct task_smack *new_tsp = new->security; 1427 char *smack = smack_from_secid(secid); 1428 1429 if (smack == NULL) 1430 return -EINVAL; 1431 1432 new_tsp->smk_task = smack; 1433 return 0; 1434 } 1435 1436 /** 1437 * smack_kernel_create_files_as - Set the file creation label in a set of creds 1438 * @new: points to the set of credentials to be modified 1439 * @inode: points to the inode to use as a reference 1440 * 1441 * Set the file creation context in a set of credentials to the same 1442 * as the objective context of the specified inode 1443 */ 1444 static int smack_kernel_create_files_as(struct cred *new, 1445 struct inode *inode) 1446 { 1447 struct inode_smack *isp = inode->i_security; 1448 struct task_smack *tsp = new->security; 1449 1450 tsp->smk_forked = isp->smk_inode; 1451 tsp->smk_task = isp->smk_inode; 1452 return 0; 1453 } 1454 1455 /** 1456 * smk_curacc_on_task - helper to log task related access 1457 * @p: the task object 1458 * @access : the access requested 1459 * 1460 * Return 0 if access is permitted 1461 */ 1462 static int smk_curacc_on_task(struct task_struct *p, int access) 1463 { 1464 struct smk_audit_info ad; 1465 1466 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK); 1467 smk_ad_setfield_u_tsk(&ad, p); 1468 return smk_curacc(smk_of_task(task_security(p)), access, &ad); 1469 } 1470 1471 /** 1472 * smack_task_setpgid - Smack check on setting pgid 1473 * @p: the task object 1474 * @pgid: unused 1475 * 1476 * Return 0 if write access is permitted 1477 */ 1478 static int smack_task_setpgid(struct task_struct *p, pid_t pgid) 1479 { 1480 return smk_curacc_on_task(p, MAY_WRITE); 1481 } 1482 1483 /** 1484 * smack_task_getpgid - Smack access check for getpgid 1485 * @p: the object task 1486 * 1487 * Returns 0 if current can read the object task, error code otherwise 1488 */ 1489 static int smack_task_getpgid(struct task_struct *p) 1490 { 1491 return smk_curacc_on_task(p, MAY_READ); 1492 } 1493 1494 /** 1495 * smack_task_getsid - Smack access check for getsid 1496 * @p: the object task 1497 * 1498 * Returns 0 if current can read the object task, error code otherwise 1499 */ 1500 static int smack_task_getsid(struct task_struct *p) 1501 { 1502 return smk_curacc_on_task(p, MAY_READ); 1503 } 1504 1505 /** 1506 * smack_task_getsecid - get the secid of the task 1507 * @p: the object task 1508 * @secid: where to put the result 1509 * 1510 * Sets the secid to contain a u32 version of the smack label. 1511 */ 1512 static void smack_task_getsecid(struct task_struct *p, u32 *secid) 1513 { 1514 *secid = smack_to_secid(smk_of_task(task_security(p))); 1515 } 1516 1517 /** 1518 * smack_task_setnice - Smack check on setting nice 1519 * @p: the task object 1520 * @nice: unused 1521 * 1522 * Return 0 if write access is permitted 1523 */ 1524 static int smack_task_setnice(struct task_struct *p, int nice) 1525 { 1526 int rc; 1527 1528 rc = cap_task_setnice(p, nice); 1529 if (rc == 0) 1530 rc = smk_curacc_on_task(p, MAY_WRITE); 1531 return rc; 1532 } 1533 1534 /** 1535 * smack_task_setioprio - Smack check on setting ioprio 1536 * @p: the task object 1537 * @ioprio: unused 1538 * 1539 * Return 0 if write access is permitted 1540 */ 1541 static int smack_task_setioprio(struct task_struct *p, int ioprio) 1542 { 1543 int rc; 1544 1545 rc = cap_task_setioprio(p, ioprio); 1546 if (rc == 0) 1547 rc = smk_curacc_on_task(p, MAY_WRITE); 1548 return rc; 1549 } 1550 1551 /** 1552 * smack_task_getioprio - Smack check on reading ioprio 1553 * @p: the task object 1554 * 1555 * Return 0 if read access is permitted 1556 */ 1557 static int smack_task_getioprio(struct task_struct *p) 1558 { 1559 return smk_curacc_on_task(p, MAY_READ); 1560 } 1561 1562 /** 1563 * smack_task_setscheduler - Smack check on setting scheduler 1564 * @p: the task object 1565 * @policy: unused 1566 * @lp: unused 1567 * 1568 * Return 0 if read access is permitted 1569 */ 1570 static int smack_task_setscheduler(struct task_struct *p) 1571 { 1572 int rc; 1573 1574 rc = cap_task_setscheduler(p); 1575 if (rc == 0) 1576 rc = smk_curacc_on_task(p, MAY_WRITE); 1577 return rc; 1578 } 1579 1580 /** 1581 * smack_task_getscheduler - Smack check on reading scheduler 1582 * @p: the task object 1583 * 1584 * Return 0 if read access is permitted 1585 */ 1586 static int smack_task_getscheduler(struct task_struct *p) 1587 { 1588 return smk_curacc_on_task(p, MAY_READ); 1589 } 1590 1591 /** 1592 * smack_task_movememory - Smack check on moving memory 1593 * @p: the task object 1594 * 1595 * Return 0 if write access is permitted 1596 */ 1597 static int smack_task_movememory(struct task_struct *p) 1598 { 1599 return smk_curacc_on_task(p, MAY_WRITE); 1600 } 1601 1602 /** 1603 * smack_task_kill - Smack check on signal delivery 1604 * @p: the task object 1605 * @info: unused 1606 * @sig: unused 1607 * @secid: identifies the smack to use in lieu of current's 1608 * 1609 * Return 0 if write access is permitted 1610 * 1611 * The secid behavior is an artifact of an SELinux hack 1612 * in the USB code. Someday it may go away. 1613 */ 1614 static int smack_task_kill(struct task_struct *p, struct siginfo *info, 1615 int sig, u32 secid) 1616 { 1617 struct smk_audit_info ad; 1618 1619 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK); 1620 smk_ad_setfield_u_tsk(&ad, p); 1621 /* 1622 * Sending a signal requires that the sender 1623 * can write the receiver. 1624 */ 1625 if (secid == 0) 1626 return smk_curacc(smk_of_task(task_security(p)), MAY_WRITE, 1627 &ad); 1628 /* 1629 * If the secid isn't 0 we're dealing with some USB IO 1630 * specific behavior. This is not clean. For one thing 1631 * we can't take privilege into account. 1632 */ 1633 return smk_access(smack_from_secid(secid), 1634 smk_of_task(task_security(p)), MAY_WRITE, &ad); 1635 } 1636 1637 /** 1638 * smack_task_wait - Smack access check for waiting 1639 * @p: task to wait for 1640 * 1641 * Returns 0 if current can wait for p, error code otherwise 1642 */ 1643 static int smack_task_wait(struct task_struct *p) 1644 { 1645 struct smk_audit_info ad; 1646 char *sp = smk_of_current(); 1647 char *tsp = smk_of_forked(task_security(p)); 1648 int rc; 1649 1650 /* we don't log here, we can be overriden */ 1651 rc = smk_access(tsp, sp, MAY_WRITE, NULL); 1652 if (rc == 0) 1653 goto out_log; 1654 1655 /* 1656 * Allow the operation to succeed if either task 1657 * has privilege to perform operations that might 1658 * account for the smack labels having gotten to 1659 * be different in the first place. 1660 * 1661 * This breaks the strict subject/object access 1662 * control ideal, taking the object's privilege 1663 * state into account in the decision as well as 1664 * the smack value. 1665 */ 1666 if (capable(CAP_MAC_OVERRIDE) || has_capability(p, CAP_MAC_OVERRIDE)) 1667 rc = 0; 1668 /* we log only if we didn't get overriden */ 1669 out_log: 1670 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK); 1671 smk_ad_setfield_u_tsk(&ad, p); 1672 smack_log(tsp, sp, MAY_WRITE, rc, &ad); 1673 return rc; 1674 } 1675 1676 /** 1677 * smack_task_to_inode - copy task smack into the inode blob 1678 * @p: task to copy from 1679 * @inode: inode to copy to 1680 * 1681 * Sets the smack pointer in the inode security blob 1682 */ 1683 static void smack_task_to_inode(struct task_struct *p, struct inode *inode) 1684 { 1685 struct inode_smack *isp = inode->i_security; 1686 isp->smk_inode = smk_of_task(task_security(p)); 1687 } 1688 1689 /* 1690 * Socket hooks. 1691 */ 1692 1693 /** 1694 * smack_sk_alloc_security - Allocate a socket blob 1695 * @sk: the socket 1696 * @family: unused 1697 * @gfp_flags: memory allocation flags 1698 * 1699 * Assign Smack pointers to current 1700 * 1701 * Returns 0 on success, -ENOMEM is there's no memory 1702 */ 1703 static int smack_sk_alloc_security(struct sock *sk, int family, gfp_t gfp_flags) 1704 { 1705 char *csp = smk_of_current(); 1706 struct socket_smack *ssp; 1707 1708 ssp = kzalloc(sizeof(struct socket_smack), gfp_flags); 1709 if (ssp == NULL) 1710 return -ENOMEM; 1711 1712 ssp->smk_in = csp; 1713 ssp->smk_out = csp; 1714 ssp->smk_packet[0] = '\0'; 1715 1716 sk->sk_security = ssp; 1717 1718 return 0; 1719 } 1720 1721 /** 1722 * smack_sk_free_security - Free a socket blob 1723 * @sk: the socket 1724 * 1725 * Clears the blob pointer 1726 */ 1727 static void smack_sk_free_security(struct sock *sk) 1728 { 1729 kfree(sk->sk_security); 1730 } 1731 1732 /** 1733 * smack_host_label - check host based restrictions 1734 * @sip: the object end 1735 * 1736 * looks for host based access restrictions 1737 * 1738 * This version will only be appropriate for really small sets of single label 1739 * hosts. The caller is responsible for ensuring that the RCU read lock is 1740 * taken before calling this function. 1741 * 1742 * Returns the label of the far end or NULL if it's not special. 1743 */ 1744 static char *smack_host_label(struct sockaddr_in *sip) 1745 { 1746 struct smk_netlbladdr *snp; 1747 struct in_addr *siap = &sip->sin_addr; 1748 1749 if (siap->s_addr == 0) 1750 return NULL; 1751 1752 list_for_each_entry_rcu(snp, &smk_netlbladdr_list, list) 1753 /* 1754 * we break after finding the first match because 1755 * the list is sorted from longest to shortest mask 1756 * so we have found the most specific match 1757 */ 1758 if ((&snp->smk_host.sin_addr)->s_addr == 1759 (siap->s_addr & (&snp->smk_mask)->s_addr)) { 1760 /* we have found the special CIPSO option */ 1761 if (snp->smk_label == smack_cipso_option) 1762 return NULL; 1763 return snp->smk_label; 1764 } 1765 1766 return NULL; 1767 } 1768 1769 /** 1770 * smack_set_catset - convert a capset to netlabel mls categories 1771 * @catset: the Smack categories 1772 * @sap: where to put the netlabel categories 1773 * 1774 * Allocates and fills attr.mls.cat 1775 */ 1776 static void smack_set_catset(char *catset, struct netlbl_lsm_secattr *sap) 1777 { 1778 unsigned char *cp; 1779 unsigned char m; 1780 int cat; 1781 int rc; 1782 int byte; 1783 1784 if (!catset) 1785 return; 1786 1787 sap->flags |= NETLBL_SECATTR_MLS_CAT; 1788 sap->attr.mls.cat = netlbl_secattr_catmap_alloc(GFP_ATOMIC); 1789 sap->attr.mls.cat->startbit = 0; 1790 1791 for (cat = 1, cp = catset, byte = 0; byte < SMK_LABELLEN; cp++, byte++) 1792 for (m = 0x80; m != 0; m >>= 1, cat++) { 1793 if ((m & *cp) == 0) 1794 continue; 1795 rc = netlbl_secattr_catmap_setbit(sap->attr.mls.cat, 1796 cat, GFP_ATOMIC); 1797 } 1798 } 1799 1800 /** 1801 * smack_to_secattr - fill a secattr from a smack value 1802 * @smack: the smack value 1803 * @nlsp: where the result goes 1804 * 1805 * Casey says that CIPSO is good enough for now. 1806 * It can be used to effect. 1807 * It can also be abused to effect when necessary. 1808 * Apologies to the TSIG group in general and GW in particular. 1809 */ 1810 static void smack_to_secattr(char *smack, struct netlbl_lsm_secattr *nlsp) 1811 { 1812 struct smack_cipso cipso; 1813 int rc; 1814 1815 nlsp->domain = smack; 1816 nlsp->flags = NETLBL_SECATTR_DOMAIN | NETLBL_SECATTR_MLS_LVL; 1817 1818 rc = smack_to_cipso(smack, &cipso); 1819 if (rc == 0) { 1820 nlsp->attr.mls.lvl = cipso.smk_level; 1821 smack_set_catset(cipso.smk_catset, nlsp); 1822 } else { 1823 nlsp->attr.mls.lvl = smack_cipso_direct; 1824 smack_set_catset(smack, nlsp); 1825 } 1826 } 1827 1828 /** 1829 * smack_netlabel - Set the secattr on a socket 1830 * @sk: the socket 1831 * @labeled: socket label scheme 1832 * 1833 * Convert the outbound smack value (smk_out) to a 1834 * secattr and attach it to the socket. 1835 * 1836 * Returns 0 on success or an error code 1837 */ 1838 static int smack_netlabel(struct sock *sk, int labeled) 1839 { 1840 struct socket_smack *ssp = sk->sk_security; 1841 struct netlbl_lsm_secattr secattr; 1842 int rc = 0; 1843 1844 /* 1845 * Usually the netlabel code will handle changing the 1846 * packet labeling based on the label. 1847 * The case of a single label host is different, because 1848 * a single label host should never get a labeled packet 1849 * even though the label is usually associated with a packet 1850 * label. 1851 */ 1852 local_bh_disable(); 1853 bh_lock_sock_nested(sk); 1854 1855 if (ssp->smk_out == smack_net_ambient || 1856 labeled == SMACK_UNLABELED_SOCKET) 1857 netlbl_sock_delattr(sk); 1858 else { 1859 netlbl_secattr_init(&secattr); 1860 smack_to_secattr(ssp->smk_out, &secattr); 1861 rc = netlbl_sock_setattr(sk, sk->sk_family, &secattr); 1862 netlbl_secattr_destroy(&secattr); 1863 } 1864 1865 bh_unlock_sock(sk); 1866 local_bh_enable(); 1867 1868 return rc; 1869 } 1870 1871 /** 1872 * smack_netlbel_send - Set the secattr on a socket and perform access checks 1873 * @sk: the socket 1874 * @sap: the destination address 1875 * 1876 * Set the correct secattr for the given socket based on the destination 1877 * address and perform any outbound access checks needed. 1878 * 1879 * Returns 0 on success or an error code. 1880 * 1881 */ 1882 static int smack_netlabel_send(struct sock *sk, struct sockaddr_in *sap) 1883 { 1884 int rc; 1885 int sk_lbl; 1886 char *hostsp; 1887 struct socket_smack *ssp = sk->sk_security; 1888 struct smk_audit_info ad; 1889 1890 rcu_read_lock(); 1891 hostsp = smack_host_label(sap); 1892 if (hostsp != NULL) { 1893 sk_lbl = SMACK_UNLABELED_SOCKET; 1894 #ifdef CONFIG_AUDIT 1895 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_NET); 1896 ad.a.u.net.family = sap->sin_family; 1897 ad.a.u.net.dport = sap->sin_port; 1898 ad.a.u.net.v4info.daddr = sap->sin_addr.s_addr; 1899 #endif 1900 rc = smk_access(ssp->smk_out, hostsp, MAY_WRITE, &ad); 1901 } else { 1902 sk_lbl = SMACK_CIPSO_SOCKET; 1903 rc = 0; 1904 } 1905 rcu_read_unlock(); 1906 if (rc != 0) 1907 return rc; 1908 1909 return smack_netlabel(sk, sk_lbl); 1910 } 1911 1912 /** 1913 * smack_inode_setsecurity - set smack xattrs 1914 * @inode: the object 1915 * @name: attribute name 1916 * @value: attribute value 1917 * @size: size of the attribute 1918 * @flags: unused 1919 * 1920 * Sets the named attribute in the appropriate blob 1921 * 1922 * Returns 0 on success, or an error code 1923 */ 1924 static int smack_inode_setsecurity(struct inode *inode, const char *name, 1925 const void *value, size_t size, int flags) 1926 { 1927 char *sp; 1928 struct inode_smack *nsp = inode->i_security; 1929 struct socket_smack *ssp; 1930 struct socket *sock; 1931 int rc = 0; 1932 1933 if (value == NULL || size > SMK_LABELLEN || size == 0) 1934 return -EACCES; 1935 1936 sp = smk_import(value, size); 1937 if (sp == NULL) 1938 return -EINVAL; 1939 1940 if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) { 1941 nsp->smk_inode = sp; 1942 nsp->smk_flags |= SMK_INODE_INSTANT; 1943 return 0; 1944 } 1945 /* 1946 * The rest of the Smack xattrs are only on sockets. 1947 */ 1948 if (inode->i_sb->s_magic != SOCKFS_MAGIC) 1949 return -EOPNOTSUPP; 1950 1951 sock = SOCKET_I(inode); 1952 if (sock == NULL || sock->sk == NULL) 1953 return -EOPNOTSUPP; 1954 1955 ssp = sock->sk->sk_security; 1956 1957 if (strcmp(name, XATTR_SMACK_IPIN) == 0) 1958 ssp->smk_in = sp; 1959 else if (strcmp(name, XATTR_SMACK_IPOUT) == 0) { 1960 ssp->smk_out = sp; 1961 if (sock->sk->sk_family != PF_UNIX) { 1962 rc = smack_netlabel(sock->sk, SMACK_CIPSO_SOCKET); 1963 if (rc != 0) 1964 printk(KERN_WARNING 1965 "Smack: \"%s\" netlbl error %d.\n", 1966 __func__, -rc); 1967 } 1968 } else 1969 return -EOPNOTSUPP; 1970 1971 return 0; 1972 } 1973 1974 /** 1975 * smack_socket_post_create - finish socket setup 1976 * @sock: the socket 1977 * @family: protocol family 1978 * @type: unused 1979 * @protocol: unused 1980 * @kern: unused 1981 * 1982 * Sets the netlabel information on the socket 1983 * 1984 * Returns 0 on success, and error code otherwise 1985 */ 1986 static int smack_socket_post_create(struct socket *sock, int family, 1987 int type, int protocol, int kern) 1988 { 1989 if (family != PF_INET || sock->sk == NULL) 1990 return 0; 1991 /* 1992 * Set the outbound netlbl. 1993 */ 1994 return smack_netlabel(sock->sk, SMACK_CIPSO_SOCKET); 1995 } 1996 1997 /** 1998 * smack_socket_connect - connect access check 1999 * @sock: the socket 2000 * @sap: the other end 2001 * @addrlen: size of sap 2002 * 2003 * Verifies that a connection may be possible 2004 * 2005 * Returns 0 on success, and error code otherwise 2006 */ 2007 static int smack_socket_connect(struct socket *sock, struct sockaddr *sap, 2008 int addrlen) 2009 { 2010 if (sock->sk == NULL || sock->sk->sk_family != PF_INET) 2011 return 0; 2012 if (addrlen < sizeof(struct sockaddr_in)) 2013 return -EINVAL; 2014 2015 return smack_netlabel_send(sock->sk, (struct sockaddr_in *)sap); 2016 } 2017 2018 /** 2019 * smack_flags_to_may - convert S_ to MAY_ values 2020 * @flags: the S_ value 2021 * 2022 * Returns the equivalent MAY_ value 2023 */ 2024 static int smack_flags_to_may(int flags) 2025 { 2026 int may = 0; 2027 2028 if (flags & S_IRUGO) 2029 may |= MAY_READ; 2030 if (flags & S_IWUGO) 2031 may |= MAY_WRITE; 2032 if (flags & S_IXUGO) 2033 may |= MAY_EXEC; 2034 2035 return may; 2036 } 2037 2038 /** 2039 * smack_msg_msg_alloc_security - Set the security blob for msg_msg 2040 * @msg: the object 2041 * 2042 * Returns 0 2043 */ 2044 static int smack_msg_msg_alloc_security(struct msg_msg *msg) 2045 { 2046 msg->security = smk_of_current(); 2047 return 0; 2048 } 2049 2050 /** 2051 * smack_msg_msg_free_security - Clear the security blob for msg_msg 2052 * @msg: the object 2053 * 2054 * Clears the blob pointer 2055 */ 2056 static void smack_msg_msg_free_security(struct msg_msg *msg) 2057 { 2058 msg->security = NULL; 2059 } 2060 2061 /** 2062 * smack_of_shm - the smack pointer for the shm 2063 * @shp: the object 2064 * 2065 * Returns a pointer to the smack value 2066 */ 2067 static char *smack_of_shm(struct shmid_kernel *shp) 2068 { 2069 return (char *)shp->shm_perm.security; 2070 } 2071 2072 /** 2073 * smack_shm_alloc_security - Set the security blob for shm 2074 * @shp: the object 2075 * 2076 * Returns 0 2077 */ 2078 static int smack_shm_alloc_security(struct shmid_kernel *shp) 2079 { 2080 struct kern_ipc_perm *isp = &shp->shm_perm; 2081 2082 isp->security = smk_of_current(); 2083 return 0; 2084 } 2085 2086 /** 2087 * smack_shm_free_security - Clear the security blob for shm 2088 * @shp: the object 2089 * 2090 * Clears the blob pointer 2091 */ 2092 static void smack_shm_free_security(struct shmid_kernel *shp) 2093 { 2094 struct kern_ipc_perm *isp = &shp->shm_perm; 2095 2096 isp->security = NULL; 2097 } 2098 2099 /** 2100 * smk_curacc_shm : check if current has access on shm 2101 * @shp : the object 2102 * @access : access requested 2103 * 2104 * Returns 0 if current has the requested access, error code otherwise 2105 */ 2106 static int smk_curacc_shm(struct shmid_kernel *shp, int access) 2107 { 2108 char *ssp = smack_of_shm(shp); 2109 struct smk_audit_info ad; 2110 2111 #ifdef CONFIG_AUDIT 2112 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC); 2113 ad.a.u.ipc_id = shp->shm_perm.id; 2114 #endif 2115 return smk_curacc(ssp, access, &ad); 2116 } 2117 2118 /** 2119 * smack_shm_associate - Smack access check for shm 2120 * @shp: the object 2121 * @shmflg: access requested 2122 * 2123 * Returns 0 if current has the requested access, error code otherwise 2124 */ 2125 static int smack_shm_associate(struct shmid_kernel *shp, int shmflg) 2126 { 2127 int may; 2128 2129 may = smack_flags_to_may(shmflg); 2130 return smk_curacc_shm(shp, may); 2131 } 2132 2133 /** 2134 * smack_shm_shmctl - Smack access check for shm 2135 * @shp: the object 2136 * @cmd: what it wants to do 2137 * 2138 * Returns 0 if current has the requested access, error code otherwise 2139 */ 2140 static int smack_shm_shmctl(struct shmid_kernel *shp, int cmd) 2141 { 2142 int may; 2143 2144 switch (cmd) { 2145 case IPC_STAT: 2146 case SHM_STAT: 2147 may = MAY_READ; 2148 break; 2149 case IPC_SET: 2150 case SHM_LOCK: 2151 case SHM_UNLOCK: 2152 case IPC_RMID: 2153 may = MAY_READWRITE; 2154 break; 2155 case IPC_INFO: 2156 case SHM_INFO: 2157 /* 2158 * System level information. 2159 */ 2160 return 0; 2161 default: 2162 return -EINVAL; 2163 } 2164 return smk_curacc_shm(shp, may); 2165 } 2166 2167 /** 2168 * smack_shm_shmat - Smack access for shmat 2169 * @shp: the object 2170 * @shmaddr: unused 2171 * @shmflg: access requested 2172 * 2173 * Returns 0 if current has the requested access, error code otherwise 2174 */ 2175 static int smack_shm_shmat(struct shmid_kernel *shp, char __user *shmaddr, 2176 int shmflg) 2177 { 2178 int may; 2179 2180 may = smack_flags_to_may(shmflg); 2181 return smk_curacc_shm(shp, may); 2182 } 2183 2184 /** 2185 * smack_of_sem - the smack pointer for the sem 2186 * @sma: the object 2187 * 2188 * Returns a pointer to the smack value 2189 */ 2190 static char *smack_of_sem(struct sem_array *sma) 2191 { 2192 return (char *)sma->sem_perm.security; 2193 } 2194 2195 /** 2196 * smack_sem_alloc_security - Set the security blob for sem 2197 * @sma: the object 2198 * 2199 * Returns 0 2200 */ 2201 static int smack_sem_alloc_security(struct sem_array *sma) 2202 { 2203 struct kern_ipc_perm *isp = &sma->sem_perm; 2204 2205 isp->security = smk_of_current(); 2206 return 0; 2207 } 2208 2209 /** 2210 * smack_sem_free_security - Clear the security blob for sem 2211 * @sma: the object 2212 * 2213 * Clears the blob pointer 2214 */ 2215 static void smack_sem_free_security(struct sem_array *sma) 2216 { 2217 struct kern_ipc_perm *isp = &sma->sem_perm; 2218 2219 isp->security = NULL; 2220 } 2221 2222 /** 2223 * smk_curacc_sem : check if current has access on sem 2224 * @sma : the object 2225 * @access : access requested 2226 * 2227 * Returns 0 if current has the requested access, error code otherwise 2228 */ 2229 static int smk_curacc_sem(struct sem_array *sma, int access) 2230 { 2231 char *ssp = smack_of_sem(sma); 2232 struct smk_audit_info ad; 2233 2234 #ifdef CONFIG_AUDIT 2235 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC); 2236 ad.a.u.ipc_id = sma->sem_perm.id; 2237 #endif 2238 return smk_curacc(ssp, access, &ad); 2239 } 2240 2241 /** 2242 * smack_sem_associate - Smack access check for sem 2243 * @sma: the object 2244 * @semflg: access requested 2245 * 2246 * Returns 0 if current has the requested access, error code otherwise 2247 */ 2248 static int smack_sem_associate(struct sem_array *sma, int semflg) 2249 { 2250 int may; 2251 2252 may = smack_flags_to_may(semflg); 2253 return smk_curacc_sem(sma, may); 2254 } 2255 2256 /** 2257 * smack_sem_shmctl - Smack access check for sem 2258 * @sma: the object 2259 * @cmd: what it wants to do 2260 * 2261 * Returns 0 if current has the requested access, error code otherwise 2262 */ 2263 static int smack_sem_semctl(struct sem_array *sma, int cmd) 2264 { 2265 int may; 2266 2267 switch (cmd) { 2268 case GETPID: 2269 case GETNCNT: 2270 case GETZCNT: 2271 case GETVAL: 2272 case GETALL: 2273 case IPC_STAT: 2274 case SEM_STAT: 2275 may = MAY_READ; 2276 break; 2277 case SETVAL: 2278 case SETALL: 2279 case IPC_RMID: 2280 case IPC_SET: 2281 may = MAY_READWRITE; 2282 break; 2283 case IPC_INFO: 2284 case SEM_INFO: 2285 /* 2286 * System level information 2287 */ 2288 return 0; 2289 default: 2290 return -EINVAL; 2291 } 2292 2293 return smk_curacc_sem(sma, may); 2294 } 2295 2296 /** 2297 * smack_sem_semop - Smack checks of semaphore operations 2298 * @sma: the object 2299 * @sops: unused 2300 * @nsops: unused 2301 * @alter: unused 2302 * 2303 * Treated as read and write in all cases. 2304 * 2305 * Returns 0 if access is allowed, error code otherwise 2306 */ 2307 static int smack_sem_semop(struct sem_array *sma, struct sembuf *sops, 2308 unsigned nsops, int alter) 2309 { 2310 return smk_curacc_sem(sma, MAY_READWRITE); 2311 } 2312 2313 /** 2314 * smack_msg_alloc_security - Set the security blob for msg 2315 * @msq: the object 2316 * 2317 * Returns 0 2318 */ 2319 static int smack_msg_queue_alloc_security(struct msg_queue *msq) 2320 { 2321 struct kern_ipc_perm *kisp = &msq->q_perm; 2322 2323 kisp->security = smk_of_current(); 2324 return 0; 2325 } 2326 2327 /** 2328 * smack_msg_free_security - Clear the security blob for msg 2329 * @msq: the object 2330 * 2331 * Clears the blob pointer 2332 */ 2333 static void smack_msg_queue_free_security(struct msg_queue *msq) 2334 { 2335 struct kern_ipc_perm *kisp = &msq->q_perm; 2336 2337 kisp->security = NULL; 2338 } 2339 2340 /** 2341 * smack_of_msq - the smack pointer for the msq 2342 * @msq: the object 2343 * 2344 * Returns a pointer to the smack value 2345 */ 2346 static char *smack_of_msq(struct msg_queue *msq) 2347 { 2348 return (char *)msq->q_perm.security; 2349 } 2350 2351 /** 2352 * smk_curacc_msq : helper to check if current has access on msq 2353 * @msq : the msq 2354 * @access : access requested 2355 * 2356 * return 0 if current has access, error otherwise 2357 */ 2358 static int smk_curacc_msq(struct msg_queue *msq, int access) 2359 { 2360 char *msp = smack_of_msq(msq); 2361 struct smk_audit_info ad; 2362 2363 #ifdef CONFIG_AUDIT 2364 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC); 2365 ad.a.u.ipc_id = msq->q_perm.id; 2366 #endif 2367 return smk_curacc(msp, access, &ad); 2368 } 2369 2370 /** 2371 * smack_msg_queue_associate - Smack access check for msg_queue 2372 * @msq: the object 2373 * @msqflg: access requested 2374 * 2375 * Returns 0 if current has the requested access, error code otherwise 2376 */ 2377 static int smack_msg_queue_associate(struct msg_queue *msq, int msqflg) 2378 { 2379 int may; 2380 2381 may = smack_flags_to_may(msqflg); 2382 return smk_curacc_msq(msq, may); 2383 } 2384 2385 /** 2386 * smack_msg_queue_msgctl - Smack access check for msg_queue 2387 * @msq: the object 2388 * @cmd: what it wants to do 2389 * 2390 * Returns 0 if current has the requested access, error code otherwise 2391 */ 2392 static int smack_msg_queue_msgctl(struct msg_queue *msq, int cmd) 2393 { 2394 int may; 2395 2396 switch (cmd) { 2397 case IPC_STAT: 2398 case MSG_STAT: 2399 may = MAY_READ; 2400 break; 2401 case IPC_SET: 2402 case IPC_RMID: 2403 may = MAY_READWRITE; 2404 break; 2405 case IPC_INFO: 2406 case MSG_INFO: 2407 /* 2408 * System level information 2409 */ 2410 return 0; 2411 default: 2412 return -EINVAL; 2413 } 2414 2415 return smk_curacc_msq(msq, may); 2416 } 2417 2418 /** 2419 * smack_msg_queue_msgsnd - Smack access check for msg_queue 2420 * @msq: the object 2421 * @msg: unused 2422 * @msqflg: access requested 2423 * 2424 * Returns 0 if current has the requested access, error code otherwise 2425 */ 2426 static int smack_msg_queue_msgsnd(struct msg_queue *msq, struct msg_msg *msg, 2427 int msqflg) 2428 { 2429 int may; 2430 2431 may = smack_flags_to_may(msqflg); 2432 return smk_curacc_msq(msq, may); 2433 } 2434 2435 /** 2436 * smack_msg_queue_msgsnd - Smack access check for msg_queue 2437 * @msq: the object 2438 * @msg: unused 2439 * @target: unused 2440 * @type: unused 2441 * @mode: unused 2442 * 2443 * Returns 0 if current has read and write access, error code otherwise 2444 */ 2445 static int smack_msg_queue_msgrcv(struct msg_queue *msq, struct msg_msg *msg, 2446 struct task_struct *target, long type, int mode) 2447 { 2448 return smk_curacc_msq(msq, MAY_READWRITE); 2449 } 2450 2451 /** 2452 * smack_ipc_permission - Smack access for ipc_permission() 2453 * @ipp: the object permissions 2454 * @flag: access requested 2455 * 2456 * Returns 0 if current has read and write access, error code otherwise 2457 */ 2458 static int smack_ipc_permission(struct kern_ipc_perm *ipp, short flag) 2459 { 2460 char *isp = ipp->security; 2461 int may = smack_flags_to_may(flag); 2462 struct smk_audit_info ad; 2463 2464 #ifdef CONFIG_AUDIT 2465 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC); 2466 ad.a.u.ipc_id = ipp->id; 2467 #endif 2468 return smk_curacc(isp, may, &ad); 2469 } 2470 2471 /** 2472 * smack_ipc_getsecid - Extract smack security id 2473 * @ipp: the object permissions 2474 * @secid: where result will be saved 2475 */ 2476 static void smack_ipc_getsecid(struct kern_ipc_perm *ipp, u32 *secid) 2477 { 2478 char *smack = ipp->security; 2479 2480 *secid = smack_to_secid(smack); 2481 } 2482 2483 /** 2484 * smack_d_instantiate - Make sure the blob is correct on an inode 2485 * @opt_dentry: dentry where inode will be attached 2486 * @inode: the object 2487 * 2488 * Set the inode's security blob if it hasn't been done already. 2489 */ 2490 static void smack_d_instantiate(struct dentry *opt_dentry, struct inode *inode) 2491 { 2492 struct super_block *sbp; 2493 struct superblock_smack *sbsp; 2494 struct inode_smack *isp; 2495 char *csp = smk_of_current(); 2496 char *fetched; 2497 char *final; 2498 char trattr[TRANS_TRUE_SIZE]; 2499 int transflag = 0; 2500 struct dentry *dp; 2501 2502 if (inode == NULL) 2503 return; 2504 2505 isp = inode->i_security; 2506 2507 mutex_lock(&isp->smk_lock); 2508 /* 2509 * If the inode is already instantiated 2510 * take the quick way out 2511 */ 2512 if (isp->smk_flags & SMK_INODE_INSTANT) 2513 goto unlockandout; 2514 2515 sbp = inode->i_sb; 2516 sbsp = sbp->s_security; 2517 /* 2518 * We're going to use the superblock default label 2519 * if there's no label on the file. 2520 */ 2521 final = sbsp->smk_default; 2522 2523 /* 2524 * If this is the root inode the superblock 2525 * may be in the process of initialization. 2526 * If that is the case use the root value out 2527 * of the superblock. 2528 */ 2529 if (opt_dentry->d_parent == opt_dentry) { 2530 isp->smk_inode = sbsp->smk_root; 2531 isp->smk_flags |= SMK_INODE_INSTANT; 2532 goto unlockandout; 2533 } 2534 2535 /* 2536 * This is pretty hackish. 2537 * Casey says that we shouldn't have to do 2538 * file system specific code, but it does help 2539 * with keeping it simple. 2540 */ 2541 switch (sbp->s_magic) { 2542 case SMACK_MAGIC: 2543 /* 2544 * Casey says that it's a little embarrassing 2545 * that the smack file system doesn't do 2546 * extended attributes. 2547 */ 2548 final = smack_known_star.smk_known; 2549 break; 2550 case PIPEFS_MAGIC: 2551 /* 2552 * Casey says pipes are easy (?) 2553 */ 2554 final = smack_known_star.smk_known; 2555 break; 2556 case DEVPTS_SUPER_MAGIC: 2557 /* 2558 * devpts seems content with the label of the task. 2559 * Programs that change smack have to treat the 2560 * pty with respect. 2561 */ 2562 final = csp; 2563 break; 2564 case SOCKFS_MAGIC: 2565 /* 2566 * Socket access is controlled by the socket 2567 * structures associated with the task involved. 2568 */ 2569 final = smack_known_star.smk_known; 2570 break; 2571 case PROC_SUPER_MAGIC: 2572 /* 2573 * Casey says procfs appears not to care. 2574 * The superblock default suffices. 2575 */ 2576 break; 2577 case TMPFS_MAGIC: 2578 /* 2579 * Device labels should come from the filesystem, 2580 * but watch out, because they're volitile, 2581 * getting recreated on every reboot. 2582 */ 2583 final = smack_known_star.smk_known; 2584 /* 2585 * No break. 2586 * 2587 * If a smack value has been set we want to use it, 2588 * but since tmpfs isn't giving us the opportunity 2589 * to set mount options simulate setting the 2590 * superblock default. 2591 */ 2592 default: 2593 /* 2594 * This isn't an understood special case. 2595 * Get the value from the xattr. 2596 */ 2597 2598 /* 2599 * UNIX domain sockets use lower level socket data. 2600 */ 2601 if (S_ISSOCK(inode->i_mode)) { 2602 final = smack_known_star.smk_known; 2603 break; 2604 } 2605 /* 2606 * No xattr support means, alas, no SMACK label. 2607 * Use the aforeapplied default. 2608 * It would be curious if the label of the task 2609 * does not match that assigned. 2610 */ 2611 if (inode->i_op->getxattr == NULL) 2612 break; 2613 /* 2614 * Get the dentry for xattr. 2615 */ 2616 dp = dget(opt_dentry); 2617 fetched = smk_fetch(XATTR_NAME_SMACK, inode, dp); 2618 if (fetched != NULL) { 2619 final = fetched; 2620 if (S_ISDIR(inode->i_mode)) { 2621 trattr[0] = '\0'; 2622 inode->i_op->getxattr(dp, 2623 XATTR_NAME_SMACKTRANSMUTE, 2624 trattr, TRANS_TRUE_SIZE); 2625 if (strncmp(trattr, TRANS_TRUE, 2626 TRANS_TRUE_SIZE) == 0) 2627 transflag = SMK_INODE_TRANSMUTE; 2628 } 2629 } 2630 isp->smk_task = smk_fetch(XATTR_NAME_SMACKEXEC, inode, dp); 2631 isp->smk_mmap = smk_fetch(XATTR_NAME_SMACKMMAP, inode, dp); 2632 2633 dput(dp); 2634 break; 2635 } 2636 2637 if (final == NULL) 2638 isp->smk_inode = csp; 2639 else 2640 isp->smk_inode = final; 2641 2642 isp->smk_flags |= (SMK_INODE_INSTANT | transflag); 2643 2644 unlockandout: 2645 mutex_unlock(&isp->smk_lock); 2646 return; 2647 } 2648 2649 /** 2650 * smack_getprocattr - Smack process attribute access 2651 * @p: the object task 2652 * @name: the name of the attribute in /proc/.../attr 2653 * @value: where to put the result 2654 * 2655 * Places a copy of the task Smack into value 2656 * 2657 * Returns the length of the smack label or an error code 2658 */ 2659 static int smack_getprocattr(struct task_struct *p, char *name, char **value) 2660 { 2661 char *cp; 2662 int slen; 2663 2664 if (strcmp(name, "current") != 0) 2665 return -EINVAL; 2666 2667 cp = kstrdup(smk_of_task(task_security(p)), GFP_KERNEL); 2668 if (cp == NULL) 2669 return -ENOMEM; 2670 2671 slen = strlen(cp); 2672 *value = cp; 2673 return slen; 2674 } 2675 2676 /** 2677 * smack_setprocattr - Smack process attribute setting 2678 * @p: the object task 2679 * @name: the name of the attribute in /proc/.../attr 2680 * @value: the value to set 2681 * @size: the size of the value 2682 * 2683 * Sets the Smack value of the task. Only setting self 2684 * is permitted and only with privilege 2685 * 2686 * Returns the length of the smack label or an error code 2687 */ 2688 static int smack_setprocattr(struct task_struct *p, char *name, 2689 void *value, size_t size) 2690 { 2691 int rc; 2692 struct task_smack *tsp; 2693 struct task_smack *oldtsp; 2694 struct cred *new; 2695 char *newsmack; 2696 2697 /* 2698 * Changing another process' Smack value is too dangerous 2699 * and supports no sane use case. 2700 */ 2701 if (p != current) 2702 return -EPERM; 2703 2704 if (!capable(CAP_MAC_ADMIN)) 2705 return -EPERM; 2706 2707 if (value == NULL || size == 0 || size >= SMK_LABELLEN) 2708 return -EINVAL; 2709 2710 if (strcmp(name, "current") != 0) 2711 return -EINVAL; 2712 2713 newsmack = smk_import(value, size); 2714 if (newsmack == NULL) 2715 return -EINVAL; 2716 2717 /* 2718 * No process is ever allowed the web ("@") label. 2719 */ 2720 if (newsmack == smack_known_web.smk_known) 2721 return -EPERM; 2722 2723 oldtsp = p->cred->security; 2724 new = prepare_creds(); 2725 if (new == NULL) 2726 return -ENOMEM; 2727 2728 tsp = new_task_smack(newsmack, oldtsp->smk_forked, GFP_KERNEL); 2729 if (tsp == NULL) { 2730 kfree(new); 2731 return -ENOMEM; 2732 } 2733 rc = smk_copy_rules(&tsp->smk_rules, &oldtsp->smk_rules, GFP_KERNEL); 2734 if (rc != 0) 2735 return rc; 2736 2737 new->security = tsp; 2738 commit_creds(new); 2739 return size; 2740 } 2741 2742 /** 2743 * smack_unix_stream_connect - Smack access on UDS 2744 * @sock: one sock 2745 * @other: the other sock 2746 * @newsk: unused 2747 * 2748 * Return 0 if a subject with the smack of sock could access 2749 * an object with the smack of other, otherwise an error code 2750 */ 2751 static int smack_unix_stream_connect(struct sock *sock, 2752 struct sock *other, struct sock *newsk) 2753 { 2754 struct socket_smack *ssp = sock->sk_security; 2755 struct socket_smack *osp = other->sk_security; 2756 struct smk_audit_info ad; 2757 int rc = 0; 2758 2759 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_NET); 2760 smk_ad_setfield_u_net_sk(&ad, other); 2761 2762 if (!capable(CAP_MAC_OVERRIDE)) 2763 rc = smk_access(ssp->smk_out, osp->smk_in, MAY_WRITE, &ad); 2764 2765 return rc; 2766 } 2767 2768 /** 2769 * smack_unix_may_send - Smack access on UDS 2770 * @sock: one socket 2771 * @other: the other socket 2772 * 2773 * Return 0 if a subject with the smack of sock could access 2774 * an object with the smack of other, otherwise an error code 2775 */ 2776 static int smack_unix_may_send(struct socket *sock, struct socket *other) 2777 { 2778 struct socket_smack *ssp = sock->sk->sk_security; 2779 struct socket_smack *osp = other->sk->sk_security; 2780 struct smk_audit_info ad; 2781 int rc = 0; 2782 2783 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_NET); 2784 smk_ad_setfield_u_net_sk(&ad, other->sk); 2785 2786 if (!capable(CAP_MAC_OVERRIDE)) 2787 rc = smk_access(ssp->smk_out, osp->smk_in, MAY_WRITE, &ad); 2788 2789 return rc; 2790 } 2791 2792 /** 2793 * smack_socket_sendmsg - Smack check based on destination host 2794 * @sock: the socket 2795 * @msg: the message 2796 * @size: the size of the message 2797 * 2798 * Return 0 if the current subject can write to the destination 2799 * host. This is only a question if the destination is a single 2800 * label host. 2801 */ 2802 static int smack_socket_sendmsg(struct socket *sock, struct msghdr *msg, 2803 int size) 2804 { 2805 struct sockaddr_in *sip = (struct sockaddr_in *) msg->msg_name; 2806 2807 /* 2808 * Perfectly reasonable for this to be NULL 2809 */ 2810 if (sip == NULL || sip->sin_family != AF_INET) 2811 return 0; 2812 2813 return smack_netlabel_send(sock->sk, sip); 2814 } 2815 2816 2817 /** 2818 * smack_from_secattr - Convert a netlabel attr.mls.lvl/attr.mls.cat pair to smack 2819 * @sap: netlabel secattr 2820 * @sip: where to put the result 2821 * 2822 * Copies a smack label into sip 2823 */ 2824 static void smack_from_secattr(struct netlbl_lsm_secattr *sap, char *sip) 2825 { 2826 char smack[SMK_LABELLEN]; 2827 char *sp; 2828 int pcat; 2829 2830 if ((sap->flags & NETLBL_SECATTR_MLS_LVL) != 0) { 2831 /* 2832 * Looks like a CIPSO packet. 2833 * If there are flags but no level netlabel isn't 2834 * behaving the way we expect it to. 2835 * 2836 * Get the categories, if any 2837 * Without guidance regarding the smack value 2838 * for the packet fall back on the network 2839 * ambient value. 2840 */ 2841 memset(smack, '\0', SMK_LABELLEN); 2842 if ((sap->flags & NETLBL_SECATTR_MLS_CAT) != 0) 2843 for (pcat = -1;;) { 2844 pcat = netlbl_secattr_catmap_walk( 2845 sap->attr.mls.cat, pcat + 1); 2846 if (pcat < 0) 2847 break; 2848 smack_catset_bit(pcat, smack); 2849 } 2850 /* 2851 * If it is CIPSO using smack direct mapping 2852 * we are already done. WeeHee. 2853 */ 2854 if (sap->attr.mls.lvl == smack_cipso_direct) { 2855 memcpy(sip, smack, SMK_MAXLEN); 2856 return; 2857 } 2858 /* 2859 * Look it up in the supplied table if it is not 2860 * a direct mapping. 2861 */ 2862 smack_from_cipso(sap->attr.mls.lvl, smack, sip); 2863 return; 2864 } 2865 if ((sap->flags & NETLBL_SECATTR_SECID) != 0) { 2866 /* 2867 * Looks like a fallback, which gives us a secid. 2868 */ 2869 sp = smack_from_secid(sap->attr.secid); 2870 /* 2871 * This has got to be a bug because it is 2872 * impossible to specify a fallback without 2873 * specifying the label, which will ensure 2874 * it has a secid, and the only way to get a 2875 * secid is from a fallback. 2876 */ 2877 BUG_ON(sp == NULL); 2878 strncpy(sip, sp, SMK_MAXLEN); 2879 return; 2880 } 2881 /* 2882 * Without guidance regarding the smack value 2883 * for the packet fall back on the network 2884 * ambient value. 2885 */ 2886 strncpy(sip, smack_net_ambient, SMK_MAXLEN); 2887 return; 2888 } 2889 2890 /** 2891 * smack_socket_sock_rcv_skb - Smack packet delivery access check 2892 * @sk: socket 2893 * @skb: packet 2894 * 2895 * Returns 0 if the packet should be delivered, an error code otherwise 2896 */ 2897 static int smack_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb) 2898 { 2899 struct netlbl_lsm_secattr secattr; 2900 struct socket_smack *ssp = sk->sk_security; 2901 char smack[SMK_LABELLEN]; 2902 char *csp; 2903 int rc; 2904 struct smk_audit_info ad; 2905 if (sk->sk_family != PF_INET && sk->sk_family != PF_INET6) 2906 return 0; 2907 2908 /* 2909 * Translate what netlabel gave us. 2910 */ 2911 netlbl_secattr_init(&secattr); 2912 2913 rc = netlbl_skbuff_getattr(skb, sk->sk_family, &secattr); 2914 if (rc == 0) { 2915 smack_from_secattr(&secattr, smack); 2916 csp = smack; 2917 } else 2918 csp = smack_net_ambient; 2919 2920 netlbl_secattr_destroy(&secattr); 2921 2922 #ifdef CONFIG_AUDIT 2923 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_NET); 2924 ad.a.u.net.family = sk->sk_family; 2925 ad.a.u.net.netif = skb->skb_iif; 2926 ipv4_skb_to_auditdata(skb, &ad.a, NULL); 2927 #endif 2928 /* 2929 * Receiving a packet requires that the other end 2930 * be able to write here. Read access is not required. 2931 * This is the simplist possible security model 2932 * for networking. 2933 */ 2934 rc = smk_access(csp, ssp->smk_in, MAY_WRITE, &ad); 2935 if (rc != 0) 2936 netlbl_skbuff_err(skb, rc, 0); 2937 return rc; 2938 } 2939 2940 /** 2941 * smack_socket_getpeersec_stream - pull in packet label 2942 * @sock: the socket 2943 * @optval: user's destination 2944 * @optlen: size thereof 2945 * @len: max thereof 2946 * 2947 * returns zero on success, an error code otherwise 2948 */ 2949 static int smack_socket_getpeersec_stream(struct socket *sock, 2950 char __user *optval, 2951 int __user *optlen, unsigned len) 2952 { 2953 struct socket_smack *ssp; 2954 int slen; 2955 int rc = 0; 2956 2957 ssp = sock->sk->sk_security; 2958 slen = strlen(ssp->smk_packet) + 1; 2959 2960 if (slen > len) 2961 rc = -ERANGE; 2962 else if (copy_to_user(optval, ssp->smk_packet, slen) != 0) 2963 rc = -EFAULT; 2964 2965 if (put_user(slen, optlen) != 0) 2966 rc = -EFAULT; 2967 2968 return rc; 2969 } 2970 2971 2972 /** 2973 * smack_socket_getpeersec_dgram - pull in packet label 2974 * @sock: the peer socket 2975 * @skb: packet data 2976 * @secid: pointer to where to put the secid of the packet 2977 * 2978 * Sets the netlabel socket state on sk from parent 2979 */ 2980 static int smack_socket_getpeersec_dgram(struct socket *sock, 2981 struct sk_buff *skb, u32 *secid) 2982 2983 { 2984 struct netlbl_lsm_secattr secattr; 2985 struct socket_smack *sp; 2986 char smack[SMK_LABELLEN]; 2987 int family = PF_UNSPEC; 2988 u32 s = 0; /* 0 is the invalid secid */ 2989 int rc; 2990 2991 if (skb != NULL) { 2992 if (skb->protocol == htons(ETH_P_IP)) 2993 family = PF_INET; 2994 else if (skb->protocol == htons(ETH_P_IPV6)) 2995 family = PF_INET6; 2996 } 2997 if (family == PF_UNSPEC && sock != NULL) 2998 family = sock->sk->sk_family; 2999 3000 if (family == PF_UNIX) { 3001 sp = sock->sk->sk_security; 3002 s = smack_to_secid(sp->smk_out); 3003 } else if (family == PF_INET || family == PF_INET6) { 3004 /* 3005 * Translate what netlabel gave us. 3006 */ 3007 netlbl_secattr_init(&secattr); 3008 rc = netlbl_skbuff_getattr(skb, family, &secattr); 3009 if (rc == 0) { 3010 smack_from_secattr(&secattr, smack); 3011 s = smack_to_secid(smack); 3012 } 3013 netlbl_secattr_destroy(&secattr); 3014 } 3015 *secid = s; 3016 if (s == 0) 3017 return -EINVAL; 3018 return 0; 3019 } 3020 3021 /** 3022 * smack_sock_graft - Initialize a newly created socket with an existing sock 3023 * @sk: child sock 3024 * @parent: parent socket 3025 * 3026 * Set the smk_{in,out} state of an existing sock based on the process that 3027 * is creating the new socket. 3028 */ 3029 static void smack_sock_graft(struct sock *sk, struct socket *parent) 3030 { 3031 struct socket_smack *ssp; 3032 3033 if (sk == NULL || 3034 (sk->sk_family != PF_INET && sk->sk_family != PF_INET6)) 3035 return; 3036 3037 ssp = sk->sk_security; 3038 ssp->smk_in = ssp->smk_out = smk_of_current(); 3039 /* cssp->smk_packet is already set in smack_inet_csk_clone() */ 3040 } 3041 3042 /** 3043 * smack_inet_conn_request - Smack access check on connect 3044 * @sk: socket involved 3045 * @skb: packet 3046 * @req: unused 3047 * 3048 * Returns 0 if a task with the packet label could write to 3049 * the socket, otherwise an error code 3050 */ 3051 static int smack_inet_conn_request(struct sock *sk, struct sk_buff *skb, 3052 struct request_sock *req) 3053 { 3054 u16 family = sk->sk_family; 3055 struct socket_smack *ssp = sk->sk_security; 3056 struct netlbl_lsm_secattr secattr; 3057 struct sockaddr_in addr; 3058 struct iphdr *hdr; 3059 char smack[SMK_LABELLEN]; 3060 int rc; 3061 struct smk_audit_info ad; 3062 3063 /* handle mapped IPv4 packets arriving via IPv6 sockets */ 3064 if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP)) 3065 family = PF_INET; 3066 3067 netlbl_secattr_init(&secattr); 3068 rc = netlbl_skbuff_getattr(skb, family, &secattr); 3069 if (rc == 0) 3070 smack_from_secattr(&secattr, smack); 3071 else 3072 strncpy(smack, smack_known_huh.smk_known, SMK_MAXLEN); 3073 netlbl_secattr_destroy(&secattr); 3074 3075 #ifdef CONFIG_AUDIT 3076 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_NET); 3077 ad.a.u.net.family = family; 3078 ad.a.u.net.netif = skb->skb_iif; 3079 ipv4_skb_to_auditdata(skb, &ad.a, NULL); 3080 #endif 3081 /* 3082 * Receiving a packet requires that the other end be able to write 3083 * here. Read access is not required. 3084 */ 3085 rc = smk_access(smack, ssp->smk_in, MAY_WRITE, &ad); 3086 if (rc != 0) 3087 return rc; 3088 3089 /* 3090 * Save the peer's label in the request_sock so we can later setup 3091 * smk_packet in the child socket so that SO_PEERCRED can report it. 3092 */ 3093 req->peer_secid = smack_to_secid(smack); 3094 3095 /* 3096 * We need to decide if we want to label the incoming connection here 3097 * if we do we only need to label the request_sock and the stack will 3098 * propagate the wire-label to the sock when it is created. 3099 */ 3100 hdr = ip_hdr(skb); 3101 addr.sin_addr.s_addr = hdr->saddr; 3102 rcu_read_lock(); 3103 if (smack_host_label(&addr) == NULL) { 3104 rcu_read_unlock(); 3105 netlbl_secattr_init(&secattr); 3106 smack_to_secattr(smack, &secattr); 3107 rc = netlbl_req_setattr(req, &secattr); 3108 netlbl_secattr_destroy(&secattr); 3109 } else { 3110 rcu_read_unlock(); 3111 netlbl_req_delattr(req); 3112 } 3113 3114 return rc; 3115 } 3116 3117 /** 3118 * smack_inet_csk_clone - Copy the connection information to the new socket 3119 * @sk: the new socket 3120 * @req: the connection's request_sock 3121 * 3122 * Transfer the connection's peer label to the newly created socket. 3123 */ 3124 static void smack_inet_csk_clone(struct sock *sk, 3125 const struct request_sock *req) 3126 { 3127 struct socket_smack *ssp = sk->sk_security; 3128 char *smack; 3129 3130 if (req->peer_secid != 0) { 3131 smack = smack_from_secid(req->peer_secid); 3132 strncpy(ssp->smk_packet, smack, SMK_MAXLEN); 3133 } else 3134 ssp->smk_packet[0] = '\0'; 3135 } 3136 3137 /* 3138 * Key management security hooks 3139 * 3140 * Casey has not tested key support very heavily. 3141 * The permission check is most likely too restrictive. 3142 * If you care about keys please have a look. 3143 */ 3144 #ifdef CONFIG_KEYS 3145 3146 /** 3147 * smack_key_alloc - Set the key security blob 3148 * @key: object 3149 * @cred: the credentials to use 3150 * @flags: unused 3151 * 3152 * No allocation required 3153 * 3154 * Returns 0 3155 */ 3156 static int smack_key_alloc(struct key *key, const struct cred *cred, 3157 unsigned long flags) 3158 { 3159 key->security = smk_of_task(cred->security); 3160 return 0; 3161 } 3162 3163 /** 3164 * smack_key_free - Clear the key security blob 3165 * @key: the object 3166 * 3167 * Clear the blob pointer 3168 */ 3169 static void smack_key_free(struct key *key) 3170 { 3171 key->security = NULL; 3172 } 3173 3174 /* 3175 * smack_key_permission - Smack access on a key 3176 * @key_ref: gets to the object 3177 * @cred: the credentials to use 3178 * @perm: unused 3179 * 3180 * Return 0 if the task has read and write to the object, 3181 * an error code otherwise 3182 */ 3183 static int smack_key_permission(key_ref_t key_ref, 3184 const struct cred *cred, key_perm_t perm) 3185 { 3186 struct key *keyp; 3187 struct smk_audit_info ad; 3188 char *tsp = smk_of_task(cred->security); 3189 3190 keyp = key_ref_to_ptr(key_ref); 3191 if (keyp == NULL) 3192 return -EINVAL; 3193 /* 3194 * If the key hasn't been initialized give it access so that 3195 * it may do so. 3196 */ 3197 if (keyp->security == NULL) 3198 return 0; 3199 /* 3200 * This should not occur 3201 */ 3202 if (tsp == NULL) 3203 return -EACCES; 3204 #ifdef CONFIG_AUDIT 3205 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_KEY); 3206 ad.a.u.key_struct.key = keyp->serial; 3207 ad.a.u.key_struct.key_desc = keyp->description; 3208 #endif 3209 return smk_access(tsp, keyp->security, 3210 MAY_READWRITE, &ad); 3211 } 3212 #endif /* CONFIG_KEYS */ 3213 3214 /* 3215 * Smack Audit hooks 3216 * 3217 * Audit requires a unique representation of each Smack specific 3218 * rule. This unique representation is used to distinguish the 3219 * object to be audited from remaining kernel objects and also 3220 * works as a glue between the audit hooks. 3221 * 3222 * Since repository entries are added but never deleted, we'll use 3223 * the smack_known label address related to the given audit rule as 3224 * the needed unique representation. This also better fits the smack 3225 * model where nearly everything is a label. 3226 */ 3227 #ifdef CONFIG_AUDIT 3228 3229 /** 3230 * smack_audit_rule_init - Initialize a smack audit rule 3231 * @field: audit rule fields given from user-space (audit.h) 3232 * @op: required testing operator (=, !=, >, <, ...) 3233 * @rulestr: smack label to be audited 3234 * @vrule: pointer to save our own audit rule representation 3235 * 3236 * Prepare to audit cases where (@field @op @rulestr) is true. 3237 * The label to be audited is created if necessay. 3238 */ 3239 static int smack_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule) 3240 { 3241 char **rule = (char **)vrule; 3242 *rule = NULL; 3243 3244 if (field != AUDIT_SUBJ_USER && field != AUDIT_OBJ_USER) 3245 return -EINVAL; 3246 3247 if (op != Audit_equal && op != Audit_not_equal) 3248 return -EINVAL; 3249 3250 *rule = smk_import(rulestr, 0); 3251 3252 return 0; 3253 } 3254 3255 /** 3256 * smack_audit_rule_known - Distinguish Smack audit rules 3257 * @krule: rule of interest, in Audit kernel representation format 3258 * 3259 * This is used to filter Smack rules from remaining Audit ones. 3260 * If it's proved that this rule belongs to us, the 3261 * audit_rule_match hook will be called to do the final judgement. 3262 */ 3263 static int smack_audit_rule_known(struct audit_krule *krule) 3264 { 3265 struct audit_field *f; 3266 int i; 3267 3268 for (i = 0; i < krule->field_count; i++) { 3269 f = &krule->fields[i]; 3270 3271 if (f->type == AUDIT_SUBJ_USER || f->type == AUDIT_OBJ_USER) 3272 return 1; 3273 } 3274 3275 return 0; 3276 } 3277 3278 /** 3279 * smack_audit_rule_match - Audit given object ? 3280 * @secid: security id for identifying the object to test 3281 * @field: audit rule flags given from user-space 3282 * @op: required testing operator 3283 * @vrule: smack internal rule presentation 3284 * @actx: audit context associated with the check 3285 * 3286 * The core Audit hook. It's used to take the decision of 3287 * whether to audit or not to audit a given object. 3288 */ 3289 static int smack_audit_rule_match(u32 secid, u32 field, u32 op, void *vrule, 3290 struct audit_context *actx) 3291 { 3292 char *smack; 3293 char *rule = vrule; 3294 3295 if (!rule) { 3296 audit_log(actx, GFP_KERNEL, AUDIT_SELINUX_ERR, 3297 "Smack: missing rule\n"); 3298 return -ENOENT; 3299 } 3300 3301 if (field != AUDIT_SUBJ_USER && field != AUDIT_OBJ_USER) 3302 return 0; 3303 3304 smack = smack_from_secid(secid); 3305 3306 /* 3307 * No need to do string comparisons. If a match occurs, 3308 * both pointers will point to the same smack_known 3309 * label. 3310 */ 3311 if (op == Audit_equal) 3312 return (rule == smack); 3313 if (op == Audit_not_equal) 3314 return (rule != smack); 3315 3316 return 0; 3317 } 3318 3319 /** 3320 * smack_audit_rule_free - free smack rule representation 3321 * @vrule: rule to be freed. 3322 * 3323 * No memory was allocated. 3324 */ 3325 static void smack_audit_rule_free(void *vrule) 3326 { 3327 /* No-op */ 3328 } 3329 3330 #endif /* CONFIG_AUDIT */ 3331 3332 /** 3333 * smack_secid_to_secctx - return the smack label for a secid 3334 * @secid: incoming integer 3335 * @secdata: destination 3336 * @seclen: how long it is 3337 * 3338 * Exists for networking code. 3339 */ 3340 static int smack_secid_to_secctx(u32 secid, char **secdata, u32 *seclen) 3341 { 3342 char *sp = smack_from_secid(secid); 3343 3344 if (secdata) 3345 *secdata = sp; 3346 *seclen = strlen(sp); 3347 return 0; 3348 } 3349 3350 /** 3351 * smack_secctx_to_secid - return the secid for a smack label 3352 * @secdata: smack label 3353 * @seclen: how long result is 3354 * @secid: outgoing integer 3355 * 3356 * Exists for audit and networking code. 3357 */ 3358 static int smack_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid) 3359 { 3360 *secid = smack_to_secid(secdata); 3361 return 0; 3362 } 3363 3364 /** 3365 * smack_release_secctx - don't do anything. 3366 * @secdata: unused 3367 * @seclen: unused 3368 * 3369 * Exists to make sure nothing gets done, and properly 3370 */ 3371 static void smack_release_secctx(char *secdata, u32 seclen) 3372 { 3373 } 3374 3375 static int smack_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen) 3376 { 3377 return smack_inode_setsecurity(inode, XATTR_SMACK_SUFFIX, ctx, ctxlen, 0); 3378 } 3379 3380 static int smack_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen) 3381 { 3382 return __vfs_setxattr_noperm(dentry, XATTR_NAME_SMACK, ctx, ctxlen, 0); 3383 } 3384 3385 static int smack_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen) 3386 { 3387 int len = 0; 3388 len = smack_inode_getsecurity(inode, XATTR_SMACK_SUFFIX, ctx, true); 3389 3390 if (len < 0) 3391 return len; 3392 *ctxlen = len; 3393 return 0; 3394 } 3395 3396 struct security_operations smack_ops = { 3397 .name = "smack", 3398 3399 .ptrace_access_check = smack_ptrace_access_check, 3400 .ptrace_traceme = smack_ptrace_traceme, 3401 .syslog = smack_syslog, 3402 3403 .sb_alloc_security = smack_sb_alloc_security, 3404 .sb_free_security = smack_sb_free_security, 3405 .sb_copy_data = smack_sb_copy_data, 3406 .sb_kern_mount = smack_sb_kern_mount, 3407 .sb_statfs = smack_sb_statfs, 3408 .sb_mount = smack_sb_mount, 3409 .sb_umount = smack_sb_umount, 3410 3411 .bprm_set_creds = smack_bprm_set_creds, 3412 3413 .inode_alloc_security = smack_inode_alloc_security, 3414 .inode_free_security = smack_inode_free_security, 3415 .inode_init_security = smack_inode_init_security, 3416 .inode_link = smack_inode_link, 3417 .inode_unlink = smack_inode_unlink, 3418 .inode_rmdir = smack_inode_rmdir, 3419 .inode_rename = smack_inode_rename, 3420 .inode_permission = smack_inode_permission, 3421 .inode_setattr = smack_inode_setattr, 3422 .inode_getattr = smack_inode_getattr, 3423 .inode_setxattr = smack_inode_setxattr, 3424 .inode_post_setxattr = smack_inode_post_setxattr, 3425 .inode_getxattr = smack_inode_getxattr, 3426 .inode_removexattr = smack_inode_removexattr, 3427 .inode_getsecurity = smack_inode_getsecurity, 3428 .inode_setsecurity = smack_inode_setsecurity, 3429 .inode_listsecurity = smack_inode_listsecurity, 3430 .inode_getsecid = smack_inode_getsecid, 3431 3432 .file_permission = smack_file_permission, 3433 .file_alloc_security = smack_file_alloc_security, 3434 .file_free_security = smack_file_free_security, 3435 .file_ioctl = smack_file_ioctl, 3436 .file_lock = smack_file_lock, 3437 .file_fcntl = smack_file_fcntl, 3438 .file_mmap = smack_file_mmap, 3439 .file_set_fowner = smack_file_set_fowner, 3440 .file_send_sigiotask = smack_file_send_sigiotask, 3441 .file_receive = smack_file_receive, 3442 3443 .cred_alloc_blank = smack_cred_alloc_blank, 3444 .cred_free = smack_cred_free, 3445 .cred_prepare = smack_cred_prepare, 3446 .cred_transfer = smack_cred_transfer, 3447 .kernel_act_as = smack_kernel_act_as, 3448 .kernel_create_files_as = smack_kernel_create_files_as, 3449 .task_setpgid = smack_task_setpgid, 3450 .task_getpgid = smack_task_getpgid, 3451 .task_getsid = smack_task_getsid, 3452 .task_getsecid = smack_task_getsecid, 3453 .task_setnice = smack_task_setnice, 3454 .task_setioprio = smack_task_setioprio, 3455 .task_getioprio = smack_task_getioprio, 3456 .task_setscheduler = smack_task_setscheduler, 3457 .task_getscheduler = smack_task_getscheduler, 3458 .task_movememory = smack_task_movememory, 3459 .task_kill = smack_task_kill, 3460 .task_wait = smack_task_wait, 3461 .task_to_inode = smack_task_to_inode, 3462 3463 .ipc_permission = smack_ipc_permission, 3464 .ipc_getsecid = smack_ipc_getsecid, 3465 3466 .msg_msg_alloc_security = smack_msg_msg_alloc_security, 3467 .msg_msg_free_security = smack_msg_msg_free_security, 3468 3469 .msg_queue_alloc_security = smack_msg_queue_alloc_security, 3470 .msg_queue_free_security = smack_msg_queue_free_security, 3471 .msg_queue_associate = smack_msg_queue_associate, 3472 .msg_queue_msgctl = smack_msg_queue_msgctl, 3473 .msg_queue_msgsnd = smack_msg_queue_msgsnd, 3474 .msg_queue_msgrcv = smack_msg_queue_msgrcv, 3475 3476 .shm_alloc_security = smack_shm_alloc_security, 3477 .shm_free_security = smack_shm_free_security, 3478 .shm_associate = smack_shm_associate, 3479 .shm_shmctl = smack_shm_shmctl, 3480 .shm_shmat = smack_shm_shmat, 3481 3482 .sem_alloc_security = smack_sem_alloc_security, 3483 .sem_free_security = smack_sem_free_security, 3484 .sem_associate = smack_sem_associate, 3485 .sem_semctl = smack_sem_semctl, 3486 .sem_semop = smack_sem_semop, 3487 3488 .d_instantiate = smack_d_instantiate, 3489 3490 .getprocattr = smack_getprocattr, 3491 .setprocattr = smack_setprocattr, 3492 3493 .unix_stream_connect = smack_unix_stream_connect, 3494 .unix_may_send = smack_unix_may_send, 3495 3496 .socket_post_create = smack_socket_post_create, 3497 .socket_connect = smack_socket_connect, 3498 .socket_sendmsg = smack_socket_sendmsg, 3499 .socket_sock_rcv_skb = smack_socket_sock_rcv_skb, 3500 .socket_getpeersec_stream = smack_socket_getpeersec_stream, 3501 .socket_getpeersec_dgram = smack_socket_getpeersec_dgram, 3502 .sk_alloc_security = smack_sk_alloc_security, 3503 .sk_free_security = smack_sk_free_security, 3504 .sock_graft = smack_sock_graft, 3505 .inet_conn_request = smack_inet_conn_request, 3506 .inet_csk_clone = smack_inet_csk_clone, 3507 3508 /* key management security hooks */ 3509 #ifdef CONFIG_KEYS 3510 .key_alloc = smack_key_alloc, 3511 .key_free = smack_key_free, 3512 .key_permission = smack_key_permission, 3513 #endif /* CONFIG_KEYS */ 3514 3515 /* Audit hooks */ 3516 #ifdef CONFIG_AUDIT 3517 .audit_rule_init = smack_audit_rule_init, 3518 .audit_rule_known = smack_audit_rule_known, 3519 .audit_rule_match = smack_audit_rule_match, 3520 .audit_rule_free = smack_audit_rule_free, 3521 #endif /* CONFIG_AUDIT */ 3522 3523 .secid_to_secctx = smack_secid_to_secctx, 3524 .secctx_to_secid = smack_secctx_to_secid, 3525 .release_secctx = smack_release_secctx, 3526 .inode_notifysecctx = smack_inode_notifysecctx, 3527 .inode_setsecctx = smack_inode_setsecctx, 3528 .inode_getsecctx = smack_inode_getsecctx, 3529 }; 3530 3531 3532 static __init void init_smack_know_list(void) 3533 { 3534 list_add(&smack_known_huh.list, &smack_known_list); 3535 list_add(&smack_known_hat.list, &smack_known_list); 3536 list_add(&smack_known_star.list, &smack_known_list); 3537 list_add(&smack_known_floor.list, &smack_known_list); 3538 list_add(&smack_known_invalid.list, &smack_known_list); 3539 list_add(&smack_known_web.list, &smack_known_list); 3540 } 3541 3542 /** 3543 * smack_init - initialize the smack system 3544 * 3545 * Returns 0 3546 */ 3547 static __init int smack_init(void) 3548 { 3549 struct cred *cred; 3550 struct task_smack *tsp; 3551 3552 if (!security_module_enable(&smack_ops)) 3553 return 0; 3554 3555 tsp = new_task_smack(smack_known_floor.smk_known, 3556 smack_known_floor.smk_known, GFP_KERNEL); 3557 if (tsp == NULL) 3558 return -ENOMEM; 3559 3560 printk(KERN_INFO "Smack: Initializing.\n"); 3561 3562 /* 3563 * Set the security state for the initial task. 3564 */ 3565 cred = (struct cred *) current->cred; 3566 cred->security = tsp; 3567 3568 /* initialize the smack_know_list */ 3569 init_smack_know_list(); 3570 /* 3571 * Initialize locks 3572 */ 3573 spin_lock_init(&smack_known_huh.smk_cipsolock); 3574 spin_lock_init(&smack_known_hat.smk_cipsolock); 3575 spin_lock_init(&smack_known_star.smk_cipsolock); 3576 spin_lock_init(&smack_known_floor.smk_cipsolock); 3577 spin_lock_init(&smack_known_invalid.smk_cipsolock); 3578 3579 /* 3580 * Register with LSM 3581 */ 3582 if (register_security(&smack_ops)) 3583 panic("smack: Unable to register with kernel.\n"); 3584 3585 return 0; 3586 } 3587 3588 /* 3589 * Smack requires early initialization in order to label 3590 * all processes and objects when they are created. 3591 */ 3592 security_initcall(smack_init); 3593