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1/* 2 * Simplified MAC Kernel (smack) security module 3 * 4 * This file contains the smack hook function implementations. 5 * 6 * Authors: 7 * Casey Schaufler <casey@schaufler-ca.com> 8 * Jarkko Sakkinen <jarkko.sakkinen@intel.com> 9 * 10 * Copyright (C) 2007 Casey Schaufler <casey@schaufler-ca.com> 11 * Copyright (C) 2009 Hewlett-Packard Development Company, L.P. 12 * Paul Moore <paul@paul-moore.com> 13 * Copyright (C) 2010 Nokia Corporation 14 * Copyright (C) 2011 Intel Corporation. 15 * 16 * This program is free software; you can redistribute it and/or modify 17 * it under the terms of the GNU General Public License version 2, 18 * as published by the Free Software Foundation. 19 */ 20 21#include <linux/xattr.h> 22#include <linux/pagemap.h> 23#include <linux/mount.h> 24#include <linux/stat.h> 25#include <linux/kd.h> 26#include <asm/ioctls.h> 27#include <linux/ip.h> 28#include <linux/tcp.h> 29#include <linux/udp.h> 30#include <linux/slab.h> 31#include <linux/mutex.h> 32#include <linux/pipe_fs_i.h> 33#include <net/netlabel.h> 34#include <net/cipso_ipv4.h> 35#include <linux/audit.h> 36#include <linux/magic.h> 37#include <linux/dcache.h> 38#include <linux/personality.h> 39#include <linux/msg.h> 40#include <linux/shm.h> 41#include <linux/binfmts.h> 42#include "smack.h" 43 44#define task_security(task) (task_cred_xxx((task), security)) 45 46#define TRANS_TRUE "TRUE" 47#define TRANS_TRUE_SIZE 4 48 49/** 50 * smk_fetch - Fetch the smack label from a file. 51 * @ip: a pointer to the inode 52 * @dp: a pointer to the dentry 53 * 54 * Returns a pointer to the master list entry for the Smack label 55 * or NULL if there was no label to fetch. 56 */ 57static char *smk_fetch(const char *name, struct inode *ip, struct dentry *dp) 58{ 59 int rc; 60 char in[SMK_LABELLEN]; 61 62 if (ip->i_op->getxattr == NULL) 63 return NULL; 64 65 rc = ip->i_op->getxattr(dp, name, in, SMK_LABELLEN); 66 if (rc < 0) 67 return NULL; 68 69 return smk_import(in, rc); 70} 71 72/** 73 * new_inode_smack - allocate an inode security blob 74 * @smack: a pointer to the Smack label to use in the blob 75 * 76 * Returns the new blob or NULL if there's no memory available 77 */ 78struct inode_smack *new_inode_smack(char *smack) 79{ 80 struct inode_smack *isp; 81 82 isp = kzalloc(sizeof(struct inode_smack), GFP_KERNEL); 83 if (isp == NULL) 84 return NULL; 85 86 isp->smk_inode = smack; 87 isp->smk_flags = 0; 88 mutex_init(&isp->smk_lock); 89 90 return isp; 91} 92 93/** 94 * new_task_smack - allocate a task security blob 95 * @smack: a pointer to the Smack label to use in the blob 96 * 97 * Returns the new blob or NULL if there's no memory available 98 */ 99static struct task_smack *new_task_smack(char *task, char *forked, gfp_t gfp) 100{ 101 struct task_smack *tsp; 102 103 tsp = kzalloc(sizeof(struct task_smack), gfp); 104 if (tsp == NULL) 105 return NULL; 106 107 tsp->smk_task = task; 108 tsp->smk_forked = forked; 109 INIT_LIST_HEAD(&tsp->smk_rules); 110 mutex_init(&tsp->smk_rules_lock); 111 112 return tsp; 113} 114 115/** 116 * smk_copy_rules - copy a rule set 117 * @nhead - new rules header pointer 118 * @ohead - old rules header pointer 119 * 120 * Returns 0 on success, -ENOMEM on error 121 */ 122static int smk_copy_rules(struct list_head *nhead, struct list_head *ohead, 123 gfp_t gfp) 124{ 125 struct smack_rule *nrp; 126 struct smack_rule *orp; 127 int rc = 0; 128 129 INIT_LIST_HEAD(nhead); 130 131 list_for_each_entry_rcu(orp, ohead, list) { 132 nrp = kzalloc(sizeof(struct smack_rule), gfp); 133 if (nrp == NULL) { 134 rc = -ENOMEM; 135 break; 136 } 137 *nrp = *orp; 138 list_add_rcu(&nrp->list, nhead); 139 } 140 return rc; 141} 142 143/* 144 * LSM hooks. 145 * We he, that is fun! 146 */ 147 148/** 149 * smack_ptrace_access_check - Smack approval on PTRACE_ATTACH 150 * @ctp: child task pointer 151 * @mode: ptrace attachment mode 152 * 153 * Returns 0 if access is OK, an error code otherwise 154 * 155 * Do the capability checks, and require read and write. 156 */ 157static int smack_ptrace_access_check(struct task_struct *ctp, unsigned int mode) 158{ 159 int rc; 160 struct smk_audit_info ad; 161 char *tsp; 162 163 rc = cap_ptrace_access_check(ctp, mode); 164 if (rc != 0) 165 return rc; 166 167 tsp = smk_of_task(task_security(ctp)); 168 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK); 169 smk_ad_setfield_u_tsk(&ad, ctp); 170 171 rc = smk_curacc(tsp, MAY_READWRITE, &ad); 172 return rc; 173} 174 175/** 176 * smack_ptrace_traceme - Smack approval on PTRACE_TRACEME 177 * @ptp: parent task pointer 178 * 179 * Returns 0 if access is OK, an error code otherwise 180 * 181 * Do the capability checks, and require read and write. 182 */ 183static int smack_ptrace_traceme(struct task_struct *ptp) 184{ 185 int rc; 186 struct smk_audit_info ad; 187 char *tsp; 188 189 rc = cap_ptrace_traceme(ptp); 190 if (rc != 0) 191 return rc; 192 193 tsp = smk_of_task(task_security(ptp)); 194 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK); 195 smk_ad_setfield_u_tsk(&ad, ptp); 196 197 rc = smk_curacc(tsp, MAY_READWRITE, &ad); 198 return rc; 199} 200 201/** 202 * smack_syslog - Smack approval on syslog 203 * @type: message type 204 * 205 * Require that the task has the floor label 206 * 207 * Returns 0 on success, error code otherwise. 208 */ 209static int smack_syslog(int typefrom_file) 210{ 211 int rc = 0; 212 char *sp = smk_of_current(); 213 214 if (capable(CAP_MAC_OVERRIDE)) 215 return 0; 216 217 if (sp != smack_known_floor.smk_known) 218 rc = -EACCES; 219 220 return rc; 221} 222 223 224/* 225 * Superblock Hooks. 226 */ 227 228/** 229 * smack_sb_alloc_security - allocate a superblock blob 230 * @sb: the superblock getting the blob 231 * 232 * Returns 0 on success or -ENOMEM on error. 233 */ 234static int smack_sb_alloc_security(struct super_block *sb) 235{ 236 struct superblock_smack *sbsp; 237 238 sbsp = kzalloc(sizeof(struct superblock_smack), GFP_KERNEL); 239 240 if (sbsp == NULL) 241 return -ENOMEM; 242 243 sbsp->smk_root = smack_known_floor.smk_known; 244 sbsp->smk_default = smack_known_floor.smk_known; 245 sbsp->smk_floor = smack_known_floor.smk_known; 246 sbsp->smk_hat = smack_known_hat.smk_known; 247 sbsp->smk_initialized = 0; 248 spin_lock_init(&sbsp->smk_sblock); 249 250 sb->s_security = sbsp; 251 252 return 0; 253} 254 255/** 256 * smack_sb_free_security - free a superblock blob 257 * @sb: the superblock getting the blob 258 * 259 */ 260static void smack_sb_free_security(struct super_block *sb) 261{ 262 kfree(sb->s_security); 263 sb->s_security = NULL; 264} 265 266/** 267 * smack_sb_copy_data - copy mount options data for processing 268 * @orig: where to start 269 * @smackopts: mount options string 270 * 271 * Returns 0 on success or -ENOMEM on error. 272 * 273 * Copy the Smack specific mount options out of the mount 274 * options list. 275 */ 276static int smack_sb_copy_data(char *orig, char *smackopts) 277{ 278 char *cp, *commap, *otheropts, *dp; 279 280 otheropts = (char *)get_zeroed_page(GFP_KERNEL); 281 if (otheropts == NULL) 282 return -ENOMEM; 283 284 for (cp = orig, commap = orig; commap != NULL; cp = commap + 1) { 285 if (strstr(cp, SMK_FSDEFAULT) == cp) 286 dp = smackopts; 287 else if (strstr(cp, SMK_FSFLOOR) == cp) 288 dp = smackopts; 289 else if (strstr(cp, SMK_FSHAT) == cp) 290 dp = smackopts; 291 else if (strstr(cp, SMK_FSROOT) == cp) 292 dp = smackopts; 293 else 294 dp = otheropts; 295 296 commap = strchr(cp, ','); 297 if (commap != NULL) 298 *commap = '\0'; 299 300 if (*dp != '\0') 301 strcat(dp, ","); 302 strcat(dp, cp); 303 } 304 305 strcpy(orig, otheropts); 306 free_page((unsigned long)otheropts); 307 308 return 0; 309} 310 311/** 312 * smack_sb_kern_mount - Smack specific mount processing 313 * @sb: the file system superblock 314 * @flags: the mount flags 315 * @data: the smack mount options 316 * 317 * Returns 0 on success, an error code on failure 318 */ 319static int smack_sb_kern_mount(struct super_block *sb, int flags, void *data) 320{ 321 struct dentry *root = sb->s_root; 322 struct inode *inode = root->d_inode; 323 struct superblock_smack *sp = sb->s_security; 324 struct inode_smack *isp; 325 char *op; 326 char *commap; 327 char *nsp; 328 329 spin_lock(&sp->smk_sblock); 330 if (sp->smk_initialized != 0) { 331 spin_unlock(&sp->smk_sblock); 332 return 0; 333 } 334 sp->smk_initialized = 1; 335 spin_unlock(&sp->smk_sblock); 336 337 for (op = data; op != NULL; op = commap) { 338 commap = strchr(op, ','); 339 if (commap != NULL) 340 *commap++ = '\0'; 341 342 if (strncmp(op, SMK_FSHAT, strlen(SMK_FSHAT)) == 0) { 343 op += strlen(SMK_FSHAT); 344 nsp = smk_import(op, 0); 345 if (nsp != NULL) 346 sp->smk_hat = nsp; 347 } else if (strncmp(op, SMK_FSFLOOR, strlen(SMK_FSFLOOR)) == 0) { 348 op += strlen(SMK_FSFLOOR); 349 nsp = smk_import(op, 0); 350 if (nsp != NULL) 351 sp->smk_floor = nsp; 352 } else if (strncmp(op, SMK_FSDEFAULT, 353 strlen(SMK_FSDEFAULT)) == 0) { 354 op += strlen(SMK_FSDEFAULT); 355 nsp = smk_import(op, 0); 356 if (nsp != NULL) 357 sp->smk_default = nsp; 358 } else if (strncmp(op, SMK_FSROOT, strlen(SMK_FSROOT)) == 0) { 359 op += strlen(SMK_FSROOT); 360 nsp = smk_import(op, 0); 361 if (nsp != NULL) 362 sp->smk_root = nsp; 363 } 364 } 365 366 /* 367 * Initialize the root inode. 368 */ 369 isp = inode->i_security; 370 if (isp == NULL) 371 inode->i_security = new_inode_smack(sp->smk_root); 372 else 373 isp->smk_inode = sp->smk_root; 374 375 return 0; 376} 377 378/** 379 * smack_sb_statfs - Smack check on statfs 380 * @dentry: identifies the file system in question 381 * 382 * Returns 0 if current can read the floor of the filesystem, 383 * and error code otherwise 384 */ 385static int smack_sb_statfs(struct dentry *dentry) 386{ 387 struct superblock_smack *sbp = dentry->d_sb->s_security; 388 int rc; 389 struct smk_audit_info ad; 390 391 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); 392 smk_ad_setfield_u_fs_path_dentry(&ad, dentry); 393 394 rc = smk_curacc(sbp->smk_floor, MAY_READ, &ad); 395 return rc; 396} 397 398/** 399 * smack_sb_mount - Smack check for mounting 400 * @dev_name: unused 401 * @path: mount point 402 * @type: unused 403 * @flags: unused 404 * @data: unused 405 * 406 * Returns 0 if current can write the floor of the filesystem 407 * being mounted on, an error code otherwise. 408 */ 409static int smack_sb_mount(char *dev_name, struct path *path, 410 char *type, unsigned long flags, void *data) 411{ 412 struct superblock_smack *sbp = path->dentry->d_sb->s_security; 413 struct smk_audit_info ad; 414 415 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH); 416 smk_ad_setfield_u_fs_path(&ad, *path); 417 418 return smk_curacc(sbp->smk_floor, MAY_WRITE, &ad); 419} 420 421/** 422 * smack_sb_umount - Smack check for unmounting 423 * @mnt: file system to unmount 424 * @flags: unused 425 * 426 * Returns 0 if current can write the floor of the filesystem 427 * being unmounted, an error code otherwise. 428 */ 429static int smack_sb_umount(struct vfsmount *mnt, int flags) 430{ 431 struct superblock_smack *sbp; 432 struct smk_audit_info ad; 433 struct path path; 434 435 path.dentry = mnt->mnt_root; 436 path.mnt = mnt; 437 438 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH); 439 smk_ad_setfield_u_fs_path(&ad, path); 440 441 sbp = path.dentry->d_sb->s_security; 442 return smk_curacc(sbp->smk_floor, MAY_WRITE, &ad); 443} 444 445/* 446 * BPRM hooks 447 */ 448 449/** 450 * smack_bprm_set_creds - set creds for exec 451 * @bprm: the exec information 452 * 453 * Returns 0 if it gets a blob, -ENOMEM otherwise 454 */ 455static int smack_bprm_set_creds(struct linux_binprm *bprm) 456{ 457 struct inode *inode = bprm->file->f_path.dentry->d_inode; 458 struct task_smack *bsp = bprm->cred->security; 459 struct inode_smack *isp; 460 int rc; 461 462 rc = cap_bprm_set_creds(bprm); 463 if (rc != 0) 464 return rc; 465 466 if (bprm->cred_prepared) 467 return 0; 468 469 isp = inode->i_security; 470 if (isp->smk_task == NULL || isp->smk_task == bsp->smk_task) 471 return 0; 472 473 if (bprm->unsafe) 474 return -EPERM; 475 476 bsp->smk_task = isp->smk_task; 477 bprm->per_clear |= PER_CLEAR_ON_SETID; 478 479 return 0; 480} 481 482/** 483 * smack_bprm_committing_creds - Prepare to install the new credentials 484 * from bprm. 485 * 486 * @bprm: binprm for exec 487 */ 488static void smack_bprm_committing_creds(struct linux_binprm *bprm) 489{ 490 struct task_smack *bsp = bprm->cred->security; 491 492 if (bsp->smk_task != bsp->smk_forked) 493 current->pdeath_signal = 0; 494} 495 496/** 497 * smack_bprm_secureexec - Return the decision to use secureexec. 498 * @bprm: binprm for exec 499 * 500 * Returns 0 on success. 501 */ 502static int smack_bprm_secureexec(struct linux_binprm *bprm) 503{ 504 struct task_smack *tsp = current_security(); 505 int ret = cap_bprm_secureexec(bprm); 506 507 if (!ret && (tsp->smk_task != tsp->smk_forked)) 508 ret = 1; 509 510 return ret; 511} 512 513/* 514 * Inode hooks 515 */ 516 517/** 518 * smack_inode_alloc_security - allocate an inode blob 519 * @inode: the inode in need of a blob 520 * 521 * Returns 0 if it gets a blob, -ENOMEM otherwise 522 */ 523static int smack_inode_alloc_security(struct inode *inode) 524{ 525 inode->i_security = new_inode_smack(smk_of_current()); 526 if (inode->i_security == NULL) 527 return -ENOMEM; 528 return 0; 529} 530 531/** 532 * smack_inode_free_security - free an inode blob 533 * @inode: the inode with a blob 534 * 535 * Clears the blob pointer in inode 536 */ 537static void smack_inode_free_security(struct inode *inode) 538{ 539 kfree(inode->i_security); 540 inode->i_security = NULL; 541} 542 543/** 544 * smack_inode_init_security - copy out the smack from an inode 545 * @inode: the inode 546 * @dir: unused 547 * @qstr: unused 548 * @name: where to put the attribute name 549 * @value: where to put the attribute value 550 * @len: where to put the length of the attribute 551 * 552 * Returns 0 if it all works out, -ENOMEM if there's no memory 553 */ 554static int smack_inode_init_security(struct inode *inode, struct inode *dir, 555 const struct qstr *qstr, char **name, 556 void **value, size_t *len) 557{ 558 struct smack_known *skp; 559 char *csp = smk_of_current(); 560 char *isp = smk_of_inode(inode); 561 char *dsp = smk_of_inode(dir); 562 int may; 563 564 if (name) { 565 *name = kstrdup(XATTR_SMACK_SUFFIX, GFP_KERNEL); 566 if (*name == NULL) 567 return -ENOMEM; 568 } 569 570 if (value) { 571 skp = smk_find_entry(csp); 572 rcu_read_lock(); 573 may = smk_access_entry(csp, dsp, &skp->smk_rules); 574 rcu_read_unlock(); 575 576 /* 577 * If the access rule allows transmutation and 578 * the directory requests transmutation then 579 * by all means transmute. 580 */ 581 if (may > 0 && ((may & MAY_TRANSMUTE) != 0) && 582 smk_inode_transmutable(dir)) 583 isp = dsp; 584 585 *value = kstrdup(isp, GFP_KERNEL); 586 if (*value == NULL) 587 return -ENOMEM; 588 } 589 590 if (len) 591 *len = strlen(isp) + 1; 592 593 return 0; 594} 595 596/** 597 * smack_inode_link - Smack check on link 598 * @old_dentry: the existing object 599 * @dir: unused 600 * @new_dentry: the new object 601 * 602 * Returns 0 if access is permitted, an error code otherwise 603 */ 604static int smack_inode_link(struct dentry *old_dentry, struct inode *dir, 605 struct dentry *new_dentry) 606{ 607 char *isp; 608 struct smk_audit_info ad; 609 int rc; 610 611 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); 612 smk_ad_setfield_u_fs_path_dentry(&ad, old_dentry); 613 614 isp = smk_of_inode(old_dentry->d_inode); 615 rc = smk_curacc(isp, MAY_WRITE, &ad); 616 617 if (rc == 0 && new_dentry->d_inode != NULL) { 618 isp = smk_of_inode(new_dentry->d_inode); 619 smk_ad_setfield_u_fs_path_dentry(&ad, new_dentry); 620 rc = smk_curacc(isp, MAY_WRITE, &ad); 621 } 622 623 return rc; 624} 625 626/** 627 * smack_inode_unlink - Smack check on inode deletion 628 * @dir: containing directory object 629 * @dentry: file to unlink 630 * 631 * Returns 0 if current can write the containing directory 632 * and the object, error code otherwise 633 */ 634static int smack_inode_unlink(struct inode *dir, struct dentry *dentry) 635{ 636 struct inode *ip = dentry->d_inode; 637 struct smk_audit_info ad; 638 int rc; 639 640 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); 641 smk_ad_setfield_u_fs_path_dentry(&ad, dentry); 642 643 /* 644 * You need write access to the thing you're unlinking 645 */ 646 rc = smk_curacc(smk_of_inode(ip), MAY_WRITE, &ad); 647 if (rc == 0) { 648 /* 649 * You also need write access to the containing directory 650 */ 651 smk_ad_setfield_u_fs_path_dentry(&ad, NULL); 652 smk_ad_setfield_u_fs_inode(&ad, dir); 653 rc = smk_curacc(smk_of_inode(dir), MAY_WRITE, &ad); 654 } 655 return rc; 656} 657 658/** 659 * smack_inode_rmdir - Smack check on directory deletion 660 * @dir: containing directory object 661 * @dentry: directory to unlink 662 * 663 * Returns 0 if current can write the containing directory 664 * and the directory, error code otherwise 665 */ 666static int smack_inode_rmdir(struct inode *dir, struct dentry *dentry) 667{ 668 struct smk_audit_info ad; 669 int rc; 670 671 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); 672 smk_ad_setfield_u_fs_path_dentry(&ad, dentry); 673 674 /* 675 * You need write access to the thing you're removing 676 */ 677 rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE, &ad); 678 if (rc == 0) { 679 /* 680 * You also need write access to the containing directory 681 */ 682 smk_ad_setfield_u_fs_path_dentry(&ad, NULL); 683 smk_ad_setfield_u_fs_inode(&ad, dir); 684 rc = smk_curacc(smk_of_inode(dir), MAY_WRITE, &ad); 685 } 686 687 return rc; 688} 689 690/** 691 * smack_inode_rename - Smack check on rename 692 * @old_inode: the old directory 693 * @old_dentry: unused 694 * @new_inode: the new directory 695 * @new_dentry: unused 696 * 697 * Read and write access is required on both the old and 698 * new directories. 699 * 700 * Returns 0 if access is permitted, an error code otherwise 701 */ 702static int smack_inode_rename(struct inode *old_inode, 703 struct dentry *old_dentry, 704 struct inode *new_inode, 705 struct dentry *new_dentry) 706{ 707 int rc; 708 char *isp; 709 struct smk_audit_info ad; 710 711 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); 712 smk_ad_setfield_u_fs_path_dentry(&ad, old_dentry); 713 714 isp = smk_of_inode(old_dentry->d_inode); 715 rc = smk_curacc(isp, MAY_READWRITE, &ad); 716 717 if (rc == 0 && new_dentry->d_inode != NULL) { 718 isp = smk_of_inode(new_dentry->d_inode); 719 smk_ad_setfield_u_fs_path_dentry(&ad, new_dentry); 720 rc = smk_curacc(isp, MAY_READWRITE, &ad); 721 } 722 return rc; 723} 724 725/** 726 * smack_inode_permission - Smack version of permission() 727 * @inode: the inode in question 728 * @mask: the access requested 729 * 730 * This is the important Smack hook. 731 * 732 * Returns 0 if access is permitted, -EACCES otherwise 733 */ 734static int smack_inode_permission(struct inode *inode, int mask) 735{ 736 struct smk_audit_info ad; 737 int no_block = mask & MAY_NOT_BLOCK; 738 739 mask &= (MAY_READ|MAY_WRITE|MAY_EXEC|MAY_APPEND); 740 /* 741 * No permission to check. Existence test. Yup, it's there. 742 */ 743 if (mask == 0) 744 return 0; 745 746 /* May be droppable after audit */ 747 if (no_block) 748 return -ECHILD; 749 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_INODE); 750 smk_ad_setfield_u_fs_inode(&ad, inode); 751 return smk_curacc(smk_of_inode(inode), mask, &ad); 752} 753 754/** 755 * smack_inode_setattr - Smack check for setting attributes 756 * @dentry: the object 757 * @iattr: for the force flag 758 * 759 * Returns 0 if access is permitted, an error code otherwise 760 */ 761static int smack_inode_setattr(struct dentry *dentry, struct iattr *iattr) 762{ 763 struct smk_audit_info ad; 764 /* 765 * Need to allow for clearing the setuid bit. 766 */ 767 if (iattr->ia_valid & ATTR_FORCE) 768 return 0; 769 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); 770 smk_ad_setfield_u_fs_path_dentry(&ad, dentry); 771 772 return smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE, &ad); 773} 774 775/** 776 * smack_inode_getattr - Smack check for getting attributes 777 * @mnt: unused 778 * @dentry: the object 779 * 780 * Returns 0 if access is permitted, an error code otherwise 781 */ 782static int smack_inode_getattr(struct vfsmount *mnt, struct dentry *dentry) 783{ 784 struct smk_audit_info ad; 785 struct path path; 786 787 path.dentry = dentry; 788 path.mnt = mnt; 789 790 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH); 791 smk_ad_setfield_u_fs_path(&ad, path); 792 return smk_curacc(smk_of_inode(dentry->d_inode), MAY_READ, &ad); 793} 794 795/** 796 * smack_inode_setxattr - Smack check for setting xattrs 797 * @dentry: the object 798 * @name: name of the attribute 799 * @value: unused 800 * @size: unused 801 * @flags: unused 802 * 803 * This protects the Smack attribute explicitly. 804 * 805 * Returns 0 if access is permitted, an error code otherwise 806 */ 807static int smack_inode_setxattr(struct dentry *dentry, const char *name, 808 const void *value, size_t size, int flags) 809{ 810 struct smk_audit_info ad; 811 int rc = 0; 812 813 if (strcmp(name, XATTR_NAME_SMACK) == 0 || 814 strcmp(name, XATTR_NAME_SMACKIPIN) == 0 || 815 strcmp(name, XATTR_NAME_SMACKIPOUT) == 0 || 816 strcmp(name, XATTR_NAME_SMACKEXEC) == 0 || 817 strcmp(name, XATTR_NAME_SMACKMMAP) == 0) { 818 if (!capable(CAP_MAC_ADMIN)) 819 rc = -EPERM; 820 /* 821 * check label validity here so import wont fail on 822 * post_setxattr 823 */ 824 if (size == 0 || size >= SMK_LABELLEN || 825 smk_import(value, size) == NULL) 826 rc = -EINVAL; 827 } else if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0) { 828 if (!capable(CAP_MAC_ADMIN)) 829 rc = -EPERM; 830 if (size != TRANS_TRUE_SIZE || 831 strncmp(value, TRANS_TRUE, TRANS_TRUE_SIZE) != 0) 832 rc = -EINVAL; 833 } else 834 rc = cap_inode_setxattr(dentry, name, value, size, flags); 835 836 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); 837 smk_ad_setfield_u_fs_path_dentry(&ad, dentry); 838 839 if (rc == 0) 840 rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE, &ad); 841 842 return rc; 843} 844 845/** 846 * smack_inode_post_setxattr - Apply the Smack update approved above 847 * @dentry: object 848 * @name: attribute name 849 * @value: attribute value 850 * @size: attribute size 851 * @flags: unused 852 * 853 * Set the pointer in the inode blob to the entry found 854 * in the master label list. 855 */ 856static void smack_inode_post_setxattr(struct dentry *dentry, const char *name, 857 const void *value, size_t size, int flags) 858{ 859 char *nsp; 860 struct inode_smack *isp = dentry->d_inode->i_security; 861 862 if (strcmp(name, XATTR_NAME_SMACK) == 0) { 863 nsp = smk_import(value, size); 864 if (nsp != NULL) 865 isp->smk_inode = nsp; 866 else 867 isp->smk_inode = smack_known_invalid.smk_known; 868 } else if (strcmp(name, XATTR_NAME_SMACKEXEC) == 0) { 869 nsp = smk_import(value, size); 870 if (nsp != NULL) 871 isp->smk_task = nsp; 872 else 873 isp->smk_task = smack_known_invalid.smk_known; 874 } else if (strcmp(name, XATTR_NAME_SMACKMMAP) == 0) { 875 nsp = smk_import(value, size); 876 if (nsp != NULL) 877 isp->smk_mmap = nsp; 878 else 879 isp->smk_mmap = smack_known_invalid.smk_known; 880 } else if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0) 881 isp->smk_flags |= SMK_INODE_TRANSMUTE; 882 883 return; 884} 885 886/** 887 * smack_inode_getxattr - Smack check on getxattr 888 * @dentry: the object 889 * @name: unused 890 * 891 * Returns 0 if access is permitted, an error code otherwise 892 */ 893static int smack_inode_getxattr(struct dentry *dentry, const char *name) 894{ 895 struct smk_audit_info ad; 896 897 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); 898 smk_ad_setfield_u_fs_path_dentry(&ad, dentry); 899 900 return smk_curacc(smk_of_inode(dentry->d_inode), MAY_READ, &ad); 901} 902 903/** 904 * smack_inode_removexattr - Smack check on removexattr 905 * @dentry: the object 906 * @name: name of the attribute 907 * 908 * Removing the Smack attribute requires CAP_MAC_ADMIN 909 * 910 * Returns 0 if access is permitted, an error code otherwise 911 */ 912static int smack_inode_removexattr(struct dentry *dentry, const char *name) 913{ 914 struct inode_smack *isp; 915 struct smk_audit_info ad; 916 int rc = 0; 917 918 if (strcmp(name, XATTR_NAME_SMACK) == 0 || 919 strcmp(name, XATTR_NAME_SMACKIPIN) == 0 || 920 strcmp(name, XATTR_NAME_SMACKIPOUT) == 0 || 921 strcmp(name, XATTR_NAME_SMACKEXEC) == 0 || 922 strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0 || 923 strcmp(name, XATTR_NAME_SMACKMMAP)) { 924 if (!capable(CAP_MAC_ADMIN)) 925 rc = -EPERM; 926 } else 927 rc = cap_inode_removexattr(dentry, name); 928 929 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); 930 smk_ad_setfield_u_fs_path_dentry(&ad, dentry); 931 if (rc == 0) 932 rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE, &ad); 933 934 if (rc == 0) { 935 isp = dentry->d_inode->i_security; 936 isp->smk_task = NULL; 937 isp->smk_mmap = NULL; 938 } 939 940 return rc; 941} 942 943/** 944 * smack_inode_getsecurity - get smack xattrs 945 * @inode: the object 946 * @name: attribute name 947 * @buffer: where to put the result 948 * @alloc: unused 949 * 950 * Returns the size of the attribute or an error code 951 */ 952static int smack_inode_getsecurity(const struct inode *inode, 953 const char *name, void **buffer, 954 bool alloc) 955{ 956 struct socket_smack *ssp; 957 struct socket *sock; 958 struct super_block *sbp; 959 struct inode *ip = (struct inode *)inode; 960 char *isp; 961 int ilen; 962 int rc = 0; 963 964 if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) { 965 isp = smk_of_inode(inode); 966 ilen = strlen(isp) + 1; 967 *buffer = isp; 968 return ilen; 969 } 970 971 /* 972 * The rest of the Smack xattrs are only on sockets. 973 */ 974 sbp = ip->i_sb; 975 if (sbp->s_magic != SOCKFS_MAGIC) 976 return -EOPNOTSUPP; 977 978 sock = SOCKET_I(ip); 979 if (sock == NULL || sock->sk == NULL) 980 return -EOPNOTSUPP; 981 982 ssp = sock->sk->sk_security; 983 984 if (strcmp(name, XATTR_SMACK_IPIN) == 0) 985 isp = ssp->smk_in; 986 else if (strcmp(name, XATTR_SMACK_IPOUT) == 0) 987 isp = ssp->smk_out; 988 else 989 return -EOPNOTSUPP; 990 991 ilen = strlen(isp) + 1; 992 if (rc == 0) { 993 *buffer = isp; 994 rc = ilen; 995 } 996 997 return rc; 998} 999 1000 1001/** 1002 * smack_inode_listsecurity - list the Smack attributes 1003 * @inode: the object 1004 * @buffer: where they go 1005 * @buffer_size: size of buffer 1006 * 1007 * Returns 0 on success, -EINVAL otherwise 1008 */ 1009static int smack_inode_listsecurity(struct inode *inode, char *buffer, 1010 size_t buffer_size) 1011{ 1012 int len = strlen(XATTR_NAME_SMACK); 1013 1014 if (buffer != NULL && len <= buffer_size) { 1015 memcpy(buffer, XATTR_NAME_SMACK, len); 1016 return len; 1017 } 1018 return -EINVAL; 1019} 1020 1021/** 1022 * smack_inode_getsecid - Extract inode's security id 1023 * @inode: inode to extract the info from 1024 * @secid: where result will be saved 1025 */ 1026static void smack_inode_getsecid(const struct inode *inode, u32 *secid) 1027{ 1028 struct inode_smack *isp = inode->i_security; 1029 1030 *secid = smack_to_secid(isp->smk_inode); 1031} 1032 1033/* 1034 * File Hooks 1035 */ 1036 1037/** 1038 * smack_file_permission - Smack check on file operations 1039 * @file: unused 1040 * @mask: unused 1041 * 1042 * Returns 0 1043 * 1044 * Should access checks be done on each read or write? 1045 * UNICOS and SELinux say yes. 1046 * Trusted Solaris, Trusted Irix, and just about everyone else says no. 1047 * 1048 * I'll say no for now. Smack does not do the frequent 1049 * label changing that SELinux does. 1050 */ 1051static int smack_file_permission(struct file *file, int mask) 1052{ 1053 return 0; 1054} 1055 1056/** 1057 * smack_file_alloc_security - assign a file security blob 1058 * @file: the object 1059 * 1060 * The security blob for a file is a pointer to the master 1061 * label list, so no allocation is done. 1062 * 1063 * Returns 0 1064 */ 1065static int smack_file_alloc_security(struct file *file) 1066{ 1067 file->f_security = smk_of_current(); 1068 return 0; 1069} 1070 1071/** 1072 * smack_file_free_security - clear a file security blob 1073 * @file: the object 1074 * 1075 * The security blob for a file is a pointer to the master 1076 * label list, so no memory is freed. 1077 */ 1078static void smack_file_free_security(struct file *file) 1079{ 1080 file->f_security = NULL; 1081} 1082 1083/** 1084 * smack_file_ioctl - Smack check on ioctls 1085 * @file: the object 1086 * @cmd: what to do 1087 * @arg: unused 1088 * 1089 * Relies heavily on the correct use of the ioctl command conventions. 1090 * 1091 * Returns 0 if allowed, error code otherwise 1092 */ 1093static int smack_file_ioctl(struct file *file, unsigned int cmd, 1094 unsigned long arg) 1095{ 1096 int rc = 0; 1097 struct smk_audit_info ad; 1098 1099 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH); 1100 smk_ad_setfield_u_fs_path(&ad, file->f_path); 1101 1102 if (_IOC_DIR(cmd) & _IOC_WRITE) 1103 rc = smk_curacc(file->f_security, MAY_WRITE, &ad); 1104 1105 if (rc == 0 && (_IOC_DIR(cmd) & _IOC_READ)) 1106 rc = smk_curacc(file->f_security, MAY_READ, &ad); 1107 1108 return rc; 1109} 1110 1111/** 1112 * smack_file_lock - Smack check on file locking 1113 * @file: the object 1114 * @cmd: unused 1115 * 1116 * Returns 0 if current has write access, error code otherwise 1117 */ 1118static int smack_file_lock(struct file *file, unsigned int cmd) 1119{ 1120 struct smk_audit_info ad; 1121 1122 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH); 1123 smk_ad_setfield_u_fs_path(&ad, file->f_path); 1124 return smk_curacc(file->f_security, MAY_WRITE, &ad); 1125} 1126 1127/** 1128 * smack_file_fcntl - Smack check on fcntl 1129 * @file: the object 1130 * @cmd: what action to check 1131 * @arg: unused 1132 * 1133 * Generally these operations are harmless. 1134 * File locking operations present an obvious mechanism 1135 * for passing information, so they require write access. 1136 * 1137 * Returns 0 if current has access, error code otherwise 1138 */ 1139static int smack_file_fcntl(struct file *file, unsigned int cmd, 1140 unsigned long arg) 1141{ 1142 struct smk_audit_info ad; 1143 int rc = 0; 1144 1145 1146 switch (cmd) { 1147 case F_GETLK: 1148 case F_SETLK: 1149 case F_SETLKW: 1150 case F_SETOWN: 1151 case F_SETSIG: 1152 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH); 1153 smk_ad_setfield_u_fs_path(&ad, file->f_path); 1154 rc = smk_curacc(file->f_security, MAY_WRITE, &ad); 1155 break; 1156 default: 1157 break; 1158 } 1159 1160 return rc; 1161} 1162 1163/** 1164 * smack_file_mmap : 1165 * Check permissions for a mmap operation. The @file may be NULL, e.g. 1166 * if mapping anonymous memory. 1167 * @file contains the file structure for file to map (may be NULL). 1168 * @reqprot contains the protection requested by the application. 1169 * @prot contains the protection that will be applied by the kernel. 1170 * @flags contains the operational flags. 1171 * Return 0 if permission is granted. 1172 */ 1173static int smack_file_mmap(struct file *file, 1174 unsigned long reqprot, unsigned long prot, 1175 unsigned long flags, unsigned long addr, 1176 unsigned long addr_only) 1177{ 1178 struct smack_known *skp; 1179 struct smack_rule *srp; 1180 struct task_smack *tsp; 1181 char *sp; 1182 char *msmack; 1183 char *osmack; 1184 struct inode_smack *isp; 1185 struct dentry *dp; 1186 int may; 1187 int mmay; 1188 int tmay; 1189 int rc; 1190 1191 /* do DAC check on address space usage */ 1192 rc = cap_file_mmap(file, reqprot, prot, flags, addr, addr_only); 1193 if (rc || addr_only) 1194 return rc; 1195 1196 if (file == NULL || file->f_dentry == NULL) 1197 return 0; 1198 1199 dp = file->f_dentry; 1200 1201 if (dp->d_inode == NULL) 1202 return 0; 1203 1204 isp = dp->d_inode->i_security; 1205 if (isp->smk_mmap == NULL) 1206 return 0; 1207 msmack = isp->smk_mmap; 1208 1209 tsp = current_security(); 1210 sp = smk_of_current(); 1211 skp = smk_find_entry(sp); 1212 rc = 0; 1213 1214 rcu_read_lock(); 1215 /* 1216 * For each Smack rule associated with the subject 1217 * label verify that the SMACK64MMAP also has access 1218 * to that rule's object label. 1219 */ 1220 list_for_each_entry_rcu(srp, &skp->smk_rules, list) { 1221 osmack = srp->smk_object; 1222 /* 1223 * Matching labels always allows access. 1224 */ 1225 if (msmack == osmack) 1226 continue; 1227 /* 1228 * If there is a matching local rule take 1229 * that into account as well. 1230 */ 1231 may = smk_access_entry(srp->smk_subject, osmack, 1232 &tsp->smk_rules); 1233 if (may == -ENOENT) 1234 may = srp->smk_access; 1235 else 1236 may &= srp->smk_access; 1237 /* 1238 * If may is zero the SMACK64MMAP subject can't 1239 * possibly have less access. 1240 */ 1241 if (may == 0) 1242 continue; 1243 1244 /* 1245 * Fetch the global list entry. 1246 * If there isn't one a SMACK64MMAP subject 1247 * can't have as much access as current. 1248 */ 1249 skp = smk_find_entry(msmack); 1250 mmay = smk_access_entry(msmack, osmack, &skp->smk_rules); 1251 if (mmay == -ENOENT) { 1252 rc = -EACCES; 1253 break; 1254 } 1255 /* 1256 * If there is a local entry it modifies the 1257 * potential access, too. 1258 */ 1259 tmay = smk_access_entry(msmack, osmack, &tsp->smk_rules); 1260 if (tmay != -ENOENT) 1261 mmay &= tmay; 1262 1263 /* 1264 * If there is any access available to current that is 1265 * not available to a SMACK64MMAP subject 1266 * deny access. 1267 */ 1268 if ((may | mmay) != mmay) { 1269 rc = -EACCES; 1270 break; 1271 } 1272 } 1273 1274 rcu_read_unlock(); 1275 1276 return rc; 1277} 1278 1279/** 1280 * smack_file_set_fowner - set the file security blob value 1281 * @file: object in question 1282 * 1283 * Returns 0 1284 * Further research may be required on this one. 1285 */ 1286static int smack_file_set_fowner(struct file *file) 1287{ 1288 file->f_security = smk_of_current(); 1289 return 0; 1290} 1291 1292/** 1293 * smack_file_send_sigiotask - Smack on sigio 1294 * @tsk: The target task 1295 * @fown: the object the signal come from 1296 * @signum: unused 1297 * 1298 * Allow a privileged task to get signals even if it shouldn't 1299 * 1300 * Returns 0 if a subject with the object's smack could 1301 * write to the task, an error code otherwise. 1302 */ 1303static int smack_file_send_sigiotask(struct task_struct *tsk, 1304 struct fown_struct *fown, int signum) 1305{ 1306 struct file *file; 1307 int rc; 1308 char *tsp = smk_of_task(tsk->cred->security); 1309 struct smk_audit_info ad; 1310 1311 /* 1312 * struct fown_struct is never outside the context of a struct file 1313 */ 1314 file = container_of(fown, struct file, f_owner); 1315 1316 /* we don't log here as rc can be overriden */ 1317 rc = smk_access(file->f_security, tsp, MAY_WRITE, NULL); 1318 if (rc != 0 && has_capability(tsk, CAP_MAC_OVERRIDE)) 1319 rc = 0; 1320 1321 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK); 1322 smk_ad_setfield_u_tsk(&ad, tsk); 1323 smack_log(file->f_security, tsp, MAY_WRITE, rc, &ad); 1324 return rc; 1325} 1326 1327/** 1328 * smack_file_receive - Smack file receive check 1329 * @file: the object 1330 * 1331 * Returns 0 if current has access, error code otherwise 1332 */ 1333static int smack_file_receive(struct file *file) 1334{ 1335 int may = 0; 1336 struct smk_audit_info ad; 1337 1338 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK); 1339 smk_ad_setfield_u_fs_path(&ad, file->f_path); 1340 /* 1341 * This code relies on bitmasks. 1342 */ 1343 if (file->f_mode & FMODE_READ) 1344 may = MAY_READ; 1345 if (file->f_mode & FMODE_WRITE) 1346 may |= MAY_WRITE; 1347 1348 return smk_curacc(file->f_security, may, &ad); 1349} 1350 1351/** 1352 * smack_dentry_open - Smack dentry open processing 1353 * @file: the object 1354 * @cred: unused 1355 * 1356 * Set the security blob in the file structure. 1357 * 1358 * Returns 0 1359 */ 1360static int smack_dentry_open(struct file *file, const struct cred *cred) 1361{ 1362 struct inode_smack *isp = file->f_path.dentry->d_inode->i_security; 1363 1364 file->f_security = isp->smk_inode; 1365 1366 return 0; 1367} 1368 1369/* 1370 * Task hooks 1371 */ 1372 1373/** 1374 * smack_cred_alloc_blank - "allocate" blank task-level security credentials 1375 * @new: the new credentials 1376 * @gfp: the atomicity of any memory allocations 1377 * 1378 * Prepare a blank set of credentials for modification. This must allocate all 1379 * the memory the LSM module might require such that cred_transfer() can 1380 * complete without error. 1381 */ 1382static int smack_cred_alloc_blank(struct cred *cred, gfp_t gfp) 1383{ 1384 struct task_smack *tsp; 1385 1386 tsp = new_task_smack(NULL, NULL, gfp); 1387 if (tsp == NULL) 1388 return -ENOMEM; 1389 1390 cred->security = tsp; 1391 1392 return 0; 1393} 1394 1395 1396/** 1397 * smack_cred_free - "free" task-level security credentials 1398 * @cred: the credentials in question 1399 * 1400 */ 1401static void smack_cred_free(struct cred *cred) 1402{ 1403 struct task_smack *tsp = cred->security; 1404 struct smack_rule *rp; 1405 struct list_head *l; 1406 struct list_head *n; 1407 1408 if (tsp == NULL) 1409 return; 1410 cred->security = NULL; 1411 1412 list_for_each_safe(l, n, &tsp->smk_rules) { 1413 rp = list_entry(l, struct smack_rule, list); 1414 list_del(&rp->list); 1415 kfree(rp); 1416 } 1417 kfree(tsp); 1418} 1419 1420/** 1421 * smack_cred_prepare - prepare new set of credentials for modification 1422 * @new: the new credentials 1423 * @old: the original credentials 1424 * @gfp: the atomicity of any memory allocations 1425 * 1426 * Prepare a new set of credentials for modification. 1427 */ 1428static int smack_cred_prepare(struct cred *new, const struct cred *old, 1429 gfp_t gfp) 1430{ 1431 struct task_smack *old_tsp = old->security; 1432 struct task_smack *new_tsp; 1433 int rc; 1434 1435 new_tsp = new_task_smack(old_tsp->smk_task, old_tsp->smk_task, gfp); 1436 if (new_tsp == NULL) 1437 return -ENOMEM; 1438 1439 rc = smk_copy_rules(&new_tsp->smk_rules, &old_tsp->smk_rules, gfp); 1440 if (rc != 0) 1441 return rc; 1442 1443 new->security = new_tsp; 1444 return 0; 1445} 1446 1447/** 1448 * smack_cred_transfer - Transfer the old credentials to the new credentials 1449 * @new: the new credentials 1450 * @old: the original credentials 1451 * 1452 * Fill in a set of blank credentials from another set of credentials. 1453 */ 1454static void smack_cred_transfer(struct cred *new, const struct cred *old) 1455{ 1456 struct task_smack *old_tsp = old->security; 1457 struct task_smack *new_tsp = new->security; 1458 1459 new_tsp->smk_task = old_tsp->smk_task; 1460 new_tsp->smk_forked = old_tsp->smk_task; 1461 mutex_init(&new_tsp->smk_rules_lock); 1462 INIT_LIST_HEAD(&new_tsp->smk_rules); 1463 1464 1465 /* cbs copy rule list */ 1466} 1467 1468/** 1469 * smack_kernel_act_as - Set the subjective context in a set of credentials 1470 * @new: points to the set of credentials to be modified. 1471 * @secid: specifies the security ID to be set 1472 * 1473 * Set the security data for a kernel service. 1474 */ 1475static int smack_kernel_act_as(struct cred *new, u32 secid) 1476{ 1477 struct task_smack *new_tsp = new->security; 1478 char *smack = smack_from_secid(secid); 1479 1480 if (smack == NULL) 1481 return -EINVAL; 1482 1483 new_tsp->smk_task = smack; 1484 return 0; 1485} 1486 1487/** 1488 * smack_kernel_create_files_as - Set the file creation label in a set of creds 1489 * @new: points to the set of credentials to be modified 1490 * @inode: points to the inode to use as a reference 1491 * 1492 * Set the file creation context in a set of credentials to the same 1493 * as the objective context of the specified inode 1494 */ 1495static int smack_kernel_create_files_as(struct cred *new, 1496 struct inode *inode) 1497{ 1498 struct inode_smack *isp = inode->i_security; 1499 struct task_smack *tsp = new->security; 1500 1501 tsp->smk_forked = isp->smk_inode; 1502 tsp->smk_task = isp->smk_inode; 1503 return 0; 1504} 1505 1506/** 1507 * smk_curacc_on_task - helper to log task related access 1508 * @p: the task object 1509 * @access: the access requested 1510 * @caller: name of the calling function for audit 1511 * 1512 * Return 0 if access is permitted 1513 */ 1514static int smk_curacc_on_task(struct task_struct *p, int access, 1515 const char *caller) 1516{ 1517 struct smk_audit_info ad; 1518 1519 smk_ad_init(&ad, caller, LSM_AUDIT_DATA_TASK); 1520 smk_ad_setfield_u_tsk(&ad, p); 1521 return smk_curacc(smk_of_task(task_security(p)), access, &ad); 1522} 1523 1524/** 1525 * smack_task_setpgid - Smack check on setting pgid 1526 * @p: the task object 1527 * @pgid: unused 1528 * 1529 * Return 0 if write access is permitted 1530 */ 1531static int smack_task_setpgid(struct task_struct *p, pid_t pgid) 1532{ 1533 return smk_curacc_on_task(p, MAY_WRITE, __func__); 1534} 1535 1536/** 1537 * smack_task_getpgid - Smack access check for getpgid 1538 * @p: the object task 1539 * 1540 * Returns 0 if current can read the object task, error code otherwise 1541 */ 1542static int smack_task_getpgid(struct task_struct *p) 1543{ 1544 return smk_curacc_on_task(p, MAY_READ, __func__); 1545} 1546 1547/** 1548 * smack_task_getsid - Smack access check for getsid 1549 * @p: the object task 1550 * 1551 * Returns 0 if current can read the object task, error code otherwise 1552 */ 1553static int smack_task_getsid(struct task_struct *p) 1554{ 1555 return smk_curacc_on_task(p, MAY_READ, __func__); 1556} 1557 1558/** 1559 * smack_task_getsecid - get the secid of the task 1560 * @p: the object task 1561 * @secid: where to put the result 1562 * 1563 * Sets the secid to contain a u32 version of the smack label. 1564 */ 1565static void smack_task_getsecid(struct task_struct *p, u32 *secid) 1566{ 1567 *secid = smack_to_secid(smk_of_task(task_security(p))); 1568} 1569 1570/** 1571 * smack_task_setnice - Smack check on setting nice 1572 * @p: the task object 1573 * @nice: unused 1574 * 1575 * Return 0 if write access is permitted 1576 */ 1577static int smack_task_setnice(struct task_struct *p, int nice) 1578{ 1579 int rc; 1580 1581 rc = cap_task_setnice(p, nice); 1582 if (rc == 0) 1583 rc = smk_curacc_on_task(p, MAY_WRITE, __func__); 1584 return rc; 1585} 1586 1587/** 1588 * smack_task_setioprio - Smack check on setting ioprio 1589 * @p: the task object 1590 * @ioprio: unused 1591 * 1592 * Return 0 if write access is permitted 1593 */ 1594static int smack_task_setioprio(struct task_struct *p, int ioprio) 1595{ 1596 int rc; 1597 1598 rc = cap_task_setioprio(p, ioprio); 1599 if (rc == 0) 1600 rc = smk_curacc_on_task(p, MAY_WRITE, __func__); 1601 return rc; 1602} 1603 1604/** 1605 * smack_task_getioprio - Smack check on reading ioprio 1606 * @p: the task object 1607 * 1608 * Return 0 if read access is permitted 1609 */ 1610static int smack_task_getioprio(struct task_struct *p) 1611{ 1612 return smk_curacc_on_task(p, MAY_READ, __func__); 1613} 1614 1615/** 1616 * smack_task_setscheduler - Smack check on setting scheduler 1617 * @p: the task object 1618 * @policy: unused 1619 * @lp: unused 1620 * 1621 * Return 0 if read access is permitted 1622 */ 1623static int smack_task_setscheduler(struct task_struct *p) 1624{ 1625 int rc; 1626 1627 rc = cap_task_setscheduler(p); 1628 if (rc == 0) 1629 rc = smk_curacc_on_task(p, MAY_WRITE, __func__); 1630 return rc; 1631} 1632 1633/** 1634 * smack_task_getscheduler - Smack check on reading scheduler 1635 * @p: the task object 1636 * 1637 * Return 0 if read access is permitted 1638 */ 1639static int smack_task_getscheduler(struct task_struct *p) 1640{ 1641 return smk_curacc_on_task(p, MAY_READ, __func__); 1642} 1643 1644/** 1645 * smack_task_movememory - Smack check on moving memory 1646 * @p: the task object 1647 * 1648 * Return 0 if write access is permitted 1649 */ 1650static int smack_task_movememory(struct task_struct *p) 1651{ 1652 return smk_curacc_on_task(p, MAY_WRITE, __func__); 1653} 1654 1655/** 1656 * smack_task_kill - Smack check on signal delivery 1657 * @p: the task object 1658 * @info: unused 1659 * @sig: unused 1660 * @secid: identifies the smack to use in lieu of current's 1661 * 1662 * Return 0 if write access is permitted 1663 * 1664 * The secid behavior is an artifact of an SELinux hack 1665 * in the USB code. Someday it may go away. 1666 */ 1667static int smack_task_kill(struct task_struct *p, struct siginfo *info, 1668 int sig, u32 secid) 1669{ 1670 struct smk_audit_info ad; 1671 1672 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK); 1673 smk_ad_setfield_u_tsk(&ad, p); 1674 /* 1675 * Sending a signal requires that the sender 1676 * can write the receiver. 1677 */ 1678 if (secid == 0) 1679 return smk_curacc(smk_of_task(task_security(p)), MAY_WRITE, 1680 &ad); 1681 /* 1682 * If the secid isn't 0 we're dealing with some USB IO 1683 * specific behavior. This is not clean. For one thing 1684 * we can't take privilege into account. 1685 */ 1686 return smk_access(smack_from_secid(secid), 1687 smk_of_task(task_security(p)), MAY_WRITE, &ad); 1688} 1689 1690/** 1691 * smack_task_wait - Smack access check for waiting 1692 * @p: task to wait for 1693 * 1694 * Returns 0 if current can wait for p, error code otherwise 1695 */ 1696static int smack_task_wait(struct task_struct *p) 1697{ 1698 struct smk_audit_info ad; 1699 char *sp = smk_of_current(); 1700 char *tsp = smk_of_forked(task_security(p)); 1701 int rc; 1702 1703 /* we don't log here, we can be overriden */ 1704 rc = smk_access(tsp, sp, MAY_WRITE, NULL); 1705 if (rc == 0) 1706 goto out_log; 1707 1708 /* 1709 * Allow the operation to succeed if either task 1710 * has privilege to perform operations that might 1711 * account for the smack labels having gotten to 1712 * be different in the first place. 1713 * 1714 * This breaks the strict subject/object access 1715 * control ideal, taking the object's privilege 1716 * state into account in the decision as well as 1717 * the smack value. 1718 */ 1719 if (capable(CAP_MAC_OVERRIDE) || has_capability(p, CAP_MAC_OVERRIDE)) 1720 rc = 0; 1721 /* we log only if we didn't get overriden */ 1722 out_log: 1723 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK); 1724 smk_ad_setfield_u_tsk(&ad, p); 1725 smack_log(tsp, sp, MAY_WRITE, rc, &ad); 1726 return rc; 1727} 1728 1729/** 1730 * smack_task_to_inode - copy task smack into the inode blob 1731 * @p: task to copy from 1732 * @inode: inode to copy to 1733 * 1734 * Sets the smack pointer in the inode security blob 1735 */ 1736static void smack_task_to_inode(struct task_struct *p, struct inode *inode) 1737{ 1738 struct inode_smack *isp = inode->i_security; 1739 isp->smk_inode = smk_of_task(task_security(p)); 1740} 1741 1742/* 1743 * Socket hooks. 1744 */ 1745 1746/** 1747 * smack_sk_alloc_security - Allocate a socket blob 1748 * @sk: the socket 1749 * @family: unused 1750 * @gfp_flags: memory allocation flags 1751 * 1752 * Assign Smack pointers to current 1753 * 1754 * Returns 0 on success, -ENOMEM is there's no memory 1755 */ 1756static int smack_sk_alloc_security(struct sock *sk, int family, gfp_t gfp_flags) 1757{ 1758 char *csp = smk_of_current(); 1759 struct socket_smack *ssp; 1760 1761 ssp = kzalloc(sizeof(struct socket_smack), gfp_flags); 1762 if (ssp == NULL) 1763 return -ENOMEM; 1764 1765 ssp->smk_in = csp; 1766 ssp->smk_out = csp; 1767 ssp->smk_packet = NULL; 1768 1769 sk->sk_security = ssp; 1770 1771 return 0; 1772} 1773 1774/** 1775 * smack_sk_free_security - Free a socket blob 1776 * @sk: the socket 1777 * 1778 * Clears the blob pointer 1779 */ 1780static void smack_sk_free_security(struct sock *sk) 1781{ 1782 kfree(sk->sk_security); 1783} 1784 1785/** 1786* smack_host_label - check host based restrictions 1787* @sip: the object end 1788* 1789* looks for host based access restrictions 1790* 1791* This version will only be appropriate for really small sets of single label 1792* hosts. The caller is responsible for ensuring that the RCU read lock is 1793* taken before calling this function. 1794* 1795* Returns the label of the far end or NULL if it's not special. 1796*/ 1797static char *smack_host_label(struct sockaddr_in *sip) 1798{ 1799 struct smk_netlbladdr *snp; 1800 struct in_addr *siap = &sip->sin_addr; 1801 1802 if (siap->s_addr == 0) 1803 return NULL; 1804 1805 list_for_each_entry_rcu(snp, &smk_netlbladdr_list, list) 1806 /* 1807 * we break after finding the first match because 1808 * the list is sorted from longest to shortest mask 1809 * so we have found the most specific match 1810 */ 1811 if ((&snp->smk_host.sin_addr)->s_addr == 1812 (siap->s_addr & (&snp->smk_mask)->s_addr)) { 1813 /* we have found the special CIPSO option */ 1814 if (snp->smk_label == smack_cipso_option) 1815 return NULL; 1816 return snp->smk_label; 1817 } 1818 1819 return NULL; 1820} 1821 1822/** 1823 * smack_set_catset - convert a capset to netlabel mls categories 1824 * @catset: the Smack categories 1825 * @sap: where to put the netlabel categories 1826 * 1827 * Allocates and fills attr.mls.cat 1828 */ 1829static void smack_set_catset(char *catset, struct netlbl_lsm_secattr *sap) 1830{ 1831 unsigned char *cp; 1832 unsigned char m; 1833 int cat; 1834 int rc; 1835 int byte; 1836 1837 if (!catset) 1838 return; 1839 1840 sap->flags |= NETLBL_SECATTR_MLS_CAT; 1841 sap->attr.mls.cat = netlbl_secattr_catmap_alloc(GFP_ATOMIC); 1842 sap->attr.mls.cat->startbit = 0; 1843 1844 for (cat = 1, cp = catset, byte = 0; byte < SMK_LABELLEN; cp++, byte++) 1845 for (m = 0x80; m != 0; m >>= 1, cat++) { 1846 if ((m & *cp) == 0) 1847 continue; 1848 rc = netlbl_secattr_catmap_setbit(sap->attr.mls.cat, 1849 cat, GFP_ATOMIC); 1850 } 1851} 1852 1853/** 1854 * smack_to_secattr - fill a secattr from a smack value 1855 * @smack: the smack value 1856 * @nlsp: where the result goes 1857 * 1858 * Casey says that CIPSO is good enough for now. 1859 * It can be used to effect. 1860 * It can also be abused to effect when necessary. 1861 * Apologies to the TSIG group in general and GW in particular. 1862 */ 1863static void smack_to_secattr(char *smack, struct netlbl_lsm_secattr *nlsp) 1864{ 1865 struct smack_cipso cipso; 1866 int rc; 1867 1868 nlsp->domain = smack; 1869 nlsp->flags = NETLBL_SECATTR_DOMAIN | NETLBL_SECATTR_MLS_LVL; 1870 1871 rc = smack_to_cipso(smack, &cipso); 1872 if (rc == 0) { 1873 nlsp->attr.mls.lvl = cipso.smk_level; 1874 smack_set_catset(cipso.smk_catset, nlsp); 1875 } else { 1876 nlsp->attr.mls.lvl = smack_cipso_direct; 1877 smack_set_catset(smack, nlsp); 1878 } 1879} 1880 1881/** 1882 * smack_netlabel - Set the secattr on a socket 1883 * @sk: the socket 1884 * @labeled: socket label scheme 1885 * 1886 * Convert the outbound smack value (smk_out) to a 1887 * secattr and attach it to the socket. 1888 * 1889 * Returns 0 on success or an error code 1890 */ 1891static int smack_netlabel(struct sock *sk, int labeled) 1892{ 1893 struct socket_smack *ssp = sk->sk_security; 1894 struct netlbl_lsm_secattr secattr; 1895 int rc = 0; 1896 1897 /* 1898 * Usually the netlabel code will handle changing the 1899 * packet labeling based on the label. 1900 * The case of a single label host is different, because 1901 * a single label host should never get a labeled packet 1902 * even though the label is usually associated with a packet 1903 * label. 1904 */ 1905 local_bh_disable(); 1906 bh_lock_sock_nested(sk); 1907 1908 if (ssp->smk_out == smack_net_ambient || 1909 labeled == SMACK_UNLABELED_SOCKET) 1910 netlbl_sock_delattr(sk); 1911 else { 1912 netlbl_secattr_init(&secattr); 1913 smack_to_secattr(ssp->smk_out, &secattr); 1914 rc = netlbl_sock_setattr(sk, sk->sk_family, &secattr); 1915 netlbl_secattr_destroy(&secattr); 1916 } 1917 1918 bh_unlock_sock(sk); 1919 local_bh_enable(); 1920 1921 return rc; 1922} 1923 1924/** 1925 * smack_netlbel_send - Set the secattr on a socket and perform access checks 1926 * @sk: the socket 1927 * @sap: the destination address 1928 * 1929 * Set the correct secattr for the given socket based on the destination 1930 * address and perform any outbound access checks needed. 1931 * 1932 * Returns 0 on success or an error code. 1933 * 1934 */ 1935static int smack_netlabel_send(struct sock *sk, struct sockaddr_in *sap) 1936{ 1937 int rc; 1938 int sk_lbl; 1939 char *hostsp; 1940 struct socket_smack *ssp = sk->sk_security; 1941 struct smk_audit_info ad; 1942 struct lsm_network_audit net; 1943 1944 rcu_read_lock(); 1945 hostsp = smack_host_label(sap); 1946 if (hostsp != NULL) { 1947 sk_lbl = SMACK_UNLABELED_SOCKET; 1948#ifdef CONFIG_AUDIT 1949 smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net); 1950 ad.a.u.net->family = sap->sin_family; 1951 ad.a.u.net->dport = sap->sin_port; 1952 ad.a.u.net->v4info.daddr = sap->sin_addr.s_addr; 1953#endif 1954 rc = smk_access(ssp->smk_out, hostsp, MAY_WRITE, &ad); 1955 } else { 1956 sk_lbl = SMACK_CIPSO_SOCKET; 1957 rc = 0; 1958 } 1959 rcu_read_unlock(); 1960 if (rc != 0) 1961 return rc; 1962 1963 return smack_netlabel(sk, sk_lbl); 1964} 1965 1966/** 1967 * smack_inode_setsecurity - set smack xattrs 1968 * @inode: the object 1969 * @name: attribute name 1970 * @value: attribute value 1971 * @size: size of the attribute 1972 * @flags: unused 1973 * 1974 * Sets the named attribute in the appropriate blob 1975 * 1976 * Returns 0 on success, or an error code 1977 */ 1978static int smack_inode_setsecurity(struct inode *inode, const char *name, 1979 const void *value, size_t size, int flags) 1980{ 1981 char *sp; 1982 struct inode_smack *nsp = inode->i_security; 1983 struct socket_smack *ssp; 1984 struct socket *sock; 1985 int rc = 0; 1986 1987 if (value == NULL || size > SMK_LABELLEN || size == 0) 1988 return -EACCES; 1989 1990 sp = smk_import(value, size); 1991 if (sp == NULL) 1992 return -EINVAL; 1993 1994 if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) { 1995 nsp->smk_inode = sp; 1996 nsp->smk_flags |= SMK_INODE_INSTANT; 1997 return 0; 1998 } 1999 /* 2000 * The rest of the Smack xattrs are only on sockets. 2001 */ 2002 if (inode->i_sb->s_magic != SOCKFS_MAGIC) 2003 return -EOPNOTSUPP; 2004 2005 sock = SOCKET_I(inode); 2006 if (sock == NULL || sock->sk == NULL) 2007 return -EOPNOTSUPP; 2008 2009 ssp = sock->sk->sk_security; 2010 2011 if (strcmp(name, XATTR_SMACK_IPIN) == 0) 2012 ssp->smk_in = sp; 2013 else if (strcmp(name, XATTR_SMACK_IPOUT) == 0) { 2014 ssp->smk_out = sp; 2015 if (sock->sk->sk_family != PF_UNIX) { 2016 rc = smack_netlabel(sock->sk, SMACK_CIPSO_SOCKET); 2017 if (rc != 0) 2018 printk(KERN_WARNING 2019 "Smack: \"%s\" netlbl error %d.\n", 2020 __func__, -rc); 2021 } 2022 } else 2023 return -EOPNOTSUPP; 2024 2025 return 0; 2026} 2027 2028/** 2029 * smack_socket_post_create - finish socket setup 2030 * @sock: the socket 2031 * @family: protocol family 2032 * @type: unused 2033 * @protocol: unused 2034 * @kern: unused 2035 * 2036 * Sets the netlabel information on the socket 2037 * 2038 * Returns 0 on success, and error code otherwise 2039 */ 2040static int smack_socket_post_create(struct socket *sock, int family, 2041 int type, int protocol, int kern) 2042{ 2043 if (family != PF_INET || sock->sk == NULL) 2044 return 0; 2045 /* 2046 * Set the outbound netlbl. 2047 */ 2048 return smack_netlabel(sock->sk, SMACK_CIPSO_SOCKET); 2049} 2050 2051/** 2052 * smack_socket_connect - connect access check 2053 * @sock: the socket 2054 * @sap: the other end 2055 * @addrlen: size of sap 2056 * 2057 * Verifies that a connection may be possible 2058 * 2059 * Returns 0 on success, and error code otherwise 2060 */ 2061static int smack_socket_connect(struct socket *sock, struct sockaddr *sap, 2062 int addrlen) 2063{ 2064 if (sock->sk == NULL || sock->sk->sk_family != PF_INET) 2065 return 0; 2066 if (addrlen < sizeof(struct sockaddr_in)) 2067 return -EINVAL; 2068 2069 return smack_netlabel_send(sock->sk, (struct sockaddr_in *)sap); 2070} 2071 2072/** 2073 * smack_flags_to_may - convert S_ to MAY_ values 2074 * @flags: the S_ value 2075 * 2076 * Returns the equivalent MAY_ value 2077 */ 2078static int smack_flags_to_may(int flags) 2079{ 2080 int may = 0; 2081 2082 if (flags & S_IRUGO) 2083 may |= MAY_READ; 2084 if (flags & S_IWUGO) 2085 may |= MAY_WRITE; 2086 if (flags & S_IXUGO) 2087 may |= MAY_EXEC; 2088 2089 return may; 2090} 2091 2092/** 2093 * smack_msg_msg_alloc_security - Set the security blob for msg_msg 2094 * @msg: the object 2095 * 2096 * Returns 0 2097 */ 2098static int smack_msg_msg_alloc_security(struct msg_msg *msg) 2099{ 2100 msg->security = smk_of_current(); 2101 return 0; 2102} 2103 2104/** 2105 * smack_msg_msg_free_security - Clear the security blob for msg_msg 2106 * @msg: the object 2107 * 2108 * Clears the blob pointer 2109 */ 2110static void smack_msg_msg_free_security(struct msg_msg *msg) 2111{ 2112 msg->security = NULL; 2113} 2114 2115/** 2116 * smack_of_shm - the smack pointer for the shm 2117 * @shp: the object 2118 * 2119 * Returns a pointer to the smack value 2120 */ 2121static char *smack_of_shm(struct shmid_kernel *shp) 2122{ 2123 return (char *)shp->shm_perm.security; 2124} 2125 2126/** 2127 * smack_shm_alloc_security - Set the security blob for shm 2128 * @shp: the object 2129 * 2130 * Returns 0 2131 */ 2132static int smack_shm_alloc_security(struct shmid_kernel *shp) 2133{ 2134 struct kern_ipc_perm *isp = &shp->shm_perm; 2135 2136 isp->security = smk_of_current(); 2137 return 0; 2138} 2139 2140/** 2141 * smack_shm_free_security - Clear the security blob for shm 2142 * @shp: the object 2143 * 2144 * Clears the blob pointer 2145 */ 2146static void smack_shm_free_security(struct shmid_kernel *shp) 2147{ 2148 struct kern_ipc_perm *isp = &shp->shm_perm; 2149 2150 isp->security = NULL; 2151} 2152 2153/** 2154 * smk_curacc_shm : check if current has access on shm 2155 * @shp : the object 2156 * @access : access requested 2157 * 2158 * Returns 0 if current has the requested access, error code otherwise 2159 */ 2160static int smk_curacc_shm(struct shmid_kernel *shp, int access) 2161{ 2162 char *ssp = smack_of_shm(shp); 2163 struct smk_audit_info ad; 2164 2165#ifdef CONFIG_AUDIT 2166 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC); 2167 ad.a.u.ipc_id = shp->shm_perm.id; 2168#endif 2169 return smk_curacc(ssp, access, &ad); 2170} 2171 2172/** 2173 * smack_shm_associate - Smack access check for shm 2174 * @shp: the object 2175 * @shmflg: access requested 2176 * 2177 * Returns 0 if current has the requested access, error code otherwise 2178 */ 2179static int smack_shm_associate(struct shmid_kernel *shp, int shmflg) 2180{ 2181 int may; 2182 2183 may = smack_flags_to_may(shmflg); 2184 return smk_curacc_shm(shp, may); 2185} 2186 2187/** 2188 * smack_shm_shmctl - Smack access check for shm 2189 * @shp: the object 2190 * @cmd: what it wants to do 2191 * 2192 * Returns 0 if current has the requested access, error code otherwise 2193 */ 2194static int smack_shm_shmctl(struct shmid_kernel *shp, int cmd) 2195{ 2196 int may; 2197 2198 switch (cmd) { 2199 case IPC_STAT: 2200 case SHM_STAT: 2201 may = MAY_READ; 2202 break; 2203 case IPC_SET: 2204 case SHM_LOCK: 2205 case SHM_UNLOCK: 2206 case IPC_RMID: 2207 may = MAY_READWRITE; 2208 break; 2209 case IPC_INFO: 2210 case SHM_INFO: 2211 /* 2212 * System level information. 2213 */ 2214 return 0; 2215 default: 2216 return -EINVAL; 2217 } 2218 return smk_curacc_shm(shp, may); 2219} 2220 2221/** 2222 * smack_shm_shmat - Smack access for shmat 2223 * @shp: the object 2224 * @shmaddr: unused 2225 * @shmflg: access requested 2226 * 2227 * Returns 0 if current has the requested access, error code otherwise 2228 */ 2229static int smack_shm_shmat(struct shmid_kernel *shp, char __user *shmaddr, 2230 int shmflg) 2231{ 2232 int may; 2233 2234 may = smack_flags_to_may(shmflg); 2235 return smk_curacc_shm(shp, may); 2236} 2237 2238/** 2239 * smack_of_sem - the smack pointer for the sem 2240 * @sma: the object 2241 * 2242 * Returns a pointer to the smack value 2243 */ 2244static char *smack_of_sem(struct sem_array *sma) 2245{ 2246 return (char *)sma->sem_perm.security; 2247} 2248 2249/** 2250 * smack_sem_alloc_security - Set the security blob for sem 2251 * @sma: the object 2252 * 2253 * Returns 0 2254 */ 2255static int smack_sem_alloc_security(struct sem_array *sma) 2256{ 2257 struct kern_ipc_perm *isp = &sma->sem_perm; 2258 2259 isp->security = smk_of_current(); 2260 return 0; 2261} 2262 2263/** 2264 * smack_sem_free_security - Clear the security blob for sem 2265 * @sma: the object 2266 * 2267 * Clears the blob pointer 2268 */ 2269static void smack_sem_free_security(struct sem_array *sma) 2270{ 2271 struct kern_ipc_perm *isp = &sma->sem_perm; 2272 2273 isp->security = NULL; 2274} 2275 2276/** 2277 * smk_curacc_sem : check if current has access on sem 2278 * @sma : the object 2279 * @access : access requested 2280 * 2281 * Returns 0 if current has the requested access, error code otherwise 2282 */ 2283static int smk_curacc_sem(struct sem_array *sma, int access) 2284{ 2285 char *ssp = smack_of_sem(sma); 2286 struct smk_audit_info ad; 2287 2288#ifdef CONFIG_AUDIT 2289 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC); 2290 ad.a.u.ipc_id = sma->sem_perm.id; 2291#endif 2292 return smk_curacc(ssp, access, &ad); 2293} 2294 2295/** 2296 * smack_sem_associate - Smack access check for sem 2297 * @sma: the object 2298 * @semflg: access requested 2299 * 2300 * Returns 0 if current has the requested access, error code otherwise 2301 */ 2302static int smack_sem_associate(struct sem_array *sma, int semflg) 2303{ 2304 int may; 2305 2306 may = smack_flags_to_may(semflg); 2307 return smk_curacc_sem(sma, may); 2308} 2309 2310/** 2311 * smack_sem_shmctl - Smack access check for sem 2312 * @sma: the object 2313 * @cmd: what it wants to do 2314 * 2315 * Returns 0 if current has the requested access, error code otherwise 2316 */ 2317static int smack_sem_semctl(struct sem_array *sma, int cmd) 2318{ 2319 int may; 2320 2321 switch (cmd) { 2322 case GETPID: 2323 case GETNCNT: 2324 case GETZCNT: 2325 case GETVAL: 2326 case GETALL: 2327 case IPC_STAT: 2328 case SEM_STAT: 2329 may = MAY_READ; 2330 break; 2331 case SETVAL: 2332 case SETALL: 2333 case IPC_RMID: 2334 case IPC_SET: 2335 may = MAY_READWRITE; 2336 break; 2337 case IPC_INFO: 2338 case SEM_INFO: 2339 /* 2340 * System level information 2341 */ 2342 return 0; 2343 default: 2344 return -EINVAL; 2345 } 2346 2347 return smk_curacc_sem(sma, may); 2348} 2349 2350/** 2351 * smack_sem_semop - Smack checks of semaphore operations 2352 * @sma: the object 2353 * @sops: unused 2354 * @nsops: unused 2355 * @alter: unused 2356 * 2357 * Treated as read and write in all cases. 2358 * 2359 * Returns 0 if access is allowed, error code otherwise 2360 */ 2361static int smack_sem_semop(struct sem_array *sma, struct sembuf *sops, 2362 unsigned nsops, int alter) 2363{ 2364 return smk_curacc_sem(sma, MAY_READWRITE); 2365} 2366 2367/** 2368 * smack_msg_alloc_security - Set the security blob for msg 2369 * @msq: the object 2370 * 2371 * Returns 0 2372 */ 2373static int smack_msg_queue_alloc_security(struct msg_queue *msq) 2374{ 2375 struct kern_ipc_perm *kisp = &msq->q_perm; 2376 2377 kisp->security = smk_of_current(); 2378 return 0; 2379} 2380 2381/** 2382 * smack_msg_free_security - Clear the security blob for msg 2383 * @msq: the object 2384 * 2385 * Clears the blob pointer 2386 */ 2387static void smack_msg_queue_free_security(struct msg_queue *msq) 2388{ 2389 struct kern_ipc_perm *kisp = &msq->q_perm; 2390 2391 kisp->security = NULL; 2392} 2393 2394/** 2395 * smack_of_msq - the smack pointer for the msq 2396 * @msq: the object 2397 * 2398 * Returns a pointer to the smack value 2399 */ 2400static char *smack_of_msq(struct msg_queue *msq) 2401{ 2402 return (char *)msq->q_perm.security; 2403} 2404 2405/** 2406 * smk_curacc_msq : helper to check if current has access on msq 2407 * @msq : the msq 2408 * @access : access requested 2409 * 2410 * return 0 if current has access, error otherwise 2411 */ 2412static int smk_curacc_msq(struct msg_queue *msq, int access) 2413{ 2414 char *msp = smack_of_msq(msq); 2415 struct smk_audit_info ad; 2416 2417#ifdef CONFIG_AUDIT 2418 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC); 2419 ad.a.u.ipc_id = msq->q_perm.id; 2420#endif 2421 return smk_curacc(msp, access, &ad); 2422} 2423 2424/** 2425 * smack_msg_queue_associate - Smack access check for msg_queue 2426 * @msq: the object 2427 * @msqflg: access requested 2428 * 2429 * Returns 0 if current has the requested access, error code otherwise 2430 */ 2431static int smack_msg_queue_associate(struct msg_queue *msq, int msqflg) 2432{ 2433 int may; 2434 2435 may = smack_flags_to_may(msqflg); 2436 return smk_curacc_msq(msq, may); 2437} 2438 2439/** 2440 * smack_msg_queue_msgctl - Smack access check for msg_queue 2441 * @msq: the object 2442 * @cmd: what it wants to do 2443 * 2444 * Returns 0 if current has the requested access, error code otherwise 2445 */ 2446static int smack_msg_queue_msgctl(struct msg_queue *msq, int cmd) 2447{ 2448 int may; 2449 2450 switch (cmd) { 2451 case IPC_STAT: 2452 case MSG_STAT: 2453 may = MAY_READ; 2454 break; 2455 case IPC_SET: 2456 case IPC_RMID: 2457 may = MAY_READWRITE; 2458 break; 2459 case IPC_INFO: 2460 case MSG_INFO: 2461 /* 2462 * System level information 2463 */ 2464 return 0; 2465 default: 2466 return -EINVAL; 2467 } 2468 2469 return smk_curacc_msq(msq, may); 2470} 2471 2472/** 2473 * smack_msg_queue_msgsnd - Smack access check for msg_queue 2474 * @msq: the object 2475 * @msg: unused 2476 * @msqflg: access requested 2477 * 2478 * Returns 0 if current has the requested access, error code otherwise 2479 */ 2480static int smack_msg_queue_msgsnd(struct msg_queue *msq, struct msg_msg *msg, 2481 int msqflg) 2482{ 2483 int may; 2484 2485 may = smack_flags_to_may(msqflg); 2486 return smk_curacc_msq(msq, may); 2487} 2488 2489/** 2490 * smack_msg_queue_msgsnd - Smack access check for msg_queue 2491 * @msq: the object 2492 * @msg: unused 2493 * @target: unused 2494 * @type: unused 2495 * @mode: unused 2496 * 2497 * Returns 0 if current has read and write access, error code otherwise 2498 */ 2499static int smack_msg_queue_msgrcv(struct msg_queue *msq, struct msg_msg *msg, 2500 struct task_struct *target, long type, int mode) 2501{ 2502 return smk_curacc_msq(msq, MAY_READWRITE); 2503} 2504 2505/** 2506 * smack_ipc_permission - Smack access for ipc_permission() 2507 * @ipp: the object permissions 2508 * @flag: access requested 2509 * 2510 * Returns 0 if current has read and write access, error code otherwise 2511 */ 2512static int smack_ipc_permission(struct kern_ipc_perm *ipp, short flag) 2513{ 2514 char *isp = ipp->security; 2515 int may = smack_flags_to_may(flag); 2516 struct smk_audit_info ad; 2517 2518#ifdef CONFIG_AUDIT 2519 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC); 2520 ad.a.u.ipc_id = ipp->id; 2521#endif 2522 return smk_curacc(isp, may, &ad); 2523} 2524 2525/** 2526 * smack_ipc_getsecid - Extract smack security id 2527 * @ipp: the object permissions 2528 * @secid: where result will be saved 2529 */ 2530static void smack_ipc_getsecid(struct kern_ipc_perm *ipp, u32 *secid) 2531{ 2532 char *smack = ipp->security; 2533 2534 *secid = smack_to_secid(smack); 2535} 2536 2537/** 2538 * smack_d_instantiate - Make sure the blob is correct on an inode 2539 * @opt_dentry: dentry where inode will be attached 2540 * @inode: the object 2541 * 2542 * Set the inode's security blob if it hasn't been done already. 2543 */ 2544static void smack_d_instantiate(struct dentry *opt_dentry, struct inode *inode) 2545{ 2546 struct super_block *sbp; 2547 struct superblock_smack *sbsp; 2548 struct inode_smack *isp; 2549 char *csp = smk_of_current(); 2550 char *fetched; 2551 char *final; 2552 char trattr[TRANS_TRUE_SIZE]; 2553 int transflag = 0; 2554 struct dentry *dp; 2555 2556 if (inode == NULL) 2557 return; 2558 2559 isp = inode->i_security; 2560 2561 mutex_lock(&isp->smk_lock); 2562 /* 2563 * If the inode is already instantiated 2564 * take the quick way out 2565 */ 2566 if (isp->smk_flags & SMK_INODE_INSTANT) 2567 goto unlockandout; 2568 2569 sbp = inode->i_sb; 2570 sbsp = sbp->s_security; 2571 /* 2572 * We're going to use the superblock default label 2573 * if there's no label on the file. 2574 */ 2575 final = sbsp->smk_default; 2576 2577 /* 2578 * If this is the root inode the superblock 2579 * may be in the process of initialization. 2580 * If that is the case use the root value out 2581 * of the superblock. 2582 */ 2583 if (opt_dentry->d_parent == opt_dentry) { 2584 isp->smk_inode = sbsp->smk_root; 2585 isp->smk_flags |= SMK_INODE_INSTANT; 2586 goto unlockandout; 2587 } 2588 2589 /* 2590 * This is pretty hackish. 2591 * Casey says that we shouldn't have to do 2592 * file system specific code, but it does help 2593 * with keeping it simple. 2594 */ 2595 switch (sbp->s_magic) { 2596 case SMACK_MAGIC: 2597 /* 2598 * Casey says that it's a little embarrassing 2599 * that the smack file system doesn't do 2600 * extended attributes. 2601 */ 2602 final = smack_known_star.smk_known; 2603 break; 2604 case PIPEFS_MAGIC: 2605 /* 2606 * Casey says pipes are easy (?) 2607 */ 2608 final = smack_known_star.smk_known; 2609 break; 2610 case DEVPTS_SUPER_MAGIC: 2611 /* 2612 * devpts seems content with the label of the task. 2613 * Programs that change smack have to treat the 2614 * pty with respect. 2615 */ 2616 final = csp; 2617 break; 2618 case SOCKFS_MAGIC: 2619 /* 2620 * Socket access is controlled by the socket 2621 * structures associated with the task involved. 2622 */ 2623 final = smack_known_star.smk_known; 2624 break; 2625 case PROC_SUPER_MAGIC: 2626 /* 2627 * Casey says procfs appears not to care. 2628 * The superblock default suffices. 2629 */ 2630 break; 2631 case TMPFS_MAGIC: 2632 /* 2633 * Device labels should come from the filesystem, 2634 * but watch out, because they're volitile, 2635 * getting recreated on every reboot. 2636 */ 2637 final = smack_known_star.smk_known; 2638 /* 2639 * No break. 2640 * 2641 * If a smack value has been set we want to use it, 2642 * but since tmpfs isn't giving us the opportunity 2643 * to set mount options simulate setting the 2644 * superblock default. 2645 */ 2646 default: 2647 /* 2648 * This isn't an understood special case. 2649 * Get the value from the xattr. 2650 */ 2651 2652 /* 2653 * UNIX domain sockets use lower level socket data. 2654 */ 2655 if (S_ISSOCK(inode->i_mode)) { 2656 final = smack_known_star.smk_known; 2657 break; 2658 } 2659 /* 2660 * No xattr support means, alas, no SMACK label. 2661 * Use the aforeapplied default. 2662 * It would be curious if the label of the task 2663 * does not match that assigned. 2664 */ 2665 if (inode->i_op->getxattr == NULL) 2666 break; 2667 /* 2668 * Get the dentry for xattr. 2669 */ 2670 dp = dget(opt_dentry); 2671 fetched = smk_fetch(XATTR_NAME_SMACK, inode, dp); 2672 if (fetched != NULL) { 2673 final = fetched; 2674 if (S_ISDIR(inode->i_mode)) { 2675 trattr[0] = '\0'; 2676 inode->i_op->getxattr(dp, 2677 XATTR_NAME_SMACKTRANSMUTE, 2678 trattr, TRANS_TRUE_SIZE); 2679 if (strncmp(trattr, TRANS_TRUE, 2680 TRANS_TRUE_SIZE) == 0) 2681 transflag = SMK_INODE_TRANSMUTE; 2682 } 2683 } 2684 isp->smk_task = smk_fetch(XATTR_NAME_SMACKEXEC, inode, dp); 2685 isp->smk_mmap = smk_fetch(XATTR_NAME_SMACKMMAP, inode, dp); 2686 2687 dput(dp); 2688 break; 2689 } 2690 2691 if (final == NULL) 2692 isp->smk_inode = csp; 2693 else 2694 isp->smk_inode = final; 2695 2696 isp->smk_flags |= (SMK_INODE_INSTANT | transflag); 2697 2698unlockandout: 2699 mutex_unlock(&isp->smk_lock); 2700 return; 2701} 2702 2703/** 2704 * smack_getprocattr - Smack process attribute access 2705 * @p: the object task 2706 * @name: the name of the attribute in /proc/.../attr 2707 * @value: where to put the result 2708 * 2709 * Places a copy of the task Smack into value 2710 * 2711 * Returns the length of the smack label or an error code 2712 */ 2713static int smack_getprocattr(struct task_struct *p, char *name, char **value) 2714{ 2715 char *cp; 2716 int slen; 2717 2718 if (strcmp(name, "current") != 0) 2719 return -EINVAL; 2720 2721 cp = kstrdup(smk_of_task(task_security(p)), GFP_KERNEL); 2722 if (cp == NULL) 2723 return -ENOMEM; 2724 2725 slen = strlen(cp); 2726 *value = cp; 2727 return slen; 2728} 2729 2730/** 2731 * smack_setprocattr - Smack process attribute setting 2732 * @p: the object task 2733 * @name: the name of the attribute in /proc/.../attr 2734 * @value: the value to set 2735 * @size: the size of the value 2736 * 2737 * Sets the Smack value of the task. Only setting self 2738 * is permitted and only with privilege 2739 * 2740 * Returns the length of the smack label or an error code 2741 */ 2742static int smack_setprocattr(struct task_struct *p, char *name, 2743 void *value, size_t size) 2744{ 2745 int rc; 2746 struct task_smack *tsp; 2747 struct task_smack *oldtsp; 2748 struct cred *new; 2749 char *newsmack; 2750 2751 /* 2752 * Changing another process' Smack value is too dangerous 2753 * and supports no sane use case. 2754 */ 2755 if (p != current) 2756 return -EPERM; 2757 2758 if (!capable(CAP_MAC_ADMIN)) 2759 return -EPERM; 2760 2761 if (value == NULL || size == 0 || size >= SMK_LABELLEN) 2762 return -EINVAL; 2763 2764 if (strcmp(name, "current") != 0) 2765 return -EINVAL; 2766 2767 newsmack = smk_import(value, size); 2768 if (newsmack == NULL) 2769 return -EINVAL; 2770 2771 /* 2772 * No process is ever allowed the web ("@") label. 2773 */ 2774 if (newsmack == smack_known_web.smk_known) 2775 return -EPERM; 2776 2777 oldtsp = p->cred->security; 2778 new = prepare_creds(); 2779 if (new == NULL) 2780 return -ENOMEM; 2781 2782 tsp = new_task_smack(newsmack, oldtsp->smk_forked, GFP_KERNEL); 2783 if (tsp == NULL) { 2784 kfree(new); 2785 return -ENOMEM; 2786 } 2787 rc = smk_copy_rules(&tsp->smk_rules, &oldtsp->smk_rules, GFP_KERNEL); 2788 if (rc != 0) 2789 return rc; 2790 2791 new->security = tsp; 2792 commit_creds(new); 2793 return size; 2794} 2795 2796/** 2797 * smack_unix_stream_connect - Smack access on UDS 2798 * @sock: one sock 2799 * @other: the other sock 2800 * @newsk: unused 2801 * 2802 * Return 0 if a subject with the smack of sock could access 2803 * an object with the smack of other, otherwise an error code 2804 */ 2805static int smack_unix_stream_connect(struct sock *sock, 2806 struct sock *other, struct sock *newsk) 2807{ 2808 struct socket_smack *ssp = sock->sk_security; 2809 struct socket_smack *osp = other->sk_security; 2810 struct socket_smack *nsp = newsk->sk_security; 2811 struct smk_audit_info ad; 2812 struct lsm_network_audit net; 2813 int rc = 0; 2814 2815 smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net); 2816 smk_ad_setfield_u_net_sk(&ad, other); 2817 2818 if (!capable(CAP_MAC_OVERRIDE)) 2819 rc = smk_access(ssp->smk_out, osp->smk_in, MAY_WRITE, &ad); 2820 2821 /* 2822 * Cross reference the peer labels for SO_PEERSEC. 2823 */ 2824 if (rc == 0) { 2825 nsp->smk_packet = ssp->smk_out; 2826 ssp->smk_packet = osp->smk_out; 2827 } 2828 2829 return rc; 2830} 2831 2832/** 2833 * smack_unix_may_send - Smack access on UDS 2834 * @sock: one socket 2835 * @other: the other socket 2836 * 2837 * Return 0 if a subject with the smack of sock could access 2838 * an object with the smack of other, otherwise an error code 2839 */ 2840static int smack_unix_may_send(struct socket *sock, struct socket *other) 2841{ 2842 struct socket_smack *ssp = sock->sk->sk_security; 2843 struct socket_smack *osp = other->sk->sk_security; 2844 struct smk_audit_info ad; 2845 struct lsm_network_audit net; 2846 int rc = 0; 2847 2848 smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net); 2849 smk_ad_setfield_u_net_sk(&ad, other->sk); 2850 2851 if (!capable(CAP_MAC_OVERRIDE)) 2852 rc = smk_access(ssp->smk_out, osp->smk_in, MAY_WRITE, &ad); 2853 2854 return rc; 2855} 2856 2857/** 2858 * smack_socket_sendmsg - Smack check based on destination host 2859 * @sock: the socket 2860 * @msg: the message 2861 * @size: the size of the message 2862 * 2863 * Return 0 if the current subject can write to the destination 2864 * host. This is only a question if the destination is a single 2865 * label host. 2866 */ 2867static int smack_socket_sendmsg(struct socket *sock, struct msghdr *msg, 2868 int size) 2869{ 2870 struct sockaddr_in *sip = (struct sockaddr_in *) msg->msg_name; 2871 2872 /* 2873 * Perfectly reasonable for this to be NULL 2874 */ 2875 if (sip == NULL || sip->sin_family != AF_INET) 2876 return 0; 2877 2878 return smack_netlabel_send(sock->sk, sip); 2879} 2880 2881/** 2882 * smack_from_secattr - Convert a netlabel attr.mls.lvl/attr.mls.cat pair to smack 2883 * @sap: netlabel secattr 2884 * @ssp: socket security information 2885 * 2886 * Returns a pointer to a Smack label found on the label list. 2887 */ 2888static char *smack_from_secattr(struct netlbl_lsm_secattr *sap, 2889 struct socket_smack *ssp) 2890{ 2891 struct smack_known *skp; 2892 char smack[SMK_LABELLEN]; 2893 char *sp; 2894 int pcat; 2895 2896 if ((sap->flags & NETLBL_SECATTR_MLS_LVL) != 0) { 2897 /* 2898 * Looks like a CIPSO packet. 2899 * If there are flags but no level netlabel isn't 2900 * behaving the way we expect it to. 2901 * 2902 * Get the categories, if any 2903 * Without guidance regarding the smack value 2904 * for the packet fall back on the network 2905 * ambient value. 2906 */ 2907 memset(smack, '\0', SMK_LABELLEN); 2908 if ((sap->flags & NETLBL_SECATTR_MLS_CAT) != 0) 2909 for (pcat = -1;;) { 2910 pcat = netlbl_secattr_catmap_walk( 2911 sap->attr.mls.cat, pcat + 1); 2912 if (pcat < 0) 2913 break; 2914 smack_catset_bit(pcat, smack); 2915 } 2916 /* 2917 * If it is CIPSO using smack direct mapping 2918 * we are already done. WeeHee. 2919 */ 2920 if (sap->attr.mls.lvl == smack_cipso_direct) { 2921 /* 2922 * The label sent is usually on the label list. 2923 * 2924 * If it is not we may still want to allow the 2925 * delivery. 2926 * 2927 * If the recipient is accepting all packets 2928 * because it is using the star ("*") label 2929 * for SMACK64IPIN provide the web ("@") label 2930 * so that a directed response will succeed. 2931 * This is not very correct from a MAC point 2932 * of view, but gets around the problem that 2933 * locking prevents adding the newly discovered 2934 * label to the list. 2935 * The case where the recipient is not using 2936 * the star label should obviously fail. 2937 * The easy way to do this is to provide the 2938 * star label as the subject label. 2939 */ 2940 skp = smk_find_entry(smack); 2941 if (skp != NULL) 2942 return skp->smk_known; 2943 if (ssp != NULL && 2944 ssp->smk_in == smack_known_star.smk_known) 2945 return smack_known_web.smk_known; 2946 return smack_known_star.smk_known; 2947 } 2948 /* 2949 * Look it up in the supplied table if it is not 2950 * a direct mapping. 2951 */ 2952 sp = smack_from_cipso(sap->attr.mls.lvl, smack); 2953 if (sp != NULL) 2954 return sp; 2955 if (ssp != NULL && ssp->smk_in == smack_known_star.smk_known) 2956 return smack_known_web.smk_known; 2957 return smack_known_star.smk_known; 2958 } 2959 if ((sap->flags & NETLBL_SECATTR_SECID) != 0) { 2960 /* 2961 * Looks like a fallback, which gives us a secid. 2962 */ 2963 sp = smack_from_secid(sap->attr.secid); 2964 /* 2965 * This has got to be a bug because it is 2966 * impossible to specify a fallback without 2967 * specifying the label, which will ensure 2968 * it has a secid, and the only way to get a 2969 * secid is from a fallback. 2970 */ 2971 BUG_ON(sp == NULL); 2972 return sp; 2973 } 2974 /* 2975 * Without guidance regarding the smack value 2976 * for the packet fall back on the network 2977 * ambient value. 2978 */ 2979 return smack_net_ambient; 2980} 2981 2982/** 2983 * smack_socket_sock_rcv_skb - Smack packet delivery access check 2984 * @sk: socket 2985 * @skb: packet 2986 * 2987 * Returns 0 if the packet should be delivered, an error code otherwise 2988 */ 2989static int smack_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb) 2990{ 2991 struct netlbl_lsm_secattr secattr; 2992 struct socket_smack *ssp = sk->sk_security; 2993 char *csp; 2994 int rc; 2995 struct smk_audit_info ad; 2996 struct lsm_network_audit net; 2997 if (sk->sk_family != PF_INET && sk->sk_family != PF_INET6) 2998 return 0; 2999 3000 /* 3001 * Translate what netlabel gave us. 3002 */ 3003 netlbl_secattr_init(&secattr); 3004 3005 rc = netlbl_skbuff_getattr(skb, sk->sk_family, &secattr); 3006 if (rc == 0) 3007 csp = smack_from_secattr(&secattr, ssp); 3008 else 3009 csp = smack_net_ambient; 3010 3011 netlbl_secattr_destroy(&secattr); 3012 3013#ifdef CONFIG_AUDIT 3014 smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net); 3015 ad.a.u.net->family = sk->sk_family; 3016 ad.a.u.net->netif = skb->skb_iif; 3017 ipv4_skb_to_auditdata(skb, &ad.a, NULL); 3018#endif 3019 /* 3020 * Receiving a packet requires that the other end 3021 * be able to write here. Read access is not required. 3022 * This is the simplist possible security model 3023 * for networking. 3024 */ 3025 rc = smk_access(csp, ssp->smk_in, MAY_WRITE, &ad); 3026 if (rc != 0) 3027 netlbl_skbuff_err(skb, rc, 0); 3028 return rc; 3029} 3030 3031/** 3032 * smack_socket_getpeersec_stream - pull in packet label 3033 * @sock: the socket 3034 * @optval: user's destination 3035 * @optlen: size thereof 3036 * @len: max thereof 3037 * 3038 * returns zero on success, an error code otherwise 3039 */ 3040static int smack_socket_getpeersec_stream(struct socket *sock, 3041 char __user *optval, 3042 int __user *optlen, unsigned len) 3043{ 3044 struct socket_smack *ssp; 3045 char *rcp = ""; 3046 int slen = 1; 3047 int rc = 0; 3048 3049 ssp = sock->sk->sk_security; 3050 if (ssp->smk_packet != NULL) { 3051 rcp = ssp->smk_packet; 3052 slen = strlen(rcp) + 1; 3053 } 3054 3055 if (slen > len) 3056 rc = -ERANGE; 3057 else if (copy_to_user(optval, rcp, slen) != 0) 3058 rc = -EFAULT; 3059 3060 if (put_user(slen, optlen) != 0) 3061 rc = -EFAULT; 3062 3063 return rc; 3064} 3065 3066 3067/** 3068 * smack_socket_getpeersec_dgram - pull in packet label 3069 * @sock: the peer socket 3070 * @skb: packet data 3071 * @secid: pointer to where to put the secid of the packet 3072 * 3073 * Sets the netlabel socket state on sk from parent 3074 */ 3075static int smack_socket_getpeersec_dgram(struct socket *sock, 3076 struct sk_buff *skb, u32 *secid) 3077 3078{ 3079 struct netlbl_lsm_secattr secattr; 3080 struct socket_smack *ssp = NULL; 3081 char *sp; 3082 int family = PF_UNSPEC; 3083 u32 s = 0; /* 0 is the invalid secid */ 3084 int rc; 3085 3086 if (skb != NULL) { 3087 if (skb->protocol == htons(ETH_P_IP)) 3088 family = PF_INET; 3089 else if (skb->protocol == htons(ETH_P_IPV6)) 3090 family = PF_INET6; 3091 } 3092 if (family == PF_UNSPEC && sock != NULL) 3093 family = sock->sk->sk_family; 3094 3095 if (family == PF_UNIX) { 3096 ssp = sock->sk->sk_security; 3097 s = smack_to_secid(ssp->smk_out); 3098 } else if (family == PF_INET || family == PF_INET6) { 3099 /* 3100 * Translate what netlabel gave us. 3101 */ 3102 if (sock != NULL && sock->sk != NULL) 3103 ssp = sock->sk->sk_security; 3104 netlbl_secattr_init(&secattr); 3105 rc = netlbl_skbuff_getattr(skb, family, &secattr); 3106 if (rc == 0) { 3107 sp = smack_from_secattr(&secattr, ssp); 3108 s = smack_to_secid(sp); 3109 } 3110 netlbl_secattr_destroy(&secattr); 3111 } 3112 *secid = s; 3113 if (s == 0) 3114 return -EINVAL; 3115 return 0; 3116} 3117 3118/** 3119 * smack_sock_graft - Initialize a newly created socket with an existing sock 3120 * @sk: child sock 3121 * @parent: parent socket 3122 * 3123 * Set the smk_{in,out} state of an existing sock based on the process that 3124 * is creating the new socket. 3125 */ 3126static void smack_sock_graft(struct sock *sk, struct socket *parent) 3127{ 3128 struct socket_smack *ssp; 3129 3130 if (sk == NULL || 3131 (sk->sk_family != PF_INET && sk->sk_family != PF_INET6)) 3132 return; 3133 3134 ssp = sk->sk_security; 3135 ssp->smk_in = ssp->smk_out = smk_of_current(); 3136 /* cssp->smk_packet is already set in smack_inet_csk_clone() */ 3137} 3138 3139/** 3140 * smack_inet_conn_request - Smack access check on connect 3141 * @sk: socket involved 3142 * @skb: packet 3143 * @req: unused 3144 * 3145 * Returns 0 if a task with the packet label could write to 3146 * the socket, otherwise an error code 3147 */ 3148static int smack_inet_conn_request(struct sock *sk, struct sk_buff *skb, 3149 struct request_sock *req) 3150{ 3151 u16 family = sk->sk_family; 3152 struct socket_smack *ssp = sk->sk_security; 3153 struct netlbl_lsm_secattr secattr; 3154 struct sockaddr_in addr; 3155 struct iphdr *hdr; 3156 char *sp; 3157 int rc; 3158 struct smk_audit_info ad; 3159 struct lsm_network_audit net; 3160 3161 /* handle mapped IPv4 packets arriving via IPv6 sockets */ 3162 if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP)) 3163 family = PF_INET; 3164 3165 netlbl_secattr_init(&secattr); 3166 rc = netlbl_skbuff_getattr(skb, family, &secattr); 3167 if (rc == 0) 3168 sp = smack_from_secattr(&secattr, ssp); 3169 else 3170 sp = smack_known_huh.smk_known; 3171 netlbl_secattr_destroy(&secattr); 3172 3173#ifdef CONFIG_AUDIT 3174 smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net); 3175 ad.a.u.net->family = family; 3176 ad.a.u.net->netif = skb->skb_iif; 3177 ipv4_skb_to_auditdata(skb, &ad.a, NULL); 3178#endif 3179 /* 3180 * Receiving a packet requires that the other end be able to write 3181 * here. Read access is not required. 3182 */ 3183 rc = smk_access(sp, ssp->smk_in, MAY_WRITE, &ad); 3184 if (rc != 0) 3185 return rc; 3186 3187 /* 3188 * Save the peer's label in the request_sock so we can later setup 3189 * smk_packet in the child socket so that SO_PEERCRED can report it. 3190 */ 3191 req->peer_secid = smack_to_secid(sp); 3192 3193 /* 3194 * We need to decide if we want to label the incoming connection here 3195 * if we do we only need to label the request_sock and the stack will 3196 * propagate the wire-label to the sock when it is created. 3197 */ 3198 hdr = ip_hdr(skb); 3199 addr.sin_addr.s_addr = hdr->saddr; 3200 rcu_read_lock(); 3201 if (smack_host_label(&addr) == NULL) { 3202 rcu_read_unlock(); 3203 netlbl_secattr_init(&secattr); 3204 smack_to_secattr(sp, &secattr); 3205 rc = netlbl_req_setattr(req, &secattr); 3206 netlbl_secattr_destroy(&secattr); 3207 } else { 3208 rcu_read_unlock(); 3209 netlbl_req_delattr(req); 3210 } 3211 3212 return rc; 3213} 3214 3215/** 3216 * smack_inet_csk_clone - Copy the connection information to the new socket 3217 * @sk: the new socket 3218 * @req: the connection's request_sock 3219 * 3220 * Transfer the connection's peer label to the newly created socket. 3221 */ 3222static void smack_inet_csk_clone(struct sock *sk, 3223 const struct request_sock *req) 3224{ 3225 struct socket_smack *ssp = sk->sk_security; 3226 3227 if (req->peer_secid != 0) 3228 ssp->smk_packet = smack_from_secid(req->peer_secid); 3229 else 3230 ssp->smk_packet = NULL; 3231} 3232 3233/* 3234 * Key management security hooks 3235 * 3236 * Casey has not tested key support very heavily. 3237 * The permission check is most likely too restrictive. 3238 * If you care about keys please have a look. 3239 */ 3240#ifdef CONFIG_KEYS 3241 3242/** 3243 * smack_key_alloc - Set the key security blob 3244 * @key: object 3245 * @cred: the credentials to use 3246 * @flags: unused 3247 * 3248 * No allocation required 3249 * 3250 * Returns 0 3251 */ 3252static int smack_key_alloc(struct key *key, const struct cred *cred, 3253 unsigned long flags) 3254{ 3255 key->security = smk_of_task(cred->security); 3256 return 0; 3257} 3258 3259/** 3260 * smack_key_free - Clear the key security blob 3261 * @key: the object 3262 * 3263 * Clear the blob pointer 3264 */ 3265static void smack_key_free(struct key *key) 3266{ 3267 key->security = NULL; 3268} 3269 3270/* 3271 * smack_key_permission - Smack access on a key 3272 * @key_ref: gets to the object 3273 * @cred: the credentials to use 3274 * @perm: unused 3275 * 3276 * Return 0 if the task has read and write to the object, 3277 * an error code otherwise 3278 */ 3279static int smack_key_permission(key_ref_t key_ref, 3280 const struct cred *cred, key_perm_t perm) 3281{ 3282 struct key *keyp; 3283 struct smk_audit_info ad; 3284 char *tsp = smk_of_task(cred->security); 3285 3286 keyp = key_ref_to_ptr(key_ref); 3287 if (keyp == NULL) 3288 return -EINVAL; 3289 /* 3290 * If the key hasn't been initialized give it access so that 3291 * it may do so. 3292 */ 3293 if (keyp->security == NULL) 3294 return 0; 3295 /* 3296 * This should not occur 3297 */ 3298 if (tsp == NULL) 3299 return -EACCES; 3300#ifdef CONFIG_AUDIT 3301 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_KEY); 3302 ad.a.u.key_struct.key = keyp->serial; 3303 ad.a.u.key_struct.key_desc = keyp->description; 3304#endif 3305 return smk_access(tsp, keyp->security, 3306 MAY_READWRITE, &ad); 3307} 3308#endif /* CONFIG_KEYS */ 3309 3310/* 3311 * Smack Audit hooks 3312 * 3313 * Audit requires a unique representation of each Smack specific 3314 * rule. This unique representation is used to distinguish the 3315 * object to be audited from remaining kernel objects and also 3316 * works as a glue between the audit hooks. 3317 * 3318 * Since repository entries are added but never deleted, we'll use 3319 * the smack_known label address related to the given audit rule as 3320 * the needed unique representation. This also better fits the smack 3321 * model where nearly everything is a label. 3322 */ 3323#ifdef CONFIG_AUDIT 3324 3325/** 3326 * smack_audit_rule_init - Initialize a smack audit rule 3327 * @field: audit rule fields given from user-space (audit.h) 3328 * @op: required testing operator (=, !=, >, <, ...) 3329 * @rulestr: smack label to be audited 3330 * @vrule: pointer to save our own audit rule representation 3331 * 3332 * Prepare to audit cases where (@field @op @rulestr) is true. 3333 * The label to be audited is created if necessay. 3334 */ 3335static int smack_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule) 3336{ 3337 char **rule = (char **)vrule; 3338 *rule = NULL; 3339 3340 if (field != AUDIT_SUBJ_USER && field != AUDIT_OBJ_USER) 3341 return -EINVAL; 3342 3343 if (op != Audit_equal && op != Audit_not_equal) 3344 return -EINVAL; 3345 3346 *rule = smk_import(rulestr, 0); 3347 3348 return 0; 3349} 3350 3351/** 3352 * smack_audit_rule_known - Distinguish Smack audit rules 3353 * @krule: rule of interest, in Audit kernel representation format 3354 * 3355 * This is used to filter Smack rules from remaining Audit ones. 3356 * If it's proved that this rule belongs to us, the 3357 * audit_rule_match hook will be called to do the final judgement. 3358 */ 3359static int smack_audit_rule_known(struct audit_krule *krule) 3360{ 3361 struct audit_field *f; 3362 int i; 3363 3364 for (i = 0; i < krule->field_count; i++) { 3365 f = &krule->fields[i]; 3366 3367 if (f->type == AUDIT_SUBJ_USER || f->type == AUDIT_OBJ_USER) 3368 return 1; 3369 } 3370 3371 return 0; 3372} 3373 3374/** 3375 * smack_audit_rule_match - Audit given object ? 3376 * @secid: security id for identifying the object to test 3377 * @field: audit rule flags given from user-space 3378 * @op: required testing operator 3379 * @vrule: smack internal rule presentation 3380 * @actx: audit context associated with the check 3381 * 3382 * The core Audit hook. It's used to take the decision of 3383 * whether to audit or not to audit a given object. 3384 */ 3385static int smack_audit_rule_match(u32 secid, u32 field, u32 op, void *vrule, 3386 struct audit_context *actx) 3387{ 3388 char *smack; 3389 char *rule = vrule; 3390 3391 if (!rule) { 3392 audit_log(actx, GFP_KERNEL, AUDIT_SELINUX_ERR, 3393 "Smack: missing rule\n"); 3394 return -ENOENT; 3395 } 3396 3397 if (field != AUDIT_SUBJ_USER && field != AUDIT_OBJ_USER) 3398 return 0; 3399 3400 smack = smack_from_secid(secid); 3401 3402 /* 3403 * No need to do string comparisons. If a match occurs, 3404 * both pointers will point to the same smack_known 3405 * label. 3406 */ 3407 if (op == Audit_equal) 3408 return (rule == smack); 3409 if (op == Audit_not_equal) 3410 return (rule != smack); 3411 3412 return 0; 3413} 3414 3415/** 3416 * smack_audit_rule_free - free smack rule representation 3417 * @vrule: rule to be freed. 3418 * 3419 * No memory was allocated. 3420 */ 3421static void smack_audit_rule_free(void *vrule) 3422{ 3423 /* No-op */ 3424} 3425 3426#endif /* CONFIG_AUDIT */ 3427 3428/** 3429 * smack_secid_to_secctx - return the smack label for a secid 3430 * @secid: incoming integer 3431 * @secdata: destination 3432 * @seclen: how long it is 3433 * 3434 * Exists for networking code. 3435 */ 3436static int smack_secid_to_secctx(u32 secid, char **secdata, u32 *seclen) 3437{ 3438 char *sp = smack_from_secid(secid); 3439 3440 if (secdata) 3441 *secdata = sp; 3442 *seclen = strlen(sp); 3443 return 0; 3444} 3445 3446/** 3447 * smack_secctx_to_secid - return the secid for a smack label 3448 * @secdata: smack label 3449 * @seclen: how long result is 3450 * @secid: outgoing integer 3451 * 3452 * Exists for audit and networking code. 3453 */ 3454static int smack_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid) 3455{ 3456 *secid = smack_to_secid(secdata); 3457 return 0; 3458} 3459 3460/** 3461 * smack_release_secctx - don't do anything. 3462 * @secdata: unused 3463 * @seclen: unused 3464 * 3465 * Exists to make sure nothing gets done, and properly 3466 */ 3467static void smack_release_secctx(char *secdata, u32 seclen) 3468{ 3469} 3470 3471static int smack_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen) 3472{ 3473 return smack_inode_setsecurity(inode, XATTR_SMACK_SUFFIX, ctx, ctxlen, 0); 3474} 3475 3476static int smack_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen) 3477{ 3478 return __vfs_setxattr_noperm(dentry, XATTR_NAME_SMACK, ctx, ctxlen, 0); 3479} 3480 3481static int smack_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen) 3482{ 3483 int len = 0; 3484 len = smack_inode_getsecurity(inode, XATTR_SMACK_SUFFIX, ctx, true); 3485 3486 if (len < 0) 3487 return len; 3488 *ctxlen = len; 3489 return 0; 3490} 3491 3492struct security_operations smack_ops = { 3493 .name = "smack", 3494 3495 .ptrace_access_check = smack_ptrace_access_check, 3496 .ptrace_traceme = smack_ptrace_traceme, 3497 .syslog = smack_syslog, 3498 3499 .sb_alloc_security = smack_sb_alloc_security, 3500 .sb_free_security = smack_sb_free_security, 3501 .sb_copy_data = smack_sb_copy_data, 3502 .sb_kern_mount = smack_sb_kern_mount, 3503 .sb_statfs = smack_sb_statfs, 3504 .sb_mount = smack_sb_mount, 3505 .sb_umount = smack_sb_umount, 3506 3507 .bprm_set_creds = smack_bprm_set_creds, 3508 .bprm_committing_creds = smack_bprm_committing_creds, 3509 .bprm_secureexec = smack_bprm_secureexec, 3510 3511 .inode_alloc_security = smack_inode_alloc_security, 3512 .inode_free_security = smack_inode_free_security, 3513 .inode_init_security = smack_inode_init_security, 3514 .inode_link = smack_inode_link, 3515 .inode_unlink = smack_inode_unlink, 3516 .inode_rmdir = smack_inode_rmdir, 3517 .inode_rename = smack_inode_rename, 3518 .inode_permission = smack_inode_permission, 3519 .inode_setattr = smack_inode_setattr, 3520 .inode_getattr = smack_inode_getattr, 3521 .inode_setxattr = smack_inode_setxattr, 3522 .inode_post_setxattr = smack_inode_post_setxattr, 3523 .inode_getxattr = smack_inode_getxattr, 3524 .inode_removexattr = smack_inode_removexattr, 3525 .inode_getsecurity = smack_inode_getsecurity, 3526 .inode_setsecurity = smack_inode_setsecurity, 3527 .inode_listsecurity = smack_inode_listsecurity, 3528 .inode_getsecid = smack_inode_getsecid, 3529 3530 .file_permission = smack_file_permission, 3531 .file_alloc_security = smack_file_alloc_security, 3532 .file_free_security = smack_file_free_security, 3533 .file_ioctl = smack_file_ioctl, 3534 .file_lock = smack_file_lock, 3535 .file_fcntl = smack_file_fcntl, 3536 .file_mmap = smack_file_mmap, 3537 .file_set_fowner = smack_file_set_fowner, 3538 .file_send_sigiotask = smack_file_send_sigiotask, 3539 .file_receive = smack_file_receive, 3540 3541 .dentry_open = smack_dentry_open, 3542 3543 .cred_alloc_blank = smack_cred_alloc_blank, 3544 .cred_free = smack_cred_free, 3545 .cred_prepare = smack_cred_prepare, 3546 .cred_transfer = smack_cred_transfer, 3547 .kernel_act_as = smack_kernel_act_as, 3548 .kernel_create_files_as = smack_kernel_create_files_as, 3549 .task_setpgid = smack_task_setpgid, 3550 .task_getpgid = smack_task_getpgid, 3551 .task_getsid = smack_task_getsid, 3552 .task_getsecid = smack_task_getsecid, 3553 .task_setnice = smack_task_setnice, 3554 .task_setioprio = smack_task_setioprio, 3555 .task_getioprio = smack_task_getioprio, 3556 .task_setscheduler = smack_task_setscheduler, 3557 .task_getscheduler = smack_task_getscheduler, 3558 .task_movememory = smack_task_movememory, 3559 .task_kill = smack_task_kill, 3560 .task_wait = smack_task_wait, 3561 .task_to_inode = smack_task_to_inode, 3562 3563 .ipc_permission = smack_ipc_permission, 3564 .ipc_getsecid = smack_ipc_getsecid, 3565 3566 .msg_msg_alloc_security = smack_msg_msg_alloc_security, 3567 .msg_msg_free_security = smack_msg_msg_free_security, 3568 3569 .msg_queue_alloc_security = smack_msg_queue_alloc_security, 3570 .msg_queue_free_security = smack_msg_queue_free_security, 3571 .msg_queue_associate = smack_msg_queue_associate, 3572 .msg_queue_msgctl = smack_msg_queue_msgctl, 3573 .msg_queue_msgsnd = smack_msg_queue_msgsnd, 3574 .msg_queue_msgrcv = smack_msg_queue_msgrcv, 3575 3576 .shm_alloc_security = smack_shm_alloc_security, 3577 .shm_free_security = smack_shm_free_security, 3578 .shm_associate = smack_shm_associate, 3579 .shm_shmctl = smack_shm_shmctl, 3580 .shm_shmat = smack_shm_shmat, 3581 3582 .sem_alloc_security = smack_sem_alloc_security, 3583 .sem_free_security = smack_sem_free_security, 3584 .sem_associate = smack_sem_associate, 3585 .sem_semctl = smack_sem_semctl, 3586 .sem_semop = smack_sem_semop, 3587 3588 .d_instantiate = smack_d_instantiate, 3589 3590 .getprocattr = smack_getprocattr, 3591 .setprocattr = smack_setprocattr, 3592 3593 .unix_stream_connect = smack_unix_stream_connect, 3594 .unix_may_send = smack_unix_may_send, 3595 3596 .socket_post_create = smack_socket_post_create, 3597 .socket_connect = smack_socket_connect, 3598 .socket_sendmsg = smack_socket_sendmsg, 3599 .socket_sock_rcv_skb = smack_socket_sock_rcv_skb, 3600 .socket_getpeersec_stream = smack_socket_getpeersec_stream, 3601 .socket_getpeersec_dgram = smack_socket_getpeersec_dgram, 3602 .sk_alloc_security = smack_sk_alloc_security, 3603 .sk_free_security = smack_sk_free_security, 3604 .sock_graft = smack_sock_graft, 3605 .inet_conn_request = smack_inet_conn_request, 3606 .inet_csk_clone = smack_inet_csk_clone, 3607 3608 /* key management security hooks */ 3609#ifdef CONFIG_KEYS 3610 .key_alloc = smack_key_alloc, 3611 .key_free = smack_key_free, 3612 .key_permission = smack_key_permission, 3613#endif /* CONFIG_KEYS */ 3614 3615 /* Audit hooks */ 3616#ifdef CONFIG_AUDIT 3617 .audit_rule_init = smack_audit_rule_init, 3618 .audit_rule_known = smack_audit_rule_known, 3619 .audit_rule_match = smack_audit_rule_match, 3620 .audit_rule_free = smack_audit_rule_free, 3621#endif /* CONFIG_AUDIT */ 3622 3623 .secid_to_secctx = smack_secid_to_secctx, 3624 .secctx_to_secid = smack_secctx_to_secid, 3625 .release_secctx = smack_release_secctx, 3626 .inode_notifysecctx = smack_inode_notifysecctx, 3627 .inode_setsecctx = smack_inode_setsecctx, 3628 .inode_getsecctx = smack_inode_getsecctx, 3629}; 3630 3631 3632static __init void init_smack_know_list(void) 3633{ 3634 list_add(&smack_known_huh.list, &smack_known_list); 3635 list_add(&smack_known_hat.list, &smack_known_list); 3636 list_add(&smack_known_star.list, &smack_known_list); 3637 list_add(&smack_known_floor.list, &smack_known_list); 3638 list_add(&smack_known_invalid.list, &smack_known_list); 3639 list_add(&smack_known_web.list, &smack_known_list); 3640} 3641 3642/** 3643 * smack_init - initialize the smack system 3644 * 3645 * Returns 0 3646 */ 3647static __init int smack_init(void) 3648{ 3649 struct cred *cred; 3650 struct task_smack *tsp; 3651 3652 if (!security_module_enable(&smack_ops)) 3653 return 0; 3654 3655 tsp = new_task_smack(smack_known_floor.smk_known, 3656 smack_known_floor.smk_known, GFP_KERNEL); 3657 if (tsp == NULL) 3658 return -ENOMEM; 3659 3660 printk(KERN_INFO "Smack: Initializing.\n"); 3661 3662 /* 3663 * Set the security state for the initial task. 3664 */ 3665 cred = (struct cred *) current->cred; 3666 cred->security = tsp; 3667 3668 /* initialize the smack_know_list */ 3669 init_smack_know_list(); 3670 /* 3671 * Initialize locks 3672 */ 3673 spin_lock_init(&smack_known_huh.smk_cipsolock); 3674 spin_lock_init(&smack_known_hat.smk_cipsolock); 3675 spin_lock_init(&smack_known_star.smk_cipsolock); 3676 spin_lock_init(&smack_known_floor.smk_cipsolock); 3677 spin_lock_init(&smack_known_invalid.smk_cipsolock); 3678 3679 /* 3680 * Register with LSM 3681 */ 3682 if (register_security(&smack_ops)) 3683 panic("smack: Unable to register with kernel.\n"); 3684 3685 return 0; 3686} 3687 3688/* 3689 * Smack requires early initialization in order to label 3690 * all processes and objects when they are created. 3691 */ 3692security_initcall(smack_init);