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/dccp.h> 31 #include <linux/slab.h> 32 #include <linux/mutex.h> 33 #include <linux/pipe_fs_i.h> 34 #include <net/cipso_ipv4.h> 35 #include <net/ip.h> 36 #include <net/ipv6.h> 37 #include <linux/audit.h> 38 #include <linux/magic.h> 39 #include <linux/dcache.h> 40 #include <linux/personality.h> 41 #include <linux/msg.h> 42 #include <linux/shm.h> 43 #include <linux/binfmts.h> 44 #include "smack.h" 45 46 #define task_security(task) (task_cred_xxx((task), security)) 47 48 #define TRANS_TRUE "TRUE" 49 #define TRANS_TRUE_SIZE 4 50 51 #define SMK_CONNECTING 0 52 #define SMK_RECEIVING 1 53 #define SMK_SENDING 2 54 55 LIST_HEAD(smk_ipv6_port_list); 56 static struct kmem_cache *smack_inode_cache; 57 58 #ifdef CONFIG_SECURITY_SMACK_BRINGUP 59 static void smk_bu_mode(int mode, char *s) 60 { 61 int i = 0; 62 63 if (mode & MAY_READ) 64 s[i++] = 'r'; 65 if (mode & MAY_WRITE) 66 s[i++] = 'w'; 67 if (mode & MAY_EXEC) 68 s[i++] = 'x'; 69 if (mode & MAY_APPEND) 70 s[i++] = 'a'; 71 if (mode & MAY_TRANSMUTE) 72 s[i++] = 't'; 73 if (mode & MAY_LOCK) 74 s[i++] = 'l'; 75 if (i == 0) 76 s[i++] = '-'; 77 s[i] = '\0'; 78 } 79 #endif 80 81 #ifdef CONFIG_SECURITY_SMACK_BRINGUP 82 static int smk_bu_note(char *note, struct smack_known *sskp, 83 struct smack_known *oskp, int mode, int rc) 84 { 85 char acc[SMK_NUM_ACCESS_TYPE + 1]; 86 87 if (rc <= 0) 88 return rc; 89 90 smk_bu_mode(mode, acc); 91 pr_info("Smack Bringup: (%s %s %s) %s\n", 92 sskp->smk_known, oskp->smk_known, acc, note); 93 return 0; 94 } 95 #else 96 #define smk_bu_note(note, sskp, oskp, mode, RC) (RC) 97 #endif 98 99 #ifdef CONFIG_SECURITY_SMACK_BRINGUP 100 static int smk_bu_current(char *note, struct smack_known *oskp, 101 int mode, int rc) 102 { 103 struct task_smack *tsp = current_security(); 104 char acc[SMK_NUM_ACCESS_TYPE + 1]; 105 106 if (rc <= 0) 107 return rc; 108 109 smk_bu_mode(mode, acc); 110 pr_info("Smack Bringup: (%s %s %s) %s %s\n", 111 tsp->smk_task->smk_known, oskp->smk_known, 112 acc, current->comm, note); 113 return 0; 114 } 115 #else 116 #define smk_bu_current(note, oskp, mode, RC) (RC) 117 #endif 118 119 #ifdef CONFIG_SECURITY_SMACK_BRINGUP 120 static int smk_bu_task(struct task_struct *otp, int mode, int rc) 121 { 122 struct task_smack *tsp = current_security(); 123 struct task_smack *otsp = task_security(otp); 124 char acc[SMK_NUM_ACCESS_TYPE + 1]; 125 126 if (rc <= 0) 127 return rc; 128 129 smk_bu_mode(mode, acc); 130 pr_info("Smack Bringup: (%s %s %s) %s to %s\n", 131 tsp->smk_task->smk_known, otsp->smk_task->smk_known, acc, 132 current->comm, otp->comm); 133 return 0; 134 } 135 #else 136 #define smk_bu_task(otp, mode, RC) (RC) 137 #endif 138 139 #ifdef CONFIG_SECURITY_SMACK_BRINGUP 140 static int smk_bu_inode(struct inode *inode, int mode, int rc) 141 { 142 struct task_smack *tsp = current_security(); 143 char acc[SMK_NUM_ACCESS_TYPE + 1]; 144 145 if (rc <= 0) 146 return rc; 147 148 smk_bu_mode(mode, acc); 149 pr_info("Smack Bringup: (%s %s %s) inode=(%s %ld) %s\n", 150 tsp->smk_task->smk_known, smk_of_inode(inode)->smk_known, acc, 151 inode->i_sb->s_id, inode->i_ino, current->comm); 152 return 0; 153 } 154 #else 155 #define smk_bu_inode(inode, mode, RC) (RC) 156 #endif 157 158 #ifdef CONFIG_SECURITY_SMACK_BRINGUP 159 static int smk_bu_file(struct file *file, int mode, int rc) 160 { 161 struct task_smack *tsp = current_security(); 162 struct smack_known *sskp = tsp->smk_task; 163 struct inode *inode = file->f_inode; 164 char acc[SMK_NUM_ACCESS_TYPE + 1]; 165 166 if (rc <= 0) 167 return rc; 168 169 smk_bu_mode(mode, acc); 170 pr_info("Smack Bringup: (%s %s %s) file=(%s %ld %pD) %s\n", 171 sskp->smk_known, (char *)file->f_security, acc, 172 inode->i_sb->s_id, inode->i_ino, file, 173 current->comm); 174 return 0; 175 } 176 #else 177 #define smk_bu_file(file, mode, RC) (RC) 178 #endif 179 180 #ifdef CONFIG_SECURITY_SMACK_BRINGUP 181 static int smk_bu_credfile(const struct cred *cred, struct file *file, 182 int mode, int rc) 183 { 184 struct task_smack *tsp = cred->security; 185 struct smack_known *sskp = tsp->smk_task; 186 struct inode *inode = file->f_inode; 187 char acc[SMK_NUM_ACCESS_TYPE + 1]; 188 189 if (rc <= 0) 190 return rc; 191 192 smk_bu_mode(mode, acc); 193 pr_info("Smack Bringup: (%s %s %s) file=(%s %ld %pD) %s\n", 194 sskp->smk_known, smk_of_inode(inode)->smk_known, acc, 195 inode->i_sb->s_id, inode->i_ino, file, 196 current->comm); 197 return 0; 198 } 199 #else 200 #define smk_bu_credfile(cred, file, mode, RC) (RC) 201 #endif 202 203 /** 204 * smk_fetch - Fetch the smack label from a file. 205 * @ip: a pointer to the inode 206 * @dp: a pointer to the dentry 207 * 208 * Returns a pointer to the master list entry for the Smack label 209 * or NULL if there was no label to fetch. 210 */ 211 static struct smack_known *smk_fetch(const char *name, struct inode *ip, 212 struct dentry *dp) 213 { 214 int rc; 215 char *buffer; 216 struct smack_known *skp = NULL; 217 218 if (ip->i_op->getxattr == NULL) 219 return NULL; 220 221 buffer = kzalloc(SMK_LONGLABEL, GFP_KERNEL); 222 if (buffer == NULL) 223 return NULL; 224 225 rc = ip->i_op->getxattr(dp, name, buffer, SMK_LONGLABEL); 226 if (rc > 0) 227 skp = smk_import_entry(buffer, rc); 228 229 kfree(buffer); 230 231 return skp; 232 } 233 234 /** 235 * new_inode_smack - allocate an inode security blob 236 * @skp: a pointer to the Smack label entry to use in the blob 237 * 238 * Returns the new blob or NULL if there's no memory available 239 */ 240 struct inode_smack *new_inode_smack(struct smack_known *skp) 241 { 242 struct inode_smack *isp; 243 244 isp = kmem_cache_zalloc(smack_inode_cache, GFP_NOFS); 245 if (isp == NULL) 246 return NULL; 247 248 isp->smk_inode = skp; 249 isp->smk_flags = 0; 250 mutex_init(&isp->smk_lock); 251 252 return isp; 253 } 254 255 /** 256 * new_task_smack - allocate a task security blob 257 * @smack: a pointer to the Smack label to use in the blob 258 * 259 * Returns the new blob or NULL if there's no memory available 260 */ 261 static struct task_smack *new_task_smack(struct smack_known *task, 262 struct smack_known *forked, gfp_t gfp) 263 { 264 struct task_smack *tsp; 265 266 tsp = kzalloc(sizeof(struct task_smack), gfp); 267 if (tsp == NULL) 268 return NULL; 269 270 tsp->smk_task = task; 271 tsp->smk_forked = forked; 272 INIT_LIST_HEAD(&tsp->smk_rules); 273 mutex_init(&tsp->smk_rules_lock); 274 275 return tsp; 276 } 277 278 /** 279 * smk_copy_rules - copy a rule set 280 * @nhead - new rules header pointer 281 * @ohead - old rules header pointer 282 * 283 * Returns 0 on success, -ENOMEM on error 284 */ 285 static int smk_copy_rules(struct list_head *nhead, struct list_head *ohead, 286 gfp_t gfp) 287 { 288 struct smack_rule *nrp; 289 struct smack_rule *orp; 290 int rc = 0; 291 292 INIT_LIST_HEAD(nhead); 293 294 list_for_each_entry_rcu(orp, ohead, list) { 295 nrp = kzalloc(sizeof(struct smack_rule), gfp); 296 if (nrp == NULL) { 297 rc = -ENOMEM; 298 break; 299 } 300 *nrp = *orp; 301 list_add_rcu(&nrp->list, nhead); 302 } 303 return rc; 304 } 305 306 /** 307 * smk_ptrace_mode - helper function for converting PTRACE_MODE_* into MAY_* 308 * @mode - input mode in form of PTRACE_MODE_* 309 * 310 * Returns a converted MAY_* mode usable by smack rules 311 */ 312 static inline unsigned int smk_ptrace_mode(unsigned int mode) 313 { 314 switch (mode) { 315 case PTRACE_MODE_READ: 316 return MAY_READ; 317 case PTRACE_MODE_ATTACH: 318 return MAY_READWRITE; 319 } 320 321 return 0; 322 } 323 324 /** 325 * smk_ptrace_rule_check - helper for ptrace access 326 * @tracer: tracer process 327 * @tracee_known: label entry of the process that's about to be traced 328 * @mode: ptrace attachment mode (PTRACE_MODE_*) 329 * @func: name of the function that called us, used for audit 330 * 331 * Returns 0 on access granted, -error on error 332 */ 333 static int smk_ptrace_rule_check(struct task_struct *tracer, 334 struct smack_known *tracee_known, 335 unsigned int mode, const char *func) 336 { 337 int rc; 338 struct smk_audit_info ad, *saip = NULL; 339 struct task_smack *tsp; 340 struct smack_known *tracer_known; 341 342 if ((mode & PTRACE_MODE_NOAUDIT) == 0) { 343 smk_ad_init(&ad, func, LSM_AUDIT_DATA_TASK); 344 smk_ad_setfield_u_tsk(&ad, tracer); 345 saip = &ad; 346 } 347 348 tsp = task_security(tracer); 349 tracer_known = smk_of_task(tsp); 350 351 if ((mode & PTRACE_MODE_ATTACH) && 352 (smack_ptrace_rule == SMACK_PTRACE_EXACT || 353 smack_ptrace_rule == SMACK_PTRACE_DRACONIAN)) { 354 if (tracer_known->smk_known == tracee_known->smk_known) 355 rc = 0; 356 else if (smack_ptrace_rule == SMACK_PTRACE_DRACONIAN) 357 rc = -EACCES; 358 else if (capable(CAP_SYS_PTRACE)) 359 rc = 0; 360 else 361 rc = -EACCES; 362 363 if (saip) 364 smack_log(tracer_known->smk_known, 365 tracee_known->smk_known, 366 0, rc, saip); 367 368 return rc; 369 } 370 371 /* In case of rule==SMACK_PTRACE_DEFAULT or mode==PTRACE_MODE_READ */ 372 rc = smk_tskacc(tsp, tracee_known, smk_ptrace_mode(mode), saip); 373 return rc; 374 } 375 376 /* 377 * LSM hooks. 378 * We he, that is fun! 379 */ 380 381 /** 382 * smack_ptrace_access_check - Smack approval on PTRACE_ATTACH 383 * @ctp: child task pointer 384 * @mode: ptrace attachment mode (PTRACE_MODE_*) 385 * 386 * Returns 0 if access is OK, an error code otherwise 387 * 388 * Do the capability checks. 389 */ 390 static int smack_ptrace_access_check(struct task_struct *ctp, unsigned int mode) 391 { 392 int rc; 393 struct smack_known *skp; 394 395 rc = cap_ptrace_access_check(ctp, mode); 396 if (rc != 0) 397 return rc; 398 399 skp = smk_of_task(task_security(ctp)); 400 401 rc = smk_ptrace_rule_check(current, skp, mode, __func__); 402 return rc; 403 } 404 405 /** 406 * smack_ptrace_traceme - Smack approval on PTRACE_TRACEME 407 * @ptp: parent task pointer 408 * 409 * Returns 0 if access is OK, an error code otherwise 410 * 411 * Do the capability checks, and require PTRACE_MODE_ATTACH. 412 */ 413 static int smack_ptrace_traceme(struct task_struct *ptp) 414 { 415 int rc; 416 struct smack_known *skp; 417 418 rc = cap_ptrace_traceme(ptp); 419 if (rc != 0) 420 return rc; 421 422 skp = smk_of_task(current_security()); 423 424 rc = smk_ptrace_rule_check(ptp, skp, PTRACE_MODE_ATTACH, __func__); 425 return rc; 426 } 427 428 /** 429 * smack_syslog - Smack approval on syslog 430 * @type: message type 431 * 432 * Returns 0 on success, error code otherwise. 433 */ 434 static int smack_syslog(int typefrom_file) 435 { 436 int rc = 0; 437 struct smack_known *skp = smk_of_current(); 438 439 if (smack_privileged(CAP_MAC_OVERRIDE)) 440 return 0; 441 442 if (smack_syslog_label != NULL && smack_syslog_label != skp) 443 rc = -EACCES; 444 445 return rc; 446 } 447 448 449 /* 450 * Superblock Hooks. 451 */ 452 453 /** 454 * smack_sb_alloc_security - allocate a superblock blob 455 * @sb: the superblock getting the blob 456 * 457 * Returns 0 on success or -ENOMEM on error. 458 */ 459 static int smack_sb_alloc_security(struct super_block *sb) 460 { 461 struct superblock_smack *sbsp; 462 463 sbsp = kzalloc(sizeof(struct superblock_smack), GFP_KERNEL); 464 465 if (sbsp == NULL) 466 return -ENOMEM; 467 468 sbsp->smk_root = &smack_known_floor; 469 sbsp->smk_default = &smack_known_floor; 470 sbsp->smk_floor = &smack_known_floor; 471 sbsp->smk_hat = &smack_known_hat; 472 /* 473 * smk_initialized will be zero from kzalloc. 474 */ 475 sb->s_security = sbsp; 476 477 return 0; 478 } 479 480 /** 481 * smack_sb_free_security - free a superblock blob 482 * @sb: the superblock getting the blob 483 * 484 */ 485 static void smack_sb_free_security(struct super_block *sb) 486 { 487 kfree(sb->s_security); 488 sb->s_security = NULL; 489 } 490 491 /** 492 * smack_sb_copy_data - copy mount options data for processing 493 * @orig: where to start 494 * @smackopts: mount options string 495 * 496 * Returns 0 on success or -ENOMEM on error. 497 * 498 * Copy the Smack specific mount options out of the mount 499 * options list. 500 */ 501 static int smack_sb_copy_data(char *orig, char *smackopts) 502 { 503 char *cp, *commap, *otheropts, *dp; 504 505 otheropts = (char *)get_zeroed_page(GFP_KERNEL); 506 if (otheropts == NULL) 507 return -ENOMEM; 508 509 for (cp = orig, commap = orig; commap != NULL; cp = commap + 1) { 510 if (strstr(cp, SMK_FSDEFAULT) == cp) 511 dp = smackopts; 512 else if (strstr(cp, SMK_FSFLOOR) == cp) 513 dp = smackopts; 514 else if (strstr(cp, SMK_FSHAT) == cp) 515 dp = smackopts; 516 else if (strstr(cp, SMK_FSROOT) == cp) 517 dp = smackopts; 518 else if (strstr(cp, SMK_FSTRANS) == cp) 519 dp = smackopts; 520 else 521 dp = otheropts; 522 523 commap = strchr(cp, ','); 524 if (commap != NULL) 525 *commap = '\0'; 526 527 if (*dp != '\0') 528 strcat(dp, ","); 529 strcat(dp, cp); 530 } 531 532 strcpy(orig, otheropts); 533 free_page((unsigned long)otheropts); 534 535 return 0; 536 } 537 538 /** 539 * smack_sb_kern_mount - Smack specific mount processing 540 * @sb: the file system superblock 541 * @flags: the mount flags 542 * @data: the smack mount options 543 * 544 * Returns 0 on success, an error code on failure 545 */ 546 static int smack_sb_kern_mount(struct super_block *sb, int flags, void *data) 547 { 548 struct dentry *root = sb->s_root; 549 struct inode *inode = root->d_inode; 550 struct superblock_smack *sp = sb->s_security; 551 struct inode_smack *isp; 552 struct smack_known *skp; 553 char *op; 554 char *commap; 555 int transmute = 0; 556 int specified = 0; 557 558 if (sp->smk_initialized) 559 return 0; 560 561 sp->smk_initialized = 1; 562 563 for (op = data; op != NULL; op = commap) { 564 commap = strchr(op, ','); 565 if (commap != NULL) 566 *commap++ = '\0'; 567 568 if (strncmp(op, SMK_FSHAT, strlen(SMK_FSHAT)) == 0) { 569 op += strlen(SMK_FSHAT); 570 skp = smk_import_entry(op, 0); 571 if (skp != NULL) { 572 sp->smk_hat = skp; 573 specified = 1; 574 } 575 } else if (strncmp(op, SMK_FSFLOOR, strlen(SMK_FSFLOOR)) == 0) { 576 op += strlen(SMK_FSFLOOR); 577 skp = smk_import_entry(op, 0); 578 if (skp != NULL) { 579 sp->smk_floor = skp; 580 specified = 1; 581 } 582 } else if (strncmp(op, SMK_FSDEFAULT, 583 strlen(SMK_FSDEFAULT)) == 0) { 584 op += strlen(SMK_FSDEFAULT); 585 skp = smk_import_entry(op, 0); 586 if (skp != NULL) { 587 sp->smk_default = skp; 588 specified = 1; 589 } 590 } else if (strncmp(op, SMK_FSROOT, strlen(SMK_FSROOT)) == 0) { 591 op += strlen(SMK_FSROOT); 592 skp = smk_import_entry(op, 0); 593 if (skp != NULL) { 594 sp->smk_root = skp; 595 specified = 1; 596 } 597 } else if (strncmp(op, SMK_FSTRANS, strlen(SMK_FSTRANS)) == 0) { 598 op += strlen(SMK_FSTRANS); 599 skp = smk_import_entry(op, 0); 600 if (skp != NULL) { 601 sp->smk_root = skp; 602 transmute = 1; 603 specified = 1; 604 } 605 } 606 } 607 608 if (!smack_privileged(CAP_MAC_ADMIN)) { 609 /* 610 * Unprivileged mounts don't get to specify Smack values. 611 */ 612 if (specified) 613 return -EPERM; 614 /* 615 * Unprivileged mounts get root and default from the caller. 616 */ 617 skp = smk_of_current(); 618 sp->smk_root = skp; 619 sp->smk_default = skp; 620 } 621 /* 622 * Initialize the root inode. 623 */ 624 isp = inode->i_security; 625 if (isp == NULL) { 626 isp = new_inode_smack(sp->smk_root); 627 if (isp == NULL) 628 return -ENOMEM; 629 inode->i_security = isp; 630 } else 631 isp->smk_inode = sp->smk_root; 632 633 if (transmute) 634 isp->smk_flags |= SMK_INODE_TRANSMUTE; 635 636 return 0; 637 } 638 639 /** 640 * smack_sb_statfs - Smack check on statfs 641 * @dentry: identifies the file system in question 642 * 643 * Returns 0 if current can read the floor of the filesystem, 644 * and error code otherwise 645 */ 646 static int smack_sb_statfs(struct dentry *dentry) 647 { 648 struct superblock_smack *sbp = dentry->d_sb->s_security; 649 int rc; 650 struct smk_audit_info ad; 651 652 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); 653 smk_ad_setfield_u_fs_path_dentry(&ad, dentry); 654 655 rc = smk_curacc(sbp->smk_floor, MAY_READ, &ad); 656 rc = smk_bu_current("statfs", sbp->smk_floor, MAY_READ, rc); 657 return rc; 658 } 659 660 /* 661 * BPRM hooks 662 */ 663 664 /** 665 * smack_bprm_set_creds - set creds for exec 666 * @bprm: the exec information 667 * 668 * Returns 0 if it gets a blob, -EPERM if exec forbidden and -ENOMEM otherwise 669 */ 670 static int smack_bprm_set_creds(struct linux_binprm *bprm) 671 { 672 struct inode *inode = file_inode(bprm->file); 673 struct task_smack *bsp = bprm->cred->security; 674 struct inode_smack *isp; 675 int rc; 676 677 rc = cap_bprm_set_creds(bprm); 678 if (rc != 0) 679 return rc; 680 681 if (bprm->cred_prepared) 682 return 0; 683 684 isp = inode->i_security; 685 if (isp->smk_task == NULL || isp->smk_task == bsp->smk_task) 686 return 0; 687 688 if (bprm->unsafe & (LSM_UNSAFE_PTRACE | LSM_UNSAFE_PTRACE_CAP)) { 689 struct task_struct *tracer; 690 rc = 0; 691 692 rcu_read_lock(); 693 tracer = ptrace_parent(current); 694 if (likely(tracer != NULL)) 695 rc = smk_ptrace_rule_check(tracer, 696 isp->smk_task, 697 PTRACE_MODE_ATTACH, 698 __func__); 699 rcu_read_unlock(); 700 701 if (rc != 0) 702 return rc; 703 } else if (bprm->unsafe) 704 return -EPERM; 705 706 bsp->smk_task = isp->smk_task; 707 bprm->per_clear |= PER_CLEAR_ON_SETID; 708 709 return 0; 710 } 711 712 /** 713 * smack_bprm_committing_creds - Prepare to install the new credentials 714 * from bprm. 715 * 716 * @bprm: binprm for exec 717 */ 718 static void smack_bprm_committing_creds(struct linux_binprm *bprm) 719 { 720 struct task_smack *bsp = bprm->cred->security; 721 722 if (bsp->smk_task != bsp->smk_forked) 723 current->pdeath_signal = 0; 724 } 725 726 /** 727 * smack_bprm_secureexec - Return the decision to use secureexec. 728 * @bprm: binprm for exec 729 * 730 * Returns 0 on success. 731 */ 732 static int smack_bprm_secureexec(struct linux_binprm *bprm) 733 { 734 struct task_smack *tsp = current_security(); 735 int ret = cap_bprm_secureexec(bprm); 736 737 if (!ret && (tsp->smk_task != tsp->smk_forked)) 738 ret = 1; 739 740 return ret; 741 } 742 743 /* 744 * Inode hooks 745 */ 746 747 /** 748 * smack_inode_alloc_security - allocate an inode blob 749 * @inode: the inode in need of a blob 750 * 751 * Returns 0 if it gets a blob, -ENOMEM otherwise 752 */ 753 static int smack_inode_alloc_security(struct inode *inode) 754 { 755 struct smack_known *skp = smk_of_current(); 756 757 inode->i_security = new_inode_smack(skp); 758 if (inode->i_security == NULL) 759 return -ENOMEM; 760 return 0; 761 } 762 763 /** 764 * smack_inode_free_security - free an inode blob 765 * @inode: the inode with a blob 766 * 767 * Clears the blob pointer in inode 768 */ 769 static void smack_inode_free_security(struct inode *inode) 770 { 771 kmem_cache_free(smack_inode_cache, inode->i_security); 772 inode->i_security = NULL; 773 } 774 775 /** 776 * smack_inode_init_security - copy out the smack from an inode 777 * @inode: the newly created inode 778 * @dir: containing directory object 779 * @qstr: unused 780 * @name: where to put the attribute name 781 * @value: where to put the attribute value 782 * @len: where to put the length of the attribute 783 * 784 * Returns 0 if it all works out, -ENOMEM if there's no memory 785 */ 786 static int smack_inode_init_security(struct inode *inode, struct inode *dir, 787 const struct qstr *qstr, const char **name, 788 void **value, size_t *len) 789 { 790 struct inode_smack *issp = inode->i_security; 791 struct smack_known *skp = smk_of_current(); 792 struct smack_known *isp = smk_of_inode(inode); 793 struct smack_known *dsp = smk_of_inode(dir); 794 int may; 795 796 if (name) 797 *name = XATTR_SMACK_SUFFIX; 798 799 if (value) { 800 rcu_read_lock(); 801 may = smk_access_entry(skp->smk_known, dsp->smk_known, 802 &skp->smk_rules); 803 rcu_read_unlock(); 804 805 /* 806 * If the access rule allows transmutation and 807 * the directory requests transmutation then 808 * by all means transmute. 809 * Mark the inode as changed. 810 */ 811 if (may > 0 && ((may & MAY_TRANSMUTE) != 0) && 812 smk_inode_transmutable(dir)) { 813 isp = dsp; 814 issp->smk_flags |= SMK_INODE_CHANGED; 815 } 816 817 *value = kstrdup(isp->smk_known, GFP_NOFS); 818 if (*value == NULL) 819 return -ENOMEM; 820 } 821 822 if (len) 823 *len = strlen(isp->smk_known); 824 825 return 0; 826 } 827 828 /** 829 * smack_inode_link - Smack check on link 830 * @old_dentry: the existing object 831 * @dir: unused 832 * @new_dentry: the new object 833 * 834 * Returns 0 if access is permitted, an error code otherwise 835 */ 836 static int smack_inode_link(struct dentry *old_dentry, struct inode *dir, 837 struct dentry *new_dentry) 838 { 839 struct smack_known *isp; 840 struct smk_audit_info ad; 841 int rc; 842 843 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); 844 smk_ad_setfield_u_fs_path_dentry(&ad, old_dentry); 845 846 isp = smk_of_inode(old_dentry->d_inode); 847 rc = smk_curacc(isp, MAY_WRITE, &ad); 848 rc = smk_bu_inode(old_dentry->d_inode, MAY_WRITE, rc); 849 850 if (rc == 0 && new_dentry->d_inode != NULL) { 851 isp = smk_of_inode(new_dentry->d_inode); 852 smk_ad_setfield_u_fs_path_dentry(&ad, new_dentry); 853 rc = smk_curacc(isp, MAY_WRITE, &ad); 854 rc = smk_bu_inode(new_dentry->d_inode, MAY_WRITE, rc); 855 } 856 857 return rc; 858 } 859 860 /** 861 * smack_inode_unlink - Smack check on inode deletion 862 * @dir: containing directory object 863 * @dentry: file to unlink 864 * 865 * Returns 0 if current can write the containing directory 866 * and the object, error code otherwise 867 */ 868 static int smack_inode_unlink(struct inode *dir, struct dentry *dentry) 869 { 870 struct inode *ip = dentry->d_inode; 871 struct smk_audit_info ad; 872 int rc; 873 874 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); 875 smk_ad_setfield_u_fs_path_dentry(&ad, dentry); 876 877 /* 878 * You need write access to the thing you're unlinking 879 */ 880 rc = smk_curacc(smk_of_inode(ip), MAY_WRITE, &ad); 881 rc = smk_bu_inode(ip, MAY_WRITE, rc); 882 if (rc == 0) { 883 /* 884 * You also need write access to the containing directory 885 */ 886 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_INODE); 887 smk_ad_setfield_u_fs_inode(&ad, dir); 888 rc = smk_curacc(smk_of_inode(dir), MAY_WRITE, &ad); 889 rc = smk_bu_inode(dir, MAY_WRITE, rc); 890 } 891 return rc; 892 } 893 894 /** 895 * smack_inode_rmdir - Smack check on directory deletion 896 * @dir: containing directory object 897 * @dentry: directory to unlink 898 * 899 * Returns 0 if current can write the containing directory 900 * and the directory, error code otherwise 901 */ 902 static int smack_inode_rmdir(struct inode *dir, struct dentry *dentry) 903 { 904 struct smk_audit_info ad; 905 int rc; 906 907 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); 908 smk_ad_setfield_u_fs_path_dentry(&ad, dentry); 909 910 /* 911 * You need write access to the thing you're removing 912 */ 913 rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE, &ad); 914 rc = smk_bu_inode(dentry->d_inode, MAY_WRITE, rc); 915 if (rc == 0) { 916 /* 917 * You also need write access to the containing directory 918 */ 919 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_INODE); 920 smk_ad_setfield_u_fs_inode(&ad, dir); 921 rc = smk_curacc(smk_of_inode(dir), MAY_WRITE, &ad); 922 rc = smk_bu_inode(dir, MAY_WRITE, rc); 923 } 924 925 return rc; 926 } 927 928 /** 929 * smack_inode_rename - Smack check on rename 930 * @old_inode: unused 931 * @old_dentry: the old object 932 * @new_inode: unused 933 * @new_dentry: the new object 934 * 935 * Read and write access is required on both the old and 936 * new directories. 937 * 938 * Returns 0 if access is permitted, an error code otherwise 939 */ 940 static int smack_inode_rename(struct inode *old_inode, 941 struct dentry *old_dentry, 942 struct inode *new_inode, 943 struct dentry *new_dentry) 944 { 945 int rc; 946 struct smack_known *isp; 947 struct smk_audit_info ad; 948 949 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); 950 smk_ad_setfield_u_fs_path_dentry(&ad, old_dentry); 951 952 isp = smk_of_inode(old_dentry->d_inode); 953 rc = smk_curacc(isp, MAY_READWRITE, &ad); 954 rc = smk_bu_inode(old_dentry->d_inode, MAY_READWRITE, rc); 955 956 if (rc == 0 && new_dentry->d_inode != NULL) { 957 isp = smk_of_inode(new_dentry->d_inode); 958 smk_ad_setfield_u_fs_path_dentry(&ad, new_dentry); 959 rc = smk_curacc(isp, MAY_READWRITE, &ad); 960 rc = smk_bu_inode(new_dentry->d_inode, MAY_READWRITE, rc); 961 } 962 return rc; 963 } 964 965 /** 966 * smack_inode_permission - Smack version of permission() 967 * @inode: the inode in question 968 * @mask: the access requested 969 * 970 * This is the important Smack hook. 971 * 972 * Returns 0 if access is permitted, -EACCES otherwise 973 */ 974 static int smack_inode_permission(struct inode *inode, int mask) 975 { 976 struct smk_audit_info ad; 977 int no_block = mask & MAY_NOT_BLOCK; 978 int rc; 979 980 mask &= (MAY_READ|MAY_WRITE|MAY_EXEC|MAY_APPEND); 981 /* 982 * No permission to check. Existence test. Yup, it's there. 983 */ 984 if (mask == 0) 985 return 0; 986 987 /* May be droppable after audit */ 988 if (no_block) 989 return -ECHILD; 990 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_INODE); 991 smk_ad_setfield_u_fs_inode(&ad, inode); 992 rc = smk_curacc(smk_of_inode(inode), mask, &ad); 993 rc = smk_bu_inode(inode, mask, rc); 994 return rc; 995 } 996 997 /** 998 * smack_inode_setattr - Smack check for setting attributes 999 * @dentry: the object 1000 * @iattr: for the force flag 1001 * 1002 * Returns 0 if access is permitted, an error code otherwise 1003 */ 1004 static int smack_inode_setattr(struct dentry *dentry, struct iattr *iattr) 1005 { 1006 struct smk_audit_info ad; 1007 int rc; 1008 1009 /* 1010 * Need to allow for clearing the setuid bit. 1011 */ 1012 if (iattr->ia_valid & ATTR_FORCE) 1013 return 0; 1014 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); 1015 smk_ad_setfield_u_fs_path_dentry(&ad, dentry); 1016 1017 rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE, &ad); 1018 rc = smk_bu_inode(dentry->d_inode, MAY_WRITE, rc); 1019 return rc; 1020 } 1021 1022 /** 1023 * smack_inode_getattr - Smack check for getting attributes 1024 * @mnt: vfsmount of the object 1025 * @dentry: the object 1026 * 1027 * Returns 0 if access is permitted, an error code otherwise 1028 */ 1029 static int smack_inode_getattr(struct vfsmount *mnt, struct dentry *dentry) 1030 { 1031 struct smk_audit_info ad; 1032 struct path path; 1033 int rc; 1034 1035 path.dentry = dentry; 1036 path.mnt = mnt; 1037 1038 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH); 1039 smk_ad_setfield_u_fs_path(&ad, path); 1040 rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_READ, &ad); 1041 rc = smk_bu_inode(dentry->d_inode, MAY_READ, rc); 1042 return rc; 1043 } 1044 1045 /** 1046 * smack_inode_setxattr - Smack check for setting xattrs 1047 * @dentry: the object 1048 * @name: name of the attribute 1049 * @value: value of the attribute 1050 * @size: size of the value 1051 * @flags: unused 1052 * 1053 * This protects the Smack attribute explicitly. 1054 * 1055 * Returns 0 if access is permitted, an error code otherwise 1056 */ 1057 static int smack_inode_setxattr(struct dentry *dentry, const char *name, 1058 const void *value, size_t size, int flags) 1059 { 1060 struct smk_audit_info ad; 1061 struct smack_known *skp; 1062 int check_priv = 0; 1063 int check_import = 0; 1064 int check_star = 0; 1065 int rc = 0; 1066 1067 /* 1068 * Check label validity here so import won't fail in post_setxattr 1069 */ 1070 if (strcmp(name, XATTR_NAME_SMACK) == 0 || 1071 strcmp(name, XATTR_NAME_SMACKIPIN) == 0 || 1072 strcmp(name, XATTR_NAME_SMACKIPOUT) == 0) { 1073 check_priv = 1; 1074 check_import = 1; 1075 } else if (strcmp(name, XATTR_NAME_SMACKEXEC) == 0 || 1076 strcmp(name, XATTR_NAME_SMACKMMAP) == 0) { 1077 check_priv = 1; 1078 check_import = 1; 1079 check_star = 1; 1080 } else if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0) { 1081 check_priv = 1; 1082 if (size != TRANS_TRUE_SIZE || 1083 strncmp(value, TRANS_TRUE, TRANS_TRUE_SIZE) != 0) 1084 rc = -EINVAL; 1085 } else 1086 rc = cap_inode_setxattr(dentry, name, value, size, flags); 1087 1088 if (check_priv && !smack_privileged(CAP_MAC_ADMIN)) 1089 rc = -EPERM; 1090 1091 if (rc == 0 && check_import) { 1092 skp = size ? smk_import_entry(value, size) : NULL; 1093 if (skp == NULL || (check_star && 1094 (skp == &smack_known_star || skp == &smack_known_web))) 1095 rc = -EINVAL; 1096 } 1097 1098 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); 1099 smk_ad_setfield_u_fs_path_dentry(&ad, dentry); 1100 1101 if (rc == 0) { 1102 rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE, &ad); 1103 rc = smk_bu_inode(dentry->d_inode, MAY_WRITE, rc); 1104 } 1105 1106 return rc; 1107 } 1108 1109 /** 1110 * smack_inode_post_setxattr - Apply the Smack update approved above 1111 * @dentry: object 1112 * @name: attribute name 1113 * @value: attribute value 1114 * @size: attribute size 1115 * @flags: unused 1116 * 1117 * Set the pointer in the inode blob to the entry found 1118 * in the master label list. 1119 */ 1120 static void smack_inode_post_setxattr(struct dentry *dentry, const char *name, 1121 const void *value, size_t size, int flags) 1122 { 1123 struct smack_known *skp; 1124 struct inode_smack *isp = dentry->d_inode->i_security; 1125 1126 if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0) { 1127 isp->smk_flags |= SMK_INODE_TRANSMUTE; 1128 return; 1129 } 1130 1131 if (strcmp(name, XATTR_NAME_SMACK) == 0) { 1132 skp = smk_import_entry(value, size); 1133 if (skp != NULL) 1134 isp->smk_inode = skp; 1135 else 1136 isp->smk_inode = &smack_known_invalid; 1137 } else if (strcmp(name, XATTR_NAME_SMACKEXEC) == 0) { 1138 skp = smk_import_entry(value, size); 1139 if (skp != NULL) 1140 isp->smk_task = skp; 1141 else 1142 isp->smk_task = &smack_known_invalid; 1143 } else if (strcmp(name, XATTR_NAME_SMACKMMAP) == 0) { 1144 skp = smk_import_entry(value, size); 1145 if (skp != NULL) 1146 isp->smk_mmap = skp; 1147 else 1148 isp->smk_mmap = &smack_known_invalid; 1149 } 1150 1151 return; 1152 } 1153 1154 /** 1155 * smack_inode_getxattr - Smack check on getxattr 1156 * @dentry: the object 1157 * @name: unused 1158 * 1159 * Returns 0 if access is permitted, an error code otherwise 1160 */ 1161 static int smack_inode_getxattr(struct dentry *dentry, const char *name) 1162 { 1163 struct smk_audit_info ad; 1164 int rc; 1165 1166 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); 1167 smk_ad_setfield_u_fs_path_dentry(&ad, dentry); 1168 1169 rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_READ, &ad); 1170 rc = smk_bu_inode(dentry->d_inode, MAY_READ, rc); 1171 return rc; 1172 } 1173 1174 /** 1175 * smack_inode_removexattr - Smack check on removexattr 1176 * @dentry: the object 1177 * @name: name of the attribute 1178 * 1179 * Removing the Smack attribute requires CAP_MAC_ADMIN 1180 * 1181 * Returns 0 if access is permitted, an error code otherwise 1182 */ 1183 static int smack_inode_removexattr(struct dentry *dentry, const char *name) 1184 { 1185 struct inode_smack *isp; 1186 struct smk_audit_info ad; 1187 int rc = 0; 1188 1189 if (strcmp(name, XATTR_NAME_SMACK) == 0 || 1190 strcmp(name, XATTR_NAME_SMACKIPIN) == 0 || 1191 strcmp(name, XATTR_NAME_SMACKIPOUT) == 0 || 1192 strcmp(name, XATTR_NAME_SMACKEXEC) == 0 || 1193 strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0 || 1194 strcmp(name, XATTR_NAME_SMACKMMAP) == 0) { 1195 if (!smack_privileged(CAP_MAC_ADMIN)) 1196 rc = -EPERM; 1197 } else 1198 rc = cap_inode_removexattr(dentry, name); 1199 1200 if (rc != 0) 1201 return rc; 1202 1203 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); 1204 smk_ad_setfield_u_fs_path_dentry(&ad, dentry); 1205 1206 rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE, &ad); 1207 rc = smk_bu_inode(dentry->d_inode, MAY_WRITE, rc); 1208 if (rc != 0) 1209 return rc; 1210 1211 isp = dentry->d_inode->i_security; 1212 /* 1213 * Don't do anything special for these. 1214 * XATTR_NAME_SMACKIPIN 1215 * XATTR_NAME_SMACKIPOUT 1216 * XATTR_NAME_SMACKEXEC 1217 */ 1218 if (strcmp(name, XATTR_NAME_SMACK) == 0) 1219 isp->smk_task = NULL; 1220 else if (strcmp(name, XATTR_NAME_SMACKMMAP) == 0) 1221 isp->smk_mmap = NULL; 1222 else if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0) 1223 isp->smk_flags &= ~SMK_INODE_TRANSMUTE; 1224 1225 return 0; 1226 } 1227 1228 /** 1229 * smack_inode_getsecurity - get smack xattrs 1230 * @inode: the object 1231 * @name: attribute name 1232 * @buffer: where to put the result 1233 * @alloc: unused 1234 * 1235 * Returns the size of the attribute or an error code 1236 */ 1237 static int smack_inode_getsecurity(const struct inode *inode, 1238 const char *name, void **buffer, 1239 bool alloc) 1240 { 1241 struct socket_smack *ssp; 1242 struct socket *sock; 1243 struct super_block *sbp; 1244 struct inode *ip = (struct inode *)inode; 1245 struct smack_known *isp; 1246 int ilen; 1247 int rc = 0; 1248 1249 if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) { 1250 isp = smk_of_inode(inode); 1251 ilen = strlen(isp->smk_known); 1252 *buffer = isp->smk_known; 1253 return ilen; 1254 } 1255 1256 /* 1257 * The rest of the Smack xattrs are only on sockets. 1258 */ 1259 sbp = ip->i_sb; 1260 if (sbp->s_magic != SOCKFS_MAGIC) 1261 return -EOPNOTSUPP; 1262 1263 sock = SOCKET_I(ip); 1264 if (sock == NULL || sock->sk == NULL) 1265 return -EOPNOTSUPP; 1266 1267 ssp = sock->sk->sk_security; 1268 1269 if (strcmp(name, XATTR_SMACK_IPIN) == 0) 1270 isp = ssp->smk_in; 1271 else if (strcmp(name, XATTR_SMACK_IPOUT) == 0) 1272 isp = ssp->smk_out; 1273 else 1274 return -EOPNOTSUPP; 1275 1276 ilen = strlen(isp->smk_known); 1277 if (rc == 0) { 1278 *buffer = isp->smk_known; 1279 rc = ilen; 1280 } 1281 1282 return rc; 1283 } 1284 1285 1286 /** 1287 * smack_inode_listsecurity - list the Smack attributes 1288 * @inode: the object 1289 * @buffer: where they go 1290 * @buffer_size: size of buffer 1291 * 1292 * Returns 0 on success, -EINVAL otherwise 1293 */ 1294 static int smack_inode_listsecurity(struct inode *inode, char *buffer, 1295 size_t buffer_size) 1296 { 1297 int len = sizeof(XATTR_NAME_SMACK); 1298 1299 if (buffer != NULL && len <= buffer_size) 1300 memcpy(buffer, XATTR_NAME_SMACK, len); 1301 1302 return len; 1303 } 1304 1305 /** 1306 * smack_inode_getsecid - Extract inode's security id 1307 * @inode: inode to extract the info from 1308 * @secid: where result will be saved 1309 */ 1310 static void smack_inode_getsecid(const struct inode *inode, u32 *secid) 1311 { 1312 struct inode_smack *isp = inode->i_security; 1313 1314 *secid = isp->smk_inode->smk_secid; 1315 } 1316 1317 /* 1318 * File Hooks 1319 */ 1320 1321 /** 1322 * smack_file_permission - Smack check on file operations 1323 * @file: unused 1324 * @mask: unused 1325 * 1326 * Returns 0 1327 * 1328 * Should access checks be done on each read or write? 1329 * UNICOS and SELinux say yes. 1330 * Trusted Solaris, Trusted Irix, and just about everyone else says no. 1331 * 1332 * I'll say no for now. Smack does not do the frequent 1333 * label changing that SELinux does. 1334 */ 1335 static int smack_file_permission(struct file *file, int mask) 1336 { 1337 return 0; 1338 } 1339 1340 /** 1341 * smack_file_alloc_security - assign a file security blob 1342 * @file: the object 1343 * 1344 * The security blob for a file is a pointer to the master 1345 * label list, so no allocation is done. 1346 * 1347 * Returns 0 1348 */ 1349 static int smack_file_alloc_security(struct file *file) 1350 { 1351 struct smack_known *skp = smk_of_current(); 1352 1353 file->f_security = skp; 1354 return 0; 1355 } 1356 1357 /** 1358 * smack_file_free_security - clear a file security blob 1359 * @file: the object 1360 * 1361 * The security blob for a file is a pointer to the master 1362 * label list, so no memory is freed. 1363 */ 1364 static void smack_file_free_security(struct file *file) 1365 { 1366 file->f_security = NULL; 1367 } 1368 1369 /** 1370 * smack_file_ioctl - Smack check on ioctls 1371 * @file: the object 1372 * @cmd: what to do 1373 * @arg: unused 1374 * 1375 * Relies heavily on the correct use of the ioctl command conventions. 1376 * 1377 * Returns 0 if allowed, error code otherwise 1378 */ 1379 static int smack_file_ioctl(struct file *file, unsigned int cmd, 1380 unsigned long arg) 1381 { 1382 int rc = 0; 1383 struct smk_audit_info ad; 1384 1385 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH); 1386 smk_ad_setfield_u_fs_path(&ad, file->f_path); 1387 1388 if (_IOC_DIR(cmd) & _IOC_WRITE) { 1389 rc = smk_curacc(file->f_security, MAY_WRITE, &ad); 1390 rc = smk_bu_file(file, MAY_WRITE, rc); 1391 } 1392 1393 if (rc == 0 && (_IOC_DIR(cmd) & _IOC_READ)) { 1394 rc = smk_curacc(file->f_security, MAY_READ, &ad); 1395 rc = smk_bu_file(file, MAY_READ, rc); 1396 } 1397 1398 return rc; 1399 } 1400 1401 /** 1402 * smack_file_lock - Smack check on file locking 1403 * @file: the object 1404 * @cmd: unused 1405 * 1406 * Returns 0 if current has lock access, error code otherwise 1407 */ 1408 static int smack_file_lock(struct file *file, unsigned int cmd) 1409 { 1410 struct smk_audit_info ad; 1411 int rc; 1412 1413 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH); 1414 smk_ad_setfield_u_fs_path(&ad, file->f_path); 1415 rc = smk_curacc(file->f_security, MAY_LOCK, &ad); 1416 rc = smk_bu_file(file, MAY_LOCK, rc); 1417 return rc; 1418 } 1419 1420 /** 1421 * smack_file_fcntl - Smack check on fcntl 1422 * @file: the object 1423 * @cmd: what action to check 1424 * @arg: unused 1425 * 1426 * Generally these operations are harmless. 1427 * File locking operations present an obvious mechanism 1428 * for passing information, so they require write access. 1429 * 1430 * Returns 0 if current has access, error code otherwise 1431 */ 1432 static int smack_file_fcntl(struct file *file, unsigned int cmd, 1433 unsigned long arg) 1434 { 1435 struct smk_audit_info ad; 1436 int rc = 0; 1437 1438 1439 switch (cmd) { 1440 case F_GETLK: 1441 break; 1442 case F_SETLK: 1443 case F_SETLKW: 1444 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH); 1445 smk_ad_setfield_u_fs_path(&ad, file->f_path); 1446 rc = smk_curacc(file->f_security, MAY_LOCK, &ad); 1447 rc = smk_bu_file(file, MAY_LOCK, rc); 1448 break; 1449 case F_SETOWN: 1450 case F_SETSIG: 1451 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH); 1452 smk_ad_setfield_u_fs_path(&ad, file->f_path); 1453 rc = smk_curacc(file->f_security, MAY_WRITE, &ad); 1454 rc = smk_bu_file(file, MAY_WRITE, rc); 1455 break; 1456 default: 1457 break; 1458 } 1459 1460 return rc; 1461 } 1462 1463 /** 1464 * smack_mmap_file : 1465 * Check permissions for a mmap operation. The @file may be NULL, e.g. 1466 * if mapping anonymous memory. 1467 * @file contains the file structure for file to map (may be NULL). 1468 * @reqprot contains the protection requested by the application. 1469 * @prot contains the protection that will be applied by the kernel. 1470 * @flags contains the operational flags. 1471 * Return 0 if permission is granted. 1472 */ 1473 static int smack_mmap_file(struct file *file, 1474 unsigned long reqprot, unsigned long prot, 1475 unsigned long flags) 1476 { 1477 struct smack_known *skp; 1478 struct smack_known *mkp; 1479 struct smack_rule *srp; 1480 struct task_smack *tsp; 1481 struct smack_known *okp; 1482 struct inode_smack *isp; 1483 int may; 1484 int mmay; 1485 int tmay; 1486 int rc; 1487 1488 if (file == NULL) 1489 return 0; 1490 1491 isp = file_inode(file)->i_security; 1492 if (isp->smk_mmap == NULL) 1493 return 0; 1494 mkp = isp->smk_mmap; 1495 1496 tsp = current_security(); 1497 skp = smk_of_current(); 1498 rc = 0; 1499 1500 rcu_read_lock(); 1501 /* 1502 * For each Smack rule associated with the subject 1503 * label verify that the SMACK64MMAP also has access 1504 * to that rule's object label. 1505 */ 1506 list_for_each_entry_rcu(srp, &skp->smk_rules, list) { 1507 okp = srp->smk_object; 1508 /* 1509 * Matching labels always allows access. 1510 */ 1511 if (mkp->smk_known == okp->smk_known) 1512 continue; 1513 /* 1514 * If there is a matching local rule take 1515 * that into account as well. 1516 */ 1517 may = smk_access_entry(srp->smk_subject->smk_known, 1518 okp->smk_known, 1519 &tsp->smk_rules); 1520 if (may == -ENOENT) 1521 may = srp->smk_access; 1522 else 1523 may &= srp->smk_access; 1524 /* 1525 * If may is zero the SMACK64MMAP subject can't 1526 * possibly have less access. 1527 */ 1528 if (may == 0) 1529 continue; 1530 1531 /* 1532 * Fetch the global list entry. 1533 * If there isn't one a SMACK64MMAP subject 1534 * can't have as much access as current. 1535 */ 1536 mmay = smk_access_entry(mkp->smk_known, okp->smk_known, 1537 &mkp->smk_rules); 1538 if (mmay == -ENOENT) { 1539 rc = -EACCES; 1540 break; 1541 } 1542 /* 1543 * If there is a local entry it modifies the 1544 * potential access, too. 1545 */ 1546 tmay = smk_access_entry(mkp->smk_known, okp->smk_known, 1547 &tsp->smk_rules); 1548 if (tmay != -ENOENT) 1549 mmay &= tmay; 1550 1551 /* 1552 * If there is any access available to current that is 1553 * not available to a SMACK64MMAP subject 1554 * deny access. 1555 */ 1556 if ((may | mmay) != mmay) { 1557 rc = -EACCES; 1558 break; 1559 } 1560 } 1561 1562 rcu_read_unlock(); 1563 1564 return rc; 1565 } 1566 1567 /** 1568 * smack_file_set_fowner - set the file security blob value 1569 * @file: object in question 1570 * 1571 * Returns 0 1572 * Further research may be required on this one. 1573 */ 1574 static void smack_file_set_fowner(struct file *file) 1575 { 1576 struct smack_known *skp = smk_of_current(); 1577 1578 file->f_security = skp; 1579 } 1580 1581 /** 1582 * smack_file_send_sigiotask - Smack on sigio 1583 * @tsk: The target task 1584 * @fown: the object the signal come from 1585 * @signum: unused 1586 * 1587 * Allow a privileged task to get signals even if it shouldn't 1588 * 1589 * Returns 0 if a subject with the object's smack could 1590 * write to the task, an error code otherwise. 1591 */ 1592 static int smack_file_send_sigiotask(struct task_struct *tsk, 1593 struct fown_struct *fown, int signum) 1594 { 1595 struct smack_known *skp; 1596 struct smack_known *tkp = smk_of_task(tsk->cred->security); 1597 struct file *file; 1598 int rc; 1599 struct smk_audit_info ad; 1600 1601 /* 1602 * struct fown_struct is never outside the context of a struct file 1603 */ 1604 file = container_of(fown, struct file, f_owner); 1605 1606 /* we don't log here as rc can be overriden */ 1607 skp = file->f_security; 1608 rc = smk_access(skp, tkp, MAY_WRITE, NULL); 1609 rc = smk_bu_note("sigiotask", skp, tkp, MAY_WRITE, rc); 1610 if (rc != 0 && has_capability(tsk, CAP_MAC_OVERRIDE)) 1611 rc = 0; 1612 1613 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK); 1614 smk_ad_setfield_u_tsk(&ad, tsk); 1615 smack_log(skp->smk_known, tkp->smk_known, MAY_WRITE, rc, &ad); 1616 return rc; 1617 } 1618 1619 /** 1620 * smack_file_receive - Smack file receive check 1621 * @file: the object 1622 * 1623 * Returns 0 if current has access, error code otherwise 1624 */ 1625 static int smack_file_receive(struct file *file) 1626 { 1627 int rc; 1628 int may = 0; 1629 struct smk_audit_info ad; 1630 1631 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH); 1632 smk_ad_setfield_u_fs_path(&ad, file->f_path); 1633 /* 1634 * This code relies on bitmasks. 1635 */ 1636 if (file->f_mode & FMODE_READ) 1637 may = MAY_READ; 1638 if (file->f_mode & FMODE_WRITE) 1639 may |= MAY_WRITE; 1640 1641 rc = smk_curacc(file->f_security, may, &ad); 1642 rc = smk_bu_file(file, may, rc); 1643 return rc; 1644 } 1645 1646 /** 1647 * smack_file_open - Smack dentry open processing 1648 * @file: the object 1649 * @cred: task credential 1650 * 1651 * Set the security blob in the file structure. 1652 * Allow the open only if the task has read access. There are 1653 * many read operations (e.g. fstat) that you can do with an 1654 * fd even if you have the file open write-only. 1655 * 1656 * Returns 0 1657 */ 1658 static int smack_file_open(struct file *file, const struct cred *cred) 1659 { 1660 struct task_smack *tsp = cred->security; 1661 struct inode_smack *isp = file_inode(file)->i_security; 1662 struct smk_audit_info ad; 1663 int rc; 1664 1665 if (smack_privileged(CAP_MAC_OVERRIDE)) { 1666 file->f_security = isp->smk_inode; 1667 return 0; 1668 } 1669 1670 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH); 1671 smk_ad_setfield_u_fs_path(&ad, file->f_path); 1672 rc = smk_access(tsp->smk_task, isp->smk_inode, MAY_READ, &ad); 1673 rc = smk_bu_credfile(cred, file, MAY_READ, rc); 1674 if (rc == 0) 1675 file->f_security = isp->smk_inode; 1676 1677 return rc; 1678 } 1679 1680 /* 1681 * Task hooks 1682 */ 1683 1684 /** 1685 * smack_cred_alloc_blank - "allocate" blank task-level security credentials 1686 * @new: the new credentials 1687 * @gfp: the atomicity of any memory allocations 1688 * 1689 * Prepare a blank set of credentials for modification. This must allocate all 1690 * the memory the LSM module might require such that cred_transfer() can 1691 * complete without error. 1692 */ 1693 static int smack_cred_alloc_blank(struct cred *cred, gfp_t gfp) 1694 { 1695 struct task_smack *tsp; 1696 1697 tsp = new_task_smack(NULL, NULL, gfp); 1698 if (tsp == NULL) 1699 return -ENOMEM; 1700 1701 cred->security = tsp; 1702 1703 return 0; 1704 } 1705 1706 1707 /** 1708 * smack_cred_free - "free" task-level security credentials 1709 * @cred: the credentials in question 1710 * 1711 */ 1712 static void smack_cred_free(struct cred *cred) 1713 { 1714 struct task_smack *tsp = cred->security; 1715 struct smack_rule *rp; 1716 struct list_head *l; 1717 struct list_head *n; 1718 1719 if (tsp == NULL) 1720 return; 1721 cred->security = NULL; 1722 1723 list_for_each_safe(l, n, &tsp->smk_rules) { 1724 rp = list_entry(l, struct smack_rule, list); 1725 list_del(&rp->list); 1726 kfree(rp); 1727 } 1728 kfree(tsp); 1729 } 1730 1731 /** 1732 * smack_cred_prepare - prepare new set of credentials for modification 1733 * @new: the new credentials 1734 * @old: the original credentials 1735 * @gfp: the atomicity of any memory allocations 1736 * 1737 * Prepare a new set of credentials for modification. 1738 */ 1739 static int smack_cred_prepare(struct cred *new, const struct cred *old, 1740 gfp_t gfp) 1741 { 1742 struct task_smack *old_tsp = old->security; 1743 struct task_smack *new_tsp; 1744 int rc; 1745 1746 new_tsp = new_task_smack(old_tsp->smk_task, old_tsp->smk_task, gfp); 1747 if (new_tsp == NULL) 1748 return -ENOMEM; 1749 1750 rc = smk_copy_rules(&new_tsp->smk_rules, &old_tsp->smk_rules, gfp); 1751 if (rc != 0) 1752 return rc; 1753 1754 new->security = new_tsp; 1755 return 0; 1756 } 1757 1758 /** 1759 * smack_cred_transfer - Transfer the old credentials to the new credentials 1760 * @new: the new credentials 1761 * @old: the original credentials 1762 * 1763 * Fill in a set of blank credentials from another set of credentials. 1764 */ 1765 static void smack_cred_transfer(struct cred *new, const struct cred *old) 1766 { 1767 struct task_smack *old_tsp = old->security; 1768 struct task_smack *new_tsp = new->security; 1769 1770 new_tsp->smk_task = old_tsp->smk_task; 1771 new_tsp->smk_forked = old_tsp->smk_task; 1772 mutex_init(&new_tsp->smk_rules_lock); 1773 INIT_LIST_HEAD(&new_tsp->smk_rules); 1774 1775 1776 /* cbs copy rule list */ 1777 } 1778 1779 /** 1780 * smack_kernel_act_as - Set the subjective context in a set of credentials 1781 * @new: points to the set of credentials to be modified. 1782 * @secid: specifies the security ID to be set 1783 * 1784 * Set the security data for a kernel service. 1785 */ 1786 static int smack_kernel_act_as(struct cred *new, u32 secid) 1787 { 1788 struct task_smack *new_tsp = new->security; 1789 struct smack_known *skp = smack_from_secid(secid); 1790 1791 if (skp == NULL) 1792 return -EINVAL; 1793 1794 new_tsp->smk_task = skp; 1795 return 0; 1796 } 1797 1798 /** 1799 * smack_kernel_create_files_as - Set the file creation label in a set of creds 1800 * @new: points to the set of credentials to be modified 1801 * @inode: points to the inode to use as a reference 1802 * 1803 * Set the file creation context in a set of credentials to the same 1804 * as the objective context of the specified inode 1805 */ 1806 static int smack_kernel_create_files_as(struct cred *new, 1807 struct inode *inode) 1808 { 1809 struct inode_smack *isp = inode->i_security; 1810 struct task_smack *tsp = new->security; 1811 1812 tsp->smk_forked = isp->smk_inode; 1813 tsp->smk_task = tsp->smk_forked; 1814 return 0; 1815 } 1816 1817 /** 1818 * smk_curacc_on_task - helper to log task related access 1819 * @p: the task object 1820 * @access: the access requested 1821 * @caller: name of the calling function for audit 1822 * 1823 * Return 0 if access is permitted 1824 */ 1825 static int smk_curacc_on_task(struct task_struct *p, int access, 1826 const char *caller) 1827 { 1828 struct smk_audit_info ad; 1829 struct smack_known *skp = smk_of_task(task_security(p)); 1830 int rc; 1831 1832 smk_ad_init(&ad, caller, LSM_AUDIT_DATA_TASK); 1833 smk_ad_setfield_u_tsk(&ad, p); 1834 rc = smk_curacc(skp, access, &ad); 1835 rc = smk_bu_task(p, access, rc); 1836 return rc; 1837 } 1838 1839 /** 1840 * smack_task_setpgid - Smack check on setting pgid 1841 * @p: the task object 1842 * @pgid: unused 1843 * 1844 * Return 0 if write access is permitted 1845 */ 1846 static int smack_task_setpgid(struct task_struct *p, pid_t pgid) 1847 { 1848 return smk_curacc_on_task(p, MAY_WRITE, __func__); 1849 } 1850 1851 /** 1852 * smack_task_getpgid - Smack access check for getpgid 1853 * @p: the object task 1854 * 1855 * Returns 0 if current can read the object task, error code otherwise 1856 */ 1857 static int smack_task_getpgid(struct task_struct *p) 1858 { 1859 return smk_curacc_on_task(p, MAY_READ, __func__); 1860 } 1861 1862 /** 1863 * smack_task_getsid - Smack access check for getsid 1864 * @p: the object task 1865 * 1866 * Returns 0 if current can read the object task, error code otherwise 1867 */ 1868 static int smack_task_getsid(struct task_struct *p) 1869 { 1870 return smk_curacc_on_task(p, MAY_READ, __func__); 1871 } 1872 1873 /** 1874 * smack_task_getsecid - get the secid of the task 1875 * @p: the object task 1876 * @secid: where to put the result 1877 * 1878 * Sets the secid to contain a u32 version of the smack label. 1879 */ 1880 static void smack_task_getsecid(struct task_struct *p, u32 *secid) 1881 { 1882 struct smack_known *skp = smk_of_task(task_security(p)); 1883 1884 *secid = skp->smk_secid; 1885 } 1886 1887 /** 1888 * smack_task_setnice - Smack check on setting nice 1889 * @p: the task object 1890 * @nice: unused 1891 * 1892 * Return 0 if write access is permitted 1893 */ 1894 static int smack_task_setnice(struct task_struct *p, int nice) 1895 { 1896 int rc; 1897 1898 rc = cap_task_setnice(p, nice); 1899 if (rc == 0) 1900 rc = smk_curacc_on_task(p, MAY_WRITE, __func__); 1901 return rc; 1902 } 1903 1904 /** 1905 * smack_task_setioprio - Smack check on setting ioprio 1906 * @p: the task object 1907 * @ioprio: unused 1908 * 1909 * Return 0 if write access is permitted 1910 */ 1911 static int smack_task_setioprio(struct task_struct *p, int ioprio) 1912 { 1913 int rc; 1914 1915 rc = cap_task_setioprio(p, ioprio); 1916 if (rc == 0) 1917 rc = smk_curacc_on_task(p, MAY_WRITE, __func__); 1918 return rc; 1919 } 1920 1921 /** 1922 * smack_task_getioprio - Smack check on reading ioprio 1923 * @p: the task object 1924 * 1925 * Return 0 if read access is permitted 1926 */ 1927 static int smack_task_getioprio(struct task_struct *p) 1928 { 1929 return smk_curacc_on_task(p, MAY_READ, __func__); 1930 } 1931 1932 /** 1933 * smack_task_setscheduler - Smack check on setting scheduler 1934 * @p: the task object 1935 * @policy: unused 1936 * @lp: unused 1937 * 1938 * Return 0 if read access is permitted 1939 */ 1940 static int smack_task_setscheduler(struct task_struct *p) 1941 { 1942 int rc; 1943 1944 rc = cap_task_setscheduler(p); 1945 if (rc == 0) 1946 rc = smk_curacc_on_task(p, MAY_WRITE, __func__); 1947 return rc; 1948 } 1949 1950 /** 1951 * smack_task_getscheduler - Smack check on reading scheduler 1952 * @p: the task object 1953 * 1954 * Return 0 if read access is permitted 1955 */ 1956 static int smack_task_getscheduler(struct task_struct *p) 1957 { 1958 return smk_curacc_on_task(p, MAY_READ, __func__); 1959 } 1960 1961 /** 1962 * smack_task_movememory - Smack check on moving memory 1963 * @p: the task object 1964 * 1965 * Return 0 if write access is permitted 1966 */ 1967 static int smack_task_movememory(struct task_struct *p) 1968 { 1969 return smk_curacc_on_task(p, MAY_WRITE, __func__); 1970 } 1971 1972 /** 1973 * smack_task_kill - Smack check on signal delivery 1974 * @p: the task object 1975 * @info: unused 1976 * @sig: unused 1977 * @secid: identifies the smack to use in lieu of current's 1978 * 1979 * Return 0 if write access is permitted 1980 * 1981 * The secid behavior is an artifact of an SELinux hack 1982 * in the USB code. Someday it may go away. 1983 */ 1984 static int smack_task_kill(struct task_struct *p, struct siginfo *info, 1985 int sig, u32 secid) 1986 { 1987 struct smk_audit_info ad; 1988 struct smack_known *skp; 1989 struct smack_known *tkp = smk_of_task(task_security(p)); 1990 int rc; 1991 1992 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK); 1993 smk_ad_setfield_u_tsk(&ad, p); 1994 /* 1995 * Sending a signal requires that the sender 1996 * can write the receiver. 1997 */ 1998 if (secid == 0) { 1999 rc = smk_curacc(tkp, MAY_WRITE, &ad); 2000 rc = smk_bu_task(p, MAY_WRITE, rc); 2001 return rc; 2002 } 2003 /* 2004 * If the secid isn't 0 we're dealing with some USB IO 2005 * specific behavior. This is not clean. For one thing 2006 * we can't take privilege into account. 2007 */ 2008 skp = smack_from_secid(secid); 2009 rc = smk_access(skp, tkp, MAY_WRITE, &ad); 2010 rc = smk_bu_note("USB signal", skp, tkp, MAY_WRITE, rc); 2011 return rc; 2012 } 2013 2014 /** 2015 * smack_task_wait - Smack access check for waiting 2016 * @p: task to wait for 2017 * 2018 * Returns 0 2019 */ 2020 static int smack_task_wait(struct task_struct *p) 2021 { 2022 /* 2023 * Allow the operation to succeed. 2024 * Zombies are bad. 2025 * In userless environments (e.g. phones) programs 2026 * get marked with SMACK64EXEC and even if the parent 2027 * and child shouldn't be talking the parent still 2028 * may expect to know when the child exits. 2029 */ 2030 return 0; 2031 } 2032 2033 /** 2034 * smack_task_to_inode - copy task smack into the inode blob 2035 * @p: task to copy from 2036 * @inode: inode to copy to 2037 * 2038 * Sets the smack pointer in the inode security blob 2039 */ 2040 static void smack_task_to_inode(struct task_struct *p, struct inode *inode) 2041 { 2042 struct inode_smack *isp = inode->i_security; 2043 struct smack_known *skp = smk_of_task(task_security(p)); 2044 2045 isp->smk_inode = skp; 2046 } 2047 2048 /* 2049 * Socket hooks. 2050 */ 2051 2052 /** 2053 * smack_sk_alloc_security - Allocate a socket blob 2054 * @sk: the socket 2055 * @family: unused 2056 * @gfp_flags: memory allocation flags 2057 * 2058 * Assign Smack pointers to current 2059 * 2060 * Returns 0 on success, -ENOMEM is there's no memory 2061 */ 2062 static int smack_sk_alloc_security(struct sock *sk, int family, gfp_t gfp_flags) 2063 { 2064 struct smack_known *skp = smk_of_current(); 2065 struct socket_smack *ssp; 2066 2067 ssp = kzalloc(sizeof(struct socket_smack), gfp_flags); 2068 if (ssp == NULL) 2069 return -ENOMEM; 2070 2071 ssp->smk_in = skp; 2072 ssp->smk_out = skp; 2073 ssp->smk_packet = NULL; 2074 2075 sk->sk_security = ssp; 2076 2077 return 0; 2078 } 2079 2080 /** 2081 * smack_sk_free_security - Free a socket blob 2082 * @sk: the socket 2083 * 2084 * Clears the blob pointer 2085 */ 2086 static void smack_sk_free_security(struct sock *sk) 2087 { 2088 kfree(sk->sk_security); 2089 } 2090 2091 /** 2092 * smack_host_label - check host based restrictions 2093 * @sip: the object end 2094 * 2095 * looks for host based access restrictions 2096 * 2097 * This version will only be appropriate for really small sets of single label 2098 * hosts. The caller is responsible for ensuring that the RCU read lock is 2099 * taken before calling this function. 2100 * 2101 * Returns the label of the far end or NULL if it's not special. 2102 */ 2103 static struct smack_known *smack_host_label(struct sockaddr_in *sip) 2104 { 2105 struct smk_netlbladdr *snp; 2106 struct in_addr *siap = &sip->sin_addr; 2107 2108 if (siap->s_addr == 0) 2109 return NULL; 2110 2111 list_for_each_entry_rcu(snp, &smk_netlbladdr_list, list) 2112 /* 2113 * we break after finding the first match because 2114 * the list is sorted from longest to shortest mask 2115 * so we have found the most specific match 2116 */ 2117 if ((&snp->smk_host.sin_addr)->s_addr == 2118 (siap->s_addr & (&snp->smk_mask)->s_addr)) { 2119 /* we have found the special CIPSO option */ 2120 if (snp->smk_label == &smack_cipso_option) 2121 return NULL; 2122 return snp->smk_label; 2123 } 2124 2125 return NULL; 2126 } 2127 2128 /** 2129 * smack_netlabel - Set the secattr on a socket 2130 * @sk: the socket 2131 * @labeled: socket label scheme 2132 * 2133 * Convert the outbound smack value (smk_out) to a 2134 * secattr and attach it to the socket. 2135 * 2136 * Returns 0 on success or an error code 2137 */ 2138 static int smack_netlabel(struct sock *sk, int labeled) 2139 { 2140 struct smack_known *skp; 2141 struct socket_smack *ssp = sk->sk_security; 2142 int rc = 0; 2143 2144 /* 2145 * Usually the netlabel code will handle changing the 2146 * packet labeling based on the label. 2147 * The case of a single label host is different, because 2148 * a single label host should never get a labeled packet 2149 * even though the label is usually associated with a packet 2150 * label. 2151 */ 2152 local_bh_disable(); 2153 bh_lock_sock_nested(sk); 2154 2155 if (ssp->smk_out == smack_net_ambient || 2156 labeled == SMACK_UNLABELED_SOCKET) 2157 netlbl_sock_delattr(sk); 2158 else { 2159 skp = ssp->smk_out; 2160 rc = netlbl_sock_setattr(sk, sk->sk_family, &skp->smk_netlabel); 2161 } 2162 2163 bh_unlock_sock(sk); 2164 local_bh_enable(); 2165 2166 return rc; 2167 } 2168 2169 /** 2170 * smack_netlbel_send - Set the secattr on a socket and perform access checks 2171 * @sk: the socket 2172 * @sap: the destination address 2173 * 2174 * Set the correct secattr for the given socket based on the destination 2175 * address and perform any outbound access checks needed. 2176 * 2177 * Returns 0 on success or an error code. 2178 * 2179 */ 2180 static int smack_netlabel_send(struct sock *sk, struct sockaddr_in *sap) 2181 { 2182 struct smack_known *skp; 2183 int rc; 2184 int sk_lbl; 2185 struct smack_known *hkp; 2186 struct socket_smack *ssp = sk->sk_security; 2187 struct smk_audit_info ad; 2188 2189 rcu_read_lock(); 2190 hkp = smack_host_label(sap); 2191 if (hkp != NULL) { 2192 #ifdef CONFIG_AUDIT 2193 struct lsm_network_audit net; 2194 2195 smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net); 2196 ad.a.u.net->family = sap->sin_family; 2197 ad.a.u.net->dport = sap->sin_port; 2198 ad.a.u.net->v4info.daddr = sap->sin_addr.s_addr; 2199 #endif 2200 sk_lbl = SMACK_UNLABELED_SOCKET; 2201 skp = ssp->smk_out; 2202 rc = smk_access(skp, hkp, MAY_WRITE, &ad); 2203 rc = smk_bu_note("IPv4 host check", skp, hkp, MAY_WRITE, rc); 2204 } else { 2205 sk_lbl = SMACK_CIPSO_SOCKET; 2206 rc = 0; 2207 } 2208 rcu_read_unlock(); 2209 if (rc != 0) 2210 return rc; 2211 2212 return smack_netlabel(sk, sk_lbl); 2213 } 2214 2215 /** 2216 * smk_ipv6_port_label - Smack port access table management 2217 * @sock: socket 2218 * @address: address 2219 * 2220 * Create or update the port list entry 2221 */ 2222 static void smk_ipv6_port_label(struct socket *sock, struct sockaddr *address) 2223 { 2224 struct sock *sk = sock->sk; 2225 struct sockaddr_in6 *addr6; 2226 struct socket_smack *ssp = sock->sk->sk_security; 2227 struct smk_port_label *spp; 2228 unsigned short port = 0; 2229 2230 if (address == NULL) { 2231 /* 2232 * This operation is changing the Smack information 2233 * on the bound socket. Take the changes to the port 2234 * as well. 2235 */ 2236 list_for_each_entry(spp, &smk_ipv6_port_list, list) { 2237 if (sk != spp->smk_sock) 2238 continue; 2239 spp->smk_in = ssp->smk_in; 2240 spp->smk_out = ssp->smk_out; 2241 return; 2242 } 2243 /* 2244 * A NULL address is only used for updating existing 2245 * bound entries. If there isn't one, it's OK. 2246 */ 2247 return; 2248 } 2249 2250 addr6 = (struct sockaddr_in6 *)address; 2251 port = ntohs(addr6->sin6_port); 2252 /* 2253 * This is a special case that is safely ignored. 2254 */ 2255 if (port == 0) 2256 return; 2257 2258 /* 2259 * Look for an existing port list entry. 2260 * This is an indication that a port is getting reused. 2261 */ 2262 list_for_each_entry(spp, &smk_ipv6_port_list, list) { 2263 if (spp->smk_port != port) 2264 continue; 2265 spp->smk_port = port; 2266 spp->smk_sock = sk; 2267 spp->smk_in = ssp->smk_in; 2268 spp->smk_out = ssp->smk_out; 2269 return; 2270 } 2271 2272 /* 2273 * A new port entry is required. 2274 */ 2275 spp = kzalloc(sizeof(*spp), GFP_KERNEL); 2276 if (spp == NULL) 2277 return; 2278 2279 spp->smk_port = port; 2280 spp->smk_sock = sk; 2281 spp->smk_in = ssp->smk_in; 2282 spp->smk_out = ssp->smk_out; 2283 2284 list_add(&spp->list, &smk_ipv6_port_list); 2285 return; 2286 } 2287 2288 /** 2289 * smk_ipv6_port_check - check Smack port access 2290 * @sock: socket 2291 * @address: address 2292 * 2293 * Create or update the port list entry 2294 */ 2295 static int smk_ipv6_port_check(struct sock *sk, struct sockaddr_in6 *address, 2296 int act) 2297 { 2298 __be16 *bep; 2299 __be32 *be32p; 2300 struct smk_port_label *spp; 2301 struct socket_smack *ssp = sk->sk_security; 2302 struct smack_known *skp; 2303 unsigned short port = 0; 2304 struct smack_known *object; 2305 struct smk_audit_info ad; 2306 int rc; 2307 #ifdef CONFIG_AUDIT 2308 struct lsm_network_audit net; 2309 #endif 2310 2311 if (act == SMK_RECEIVING) { 2312 skp = smack_net_ambient; 2313 object = ssp->smk_in; 2314 } else { 2315 skp = ssp->smk_out; 2316 object = smack_net_ambient; 2317 } 2318 2319 /* 2320 * Get the IP address and port from the address. 2321 */ 2322 port = ntohs(address->sin6_port); 2323 bep = (__be16 *)(&address->sin6_addr); 2324 be32p = (__be32 *)(&address->sin6_addr); 2325 2326 /* 2327 * It's remote, so port lookup does no good. 2328 */ 2329 if (be32p[0] || be32p[1] || be32p[2] || bep[6] || ntohs(bep[7]) != 1) 2330 goto auditout; 2331 2332 /* 2333 * It's local so the send check has to have passed. 2334 */ 2335 if (act == SMK_RECEIVING) { 2336 skp = &smack_known_web; 2337 goto auditout; 2338 } 2339 2340 list_for_each_entry(spp, &smk_ipv6_port_list, list) { 2341 if (spp->smk_port != port) 2342 continue; 2343 object = spp->smk_in; 2344 if (act == SMK_CONNECTING) 2345 ssp->smk_packet = spp->smk_out; 2346 break; 2347 } 2348 2349 auditout: 2350 2351 #ifdef CONFIG_AUDIT 2352 smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net); 2353 ad.a.u.net->family = sk->sk_family; 2354 ad.a.u.net->dport = port; 2355 if (act == SMK_RECEIVING) 2356 ad.a.u.net->v6info.saddr = address->sin6_addr; 2357 else 2358 ad.a.u.net->v6info.daddr = address->sin6_addr; 2359 #endif 2360 rc = smk_access(skp, object, MAY_WRITE, &ad); 2361 rc = smk_bu_note("IPv6 port check", skp, object, MAY_WRITE, rc); 2362 return rc; 2363 } 2364 2365 /** 2366 * smack_inode_setsecurity - set smack xattrs 2367 * @inode: the object 2368 * @name: attribute name 2369 * @value: attribute value 2370 * @size: size of the attribute 2371 * @flags: unused 2372 * 2373 * Sets the named attribute in the appropriate blob 2374 * 2375 * Returns 0 on success, or an error code 2376 */ 2377 static int smack_inode_setsecurity(struct inode *inode, const char *name, 2378 const void *value, size_t size, int flags) 2379 { 2380 struct smack_known *skp; 2381 struct inode_smack *nsp = inode->i_security; 2382 struct socket_smack *ssp; 2383 struct socket *sock; 2384 int rc = 0; 2385 2386 if (value == NULL || size > SMK_LONGLABEL || size == 0) 2387 return -EINVAL; 2388 2389 skp = smk_import_entry(value, size); 2390 if (skp == NULL) 2391 return -EINVAL; 2392 2393 if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) { 2394 nsp->smk_inode = skp; 2395 nsp->smk_flags |= SMK_INODE_INSTANT; 2396 return 0; 2397 } 2398 /* 2399 * The rest of the Smack xattrs are only on sockets. 2400 */ 2401 if (inode->i_sb->s_magic != SOCKFS_MAGIC) 2402 return -EOPNOTSUPP; 2403 2404 sock = SOCKET_I(inode); 2405 if (sock == NULL || sock->sk == NULL) 2406 return -EOPNOTSUPP; 2407 2408 ssp = sock->sk->sk_security; 2409 2410 if (strcmp(name, XATTR_SMACK_IPIN) == 0) 2411 ssp->smk_in = skp; 2412 else if (strcmp(name, XATTR_SMACK_IPOUT) == 0) { 2413 ssp->smk_out = skp; 2414 if (sock->sk->sk_family == PF_INET) { 2415 rc = smack_netlabel(sock->sk, SMACK_CIPSO_SOCKET); 2416 if (rc != 0) 2417 printk(KERN_WARNING 2418 "Smack: \"%s\" netlbl error %d.\n", 2419 __func__, -rc); 2420 } 2421 } else 2422 return -EOPNOTSUPP; 2423 2424 if (sock->sk->sk_family == PF_INET6) 2425 smk_ipv6_port_label(sock, NULL); 2426 2427 return 0; 2428 } 2429 2430 /** 2431 * smack_socket_post_create - finish socket setup 2432 * @sock: the socket 2433 * @family: protocol family 2434 * @type: unused 2435 * @protocol: unused 2436 * @kern: unused 2437 * 2438 * Sets the netlabel information on the socket 2439 * 2440 * Returns 0 on success, and error code otherwise 2441 */ 2442 static int smack_socket_post_create(struct socket *sock, int family, 2443 int type, int protocol, int kern) 2444 { 2445 if (family != PF_INET || sock->sk == NULL) 2446 return 0; 2447 /* 2448 * Set the outbound netlbl. 2449 */ 2450 return smack_netlabel(sock->sk, SMACK_CIPSO_SOCKET); 2451 } 2452 2453 /** 2454 * smack_socket_bind - record port binding information. 2455 * @sock: the socket 2456 * @address: the port address 2457 * @addrlen: size of the address 2458 * 2459 * Records the label bound to a port. 2460 * 2461 * Returns 0 2462 */ 2463 static int smack_socket_bind(struct socket *sock, struct sockaddr *address, 2464 int addrlen) 2465 { 2466 if (sock->sk != NULL && sock->sk->sk_family == PF_INET6) 2467 smk_ipv6_port_label(sock, address); 2468 2469 return 0; 2470 } 2471 2472 /** 2473 * smack_socket_connect - connect access check 2474 * @sock: the socket 2475 * @sap: the other end 2476 * @addrlen: size of sap 2477 * 2478 * Verifies that a connection may be possible 2479 * 2480 * Returns 0 on success, and error code otherwise 2481 */ 2482 static int smack_socket_connect(struct socket *sock, struct sockaddr *sap, 2483 int addrlen) 2484 { 2485 int rc = 0; 2486 2487 if (sock->sk == NULL) 2488 return 0; 2489 2490 switch (sock->sk->sk_family) { 2491 case PF_INET: 2492 if (addrlen < sizeof(struct sockaddr_in)) 2493 return -EINVAL; 2494 rc = smack_netlabel_send(sock->sk, (struct sockaddr_in *)sap); 2495 break; 2496 case PF_INET6: 2497 if (addrlen < sizeof(struct sockaddr_in6)) 2498 return -EINVAL; 2499 rc = smk_ipv6_port_check(sock->sk, (struct sockaddr_in6 *)sap, 2500 SMK_CONNECTING); 2501 break; 2502 } 2503 return rc; 2504 } 2505 2506 /** 2507 * smack_flags_to_may - convert S_ to MAY_ values 2508 * @flags: the S_ value 2509 * 2510 * Returns the equivalent MAY_ value 2511 */ 2512 static int smack_flags_to_may(int flags) 2513 { 2514 int may = 0; 2515 2516 if (flags & S_IRUGO) 2517 may |= MAY_READ; 2518 if (flags & S_IWUGO) 2519 may |= MAY_WRITE; 2520 if (flags & S_IXUGO) 2521 may |= MAY_EXEC; 2522 2523 return may; 2524 } 2525 2526 /** 2527 * smack_msg_msg_alloc_security - Set the security blob for msg_msg 2528 * @msg: the object 2529 * 2530 * Returns 0 2531 */ 2532 static int smack_msg_msg_alloc_security(struct msg_msg *msg) 2533 { 2534 struct smack_known *skp = smk_of_current(); 2535 2536 msg->security = skp; 2537 return 0; 2538 } 2539 2540 /** 2541 * smack_msg_msg_free_security - Clear the security blob for msg_msg 2542 * @msg: the object 2543 * 2544 * Clears the blob pointer 2545 */ 2546 static void smack_msg_msg_free_security(struct msg_msg *msg) 2547 { 2548 msg->security = NULL; 2549 } 2550 2551 /** 2552 * smack_of_shm - the smack pointer for the shm 2553 * @shp: the object 2554 * 2555 * Returns a pointer to the smack value 2556 */ 2557 static struct smack_known *smack_of_shm(struct shmid_kernel *shp) 2558 { 2559 return (struct smack_known *)shp->shm_perm.security; 2560 } 2561 2562 /** 2563 * smack_shm_alloc_security - Set the security blob for shm 2564 * @shp: the object 2565 * 2566 * Returns 0 2567 */ 2568 static int smack_shm_alloc_security(struct shmid_kernel *shp) 2569 { 2570 struct kern_ipc_perm *isp = &shp->shm_perm; 2571 struct smack_known *skp = smk_of_current(); 2572 2573 isp->security = skp; 2574 return 0; 2575 } 2576 2577 /** 2578 * smack_shm_free_security - Clear the security blob for shm 2579 * @shp: the object 2580 * 2581 * Clears the blob pointer 2582 */ 2583 static void smack_shm_free_security(struct shmid_kernel *shp) 2584 { 2585 struct kern_ipc_perm *isp = &shp->shm_perm; 2586 2587 isp->security = NULL; 2588 } 2589 2590 /** 2591 * smk_curacc_shm : check if current has access on shm 2592 * @shp : the object 2593 * @access : access requested 2594 * 2595 * Returns 0 if current has the requested access, error code otherwise 2596 */ 2597 static int smk_curacc_shm(struct shmid_kernel *shp, int access) 2598 { 2599 struct smack_known *ssp = smack_of_shm(shp); 2600 struct smk_audit_info ad; 2601 int rc; 2602 2603 #ifdef CONFIG_AUDIT 2604 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC); 2605 ad.a.u.ipc_id = shp->shm_perm.id; 2606 #endif 2607 rc = smk_curacc(ssp, access, &ad); 2608 rc = smk_bu_current("shm", ssp, access, rc); 2609 return rc; 2610 } 2611 2612 /** 2613 * smack_shm_associate - Smack access check for shm 2614 * @shp: the object 2615 * @shmflg: access requested 2616 * 2617 * Returns 0 if current has the requested access, error code otherwise 2618 */ 2619 static int smack_shm_associate(struct shmid_kernel *shp, int shmflg) 2620 { 2621 int may; 2622 2623 may = smack_flags_to_may(shmflg); 2624 return smk_curacc_shm(shp, may); 2625 } 2626 2627 /** 2628 * smack_shm_shmctl - Smack access check for shm 2629 * @shp: the object 2630 * @cmd: what it wants to do 2631 * 2632 * Returns 0 if current has the requested access, error code otherwise 2633 */ 2634 static int smack_shm_shmctl(struct shmid_kernel *shp, int cmd) 2635 { 2636 int may; 2637 2638 switch (cmd) { 2639 case IPC_STAT: 2640 case SHM_STAT: 2641 may = MAY_READ; 2642 break; 2643 case IPC_SET: 2644 case SHM_LOCK: 2645 case SHM_UNLOCK: 2646 case IPC_RMID: 2647 may = MAY_READWRITE; 2648 break; 2649 case IPC_INFO: 2650 case SHM_INFO: 2651 /* 2652 * System level information. 2653 */ 2654 return 0; 2655 default: 2656 return -EINVAL; 2657 } 2658 return smk_curacc_shm(shp, may); 2659 } 2660 2661 /** 2662 * smack_shm_shmat - Smack access for shmat 2663 * @shp: the object 2664 * @shmaddr: unused 2665 * @shmflg: access requested 2666 * 2667 * Returns 0 if current has the requested access, error code otherwise 2668 */ 2669 static int smack_shm_shmat(struct shmid_kernel *shp, char __user *shmaddr, 2670 int shmflg) 2671 { 2672 int may; 2673 2674 may = smack_flags_to_may(shmflg); 2675 return smk_curacc_shm(shp, may); 2676 } 2677 2678 /** 2679 * smack_of_sem - the smack pointer for the sem 2680 * @sma: the object 2681 * 2682 * Returns a pointer to the smack value 2683 */ 2684 static struct smack_known *smack_of_sem(struct sem_array *sma) 2685 { 2686 return (struct smack_known *)sma->sem_perm.security; 2687 } 2688 2689 /** 2690 * smack_sem_alloc_security - Set the security blob for sem 2691 * @sma: the object 2692 * 2693 * Returns 0 2694 */ 2695 static int smack_sem_alloc_security(struct sem_array *sma) 2696 { 2697 struct kern_ipc_perm *isp = &sma->sem_perm; 2698 struct smack_known *skp = smk_of_current(); 2699 2700 isp->security = skp; 2701 return 0; 2702 } 2703 2704 /** 2705 * smack_sem_free_security - Clear the security blob for sem 2706 * @sma: the object 2707 * 2708 * Clears the blob pointer 2709 */ 2710 static void smack_sem_free_security(struct sem_array *sma) 2711 { 2712 struct kern_ipc_perm *isp = &sma->sem_perm; 2713 2714 isp->security = NULL; 2715 } 2716 2717 /** 2718 * smk_curacc_sem : check if current has access on sem 2719 * @sma : the object 2720 * @access : access requested 2721 * 2722 * Returns 0 if current has the requested access, error code otherwise 2723 */ 2724 static int smk_curacc_sem(struct sem_array *sma, int access) 2725 { 2726 struct smack_known *ssp = smack_of_sem(sma); 2727 struct smk_audit_info ad; 2728 int rc; 2729 2730 #ifdef CONFIG_AUDIT 2731 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC); 2732 ad.a.u.ipc_id = sma->sem_perm.id; 2733 #endif 2734 rc = smk_curacc(ssp, access, &ad); 2735 rc = smk_bu_current("sem", ssp, access, rc); 2736 return rc; 2737 } 2738 2739 /** 2740 * smack_sem_associate - Smack access check for sem 2741 * @sma: the object 2742 * @semflg: access requested 2743 * 2744 * Returns 0 if current has the requested access, error code otherwise 2745 */ 2746 static int smack_sem_associate(struct sem_array *sma, int semflg) 2747 { 2748 int may; 2749 2750 may = smack_flags_to_may(semflg); 2751 return smk_curacc_sem(sma, may); 2752 } 2753 2754 /** 2755 * smack_sem_shmctl - Smack access check for sem 2756 * @sma: the object 2757 * @cmd: what it wants to do 2758 * 2759 * Returns 0 if current has the requested access, error code otherwise 2760 */ 2761 static int smack_sem_semctl(struct sem_array *sma, int cmd) 2762 { 2763 int may; 2764 2765 switch (cmd) { 2766 case GETPID: 2767 case GETNCNT: 2768 case GETZCNT: 2769 case GETVAL: 2770 case GETALL: 2771 case IPC_STAT: 2772 case SEM_STAT: 2773 may = MAY_READ; 2774 break; 2775 case SETVAL: 2776 case SETALL: 2777 case IPC_RMID: 2778 case IPC_SET: 2779 may = MAY_READWRITE; 2780 break; 2781 case IPC_INFO: 2782 case SEM_INFO: 2783 /* 2784 * System level information 2785 */ 2786 return 0; 2787 default: 2788 return -EINVAL; 2789 } 2790 2791 return smk_curacc_sem(sma, may); 2792 } 2793 2794 /** 2795 * smack_sem_semop - Smack checks of semaphore operations 2796 * @sma: the object 2797 * @sops: unused 2798 * @nsops: unused 2799 * @alter: unused 2800 * 2801 * Treated as read and write in all cases. 2802 * 2803 * Returns 0 if access is allowed, error code otherwise 2804 */ 2805 static int smack_sem_semop(struct sem_array *sma, struct sembuf *sops, 2806 unsigned nsops, int alter) 2807 { 2808 return smk_curacc_sem(sma, MAY_READWRITE); 2809 } 2810 2811 /** 2812 * smack_msg_alloc_security - Set the security blob for msg 2813 * @msq: the object 2814 * 2815 * Returns 0 2816 */ 2817 static int smack_msg_queue_alloc_security(struct msg_queue *msq) 2818 { 2819 struct kern_ipc_perm *kisp = &msq->q_perm; 2820 struct smack_known *skp = smk_of_current(); 2821 2822 kisp->security = skp; 2823 return 0; 2824 } 2825 2826 /** 2827 * smack_msg_free_security - Clear the security blob for msg 2828 * @msq: the object 2829 * 2830 * Clears the blob pointer 2831 */ 2832 static void smack_msg_queue_free_security(struct msg_queue *msq) 2833 { 2834 struct kern_ipc_perm *kisp = &msq->q_perm; 2835 2836 kisp->security = NULL; 2837 } 2838 2839 /** 2840 * smack_of_msq - the smack pointer for the msq 2841 * @msq: the object 2842 * 2843 * Returns a pointer to the smack label entry 2844 */ 2845 static struct smack_known *smack_of_msq(struct msg_queue *msq) 2846 { 2847 return (struct smack_known *)msq->q_perm.security; 2848 } 2849 2850 /** 2851 * smk_curacc_msq : helper to check if current has access on msq 2852 * @msq : the msq 2853 * @access : access requested 2854 * 2855 * return 0 if current has access, error otherwise 2856 */ 2857 static int smk_curacc_msq(struct msg_queue *msq, int access) 2858 { 2859 struct smack_known *msp = smack_of_msq(msq); 2860 struct smk_audit_info ad; 2861 int rc; 2862 2863 #ifdef CONFIG_AUDIT 2864 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC); 2865 ad.a.u.ipc_id = msq->q_perm.id; 2866 #endif 2867 rc = smk_curacc(msp, access, &ad); 2868 rc = smk_bu_current("msq", msp, access, rc); 2869 return rc; 2870 } 2871 2872 /** 2873 * smack_msg_queue_associate - Smack access check for msg_queue 2874 * @msq: the object 2875 * @msqflg: access requested 2876 * 2877 * Returns 0 if current has the requested access, error code otherwise 2878 */ 2879 static int smack_msg_queue_associate(struct msg_queue *msq, int msqflg) 2880 { 2881 int may; 2882 2883 may = smack_flags_to_may(msqflg); 2884 return smk_curacc_msq(msq, may); 2885 } 2886 2887 /** 2888 * smack_msg_queue_msgctl - Smack access check for msg_queue 2889 * @msq: the object 2890 * @cmd: what it wants to do 2891 * 2892 * Returns 0 if current has the requested access, error code otherwise 2893 */ 2894 static int smack_msg_queue_msgctl(struct msg_queue *msq, int cmd) 2895 { 2896 int may; 2897 2898 switch (cmd) { 2899 case IPC_STAT: 2900 case MSG_STAT: 2901 may = MAY_READ; 2902 break; 2903 case IPC_SET: 2904 case IPC_RMID: 2905 may = MAY_READWRITE; 2906 break; 2907 case IPC_INFO: 2908 case MSG_INFO: 2909 /* 2910 * System level information 2911 */ 2912 return 0; 2913 default: 2914 return -EINVAL; 2915 } 2916 2917 return smk_curacc_msq(msq, may); 2918 } 2919 2920 /** 2921 * smack_msg_queue_msgsnd - Smack access check for msg_queue 2922 * @msq: the object 2923 * @msg: unused 2924 * @msqflg: access requested 2925 * 2926 * Returns 0 if current has the requested access, error code otherwise 2927 */ 2928 static int smack_msg_queue_msgsnd(struct msg_queue *msq, struct msg_msg *msg, 2929 int msqflg) 2930 { 2931 int may; 2932 2933 may = smack_flags_to_may(msqflg); 2934 return smk_curacc_msq(msq, may); 2935 } 2936 2937 /** 2938 * smack_msg_queue_msgsnd - Smack access check for msg_queue 2939 * @msq: the object 2940 * @msg: unused 2941 * @target: unused 2942 * @type: unused 2943 * @mode: unused 2944 * 2945 * Returns 0 if current has read and write access, error code otherwise 2946 */ 2947 static int smack_msg_queue_msgrcv(struct msg_queue *msq, struct msg_msg *msg, 2948 struct task_struct *target, long type, int mode) 2949 { 2950 return smk_curacc_msq(msq, MAY_READWRITE); 2951 } 2952 2953 /** 2954 * smack_ipc_permission - Smack access for ipc_permission() 2955 * @ipp: the object permissions 2956 * @flag: access requested 2957 * 2958 * Returns 0 if current has read and write access, error code otherwise 2959 */ 2960 static int smack_ipc_permission(struct kern_ipc_perm *ipp, short flag) 2961 { 2962 struct smack_known *iskp = ipp->security; 2963 int may = smack_flags_to_may(flag); 2964 struct smk_audit_info ad; 2965 int rc; 2966 2967 #ifdef CONFIG_AUDIT 2968 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC); 2969 ad.a.u.ipc_id = ipp->id; 2970 #endif 2971 rc = smk_curacc(iskp, may, &ad); 2972 rc = smk_bu_current("svipc", iskp, may, rc); 2973 return rc; 2974 } 2975 2976 /** 2977 * smack_ipc_getsecid - Extract smack security id 2978 * @ipp: the object permissions 2979 * @secid: where result will be saved 2980 */ 2981 static void smack_ipc_getsecid(struct kern_ipc_perm *ipp, u32 *secid) 2982 { 2983 struct smack_known *iskp = ipp->security; 2984 2985 *secid = iskp->smk_secid; 2986 } 2987 2988 /** 2989 * smack_d_instantiate - Make sure the blob is correct on an inode 2990 * @opt_dentry: dentry where inode will be attached 2991 * @inode: the object 2992 * 2993 * Set the inode's security blob if it hasn't been done already. 2994 */ 2995 static void smack_d_instantiate(struct dentry *opt_dentry, struct inode *inode) 2996 { 2997 struct super_block *sbp; 2998 struct superblock_smack *sbsp; 2999 struct inode_smack *isp; 3000 struct smack_known *skp; 3001 struct smack_known *ckp = smk_of_current(); 3002 struct smack_known *final; 3003 char trattr[TRANS_TRUE_SIZE]; 3004 int transflag = 0; 3005 int rc; 3006 struct dentry *dp; 3007 3008 if (inode == NULL) 3009 return; 3010 3011 isp = inode->i_security; 3012 3013 mutex_lock(&isp->smk_lock); 3014 /* 3015 * If the inode is already instantiated 3016 * take the quick way out 3017 */ 3018 if (isp->smk_flags & SMK_INODE_INSTANT) 3019 goto unlockandout; 3020 3021 sbp = inode->i_sb; 3022 sbsp = sbp->s_security; 3023 /* 3024 * We're going to use the superblock default label 3025 * if there's no label on the file. 3026 */ 3027 final = sbsp->smk_default; 3028 3029 /* 3030 * If this is the root inode the superblock 3031 * may be in the process of initialization. 3032 * If that is the case use the root value out 3033 * of the superblock. 3034 */ 3035 if (opt_dentry->d_parent == opt_dentry) { 3036 if (sbp->s_magic == CGROUP_SUPER_MAGIC) { 3037 /* 3038 * The cgroup filesystem is never mounted, 3039 * so there's no opportunity to set the mount 3040 * options. 3041 */ 3042 sbsp->smk_root = &smack_known_star; 3043 sbsp->smk_default = &smack_known_star; 3044 } 3045 isp->smk_inode = sbsp->smk_root; 3046 isp->smk_flags |= SMK_INODE_INSTANT; 3047 goto unlockandout; 3048 } 3049 3050 /* 3051 * This is pretty hackish. 3052 * Casey says that we shouldn't have to do 3053 * file system specific code, but it does help 3054 * with keeping it simple. 3055 */ 3056 switch (sbp->s_magic) { 3057 case SMACK_MAGIC: 3058 case PIPEFS_MAGIC: 3059 case SOCKFS_MAGIC: 3060 case CGROUP_SUPER_MAGIC: 3061 /* 3062 * Casey says that it's a little embarrassing 3063 * that the smack file system doesn't do 3064 * extended attributes. 3065 * 3066 * Casey says pipes are easy (?) 3067 * 3068 * Socket access is controlled by the socket 3069 * structures associated with the task involved. 3070 * 3071 * Cgroupfs is special 3072 */ 3073 final = &smack_known_star; 3074 break; 3075 case DEVPTS_SUPER_MAGIC: 3076 /* 3077 * devpts seems content with the label of the task. 3078 * Programs that change smack have to treat the 3079 * pty with respect. 3080 */ 3081 final = ckp; 3082 break; 3083 case PROC_SUPER_MAGIC: 3084 /* 3085 * Casey says procfs appears not to care. 3086 * The superblock default suffices. 3087 */ 3088 break; 3089 case TMPFS_MAGIC: 3090 /* 3091 * Device labels should come from the filesystem, 3092 * but watch out, because they're volitile, 3093 * getting recreated on every reboot. 3094 */ 3095 final = &smack_known_star; 3096 /* 3097 * No break. 3098 * 3099 * If a smack value has been set we want to use it, 3100 * but since tmpfs isn't giving us the opportunity 3101 * to set mount options simulate setting the 3102 * superblock default. 3103 */ 3104 default: 3105 /* 3106 * This isn't an understood special case. 3107 * Get the value from the xattr. 3108 */ 3109 3110 /* 3111 * UNIX domain sockets use lower level socket data. 3112 */ 3113 if (S_ISSOCK(inode->i_mode)) { 3114 final = &smack_known_star; 3115 break; 3116 } 3117 /* 3118 * No xattr support means, alas, no SMACK label. 3119 * Use the aforeapplied default. 3120 * It would be curious if the label of the task 3121 * does not match that assigned. 3122 */ 3123 if (inode->i_op->getxattr == NULL) 3124 break; 3125 /* 3126 * Get the dentry for xattr. 3127 */ 3128 dp = dget(opt_dentry); 3129 skp = smk_fetch(XATTR_NAME_SMACK, inode, dp); 3130 if (skp != NULL) 3131 final = skp; 3132 3133 /* 3134 * Transmuting directory 3135 */ 3136 if (S_ISDIR(inode->i_mode)) { 3137 /* 3138 * If this is a new directory and the label was 3139 * transmuted when the inode was initialized 3140 * set the transmute attribute on the directory 3141 * and mark the inode. 3142 * 3143 * If there is a transmute attribute on the 3144 * directory mark the inode. 3145 */ 3146 if (isp->smk_flags & SMK_INODE_CHANGED) { 3147 isp->smk_flags &= ~SMK_INODE_CHANGED; 3148 rc = inode->i_op->setxattr(dp, 3149 XATTR_NAME_SMACKTRANSMUTE, 3150 TRANS_TRUE, TRANS_TRUE_SIZE, 3151 0); 3152 } else { 3153 rc = inode->i_op->getxattr(dp, 3154 XATTR_NAME_SMACKTRANSMUTE, trattr, 3155 TRANS_TRUE_SIZE); 3156 if (rc >= 0 && strncmp(trattr, TRANS_TRUE, 3157 TRANS_TRUE_SIZE) != 0) 3158 rc = -EINVAL; 3159 } 3160 if (rc >= 0) 3161 transflag = SMK_INODE_TRANSMUTE; 3162 } 3163 /* 3164 * Don't let the exec or mmap label be "*" or "@". 3165 */ 3166 skp = smk_fetch(XATTR_NAME_SMACKEXEC, inode, dp); 3167 if (skp == &smack_known_star || skp == &smack_known_web) 3168 skp = NULL; 3169 isp->smk_task = skp; 3170 skp = smk_fetch(XATTR_NAME_SMACKMMAP, inode, dp); 3171 if (skp == &smack_known_star || skp == &smack_known_web) 3172 skp = NULL; 3173 isp->smk_mmap = skp; 3174 3175 dput(dp); 3176 break; 3177 } 3178 3179 if (final == NULL) 3180 isp->smk_inode = ckp; 3181 else 3182 isp->smk_inode = final; 3183 3184 isp->smk_flags |= (SMK_INODE_INSTANT | transflag); 3185 3186 unlockandout: 3187 mutex_unlock(&isp->smk_lock); 3188 return; 3189 } 3190 3191 /** 3192 * smack_getprocattr - Smack process attribute access 3193 * @p: the object task 3194 * @name: the name of the attribute in /proc/.../attr 3195 * @value: where to put the result 3196 * 3197 * Places a copy of the task Smack into value 3198 * 3199 * Returns the length of the smack label or an error code 3200 */ 3201 static int smack_getprocattr(struct task_struct *p, char *name, char **value) 3202 { 3203 struct smack_known *skp = smk_of_task(task_security(p)); 3204 char *cp; 3205 int slen; 3206 3207 if (strcmp(name, "current") != 0) 3208 return -EINVAL; 3209 3210 cp = kstrdup(skp->smk_known, GFP_KERNEL); 3211 if (cp == NULL) 3212 return -ENOMEM; 3213 3214 slen = strlen(cp); 3215 *value = cp; 3216 return slen; 3217 } 3218 3219 /** 3220 * smack_setprocattr - Smack process attribute setting 3221 * @p: the object task 3222 * @name: the name of the attribute in /proc/.../attr 3223 * @value: the value to set 3224 * @size: the size of the value 3225 * 3226 * Sets the Smack value of the task. Only setting self 3227 * is permitted and only with privilege 3228 * 3229 * Returns the length of the smack label or an error code 3230 */ 3231 static int smack_setprocattr(struct task_struct *p, char *name, 3232 void *value, size_t size) 3233 { 3234 struct task_smack *tsp; 3235 struct cred *new; 3236 struct smack_known *skp; 3237 3238 /* 3239 * Changing another process' Smack value is too dangerous 3240 * and supports no sane use case. 3241 */ 3242 if (p != current) 3243 return -EPERM; 3244 3245 if (!smack_privileged(CAP_MAC_ADMIN)) 3246 return -EPERM; 3247 3248 if (value == NULL || size == 0 || size >= SMK_LONGLABEL) 3249 return -EINVAL; 3250 3251 if (strcmp(name, "current") != 0) 3252 return -EINVAL; 3253 3254 skp = smk_import_entry(value, size); 3255 if (skp == NULL) 3256 return -EINVAL; 3257 3258 /* 3259 * No process is ever allowed the web ("@") label. 3260 */ 3261 if (skp == &smack_known_web) 3262 return -EPERM; 3263 3264 new = prepare_creds(); 3265 if (new == NULL) 3266 return -ENOMEM; 3267 3268 tsp = new->security; 3269 tsp->smk_task = skp; 3270 3271 commit_creds(new); 3272 return size; 3273 } 3274 3275 /** 3276 * smack_unix_stream_connect - Smack access on UDS 3277 * @sock: one sock 3278 * @other: the other sock 3279 * @newsk: unused 3280 * 3281 * Return 0 if a subject with the smack of sock could access 3282 * an object with the smack of other, otherwise an error code 3283 */ 3284 static int smack_unix_stream_connect(struct sock *sock, 3285 struct sock *other, struct sock *newsk) 3286 { 3287 struct smack_known *skp; 3288 struct smack_known *okp; 3289 struct socket_smack *ssp = sock->sk_security; 3290 struct socket_smack *osp = other->sk_security; 3291 struct socket_smack *nsp = newsk->sk_security; 3292 struct smk_audit_info ad; 3293 int rc = 0; 3294 #ifdef CONFIG_AUDIT 3295 struct lsm_network_audit net; 3296 #endif 3297 3298 if (!smack_privileged(CAP_MAC_OVERRIDE)) { 3299 skp = ssp->smk_out; 3300 okp = osp->smk_out; 3301 #ifdef CONFIG_AUDIT 3302 smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net); 3303 smk_ad_setfield_u_net_sk(&ad, other); 3304 #endif 3305 rc = smk_access(skp, okp, MAY_WRITE, &ad); 3306 rc = smk_bu_note("UDS connect", skp, okp, MAY_WRITE, rc); 3307 if (rc == 0) { 3308 rc = smk_access(okp, skp, MAY_WRITE, NULL); 3309 rc = smk_bu_note("UDS connect", okp, skp, 3310 MAY_WRITE, rc); 3311 } 3312 } 3313 3314 /* 3315 * Cross reference the peer labels for SO_PEERSEC. 3316 */ 3317 if (rc == 0) { 3318 nsp->smk_packet = ssp->smk_out; 3319 ssp->smk_packet = osp->smk_out; 3320 } 3321 3322 return rc; 3323 } 3324 3325 /** 3326 * smack_unix_may_send - Smack access on UDS 3327 * @sock: one socket 3328 * @other: the other socket 3329 * 3330 * Return 0 if a subject with the smack of sock could access 3331 * an object with the smack of other, otherwise an error code 3332 */ 3333 static int smack_unix_may_send(struct socket *sock, struct socket *other) 3334 { 3335 struct socket_smack *ssp = sock->sk->sk_security; 3336 struct socket_smack *osp = other->sk->sk_security; 3337 struct smk_audit_info ad; 3338 int rc; 3339 3340 #ifdef CONFIG_AUDIT 3341 struct lsm_network_audit net; 3342 3343 smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net); 3344 smk_ad_setfield_u_net_sk(&ad, other->sk); 3345 #endif 3346 3347 if (smack_privileged(CAP_MAC_OVERRIDE)) 3348 return 0; 3349 3350 rc = smk_access(ssp->smk_out, osp->smk_in, MAY_WRITE, &ad); 3351 rc = smk_bu_note("UDS send", ssp->smk_out, osp->smk_in, MAY_WRITE, rc); 3352 return rc; 3353 } 3354 3355 /** 3356 * smack_socket_sendmsg - Smack check based on destination host 3357 * @sock: the socket 3358 * @msg: the message 3359 * @size: the size of the message 3360 * 3361 * Return 0 if the current subject can write to the destination host. 3362 * For IPv4 this is only a question if the destination is a single label host. 3363 * For IPv6 this is a check against the label of the port. 3364 */ 3365 static int smack_socket_sendmsg(struct socket *sock, struct msghdr *msg, 3366 int size) 3367 { 3368 struct sockaddr_in *sip = (struct sockaddr_in *) msg->msg_name; 3369 struct sockaddr_in6 *sap = (struct sockaddr_in6 *) msg->msg_name; 3370 int rc = 0; 3371 3372 /* 3373 * Perfectly reasonable for this to be NULL 3374 */ 3375 if (sip == NULL) 3376 return 0; 3377 3378 switch (sip->sin_family) { 3379 case AF_INET: 3380 rc = smack_netlabel_send(sock->sk, sip); 3381 break; 3382 case AF_INET6: 3383 rc = smk_ipv6_port_check(sock->sk, sap, SMK_SENDING); 3384 break; 3385 } 3386 return rc; 3387 } 3388 3389 /** 3390 * smack_from_secattr - Convert a netlabel attr.mls.lvl/attr.mls.cat pair to smack 3391 * @sap: netlabel secattr 3392 * @ssp: socket security information 3393 * 3394 * Returns a pointer to a Smack label entry found on the label list. 3395 */ 3396 static struct smack_known *smack_from_secattr(struct netlbl_lsm_secattr *sap, 3397 struct socket_smack *ssp) 3398 { 3399 struct smack_known *skp; 3400 int found = 0; 3401 int acat; 3402 int kcat; 3403 3404 if ((sap->flags & NETLBL_SECATTR_MLS_LVL) != 0) { 3405 /* 3406 * Looks like a CIPSO packet. 3407 * If there are flags but no level netlabel isn't 3408 * behaving the way we expect it to. 3409 * 3410 * Look it up in the label table 3411 * Without guidance regarding the smack value 3412 * for the packet fall back on the network 3413 * ambient value. 3414 */ 3415 rcu_read_lock(); 3416 list_for_each_entry(skp, &smack_known_list, list) { 3417 if (sap->attr.mls.lvl != skp->smk_netlabel.attr.mls.lvl) 3418 continue; 3419 /* 3420 * Compare the catsets. Use the netlbl APIs. 3421 */ 3422 if ((sap->flags & NETLBL_SECATTR_MLS_CAT) == 0) { 3423 if ((skp->smk_netlabel.flags & 3424 NETLBL_SECATTR_MLS_CAT) == 0) 3425 found = 1; 3426 break; 3427 } 3428 for (acat = -1, kcat = -1; acat == kcat; ) { 3429 acat = netlbl_catmap_walk(sap->attr.mls.cat, 3430 acat + 1); 3431 kcat = netlbl_catmap_walk( 3432 skp->smk_netlabel.attr.mls.cat, 3433 kcat + 1); 3434 if (acat < 0 || kcat < 0) 3435 break; 3436 } 3437 if (acat == kcat) { 3438 found = 1; 3439 break; 3440 } 3441 } 3442 rcu_read_unlock(); 3443 3444 if (found) 3445 return skp; 3446 3447 if (ssp != NULL && ssp->smk_in == &smack_known_star) 3448 return &smack_known_web; 3449 return &smack_known_star; 3450 } 3451 if ((sap->flags & NETLBL_SECATTR_SECID) != 0) { 3452 /* 3453 * Looks like a fallback, which gives us a secid. 3454 */ 3455 skp = smack_from_secid(sap->attr.secid); 3456 /* 3457 * This has got to be a bug because it is 3458 * impossible to specify a fallback without 3459 * specifying the label, which will ensure 3460 * it has a secid, and the only way to get a 3461 * secid is from a fallback. 3462 */ 3463 BUG_ON(skp == NULL); 3464 return skp; 3465 } 3466 /* 3467 * Without guidance regarding the smack value 3468 * for the packet fall back on the network 3469 * ambient value. 3470 */ 3471 return smack_net_ambient; 3472 } 3473 3474 static int smk_skb_to_addr_ipv6(struct sk_buff *skb, struct sockaddr_in6 *sip) 3475 { 3476 u8 nexthdr; 3477 int offset; 3478 int proto = -EINVAL; 3479 struct ipv6hdr _ipv6h; 3480 struct ipv6hdr *ip6; 3481 __be16 frag_off; 3482 struct tcphdr _tcph, *th; 3483 struct udphdr _udph, *uh; 3484 struct dccp_hdr _dccph, *dh; 3485 3486 sip->sin6_port = 0; 3487 3488 offset = skb_network_offset(skb); 3489 ip6 = skb_header_pointer(skb, offset, sizeof(_ipv6h), &_ipv6h); 3490 if (ip6 == NULL) 3491 return -EINVAL; 3492 sip->sin6_addr = ip6->saddr; 3493 3494 nexthdr = ip6->nexthdr; 3495 offset += sizeof(_ipv6h); 3496 offset = ipv6_skip_exthdr(skb, offset, &nexthdr, &frag_off); 3497 if (offset < 0) 3498 return -EINVAL; 3499 3500 proto = nexthdr; 3501 switch (proto) { 3502 case IPPROTO_TCP: 3503 th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph); 3504 if (th != NULL) 3505 sip->sin6_port = th->source; 3506 break; 3507 case IPPROTO_UDP: 3508 uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph); 3509 if (uh != NULL) 3510 sip->sin6_port = uh->source; 3511 break; 3512 case IPPROTO_DCCP: 3513 dh = skb_header_pointer(skb, offset, sizeof(_dccph), &_dccph); 3514 if (dh != NULL) 3515 sip->sin6_port = dh->dccph_sport; 3516 break; 3517 } 3518 return proto; 3519 } 3520 3521 /** 3522 * smack_socket_sock_rcv_skb - Smack packet delivery access check 3523 * @sk: socket 3524 * @skb: packet 3525 * 3526 * Returns 0 if the packet should be delivered, an error code otherwise 3527 */ 3528 static int smack_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb) 3529 { 3530 struct netlbl_lsm_secattr secattr; 3531 struct socket_smack *ssp = sk->sk_security; 3532 struct smack_known *skp; 3533 struct sockaddr_in6 sadd; 3534 int rc = 0; 3535 struct smk_audit_info ad; 3536 #ifdef CONFIG_AUDIT 3537 struct lsm_network_audit net; 3538 #endif 3539 switch (sk->sk_family) { 3540 case PF_INET: 3541 /* 3542 * Translate what netlabel gave us. 3543 */ 3544 netlbl_secattr_init(&secattr); 3545 3546 rc = netlbl_skbuff_getattr(skb, sk->sk_family, &secattr); 3547 if (rc == 0) 3548 skp = smack_from_secattr(&secattr, ssp); 3549 else 3550 skp = smack_net_ambient; 3551 3552 netlbl_secattr_destroy(&secattr); 3553 3554 #ifdef CONFIG_AUDIT 3555 smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net); 3556 ad.a.u.net->family = sk->sk_family; 3557 ad.a.u.net->netif = skb->skb_iif; 3558 ipv4_skb_to_auditdata(skb, &ad.a, NULL); 3559 #endif 3560 /* 3561 * Receiving a packet requires that the other end 3562 * be able to write here. Read access is not required. 3563 * This is the simplist possible security model 3564 * for networking. 3565 */ 3566 rc = smk_access(skp, ssp->smk_in, MAY_WRITE, &ad); 3567 rc = smk_bu_note("IPv4 delivery", skp, ssp->smk_in, 3568 MAY_WRITE, rc); 3569 if (rc != 0) 3570 netlbl_skbuff_err(skb, rc, 0); 3571 break; 3572 case PF_INET6: 3573 rc = smk_skb_to_addr_ipv6(skb, &sadd); 3574 if (rc == IPPROTO_UDP || rc == IPPROTO_TCP) 3575 rc = smk_ipv6_port_check(sk, &sadd, SMK_RECEIVING); 3576 else 3577 rc = 0; 3578 break; 3579 } 3580 return rc; 3581 } 3582 3583 /** 3584 * smack_socket_getpeersec_stream - pull in packet label 3585 * @sock: the socket 3586 * @optval: user's destination 3587 * @optlen: size thereof 3588 * @len: max thereof 3589 * 3590 * returns zero on success, an error code otherwise 3591 */ 3592 static int smack_socket_getpeersec_stream(struct socket *sock, 3593 char __user *optval, 3594 int __user *optlen, unsigned len) 3595 { 3596 struct socket_smack *ssp; 3597 char *rcp = ""; 3598 int slen = 1; 3599 int rc = 0; 3600 3601 ssp = sock->sk->sk_security; 3602 if (ssp->smk_packet != NULL) { 3603 rcp = ssp->smk_packet->smk_known; 3604 slen = strlen(rcp) + 1; 3605 } 3606 3607 if (slen > len) 3608 rc = -ERANGE; 3609 else if (copy_to_user(optval, rcp, slen) != 0) 3610 rc = -EFAULT; 3611 3612 if (put_user(slen, optlen) != 0) 3613 rc = -EFAULT; 3614 3615 return rc; 3616 } 3617 3618 3619 /** 3620 * smack_socket_getpeersec_dgram - pull in packet label 3621 * @sock: the peer socket 3622 * @skb: packet data 3623 * @secid: pointer to where to put the secid of the packet 3624 * 3625 * Sets the netlabel socket state on sk from parent 3626 */ 3627 static int smack_socket_getpeersec_dgram(struct socket *sock, 3628 struct sk_buff *skb, u32 *secid) 3629 3630 { 3631 struct netlbl_lsm_secattr secattr; 3632 struct socket_smack *ssp = NULL; 3633 struct smack_known *skp; 3634 int family = PF_UNSPEC; 3635 u32 s = 0; /* 0 is the invalid secid */ 3636 int rc; 3637 3638 if (skb != NULL) { 3639 if (skb->protocol == htons(ETH_P_IP)) 3640 family = PF_INET; 3641 else if (skb->protocol == htons(ETH_P_IPV6)) 3642 family = PF_INET6; 3643 } 3644 if (family == PF_UNSPEC && sock != NULL) 3645 family = sock->sk->sk_family; 3646 3647 if (family == PF_UNIX) { 3648 ssp = sock->sk->sk_security; 3649 s = ssp->smk_out->smk_secid; 3650 } else if (family == PF_INET || family == PF_INET6) { 3651 /* 3652 * Translate what netlabel gave us. 3653 */ 3654 if (sock != NULL && sock->sk != NULL) 3655 ssp = sock->sk->sk_security; 3656 netlbl_secattr_init(&secattr); 3657 rc = netlbl_skbuff_getattr(skb, family, &secattr); 3658 if (rc == 0) { 3659 skp = smack_from_secattr(&secattr, ssp); 3660 s = skp->smk_secid; 3661 } 3662 netlbl_secattr_destroy(&secattr); 3663 } 3664 *secid = s; 3665 if (s == 0) 3666 return -EINVAL; 3667 return 0; 3668 } 3669 3670 /** 3671 * smack_sock_graft - Initialize a newly created socket with an existing sock 3672 * @sk: child sock 3673 * @parent: parent socket 3674 * 3675 * Set the smk_{in,out} state of an existing sock based on the process that 3676 * is creating the new socket. 3677 */ 3678 static void smack_sock_graft(struct sock *sk, struct socket *parent) 3679 { 3680 struct socket_smack *ssp; 3681 struct smack_known *skp = smk_of_current(); 3682 3683 if (sk == NULL || 3684 (sk->sk_family != PF_INET && sk->sk_family != PF_INET6)) 3685 return; 3686 3687 ssp = sk->sk_security; 3688 ssp->smk_in = skp; 3689 ssp->smk_out = skp; 3690 /* cssp->smk_packet is already set in smack_inet_csk_clone() */ 3691 } 3692 3693 /** 3694 * smack_inet_conn_request - Smack access check on connect 3695 * @sk: socket involved 3696 * @skb: packet 3697 * @req: unused 3698 * 3699 * Returns 0 if a task with the packet label could write to 3700 * the socket, otherwise an error code 3701 */ 3702 static int smack_inet_conn_request(struct sock *sk, struct sk_buff *skb, 3703 struct request_sock *req) 3704 { 3705 u16 family = sk->sk_family; 3706 struct smack_known *skp; 3707 struct socket_smack *ssp = sk->sk_security; 3708 struct netlbl_lsm_secattr secattr; 3709 struct sockaddr_in addr; 3710 struct iphdr *hdr; 3711 struct smack_known *hskp; 3712 int rc; 3713 struct smk_audit_info ad; 3714 #ifdef CONFIG_AUDIT 3715 struct lsm_network_audit net; 3716 #endif 3717 3718 if (family == PF_INET6) { 3719 /* 3720 * Handle mapped IPv4 packets arriving 3721 * via IPv6 sockets. Don't set up netlabel 3722 * processing on IPv6. 3723 */ 3724 if (skb->protocol == htons(ETH_P_IP)) 3725 family = PF_INET; 3726 else 3727 return 0; 3728 } 3729 3730 netlbl_secattr_init(&secattr); 3731 rc = netlbl_skbuff_getattr(skb, family, &secattr); 3732 if (rc == 0) 3733 skp = smack_from_secattr(&secattr, ssp); 3734 else 3735 skp = &smack_known_huh; 3736 netlbl_secattr_destroy(&secattr); 3737 3738 #ifdef CONFIG_AUDIT 3739 smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net); 3740 ad.a.u.net->family = family; 3741 ad.a.u.net->netif = skb->skb_iif; 3742 ipv4_skb_to_auditdata(skb, &ad.a, NULL); 3743 #endif 3744 /* 3745 * Receiving a packet requires that the other end be able to write 3746 * here. Read access is not required. 3747 */ 3748 rc = smk_access(skp, ssp->smk_in, MAY_WRITE, &ad); 3749 rc = smk_bu_note("IPv4 connect", skp, ssp->smk_in, MAY_WRITE, rc); 3750 if (rc != 0) 3751 return rc; 3752 3753 /* 3754 * Save the peer's label in the request_sock so we can later setup 3755 * smk_packet in the child socket so that SO_PEERCRED can report it. 3756 */ 3757 req->peer_secid = skp->smk_secid; 3758 3759 /* 3760 * We need to decide if we want to label the incoming connection here 3761 * if we do we only need to label the request_sock and the stack will 3762 * propagate the wire-label to the sock when it is created. 3763 */ 3764 hdr = ip_hdr(skb); 3765 addr.sin_addr.s_addr = hdr->saddr; 3766 rcu_read_lock(); 3767 hskp = smack_host_label(&addr); 3768 rcu_read_unlock(); 3769 3770 if (hskp == NULL) 3771 rc = netlbl_req_setattr(req, &skp->smk_netlabel); 3772 else 3773 netlbl_req_delattr(req); 3774 3775 return rc; 3776 } 3777 3778 /** 3779 * smack_inet_csk_clone - Copy the connection information to the new socket 3780 * @sk: the new socket 3781 * @req: the connection's request_sock 3782 * 3783 * Transfer the connection's peer label to the newly created socket. 3784 */ 3785 static void smack_inet_csk_clone(struct sock *sk, 3786 const struct request_sock *req) 3787 { 3788 struct socket_smack *ssp = sk->sk_security; 3789 struct smack_known *skp; 3790 3791 if (req->peer_secid != 0) { 3792 skp = smack_from_secid(req->peer_secid); 3793 ssp->smk_packet = skp; 3794 } else 3795 ssp->smk_packet = NULL; 3796 } 3797 3798 /* 3799 * Key management security hooks 3800 * 3801 * Casey has not tested key support very heavily. 3802 * The permission check is most likely too restrictive. 3803 * If you care about keys please have a look. 3804 */ 3805 #ifdef CONFIG_KEYS 3806 3807 /** 3808 * smack_key_alloc - Set the key security blob 3809 * @key: object 3810 * @cred: the credentials to use 3811 * @flags: unused 3812 * 3813 * No allocation required 3814 * 3815 * Returns 0 3816 */ 3817 static int smack_key_alloc(struct key *key, const struct cred *cred, 3818 unsigned long flags) 3819 { 3820 struct smack_known *skp = smk_of_task(cred->security); 3821 3822 key->security = skp; 3823 return 0; 3824 } 3825 3826 /** 3827 * smack_key_free - Clear the key security blob 3828 * @key: the object 3829 * 3830 * Clear the blob pointer 3831 */ 3832 static void smack_key_free(struct key *key) 3833 { 3834 key->security = NULL; 3835 } 3836 3837 /* 3838 * smack_key_permission - Smack access on a key 3839 * @key_ref: gets to the object 3840 * @cred: the credentials to use 3841 * @perm: unused 3842 * 3843 * Return 0 if the task has read and write to the object, 3844 * an error code otherwise 3845 */ 3846 static int smack_key_permission(key_ref_t key_ref, 3847 const struct cred *cred, unsigned perm) 3848 { 3849 struct key *keyp; 3850 struct smk_audit_info ad; 3851 struct smack_known *tkp = smk_of_task(cred->security); 3852 int request = 0; 3853 int rc; 3854 3855 keyp = key_ref_to_ptr(key_ref); 3856 if (keyp == NULL) 3857 return -EINVAL; 3858 /* 3859 * If the key hasn't been initialized give it access so that 3860 * it may do so. 3861 */ 3862 if (keyp->security == NULL) 3863 return 0; 3864 /* 3865 * This should not occur 3866 */ 3867 if (tkp == NULL) 3868 return -EACCES; 3869 #ifdef CONFIG_AUDIT 3870 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_KEY); 3871 ad.a.u.key_struct.key = keyp->serial; 3872 ad.a.u.key_struct.key_desc = keyp->description; 3873 #endif 3874 if (perm & KEY_NEED_READ) 3875 request = MAY_READ; 3876 if (perm & (KEY_NEED_WRITE | KEY_NEED_LINK | KEY_NEED_SETATTR)) 3877 request = MAY_WRITE; 3878 rc = smk_access(tkp, keyp->security, request, &ad); 3879 rc = smk_bu_note("key access", tkp, keyp->security, request, rc); 3880 return rc; 3881 } 3882 #endif /* CONFIG_KEYS */ 3883 3884 /* 3885 * Smack Audit hooks 3886 * 3887 * Audit requires a unique representation of each Smack specific 3888 * rule. This unique representation is used to distinguish the 3889 * object to be audited from remaining kernel objects and also 3890 * works as a glue between the audit hooks. 3891 * 3892 * Since repository entries are added but never deleted, we'll use 3893 * the smack_known label address related to the given audit rule as 3894 * the needed unique representation. This also better fits the smack 3895 * model where nearly everything is a label. 3896 */ 3897 #ifdef CONFIG_AUDIT 3898 3899 /** 3900 * smack_audit_rule_init - Initialize a smack audit rule 3901 * @field: audit rule fields given from user-space (audit.h) 3902 * @op: required testing operator (=, !=, >, <, ...) 3903 * @rulestr: smack label to be audited 3904 * @vrule: pointer to save our own audit rule representation 3905 * 3906 * Prepare to audit cases where (@field @op @rulestr) is true. 3907 * The label to be audited is created if necessay. 3908 */ 3909 static int smack_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule) 3910 { 3911 struct smack_known *skp; 3912 char **rule = (char **)vrule; 3913 *rule = NULL; 3914 3915 if (field != AUDIT_SUBJ_USER && field != AUDIT_OBJ_USER) 3916 return -EINVAL; 3917 3918 if (op != Audit_equal && op != Audit_not_equal) 3919 return -EINVAL; 3920 3921 skp = smk_import_entry(rulestr, 0); 3922 if (skp) 3923 *rule = skp->smk_known; 3924 3925 return 0; 3926 } 3927 3928 /** 3929 * smack_audit_rule_known - Distinguish Smack audit rules 3930 * @krule: rule of interest, in Audit kernel representation format 3931 * 3932 * This is used to filter Smack rules from remaining Audit ones. 3933 * If it's proved that this rule belongs to us, the 3934 * audit_rule_match hook will be called to do the final judgement. 3935 */ 3936 static int smack_audit_rule_known(struct audit_krule *krule) 3937 { 3938 struct audit_field *f; 3939 int i; 3940 3941 for (i = 0; i < krule->field_count; i++) { 3942 f = &krule->fields[i]; 3943 3944 if (f->type == AUDIT_SUBJ_USER || f->type == AUDIT_OBJ_USER) 3945 return 1; 3946 } 3947 3948 return 0; 3949 } 3950 3951 /** 3952 * smack_audit_rule_match - Audit given object ? 3953 * @secid: security id for identifying the object to test 3954 * @field: audit rule flags given from user-space 3955 * @op: required testing operator 3956 * @vrule: smack internal rule presentation 3957 * @actx: audit context associated with the check 3958 * 3959 * The core Audit hook. It's used to take the decision of 3960 * whether to audit or not to audit a given object. 3961 */ 3962 static int smack_audit_rule_match(u32 secid, u32 field, u32 op, void *vrule, 3963 struct audit_context *actx) 3964 { 3965 struct smack_known *skp; 3966 char *rule = vrule; 3967 3968 if (unlikely(!rule)) { 3969 WARN_ONCE(1, "Smack: missing rule\n"); 3970 return -ENOENT; 3971 } 3972 3973 if (field != AUDIT_SUBJ_USER && field != AUDIT_OBJ_USER) 3974 return 0; 3975 3976 skp = smack_from_secid(secid); 3977 3978 /* 3979 * No need to do string comparisons. If a match occurs, 3980 * both pointers will point to the same smack_known 3981 * label. 3982 */ 3983 if (op == Audit_equal) 3984 return (rule == skp->smk_known); 3985 if (op == Audit_not_equal) 3986 return (rule != skp->smk_known); 3987 3988 return 0; 3989 } 3990 3991 /** 3992 * smack_audit_rule_free - free smack rule representation 3993 * @vrule: rule to be freed. 3994 * 3995 * No memory was allocated. 3996 */ 3997 static void smack_audit_rule_free(void *vrule) 3998 { 3999 /* No-op */ 4000 } 4001 4002 #endif /* CONFIG_AUDIT */ 4003 4004 /** 4005 * smack_ismaclabel - check if xattr @name references a smack MAC label 4006 * @name: Full xattr name to check. 4007 */ 4008 static int smack_ismaclabel(const char *name) 4009 { 4010 return (strcmp(name, XATTR_SMACK_SUFFIX) == 0); 4011 } 4012 4013 4014 /** 4015 * smack_secid_to_secctx - return the smack label for a secid 4016 * @secid: incoming integer 4017 * @secdata: destination 4018 * @seclen: how long it is 4019 * 4020 * Exists for networking code. 4021 */ 4022 static int smack_secid_to_secctx(u32 secid, char **secdata, u32 *seclen) 4023 { 4024 struct smack_known *skp = smack_from_secid(secid); 4025 4026 if (secdata) 4027 *secdata = skp->smk_known; 4028 *seclen = strlen(skp->smk_known); 4029 return 0; 4030 } 4031 4032 /** 4033 * smack_secctx_to_secid - return the secid for a smack label 4034 * @secdata: smack label 4035 * @seclen: how long result is 4036 * @secid: outgoing integer 4037 * 4038 * Exists for audit and networking code. 4039 */ 4040 static int smack_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid) 4041 { 4042 struct smack_known *skp = smk_find_entry(secdata); 4043 4044 if (skp) 4045 *secid = skp->smk_secid; 4046 else 4047 *secid = 0; 4048 return 0; 4049 } 4050 4051 /** 4052 * smack_release_secctx - don't do anything. 4053 * @secdata: unused 4054 * @seclen: unused 4055 * 4056 * Exists to make sure nothing gets done, and properly 4057 */ 4058 static void smack_release_secctx(char *secdata, u32 seclen) 4059 { 4060 } 4061 4062 static int smack_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen) 4063 { 4064 return smack_inode_setsecurity(inode, XATTR_SMACK_SUFFIX, ctx, ctxlen, 0); 4065 } 4066 4067 static int smack_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen) 4068 { 4069 return __vfs_setxattr_noperm(dentry, XATTR_NAME_SMACK, ctx, ctxlen, 0); 4070 } 4071 4072 static int smack_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen) 4073 { 4074 int len = 0; 4075 len = smack_inode_getsecurity(inode, XATTR_SMACK_SUFFIX, ctx, true); 4076 4077 if (len < 0) 4078 return len; 4079 *ctxlen = len; 4080 return 0; 4081 } 4082 4083 struct security_operations smack_ops = { 4084 .name = "smack", 4085 4086 .ptrace_access_check = smack_ptrace_access_check, 4087 .ptrace_traceme = smack_ptrace_traceme, 4088 .syslog = smack_syslog, 4089 4090 .sb_alloc_security = smack_sb_alloc_security, 4091 .sb_free_security = smack_sb_free_security, 4092 .sb_copy_data = smack_sb_copy_data, 4093 .sb_kern_mount = smack_sb_kern_mount, 4094 .sb_statfs = smack_sb_statfs, 4095 4096 .bprm_set_creds = smack_bprm_set_creds, 4097 .bprm_committing_creds = smack_bprm_committing_creds, 4098 .bprm_secureexec = smack_bprm_secureexec, 4099 4100 .inode_alloc_security = smack_inode_alloc_security, 4101 .inode_free_security = smack_inode_free_security, 4102 .inode_init_security = smack_inode_init_security, 4103 .inode_link = smack_inode_link, 4104 .inode_unlink = smack_inode_unlink, 4105 .inode_rmdir = smack_inode_rmdir, 4106 .inode_rename = smack_inode_rename, 4107 .inode_permission = smack_inode_permission, 4108 .inode_setattr = smack_inode_setattr, 4109 .inode_getattr = smack_inode_getattr, 4110 .inode_setxattr = smack_inode_setxattr, 4111 .inode_post_setxattr = smack_inode_post_setxattr, 4112 .inode_getxattr = smack_inode_getxattr, 4113 .inode_removexattr = smack_inode_removexattr, 4114 .inode_getsecurity = smack_inode_getsecurity, 4115 .inode_setsecurity = smack_inode_setsecurity, 4116 .inode_listsecurity = smack_inode_listsecurity, 4117 .inode_getsecid = smack_inode_getsecid, 4118 4119 .file_permission = smack_file_permission, 4120 .file_alloc_security = smack_file_alloc_security, 4121 .file_free_security = smack_file_free_security, 4122 .file_ioctl = smack_file_ioctl, 4123 .file_lock = smack_file_lock, 4124 .file_fcntl = smack_file_fcntl, 4125 .mmap_file = smack_mmap_file, 4126 .mmap_addr = cap_mmap_addr, 4127 .file_set_fowner = smack_file_set_fowner, 4128 .file_send_sigiotask = smack_file_send_sigiotask, 4129 .file_receive = smack_file_receive, 4130 4131 .file_open = smack_file_open, 4132 4133 .cred_alloc_blank = smack_cred_alloc_blank, 4134 .cred_free = smack_cred_free, 4135 .cred_prepare = smack_cred_prepare, 4136 .cred_transfer = smack_cred_transfer, 4137 .kernel_act_as = smack_kernel_act_as, 4138 .kernel_create_files_as = smack_kernel_create_files_as, 4139 .task_setpgid = smack_task_setpgid, 4140 .task_getpgid = smack_task_getpgid, 4141 .task_getsid = smack_task_getsid, 4142 .task_getsecid = smack_task_getsecid, 4143 .task_setnice = smack_task_setnice, 4144 .task_setioprio = smack_task_setioprio, 4145 .task_getioprio = smack_task_getioprio, 4146 .task_setscheduler = smack_task_setscheduler, 4147 .task_getscheduler = smack_task_getscheduler, 4148 .task_movememory = smack_task_movememory, 4149 .task_kill = smack_task_kill, 4150 .task_wait = smack_task_wait, 4151 .task_to_inode = smack_task_to_inode, 4152 4153 .ipc_permission = smack_ipc_permission, 4154 .ipc_getsecid = smack_ipc_getsecid, 4155 4156 .msg_msg_alloc_security = smack_msg_msg_alloc_security, 4157 .msg_msg_free_security = smack_msg_msg_free_security, 4158 4159 .msg_queue_alloc_security = smack_msg_queue_alloc_security, 4160 .msg_queue_free_security = smack_msg_queue_free_security, 4161 .msg_queue_associate = smack_msg_queue_associate, 4162 .msg_queue_msgctl = smack_msg_queue_msgctl, 4163 .msg_queue_msgsnd = smack_msg_queue_msgsnd, 4164 .msg_queue_msgrcv = smack_msg_queue_msgrcv, 4165 4166 .shm_alloc_security = smack_shm_alloc_security, 4167 .shm_free_security = smack_shm_free_security, 4168 .shm_associate = smack_shm_associate, 4169 .shm_shmctl = smack_shm_shmctl, 4170 .shm_shmat = smack_shm_shmat, 4171 4172 .sem_alloc_security = smack_sem_alloc_security, 4173 .sem_free_security = smack_sem_free_security, 4174 .sem_associate = smack_sem_associate, 4175 .sem_semctl = smack_sem_semctl, 4176 .sem_semop = smack_sem_semop, 4177 4178 .d_instantiate = smack_d_instantiate, 4179 4180 .getprocattr = smack_getprocattr, 4181 .setprocattr = smack_setprocattr, 4182 4183 .unix_stream_connect = smack_unix_stream_connect, 4184 .unix_may_send = smack_unix_may_send, 4185 4186 .socket_post_create = smack_socket_post_create, 4187 .socket_bind = smack_socket_bind, 4188 .socket_connect = smack_socket_connect, 4189 .socket_sendmsg = smack_socket_sendmsg, 4190 .socket_sock_rcv_skb = smack_socket_sock_rcv_skb, 4191 .socket_getpeersec_stream = smack_socket_getpeersec_stream, 4192 .socket_getpeersec_dgram = smack_socket_getpeersec_dgram, 4193 .sk_alloc_security = smack_sk_alloc_security, 4194 .sk_free_security = smack_sk_free_security, 4195 .sock_graft = smack_sock_graft, 4196 .inet_conn_request = smack_inet_conn_request, 4197 .inet_csk_clone = smack_inet_csk_clone, 4198 4199 /* key management security hooks */ 4200 #ifdef CONFIG_KEYS 4201 .key_alloc = smack_key_alloc, 4202 .key_free = smack_key_free, 4203 .key_permission = smack_key_permission, 4204 #endif /* CONFIG_KEYS */ 4205 4206 /* Audit hooks */ 4207 #ifdef CONFIG_AUDIT 4208 .audit_rule_init = smack_audit_rule_init, 4209 .audit_rule_known = smack_audit_rule_known, 4210 .audit_rule_match = smack_audit_rule_match, 4211 .audit_rule_free = smack_audit_rule_free, 4212 #endif /* CONFIG_AUDIT */ 4213 4214 .ismaclabel = smack_ismaclabel, 4215 .secid_to_secctx = smack_secid_to_secctx, 4216 .secctx_to_secid = smack_secctx_to_secid, 4217 .release_secctx = smack_release_secctx, 4218 .inode_notifysecctx = smack_inode_notifysecctx, 4219 .inode_setsecctx = smack_inode_setsecctx, 4220 .inode_getsecctx = smack_inode_getsecctx, 4221 }; 4222 4223 4224 static __init void init_smack_known_list(void) 4225 { 4226 /* 4227 * Initialize rule list locks 4228 */ 4229 mutex_init(&smack_known_huh.smk_rules_lock); 4230 mutex_init(&smack_known_hat.smk_rules_lock); 4231 mutex_init(&smack_known_floor.smk_rules_lock); 4232 mutex_init(&smack_known_star.smk_rules_lock); 4233 mutex_init(&smack_known_invalid.smk_rules_lock); 4234 mutex_init(&smack_known_web.smk_rules_lock); 4235 /* 4236 * Initialize rule lists 4237 */ 4238 INIT_LIST_HEAD(&smack_known_huh.smk_rules); 4239 INIT_LIST_HEAD(&smack_known_hat.smk_rules); 4240 INIT_LIST_HEAD(&smack_known_star.smk_rules); 4241 INIT_LIST_HEAD(&smack_known_floor.smk_rules); 4242 INIT_LIST_HEAD(&smack_known_invalid.smk_rules); 4243 INIT_LIST_HEAD(&smack_known_web.smk_rules); 4244 /* 4245 * Create the known labels list 4246 */ 4247 smk_insert_entry(&smack_known_huh); 4248 smk_insert_entry(&smack_known_hat); 4249 smk_insert_entry(&smack_known_star); 4250 smk_insert_entry(&smack_known_floor); 4251 smk_insert_entry(&smack_known_invalid); 4252 smk_insert_entry(&smack_known_web); 4253 } 4254 4255 /** 4256 * smack_init - initialize the smack system 4257 * 4258 * Returns 0 4259 */ 4260 static __init int smack_init(void) 4261 { 4262 struct cred *cred; 4263 struct task_smack *tsp; 4264 4265 if (!security_module_enable(&smack_ops)) 4266 return 0; 4267 4268 smack_inode_cache = KMEM_CACHE(inode_smack, 0); 4269 if (!smack_inode_cache) 4270 return -ENOMEM; 4271 4272 tsp = new_task_smack(&smack_known_floor, &smack_known_floor, 4273 GFP_KERNEL); 4274 if (tsp == NULL) { 4275 kmem_cache_destroy(smack_inode_cache); 4276 return -ENOMEM; 4277 } 4278 4279 printk(KERN_INFO "Smack: Initializing.\n"); 4280 4281 /* 4282 * Set the security state for the initial task. 4283 */ 4284 cred = (struct cred *) current->cred; 4285 cred->security = tsp; 4286 4287 /* initialize the smack_known_list */ 4288 init_smack_known_list(); 4289 4290 /* 4291 * Register with LSM 4292 */ 4293 if (register_security(&smack_ops)) 4294 panic("smack: Unable to register with kernel.\n"); 4295 4296 return 0; 4297 } 4298 4299 /* 4300 * Smack requires early initialization in order to label 4301 * all processes and objects when they are created. 4302 */ 4303 security_initcall(smack_init); 4304