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