1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Simplified MAC Kernel (smack) security module 4 * 5 * This file contains the smack hook function implementations. 6 * 7 * Authors: 8 * Casey Schaufler <casey@schaufler-ca.com> 9 * Jarkko Sakkinen <jarkko.sakkinen@intel.com> 10 * 11 * Copyright (C) 2007 Casey Schaufler <casey@schaufler-ca.com> 12 * Copyright (C) 2009 Hewlett-Packard Development Company, L.P. 13 * Paul Moore <paul@paul-moore.com> 14 * Copyright (C) 2010 Nokia Corporation 15 * Copyright (C) 2011 Intel Corporation. 16 */ 17 18 #include <linux/xattr.h> 19 #include <linux/pagemap.h> 20 #include <linux/mount.h> 21 #include <linux/stat.h> 22 #include <linux/kd.h> 23 #include <asm/ioctls.h> 24 #include <linux/ip.h> 25 #include <linux/tcp.h> 26 #include <linux/udp.h> 27 #include <linux/dccp.h> 28 #include <linux/icmpv6.h> 29 #include <linux/slab.h> 30 #include <linux/mutex.h> 31 #include <net/cipso_ipv4.h> 32 #include <net/ip.h> 33 #include <net/ipv6.h> 34 #include <linux/audit.h> 35 #include <linux/magic.h> 36 #include <linux/dcache.h> 37 #include <linux/personality.h> 38 #include <linux/msg.h> 39 #include <linux/shm.h> 40 #include <uapi/linux/shm.h> 41 #include <linux/binfmts.h> 42 #include <linux/parser.h> 43 #include <linux/fs_context.h> 44 #include <linux/fs_parser.h> 45 #include <linux/watch_queue.h> 46 #include <linux/io_uring/cmd.h> 47 #include <uapi/linux/lsm.h> 48 #include "smack.h" 49 50 #define TRANS_TRUE "TRUE" 51 #define TRANS_TRUE_SIZE 4 52 53 #define SMK_CONNECTING 0 54 #define SMK_RECEIVING 1 55 #define SMK_SENDING 2 56 57 /* 58 * Smack uses multiple xattrs. 59 * SMACK64 - for access control, 60 * SMACK64TRANSMUTE - label initialization, 61 * Not saved on files - SMACK64IPIN and SMACK64IPOUT, 62 * Must be set explicitly - SMACK64EXEC and SMACK64MMAP 63 */ 64 #define SMACK_INODE_INIT_XATTRS 2 65 66 #ifdef SMACK_IPV6_PORT_LABELING 67 static DEFINE_MUTEX(smack_ipv6_lock); 68 static LIST_HEAD(smk_ipv6_port_list); 69 #endif 70 struct kmem_cache *smack_rule_cache; 71 int smack_enabled __initdata; 72 73 #define A(s) {"smack"#s, sizeof("smack"#s) - 1, Opt_##s} 74 static struct { 75 const char *name; 76 int len; 77 int opt; 78 } smk_mount_opts[] = { 79 {"smackfsdef", sizeof("smackfsdef") - 1, Opt_fsdefault}, 80 A(fsdefault), A(fsfloor), A(fshat), A(fsroot), A(fstransmute) 81 }; 82 #undef A 83 84 static int match_opt_prefix(char *s, int l, char **arg) 85 { 86 int i; 87 88 for (i = 0; i < ARRAY_SIZE(smk_mount_opts); i++) { 89 size_t len = smk_mount_opts[i].len; 90 if (len > l || memcmp(s, smk_mount_opts[i].name, len)) 91 continue; 92 if (len == l || s[len] != '=') 93 continue; 94 *arg = s + len + 1; 95 return smk_mount_opts[i].opt; 96 } 97 return Opt_error; 98 } 99 100 #ifdef CONFIG_SECURITY_SMACK_BRINGUP 101 static char *smk_bu_mess[] = { 102 "Bringup Error", /* Unused */ 103 "Bringup", /* SMACK_BRINGUP_ALLOW */ 104 "Unconfined Subject", /* SMACK_UNCONFINED_SUBJECT */ 105 "Unconfined Object", /* SMACK_UNCONFINED_OBJECT */ 106 }; 107 108 static void smk_bu_mode(int mode, char *s) 109 { 110 int i = 0; 111 112 if (mode & MAY_READ) 113 s[i++] = 'r'; 114 if (mode & MAY_WRITE) 115 s[i++] = 'w'; 116 if (mode & MAY_EXEC) 117 s[i++] = 'x'; 118 if (mode & MAY_APPEND) 119 s[i++] = 'a'; 120 if (mode & MAY_TRANSMUTE) 121 s[i++] = 't'; 122 if (mode & MAY_LOCK) 123 s[i++] = 'l'; 124 if (i == 0) 125 s[i++] = '-'; 126 s[i] = '\0'; 127 } 128 #endif 129 130 #ifdef CONFIG_SECURITY_SMACK_BRINGUP 131 static int smk_bu_note(char *note, struct smack_known *sskp, 132 struct smack_known *oskp, int mode, int rc) 133 { 134 char acc[SMK_NUM_ACCESS_TYPE + 1]; 135 136 if (rc <= 0) 137 return rc; 138 if (rc > SMACK_UNCONFINED_OBJECT) 139 rc = 0; 140 141 smk_bu_mode(mode, acc); 142 pr_info("Smack %s: (%s %s %s) %s\n", smk_bu_mess[rc], 143 sskp->smk_known, oskp->smk_known, acc, note); 144 return 0; 145 } 146 #else 147 #define smk_bu_note(note, sskp, oskp, mode, RC) (RC) 148 #endif 149 150 #ifdef CONFIG_SECURITY_SMACK_BRINGUP 151 static int smk_bu_current(char *note, struct smack_known *oskp, 152 int mode, int rc) 153 { 154 struct task_smack *tsp = smack_cred(current_cred()); 155 char acc[SMK_NUM_ACCESS_TYPE + 1]; 156 157 if (rc <= 0) 158 return rc; 159 if (rc > SMACK_UNCONFINED_OBJECT) 160 rc = 0; 161 162 smk_bu_mode(mode, acc); 163 pr_info("Smack %s: (%s %s %s) %s %s\n", smk_bu_mess[rc], 164 tsp->smk_task->smk_known, oskp->smk_known, 165 acc, current->comm, note); 166 return 0; 167 } 168 #else 169 #define smk_bu_current(note, oskp, mode, RC) (RC) 170 #endif 171 172 #ifdef CONFIG_SECURITY_SMACK_BRINGUP 173 static int smk_bu_task(struct task_struct *otp, int mode, int rc) 174 { 175 struct task_smack *tsp = smack_cred(current_cred()); 176 struct smack_known *smk_task = smk_of_task_struct_obj(otp); 177 char acc[SMK_NUM_ACCESS_TYPE + 1]; 178 179 if (rc <= 0) 180 return rc; 181 if (rc > SMACK_UNCONFINED_OBJECT) 182 rc = 0; 183 184 smk_bu_mode(mode, acc); 185 pr_info("Smack %s: (%s %s %s) %s to %s\n", smk_bu_mess[rc], 186 tsp->smk_task->smk_known, smk_task->smk_known, acc, 187 current->comm, otp->comm); 188 return 0; 189 } 190 #else 191 #define smk_bu_task(otp, mode, RC) (RC) 192 #endif 193 194 #ifdef CONFIG_SECURITY_SMACK_BRINGUP 195 static int smk_bu_inode(struct inode *inode, int mode, int rc) 196 { 197 struct task_smack *tsp = smack_cred(current_cred()); 198 struct inode_smack *isp = smack_inode(inode); 199 char acc[SMK_NUM_ACCESS_TYPE + 1]; 200 201 if (isp->smk_flags & SMK_INODE_IMPURE) 202 pr_info("Smack Unconfined Corruption: inode=(%s %ld) %s\n", 203 inode->i_sb->s_id, inode->i_ino, current->comm); 204 205 if (rc <= 0) 206 return rc; 207 if (rc > SMACK_UNCONFINED_OBJECT) 208 rc = 0; 209 if (rc == SMACK_UNCONFINED_SUBJECT && 210 (mode & (MAY_WRITE | MAY_APPEND))) 211 isp->smk_flags |= SMK_INODE_IMPURE; 212 213 smk_bu_mode(mode, acc); 214 215 pr_info("Smack %s: (%s %s %s) inode=(%s %ld) %s\n", smk_bu_mess[rc], 216 tsp->smk_task->smk_known, isp->smk_inode->smk_known, acc, 217 inode->i_sb->s_id, inode->i_ino, current->comm); 218 return 0; 219 } 220 #else 221 #define smk_bu_inode(inode, mode, RC) (RC) 222 #endif 223 224 #ifdef CONFIG_SECURITY_SMACK_BRINGUP 225 static int smk_bu_file(struct file *file, int mode, int rc) 226 { 227 struct task_smack *tsp = smack_cred(current_cred()); 228 struct smack_known *sskp = tsp->smk_task; 229 struct inode *inode = file_inode(file); 230 struct inode_smack *isp = smack_inode(inode); 231 char acc[SMK_NUM_ACCESS_TYPE + 1]; 232 233 if (isp->smk_flags & SMK_INODE_IMPURE) 234 pr_info("Smack Unconfined Corruption: inode=(%s %ld) %s\n", 235 inode->i_sb->s_id, inode->i_ino, current->comm); 236 237 if (rc <= 0) 238 return rc; 239 if (rc > SMACK_UNCONFINED_OBJECT) 240 rc = 0; 241 242 smk_bu_mode(mode, acc); 243 pr_info("Smack %s: (%s %s %s) file=(%s %ld %pD) %s\n", smk_bu_mess[rc], 244 sskp->smk_known, smk_of_inode(inode)->smk_known, acc, 245 inode->i_sb->s_id, inode->i_ino, file, 246 current->comm); 247 return 0; 248 } 249 #else 250 #define smk_bu_file(file, mode, RC) (RC) 251 #endif 252 253 #ifdef CONFIG_SECURITY_SMACK_BRINGUP 254 static int smk_bu_credfile(const struct cred *cred, struct file *file, 255 int mode, int rc) 256 { 257 struct task_smack *tsp = smack_cred(cred); 258 struct smack_known *sskp = tsp->smk_task; 259 struct inode *inode = file_inode(file); 260 struct inode_smack *isp = smack_inode(inode); 261 char acc[SMK_NUM_ACCESS_TYPE + 1]; 262 263 if (isp->smk_flags & SMK_INODE_IMPURE) 264 pr_info("Smack Unconfined Corruption: inode=(%s %ld) %s\n", 265 inode->i_sb->s_id, inode->i_ino, current->comm); 266 267 if (rc <= 0) 268 return rc; 269 if (rc > SMACK_UNCONFINED_OBJECT) 270 rc = 0; 271 272 smk_bu_mode(mode, acc); 273 pr_info("Smack %s: (%s %s %s) file=(%s %ld %pD) %s\n", smk_bu_mess[rc], 274 sskp->smk_known, smk_of_inode(inode)->smk_known, acc, 275 inode->i_sb->s_id, inode->i_ino, file, 276 current->comm); 277 return 0; 278 } 279 #else 280 #define smk_bu_credfile(cred, file, mode, RC) (RC) 281 #endif 282 283 /** 284 * smk_fetch - Fetch the smack label from a file. 285 * @name: type of the label (attribute) 286 * @ip: a pointer to the inode 287 * @dp: a pointer to the dentry 288 * 289 * Returns a pointer to the master list entry for the Smack label, 290 * NULL if there was no label to fetch, or an error code. 291 */ 292 static struct smack_known *smk_fetch(const char *name, struct inode *ip, 293 struct dentry *dp) 294 { 295 int rc; 296 char *buffer; 297 struct smack_known *skp = NULL; 298 299 if (!(ip->i_opflags & IOP_XATTR)) 300 return ERR_PTR(-EOPNOTSUPP); 301 302 buffer = kzalloc(SMK_LONGLABEL, GFP_NOFS); 303 if (buffer == NULL) 304 return ERR_PTR(-ENOMEM); 305 306 rc = __vfs_getxattr(dp, ip, name, buffer, SMK_LONGLABEL); 307 if (rc < 0) 308 skp = ERR_PTR(rc); 309 else if (rc == 0) 310 skp = NULL; 311 else 312 skp = smk_import_entry(buffer, rc); 313 314 kfree(buffer); 315 316 return skp; 317 } 318 319 /** 320 * init_inode_smack - initialize an inode security blob 321 * @inode: inode to extract the info from 322 * @skp: a pointer to the Smack label entry to use in the blob 323 * 324 */ 325 static void init_inode_smack(struct inode *inode, struct smack_known *skp) 326 { 327 struct inode_smack *isp = smack_inode(inode); 328 329 isp->smk_inode = skp; 330 isp->smk_flags = 0; 331 } 332 333 /** 334 * init_task_smack - initialize a task security blob 335 * @tsp: blob to initialize 336 * @task: a pointer to the Smack label for the running task 337 * @forked: a pointer to the Smack label for the forked task 338 * 339 */ 340 static void init_task_smack(struct task_smack *tsp, struct smack_known *task, 341 struct smack_known *forked) 342 { 343 tsp->smk_task = task; 344 tsp->smk_forked = forked; 345 INIT_LIST_HEAD(&tsp->smk_rules); 346 INIT_LIST_HEAD(&tsp->smk_relabel); 347 mutex_init(&tsp->smk_rules_lock); 348 } 349 350 /** 351 * smk_copy_rules - copy a rule set 352 * @nhead: new rules header pointer 353 * @ohead: old rules header pointer 354 * @gfp: type of the memory for the allocation 355 * 356 * Returns 0 on success, -ENOMEM on error 357 */ 358 static int smk_copy_rules(struct list_head *nhead, struct list_head *ohead, 359 gfp_t gfp) 360 { 361 struct smack_rule *nrp; 362 struct smack_rule *orp; 363 int rc = 0; 364 365 list_for_each_entry_rcu(orp, ohead, list) { 366 nrp = kmem_cache_zalloc(smack_rule_cache, gfp); 367 if (nrp == NULL) { 368 rc = -ENOMEM; 369 break; 370 } 371 *nrp = *orp; 372 list_add_rcu(&nrp->list, nhead); 373 } 374 return rc; 375 } 376 377 /** 378 * smk_copy_relabel - copy smk_relabel labels list 379 * @nhead: new rules header pointer 380 * @ohead: old rules header pointer 381 * @gfp: type of the memory for the allocation 382 * 383 * Returns 0 on success, -ENOMEM on error 384 */ 385 static int smk_copy_relabel(struct list_head *nhead, struct list_head *ohead, 386 gfp_t gfp) 387 { 388 struct smack_known_list_elem *nklep; 389 struct smack_known_list_elem *oklep; 390 391 list_for_each_entry(oklep, ohead, list) { 392 nklep = kzalloc(sizeof(struct smack_known_list_elem), gfp); 393 if (nklep == NULL) { 394 smk_destroy_label_list(nhead); 395 return -ENOMEM; 396 } 397 nklep->smk_label = oklep->smk_label; 398 list_add(&nklep->list, nhead); 399 } 400 401 return 0; 402 } 403 404 /** 405 * smk_ptrace_mode - helper function for converting PTRACE_MODE_* into MAY_* 406 * @mode: input mode in form of PTRACE_MODE_* 407 * 408 * Returns a converted MAY_* mode usable by smack rules 409 */ 410 static inline unsigned int smk_ptrace_mode(unsigned int mode) 411 { 412 if (mode & PTRACE_MODE_ATTACH) 413 return MAY_READWRITE; 414 if (mode & PTRACE_MODE_READ) 415 return MAY_READ; 416 417 return 0; 418 } 419 420 /** 421 * smk_ptrace_rule_check - helper for ptrace access 422 * @tracer: tracer process 423 * @tracee_known: label entry of the process that's about to be traced 424 * @mode: ptrace attachment mode (PTRACE_MODE_*) 425 * @func: name of the function that called us, used for audit 426 * 427 * Returns 0 on access granted, -error on error 428 */ 429 static int smk_ptrace_rule_check(struct task_struct *tracer, 430 struct smack_known *tracee_known, 431 unsigned int mode, const char *func) 432 { 433 int rc; 434 struct smk_audit_info ad, *saip = NULL; 435 struct task_smack *tsp; 436 struct smack_known *tracer_known; 437 const struct cred *tracercred; 438 439 if ((mode & PTRACE_MODE_NOAUDIT) == 0) { 440 smk_ad_init(&ad, func, LSM_AUDIT_DATA_TASK); 441 smk_ad_setfield_u_tsk(&ad, tracer); 442 saip = &ad; 443 } 444 445 rcu_read_lock(); 446 tracercred = __task_cred(tracer); 447 tsp = smack_cred(tracercred); 448 tracer_known = smk_of_task(tsp); 449 450 if ((mode & PTRACE_MODE_ATTACH) && 451 (smack_ptrace_rule == SMACK_PTRACE_EXACT || 452 smack_ptrace_rule == SMACK_PTRACE_DRACONIAN)) { 453 if (tracer_known->smk_known == tracee_known->smk_known) 454 rc = 0; 455 else if (smack_ptrace_rule == SMACK_PTRACE_DRACONIAN) 456 rc = -EACCES; 457 else if (smack_privileged_cred(CAP_SYS_PTRACE, tracercred)) 458 rc = 0; 459 else 460 rc = -EACCES; 461 462 if (saip) 463 smack_log(tracer_known->smk_known, 464 tracee_known->smk_known, 465 0, rc, saip); 466 467 rcu_read_unlock(); 468 return rc; 469 } 470 471 /* In case of rule==SMACK_PTRACE_DEFAULT or mode==PTRACE_MODE_READ */ 472 rc = smk_tskacc(tsp, tracee_known, smk_ptrace_mode(mode), saip); 473 474 rcu_read_unlock(); 475 return rc; 476 } 477 478 /* 479 * LSM hooks. 480 * We he, that is fun! 481 */ 482 483 /** 484 * smack_ptrace_access_check - Smack approval on PTRACE_ATTACH 485 * @ctp: child task pointer 486 * @mode: ptrace attachment mode (PTRACE_MODE_*) 487 * 488 * Returns 0 if access is OK, an error code otherwise 489 * 490 * Do the capability checks. 491 */ 492 static int smack_ptrace_access_check(struct task_struct *ctp, unsigned int mode) 493 { 494 struct smack_known *skp; 495 496 skp = smk_of_task_struct_obj(ctp); 497 498 return smk_ptrace_rule_check(current, skp, mode, __func__); 499 } 500 501 /** 502 * smack_ptrace_traceme - Smack approval on PTRACE_TRACEME 503 * @ptp: parent task pointer 504 * 505 * Returns 0 if access is OK, an error code otherwise 506 * 507 * Do the capability checks, and require PTRACE_MODE_ATTACH. 508 */ 509 static int smack_ptrace_traceme(struct task_struct *ptp) 510 { 511 struct smack_known *skp; 512 513 skp = smk_of_task(smack_cred(current_cred())); 514 515 return smk_ptrace_rule_check(ptp, skp, PTRACE_MODE_ATTACH, __func__); 516 } 517 518 /** 519 * smack_syslog - Smack approval on syslog 520 * @typefrom_file: unused 521 * 522 * Returns 0 on success, error code otherwise. 523 */ 524 static int smack_syslog(int typefrom_file) 525 { 526 int rc = 0; 527 struct smack_known *skp = smk_of_current(); 528 529 if (smack_privileged(CAP_MAC_OVERRIDE)) 530 return 0; 531 532 if (smack_syslog_label != NULL && smack_syslog_label != skp) 533 rc = -EACCES; 534 535 return rc; 536 } 537 538 /* 539 * Superblock Hooks. 540 */ 541 542 /** 543 * smack_sb_alloc_security - allocate a superblock blob 544 * @sb: the superblock getting the blob 545 * 546 * Returns 0 on success or -ENOMEM on error. 547 */ 548 static int smack_sb_alloc_security(struct super_block *sb) 549 { 550 struct superblock_smack *sbsp = smack_superblock(sb); 551 552 sbsp->smk_root = &smack_known_floor; 553 sbsp->smk_default = &smack_known_floor; 554 sbsp->smk_floor = &smack_known_floor; 555 sbsp->smk_hat = &smack_known_hat; 556 /* 557 * SMK_SB_INITIALIZED will be zero from kzalloc. 558 */ 559 560 return 0; 561 } 562 563 struct smack_mnt_opts { 564 const char *fsdefault; 565 const char *fsfloor; 566 const char *fshat; 567 const char *fsroot; 568 const char *fstransmute; 569 }; 570 571 static void smack_free_mnt_opts(void *mnt_opts) 572 { 573 kfree(mnt_opts); 574 } 575 576 static int smack_add_opt(int token, const char *s, void **mnt_opts) 577 { 578 struct smack_mnt_opts *opts = *mnt_opts; 579 struct smack_known *skp; 580 581 if (!opts) { 582 opts = kzalloc(sizeof(struct smack_mnt_opts), GFP_KERNEL); 583 if (!opts) 584 return -ENOMEM; 585 *mnt_opts = opts; 586 } 587 if (!s) 588 return -ENOMEM; 589 590 skp = smk_import_entry(s, 0); 591 if (IS_ERR(skp)) 592 return PTR_ERR(skp); 593 594 switch (token) { 595 case Opt_fsdefault: 596 if (opts->fsdefault) 597 goto out_opt_err; 598 opts->fsdefault = skp->smk_known; 599 break; 600 case Opt_fsfloor: 601 if (opts->fsfloor) 602 goto out_opt_err; 603 opts->fsfloor = skp->smk_known; 604 break; 605 case Opt_fshat: 606 if (opts->fshat) 607 goto out_opt_err; 608 opts->fshat = skp->smk_known; 609 break; 610 case Opt_fsroot: 611 if (opts->fsroot) 612 goto out_opt_err; 613 opts->fsroot = skp->smk_known; 614 break; 615 case Opt_fstransmute: 616 if (opts->fstransmute) 617 goto out_opt_err; 618 opts->fstransmute = skp->smk_known; 619 break; 620 } 621 return 0; 622 623 out_opt_err: 624 pr_warn("Smack: duplicate mount options\n"); 625 return -EINVAL; 626 } 627 628 /** 629 * smack_fs_context_submount - Initialise security data for a filesystem context 630 * @fc: The filesystem context. 631 * @reference: reference superblock 632 * 633 * Returns 0 on success or -ENOMEM on error. 634 */ 635 static int smack_fs_context_submount(struct fs_context *fc, 636 struct super_block *reference) 637 { 638 struct superblock_smack *sbsp; 639 struct smack_mnt_opts *ctx; 640 struct inode_smack *isp; 641 642 ctx = kzalloc(sizeof(*ctx), GFP_KERNEL); 643 if (!ctx) 644 return -ENOMEM; 645 fc->security = ctx; 646 647 sbsp = smack_superblock(reference); 648 isp = smack_inode(reference->s_root->d_inode); 649 650 if (sbsp->smk_default) { 651 ctx->fsdefault = kstrdup(sbsp->smk_default->smk_known, GFP_KERNEL); 652 if (!ctx->fsdefault) 653 return -ENOMEM; 654 } 655 656 if (sbsp->smk_floor) { 657 ctx->fsfloor = kstrdup(sbsp->smk_floor->smk_known, GFP_KERNEL); 658 if (!ctx->fsfloor) 659 return -ENOMEM; 660 } 661 662 if (sbsp->smk_hat) { 663 ctx->fshat = kstrdup(sbsp->smk_hat->smk_known, GFP_KERNEL); 664 if (!ctx->fshat) 665 return -ENOMEM; 666 } 667 668 if (isp->smk_flags & SMK_INODE_TRANSMUTE) { 669 if (sbsp->smk_root) { 670 ctx->fstransmute = kstrdup(sbsp->smk_root->smk_known, GFP_KERNEL); 671 if (!ctx->fstransmute) 672 return -ENOMEM; 673 } 674 } 675 return 0; 676 } 677 678 /** 679 * smack_fs_context_dup - Duplicate the security data on fs_context duplication 680 * @fc: The new filesystem context. 681 * @src_fc: The source filesystem context being duplicated. 682 * 683 * Returns 0 on success or -ENOMEM on error. 684 */ 685 static int smack_fs_context_dup(struct fs_context *fc, 686 struct fs_context *src_fc) 687 { 688 struct smack_mnt_opts *dst, *src = src_fc->security; 689 690 if (!src) 691 return 0; 692 693 fc->security = kzalloc(sizeof(struct smack_mnt_opts), GFP_KERNEL); 694 if (!fc->security) 695 return -ENOMEM; 696 697 dst = fc->security; 698 dst->fsdefault = src->fsdefault; 699 dst->fsfloor = src->fsfloor; 700 dst->fshat = src->fshat; 701 dst->fsroot = src->fsroot; 702 dst->fstransmute = src->fstransmute; 703 704 return 0; 705 } 706 707 static const struct fs_parameter_spec smack_fs_parameters[] = { 708 fsparam_string("smackfsdef", Opt_fsdefault), 709 fsparam_string("smackfsdefault", Opt_fsdefault), 710 fsparam_string("smackfsfloor", Opt_fsfloor), 711 fsparam_string("smackfshat", Opt_fshat), 712 fsparam_string("smackfsroot", Opt_fsroot), 713 fsparam_string("smackfstransmute", Opt_fstransmute), 714 {} 715 }; 716 717 /** 718 * smack_fs_context_parse_param - Parse a single mount parameter 719 * @fc: The new filesystem context being constructed. 720 * @param: The parameter. 721 * 722 * Returns 0 on success, -ENOPARAM to pass the parameter on or anything else on 723 * error. 724 */ 725 static int smack_fs_context_parse_param(struct fs_context *fc, 726 struct fs_parameter *param) 727 { 728 struct fs_parse_result result; 729 int opt, rc; 730 731 opt = fs_parse(fc, smack_fs_parameters, param, &result); 732 if (opt < 0) 733 return opt; 734 735 rc = smack_add_opt(opt, param->string, &fc->security); 736 if (!rc) 737 param->string = NULL; 738 return rc; 739 } 740 741 static int smack_sb_eat_lsm_opts(char *options, void **mnt_opts) 742 { 743 char *from = options, *to = options; 744 bool first = true; 745 746 while (1) { 747 char *next = strchr(from, ','); 748 int token, len, rc; 749 char *arg = NULL; 750 751 if (next) 752 len = next - from; 753 else 754 len = strlen(from); 755 756 token = match_opt_prefix(from, len, &arg); 757 if (token != Opt_error) { 758 arg = kmemdup_nul(arg, from + len - arg, GFP_KERNEL); 759 rc = smack_add_opt(token, arg, mnt_opts); 760 kfree(arg); 761 if (unlikely(rc)) { 762 if (*mnt_opts) 763 smack_free_mnt_opts(*mnt_opts); 764 *mnt_opts = NULL; 765 return rc; 766 } 767 } else { 768 if (!first) { // copy with preceding comma 769 from--; 770 len++; 771 } 772 if (to != from) 773 memmove(to, from, len); 774 to += len; 775 first = false; 776 } 777 if (!from[len]) 778 break; 779 from += len + 1; 780 } 781 *to = '\0'; 782 return 0; 783 } 784 785 /** 786 * smack_set_mnt_opts - set Smack specific mount options 787 * @sb: the file system superblock 788 * @mnt_opts: Smack mount options 789 * @kern_flags: mount option from kernel space or user space 790 * @set_kern_flags: where to store converted mount opts 791 * 792 * Returns 0 on success, an error code on failure 793 * 794 * Allow filesystems with binary mount data to explicitly set Smack mount 795 * labels. 796 */ 797 static int smack_set_mnt_opts(struct super_block *sb, 798 void *mnt_opts, 799 unsigned long kern_flags, 800 unsigned long *set_kern_flags) 801 { 802 struct dentry *root = sb->s_root; 803 struct inode *inode = d_backing_inode(root); 804 struct superblock_smack *sp = smack_superblock(sb); 805 struct inode_smack *isp; 806 struct smack_known *skp; 807 struct smack_mnt_opts *opts = mnt_opts; 808 bool transmute = false; 809 810 if (sp->smk_flags & SMK_SB_INITIALIZED) 811 return 0; 812 813 if (!smack_privileged(CAP_MAC_ADMIN)) { 814 /* 815 * Unprivileged mounts don't get to specify Smack values. 816 */ 817 if (opts) 818 return -EPERM; 819 /* 820 * Unprivileged mounts get root and default from the caller. 821 */ 822 skp = smk_of_current(); 823 sp->smk_root = skp; 824 sp->smk_default = skp; 825 /* 826 * For a handful of fs types with no user-controlled 827 * backing store it's okay to trust security labels 828 * in the filesystem. The rest are untrusted. 829 */ 830 if (sb->s_user_ns != &init_user_ns && 831 sb->s_magic != SYSFS_MAGIC && sb->s_magic != TMPFS_MAGIC && 832 sb->s_magic != RAMFS_MAGIC) { 833 transmute = true; 834 sp->smk_flags |= SMK_SB_UNTRUSTED; 835 } 836 } 837 838 sp->smk_flags |= SMK_SB_INITIALIZED; 839 840 if (opts) { 841 if (opts->fsdefault) { 842 skp = smk_import_entry(opts->fsdefault, 0); 843 if (IS_ERR(skp)) 844 return PTR_ERR(skp); 845 sp->smk_default = skp; 846 } 847 if (opts->fsfloor) { 848 skp = smk_import_entry(opts->fsfloor, 0); 849 if (IS_ERR(skp)) 850 return PTR_ERR(skp); 851 sp->smk_floor = skp; 852 } 853 if (opts->fshat) { 854 skp = smk_import_entry(opts->fshat, 0); 855 if (IS_ERR(skp)) 856 return PTR_ERR(skp); 857 sp->smk_hat = skp; 858 } 859 if (opts->fsroot) { 860 skp = smk_import_entry(opts->fsroot, 0); 861 if (IS_ERR(skp)) 862 return PTR_ERR(skp); 863 sp->smk_root = skp; 864 } 865 if (opts->fstransmute) { 866 skp = smk_import_entry(opts->fstransmute, 0); 867 if (IS_ERR(skp)) 868 return PTR_ERR(skp); 869 sp->smk_root = skp; 870 transmute = true; 871 } 872 } 873 874 /* 875 * Initialize the root inode. 876 */ 877 init_inode_smack(inode, sp->smk_root); 878 879 if (transmute) { 880 isp = smack_inode(inode); 881 isp->smk_flags |= SMK_INODE_TRANSMUTE; 882 } 883 884 return 0; 885 } 886 887 /** 888 * smack_sb_statfs - Smack check on statfs 889 * @dentry: identifies the file system in question 890 * 891 * Returns 0 if current can read the floor of the filesystem, 892 * and error code otherwise 893 */ 894 static int smack_sb_statfs(struct dentry *dentry) 895 { 896 struct superblock_smack *sbp = smack_superblock(dentry->d_sb); 897 int rc; 898 struct smk_audit_info ad; 899 900 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); 901 smk_ad_setfield_u_fs_path_dentry(&ad, dentry); 902 903 rc = smk_curacc(sbp->smk_floor, MAY_READ, &ad); 904 rc = smk_bu_current("statfs", sbp->smk_floor, MAY_READ, rc); 905 return rc; 906 } 907 908 /* 909 * BPRM hooks 910 */ 911 912 /** 913 * smack_bprm_creds_for_exec - Update bprm->cred if needed for exec 914 * @bprm: the exec information 915 * 916 * Returns 0 if it gets a blob, -EPERM if exec forbidden and -ENOMEM otherwise 917 */ 918 static int smack_bprm_creds_for_exec(struct linux_binprm *bprm) 919 { 920 struct inode *inode = file_inode(bprm->file); 921 struct task_smack *bsp = smack_cred(bprm->cred); 922 struct inode_smack *isp; 923 struct superblock_smack *sbsp; 924 int rc; 925 926 isp = smack_inode(inode); 927 if (isp->smk_task == NULL || isp->smk_task == bsp->smk_task) 928 return 0; 929 930 sbsp = smack_superblock(inode->i_sb); 931 if ((sbsp->smk_flags & SMK_SB_UNTRUSTED) && 932 isp->smk_task != sbsp->smk_root) 933 return 0; 934 935 if (bprm->unsafe & LSM_UNSAFE_PTRACE) { 936 struct task_struct *tracer; 937 rc = 0; 938 939 rcu_read_lock(); 940 tracer = ptrace_parent(current); 941 if (likely(tracer != NULL)) 942 rc = smk_ptrace_rule_check(tracer, 943 isp->smk_task, 944 PTRACE_MODE_ATTACH, 945 __func__); 946 rcu_read_unlock(); 947 948 if (rc != 0) 949 return rc; 950 } 951 if (bprm->unsafe & ~LSM_UNSAFE_PTRACE) 952 return -EPERM; 953 954 bsp->smk_task = isp->smk_task; 955 bprm->per_clear |= PER_CLEAR_ON_SETID; 956 957 /* Decide if this is a secure exec. */ 958 if (bsp->smk_task != bsp->smk_forked) 959 bprm->secureexec = 1; 960 961 return 0; 962 } 963 964 /* 965 * Inode hooks 966 */ 967 968 /** 969 * smack_inode_alloc_security - allocate an inode blob 970 * @inode: the inode in need of a blob 971 * 972 * Returns 0 973 */ 974 static int smack_inode_alloc_security(struct inode *inode) 975 { 976 struct smack_known *skp = smk_of_current(); 977 978 init_inode_smack(inode, skp); 979 return 0; 980 } 981 982 /** 983 * smack_inode_init_security - copy out the smack from an inode 984 * @inode: the newly created inode 985 * @dir: containing directory object 986 * @qstr: unused 987 * @xattrs: where to put the attributes 988 * @xattr_count: current number of LSM-provided xattrs (updated) 989 * 990 * Returns 0 if it all works out, -ENOMEM if there's no memory 991 */ 992 static int smack_inode_init_security(struct inode *inode, struct inode *dir, 993 const struct qstr *qstr, 994 struct xattr *xattrs, int *xattr_count) 995 { 996 struct task_smack *tsp = smack_cred(current_cred()); 997 struct inode_smack *issp = smack_inode(inode); 998 struct smack_known *skp = smk_of_task(tsp); 999 struct smack_known *isp = smk_of_inode(inode); 1000 struct smack_known *dsp = smk_of_inode(dir); 1001 struct xattr *xattr = lsm_get_xattr_slot(xattrs, xattr_count); 1002 int may; 1003 1004 /* 1005 * If equal, transmuting already occurred in 1006 * smack_dentry_create_files_as(). No need to check again. 1007 */ 1008 if (tsp->smk_task != tsp->smk_transmuted) { 1009 rcu_read_lock(); 1010 may = smk_access_entry(skp->smk_known, dsp->smk_known, 1011 &skp->smk_rules); 1012 rcu_read_unlock(); 1013 } 1014 1015 /* 1016 * In addition to having smk_task equal to smk_transmuted, 1017 * if the access rule allows transmutation and the directory 1018 * requests transmutation then by all means transmute. 1019 * Mark the inode as changed. 1020 */ 1021 if ((tsp->smk_task == tsp->smk_transmuted) || 1022 (may > 0 && ((may & MAY_TRANSMUTE) != 0) && 1023 smk_inode_transmutable(dir))) { 1024 struct xattr *xattr_transmute; 1025 1026 /* 1027 * The caller of smack_dentry_create_files_as() 1028 * should have overridden the current cred, so the 1029 * inode label was already set correctly in 1030 * smack_inode_alloc_security(). 1031 */ 1032 if (tsp->smk_task != tsp->smk_transmuted) 1033 isp = issp->smk_inode = dsp; 1034 1035 issp->smk_flags |= SMK_INODE_TRANSMUTE; 1036 xattr_transmute = lsm_get_xattr_slot(xattrs, 1037 xattr_count); 1038 if (xattr_transmute) { 1039 xattr_transmute->value = kmemdup(TRANS_TRUE, 1040 TRANS_TRUE_SIZE, 1041 GFP_NOFS); 1042 if (!xattr_transmute->value) 1043 return -ENOMEM; 1044 1045 xattr_transmute->value_len = TRANS_TRUE_SIZE; 1046 xattr_transmute->name = XATTR_SMACK_TRANSMUTE; 1047 } 1048 } 1049 1050 issp->smk_flags |= SMK_INODE_INSTANT; 1051 1052 if (xattr) { 1053 xattr->value = kstrdup(isp->smk_known, GFP_NOFS); 1054 if (!xattr->value) 1055 return -ENOMEM; 1056 1057 xattr->value_len = strlen(isp->smk_known); 1058 xattr->name = XATTR_SMACK_SUFFIX; 1059 } 1060 1061 return 0; 1062 } 1063 1064 /** 1065 * smack_inode_link - Smack check on link 1066 * @old_dentry: the existing object 1067 * @dir: unused 1068 * @new_dentry: the new object 1069 * 1070 * Returns 0 if access is permitted, an error code otherwise 1071 */ 1072 static int smack_inode_link(struct dentry *old_dentry, struct inode *dir, 1073 struct dentry *new_dentry) 1074 { 1075 struct smack_known *isp; 1076 struct smk_audit_info ad; 1077 int rc; 1078 1079 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); 1080 smk_ad_setfield_u_fs_path_dentry(&ad, old_dentry); 1081 1082 isp = smk_of_inode(d_backing_inode(old_dentry)); 1083 rc = smk_curacc(isp, MAY_WRITE, &ad); 1084 rc = smk_bu_inode(d_backing_inode(old_dentry), MAY_WRITE, rc); 1085 1086 if (rc == 0 && d_is_positive(new_dentry)) { 1087 isp = smk_of_inode(d_backing_inode(new_dentry)); 1088 smk_ad_setfield_u_fs_path_dentry(&ad, new_dentry); 1089 rc = smk_curacc(isp, MAY_WRITE, &ad); 1090 rc = smk_bu_inode(d_backing_inode(new_dentry), MAY_WRITE, rc); 1091 } 1092 1093 return rc; 1094 } 1095 1096 /** 1097 * smack_inode_unlink - Smack check on inode deletion 1098 * @dir: containing directory object 1099 * @dentry: file to unlink 1100 * 1101 * Returns 0 if current can write the containing directory 1102 * and the object, error code otherwise 1103 */ 1104 static int smack_inode_unlink(struct inode *dir, struct dentry *dentry) 1105 { 1106 struct inode *ip = d_backing_inode(dentry); 1107 struct smk_audit_info ad; 1108 int rc; 1109 1110 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); 1111 smk_ad_setfield_u_fs_path_dentry(&ad, dentry); 1112 1113 /* 1114 * You need write access to the thing you're unlinking 1115 */ 1116 rc = smk_curacc(smk_of_inode(ip), MAY_WRITE, &ad); 1117 rc = smk_bu_inode(ip, MAY_WRITE, rc); 1118 if (rc == 0) { 1119 /* 1120 * You also need write access to the containing directory 1121 */ 1122 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_INODE); 1123 smk_ad_setfield_u_fs_inode(&ad, dir); 1124 rc = smk_curacc(smk_of_inode(dir), MAY_WRITE, &ad); 1125 rc = smk_bu_inode(dir, MAY_WRITE, rc); 1126 } 1127 return rc; 1128 } 1129 1130 /** 1131 * smack_inode_rmdir - Smack check on directory deletion 1132 * @dir: containing directory object 1133 * @dentry: directory to unlink 1134 * 1135 * Returns 0 if current can write the containing directory 1136 * and the directory, error code otherwise 1137 */ 1138 static int smack_inode_rmdir(struct inode *dir, struct dentry *dentry) 1139 { 1140 struct smk_audit_info ad; 1141 int rc; 1142 1143 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); 1144 smk_ad_setfield_u_fs_path_dentry(&ad, dentry); 1145 1146 /* 1147 * You need write access to the thing you're removing 1148 */ 1149 rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_WRITE, &ad); 1150 rc = smk_bu_inode(d_backing_inode(dentry), MAY_WRITE, rc); 1151 if (rc == 0) { 1152 /* 1153 * You also need write access to the containing directory 1154 */ 1155 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_INODE); 1156 smk_ad_setfield_u_fs_inode(&ad, dir); 1157 rc = smk_curacc(smk_of_inode(dir), MAY_WRITE, &ad); 1158 rc = smk_bu_inode(dir, MAY_WRITE, rc); 1159 } 1160 1161 return rc; 1162 } 1163 1164 /** 1165 * smack_inode_rename - Smack check on rename 1166 * @old_inode: unused 1167 * @old_dentry: the old object 1168 * @new_inode: unused 1169 * @new_dentry: the new object 1170 * 1171 * Read and write access is required on both the old and 1172 * new directories. 1173 * 1174 * Returns 0 if access is permitted, an error code otherwise 1175 */ 1176 static int smack_inode_rename(struct inode *old_inode, 1177 struct dentry *old_dentry, 1178 struct inode *new_inode, 1179 struct dentry *new_dentry) 1180 { 1181 int rc; 1182 struct smack_known *isp; 1183 struct smk_audit_info ad; 1184 1185 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); 1186 smk_ad_setfield_u_fs_path_dentry(&ad, old_dentry); 1187 1188 isp = smk_of_inode(d_backing_inode(old_dentry)); 1189 rc = smk_curacc(isp, MAY_READWRITE, &ad); 1190 rc = smk_bu_inode(d_backing_inode(old_dentry), MAY_READWRITE, rc); 1191 1192 if (rc == 0 && d_is_positive(new_dentry)) { 1193 isp = smk_of_inode(d_backing_inode(new_dentry)); 1194 smk_ad_setfield_u_fs_path_dentry(&ad, new_dentry); 1195 rc = smk_curacc(isp, MAY_READWRITE, &ad); 1196 rc = smk_bu_inode(d_backing_inode(new_dentry), MAY_READWRITE, rc); 1197 } 1198 return rc; 1199 } 1200 1201 /** 1202 * smack_inode_permission - Smack version of permission() 1203 * @inode: the inode in question 1204 * @mask: the access requested 1205 * 1206 * This is the important Smack hook. 1207 * 1208 * Returns 0 if access is permitted, an error code otherwise 1209 */ 1210 static int smack_inode_permission(struct inode *inode, int mask) 1211 { 1212 struct superblock_smack *sbsp = smack_superblock(inode->i_sb); 1213 struct smk_audit_info ad; 1214 int no_block = mask & MAY_NOT_BLOCK; 1215 int rc; 1216 1217 mask &= (MAY_READ|MAY_WRITE|MAY_EXEC|MAY_APPEND); 1218 /* 1219 * No permission to check. Existence test. Yup, it's there. 1220 */ 1221 if (mask == 0) 1222 return 0; 1223 1224 if (sbsp->smk_flags & SMK_SB_UNTRUSTED) { 1225 if (smk_of_inode(inode) != sbsp->smk_root) 1226 return -EACCES; 1227 } 1228 1229 /* May be droppable after audit */ 1230 if (no_block) 1231 return -ECHILD; 1232 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_INODE); 1233 smk_ad_setfield_u_fs_inode(&ad, inode); 1234 rc = smk_curacc(smk_of_inode(inode), mask, &ad); 1235 rc = smk_bu_inode(inode, mask, rc); 1236 return rc; 1237 } 1238 1239 /** 1240 * smack_inode_setattr - Smack check for setting attributes 1241 * @idmap: idmap of the mount 1242 * @dentry: the object 1243 * @iattr: for the force flag 1244 * 1245 * Returns 0 if access is permitted, an error code otherwise 1246 */ 1247 static int smack_inode_setattr(struct mnt_idmap *idmap, struct dentry *dentry, 1248 struct iattr *iattr) 1249 { 1250 struct smk_audit_info ad; 1251 int rc; 1252 1253 /* 1254 * Need to allow for clearing the setuid bit. 1255 */ 1256 if (iattr->ia_valid & ATTR_FORCE) 1257 return 0; 1258 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); 1259 smk_ad_setfield_u_fs_path_dentry(&ad, dentry); 1260 1261 rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_WRITE, &ad); 1262 rc = smk_bu_inode(d_backing_inode(dentry), MAY_WRITE, rc); 1263 return rc; 1264 } 1265 1266 /** 1267 * smack_inode_getattr - Smack check for getting attributes 1268 * @path: path to extract the info from 1269 * 1270 * Returns 0 if access is permitted, an error code otherwise 1271 */ 1272 static int smack_inode_getattr(const struct path *path) 1273 { 1274 struct smk_audit_info ad; 1275 struct inode *inode = d_backing_inode(path->dentry); 1276 int rc; 1277 1278 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH); 1279 smk_ad_setfield_u_fs_path(&ad, *path); 1280 rc = smk_curacc(smk_of_inode(inode), MAY_READ, &ad); 1281 rc = smk_bu_inode(inode, MAY_READ, rc); 1282 return rc; 1283 } 1284 1285 /** 1286 * smack_inode_xattr_skipcap - Skip the xattr capability checks? 1287 * @name: name of the xattr 1288 * 1289 * Returns 1 to indicate that Smack "owns" the access control rights to xattrs 1290 * named @name; the LSM layer should avoid enforcing any traditional 1291 * capability based access controls on this xattr. Returns 0 to indicate that 1292 * Smack does not "own" the access control rights to xattrs named @name and is 1293 * deferring to the LSM layer for further access controls, including capability 1294 * based controls. 1295 */ 1296 static int smack_inode_xattr_skipcap(const char *name) 1297 { 1298 if (strncmp(name, XATTR_SMACK_SUFFIX, strlen(XATTR_SMACK_SUFFIX))) 1299 return 0; 1300 1301 if (strcmp(name, XATTR_NAME_SMACK) == 0 || 1302 strcmp(name, XATTR_NAME_SMACKIPIN) == 0 || 1303 strcmp(name, XATTR_NAME_SMACKIPOUT) == 0 || 1304 strcmp(name, XATTR_NAME_SMACKEXEC) == 0 || 1305 strcmp(name, XATTR_NAME_SMACKMMAP) == 0 || 1306 strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0) 1307 return 1; 1308 1309 return 0; 1310 } 1311 1312 /** 1313 * smack_inode_setxattr - Smack check for setting xattrs 1314 * @idmap: idmap of the mount 1315 * @dentry: the object 1316 * @name: name of the attribute 1317 * @value: value of the attribute 1318 * @size: size of the value 1319 * @flags: unused 1320 * 1321 * This protects the Smack attribute explicitly. 1322 * 1323 * Returns 0 if access is permitted, an error code otherwise 1324 */ 1325 static int smack_inode_setxattr(struct mnt_idmap *idmap, 1326 struct dentry *dentry, const char *name, 1327 const void *value, size_t size, int flags) 1328 { 1329 struct smk_audit_info ad; 1330 struct smack_known *skp; 1331 int check_priv = 0; 1332 int check_import = 0; 1333 int check_star = 0; 1334 int rc = 0; 1335 1336 /* 1337 * Check label validity here so import won't fail in post_setxattr 1338 */ 1339 if (strcmp(name, XATTR_NAME_SMACK) == 0 || 1340 strcmp(name, XATTR_NAME_SMACKIPIN) == 0 || 1341 strcmp(name, XATTR_NAME_SMACKIPOUT) == 0) { 1342 check_priv = 1; 1343 check_import = 1; 1344 } else if (strcmp(name, XATTR_NAME_SMACKEXEC) == 0 || 1345 strcmp(name, XATTR_NAME_SMACKMMAP) == 0) { 1346 check_priv = 1; 1347 check_import = 1; 1348 check_star = 1; 1349 } else if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0) { 1350 check_priv = 1; 1351 if (!S_ISDIR(d_backing_inode(dentry)->i_mode) || 1352 size != TRANS_TRUE_SIZE || 1353 strncmp(value, TRANS_TRUE, TRANS_TRUE_SIZE) != 0) 1354 rc = -EINVAL; 1355 } 1356 1357 if (check_priv && !smack_privileged(CAP_MAC_ADMIN)) 1358 rc = -EPERM; 1359 1360 if (rc == 0 && check_import) { 1361 skp = size ? smk_import_entry(value, size) : NULL; 1362 if (IS_ERR(skp)) 1363 rc = PTR_ERR(skp); 1364 else if (skp == NULL || (check_star && 1365 (skp == &smack_known_star || skp == &smack_known_web))) 1366 rc = -EINVAL; 1367 } 1368 1369 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); 1370 smk_ad_setfield_u_fs_path_dentry(&ad, dentry); 1371 1372 if (rc == 0) { 1373 rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_WRITE, &ad); 1374 rc = smk_bu_inode(d_backing_inode(dentry), MAY_WRITE, rc); 1375 } 1376 1377 return rc; 1378 } 1379 1380 /** 1381 * smack_inode_post_setxattr - Apply the Smack update approved above 1382 * @dentry: object 1383 * @name: attribute name 1384 * @value: attribute value 1385 * @size: attribute size 1386 * @flags: unused 1387 * 1388 * Set the pointer in the inode blob to the entry found 1389 * in the master label list. 1390 */ 1391 static void smack_inode_post_setxattr(struct dentry *dentry, const char *name, 1392 const void *value, size_t size, int flags) 1393 { 1394 struct smack_known *skp; 1395 struct inode_smack *isp = smack_inode(d_backing_inode(dentry)); 1396 1397 if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0) { 1398 isp->smk_flags |= SMK_INODE_TRANSMUTE; 1399 return; 1400 } 1401 1402 if (strcmp(name, XATTR_NAME_SMACK) == 0) { 1403 skp = smk_import_entry(value, size); 1404 if (!IS_ERR(skp)) 1405 isp->smk_inode = skp; 1406 } else if (strcmp(name, XATTR_NAME_SMACKEXEC) == 0) { 1407 skp = smk_import_entry(value, size); 1408 if (!IS_ERR(skp)) 1409 isp->smk_task = skp; 1410 } else if (strcmp(name, XATTR_NAME_SMACKMMAP) == 0) { 1411 skp = smk_import_entry(value, size); 1412 if (!IS_ERR(skp)) 1413 isp->smk_mmap = skp; 1414 } 1415 1416 return; 1417 } 1418 1419 /** 1420 * smack_inode_getxattr - Smack check on getxattr 1421 * @dentry: the object 1422 * @name: unused 1423 * 1424 * Returns 0 if access is permitted, an error code otherwise 1425 */ 1426 static int smack_inode_getxattr(struct dentry *dentry, const char *name) 1427 { 1428 struct smk_audit_info ad; 1429 int rc; 1430 1431 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); 1432 smk_ad_setfield_u_fs_path_dentry(&ad, dentry); 1433 1434 rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_READ, &ad); 1435 rc = smk_bu_inode(d_backing_inode(dentry), MAY_READ, rc); 1436 return rc; 1437 } 1438 1439 /** 1440 * smack_inode_removexattr - Smack check on removexattr 1441 * @idmap: idmap of the mount 1442 * @dentry: the object 1443 * @name: name of the attribute 1444 * 1445 * Removing the Smack attribute requires CAP_MAC_ADMIN 1446 * 1447 * Returns 0 if access is permitted, an error code otherwise 1448 */ 1449 static int smack_inode_removexattr(struct mnt_idmap *idmap, 1450 struct dentry *dentry, const char *name) 1451 { 1452 struct inode_smack *isp; 1453 struct smk_audit_info ad; 1454 int rc = 0; 1455 1456 if (strcmp(name, XATTR_NAME_SMACK) == 0 || 1457 strcmp(name, XATTR_NAME_SMACKIPIN) == 0 || 1458 strcmp(name, XATTR_NAME_SMACKIPOUT) == 0 || 1459 strcmp(name, XATTR_NAME_SMACKEXEC) == 0 || 1460 strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0 || 1461 strcmp(name, XATTR_NAME_SMACKMMAP) == 0) { 1462 if (!smack_privileged(CAP_MAC_ADMIN)) 1463 rc = -EPERM; 1464 } 1465 1466 if (rc != 0) 1467 return rc; 1468 1469 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); 1470 smk_ad_setfield_u_fs_path_dentry(&ad, dentry); 1471 1472 rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_WRITE, &ad); 1473 rc = smk_bu_inode(d_backing_inode(dentry), MAY_WRITE, rc); 1474 if (rc != 0) 1475 return rc; 1476 1477 isp = smack_inode(d_backing_inode(dentry)); 1478 /* 1479 * Don't do anything special for these. 1480 * XATTR_NAME_SMACKIPIN 1481 * XATTR_NAME_SMACKIPOUT 1482 */ 1483 if (strcmp(name, XATTR_NAME_SMACK) == 0) { 1484 struct super_block *sbp = dentry->d_sb; 1485 struct superblock_smack *sbsp = smack_superblock(sbp); 1486 1487 isp->smk_inode = sbsp->smk_default; 1488 } else if (strcmp(name, XATTR_NAME_SMACKEXEC) == 0) 1489 isp->smk_task = NULL; 1490 else if (strcmp(name, XATTR_NAME_SMACKMMAP) == 0) 1491 isp->smk_mmap = NULL; 1492 else if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0) 1493 isp->smk_flags &= ~SMK_INODE_TRANSMUTE; 1494 1495 return 0; 1496 } 1497 1498 /** 1499 * smack_inode_set_acl - Smack check for setting posix acls 1500 * @idmap: idmap of the mnt this request came from 1501 * @dentry: the object 1502 * @acl_name: name of the posix acl 1503 * @kacl: the posix acls 1504 * 1505 * Returns 0 if access is permitted, an error code otherwise 1506 */ 1507 static int smack_inode_set_acl(struct mnt_idmap *idmap, 1508 struct dentry *dentry, const char *acl_name, 1509 struct posix_acl *kacl) 1510 { 1511 struct smk_audit_info ad; 1512 int rc; 1513 1514 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); 1515 smk_ad_setfield_u_fs_path_dentry(&ad, dentry); 1516 1517 rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_WRITE, &ad); 1518 rc = smk_bu_inode(d_backing_inode(dentry), MAY_WRITE, rc); 1519 return rc; 1520 } 1521 1522 /** 1523 * smack_inode_get_acl - Smack check for getting posix acls 1524 * @idmap: idmap of the mnt this request came from 1525 * @dentry: the object 1526 * @acl_name: name of the posix acl 1527 * 1528 * Returns 0 if access is permitted, an error code otherwise 1529 */ 1530 static int smack_inode_get_acl(struct mnt_idmap *idmap, 1531 struct dentry *dentry, const char *acl_name) 1532 { 1533 struct smk_audit_info ad; 1534 int rc; 1535 1536 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); 1537 smk_ad_setfield_u_fs_path_dentry(&ad, dentry); 1538 1539 rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_READ, &ad); 1540 rc = smk_bu_inode(d_backing_inode(dentry), MAY_READ, rc); 1541 return rc; 1542 } 1543 1544 /** 1545 * smack_inode_remove_acl - Smack check for getting posix acls 1546 * @idmap: idmap of the mnt this request came from 1547 * @dentry: the object 1548 * @acl_name: name of the posix acl 1549 * 1550 * Returns 0 if access is permitted, an error code otherwise 1551 */ 1552 static int smack_inode_remove_acl(struct mnt_idmap *idmap, 1553 struct dentry *dentry, const char *acl_name) 1554 { 1555 struct smk_audit_info ad; 1556 int rc; 1557 1558 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); 1559 smk_ad_setfield_u_fs_path_dentry(&ad, dentry); 1560 1561 rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_WRITE, &ad); 1562 rc = smk_bu_inode(d_backing_inode(dentry), MAY_WRITE, rc); 1563 return rc; 1564 } 1565 1566 /** 1567 * smack_inode_getsecurity - get smack xattrs 1568 * @idmap: idmap of the mount 1569 * @inode: the object 1570 * @name: attribute name 1571 * @buffer: where to put the result 1572 * @alloc: duplicate memory 1573 * 1574 * Returns the size of the attribute or an error code 1575 */ 1576 static int smack_inode_getsecurity(struct mnt_idmap *idmap, 1577 struct inode *inode, const char *name, 1578 void **buffer, bool alloc) 1579 { 1580 struct socket_smack *ssp; 1581 struct socket *sock; 1582 struct super_block *sbp; 1583 struct inode *ip = inode; 1584 struct smack_known *isp; 1585 struct inode_smack *ispp; 1586 size_t label_len; 1587 char *label = NULL; 1588 1589 if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) { 1590 isp = smk_of_inode(inode); 1591 } else if (strcmp(name, XATTR_SMACK_TRANSMUTE) == 0) { 1592 ispp = smack_inode(inode); 1593 if (ispp->smk_flags & SMK_INODE_TRANSMUTE) 1594 label = TRANS_TRUE; 1595 else 1596 label = ""; 1597 } else { 1598 /* 1599 * The rest of the Smack xattrs are only on sockets. 1600 */ 1601 sbp = ip->i_sb; 1602 if (sbp->s_magic != SOCKFS_MAGIC) 1603 return -EOPNOTSUPP; 1604 1605 sock = SOCKET_I(ip); 1606 if (sock == NULL || sock->sk == NULL) 1607 return -EOPNOTSUPP; 1608 1609 ssp = smack_sock(sock->sk); 1610 1611 if (strcmp(name, XATTR_SMACK_IPIN) == 0) 1612 isp = ssp->smk_in; 1613 else if (strcmp(name, XATTR_SMACK_IPOUT) == 0) 1614 isp = ssp->smk_out; 1615 else 1616 return -EOPNOTSUPP; 1617 } 1618 1619 if (!label) 1620 label = isp->smk_known; 1621 1622 label_len = strlen(label); 1623 1624 if (alloc) { 1625 *buffer = kstrdup(label, GFP_KERNEL); 1626 if (*buffer == NULL) 1627 return -ENOMEM; 1628 } 1629 1630 return label_len; 1631 } 1632 1633 1634 /** 1635 * smack_inode_listsecurity - list the Smack attributes 1636 * @inode: the object 1637 * @buffer: where they go 1638 * @buffer_size: size of buffer 1639 */ 1640 static int smack_inode_listsecurity(struct inode *inode, char *buffer, 1641 size_t buffer_size) 1642 { 1643 int len = sizeof(XATTR_NAME_SMACK); 1644 1645 if (buffer != NULL && len <= buffer_size) 1646 memcpy(buffer, XATTR_NAME_SMACK, len); 1647 1648 return len; 1649 } 1650 1651 /** 1652 * smack_inode_getsecid - Extract inode's security id 1653 * @inode: inode to extract the info from 1654 * @secid: where result will be saved 1655 */ 1656 static void smack_inode_getsecid(struct inode *inode, u32 *secid) 1657 { 1658 struct smack_known *skp = smk_of_inode(inode); 1659 1660 *secid = skp->smk_secid; 1661 } 1662 1663 /* 1664 * File Hooks 1665 */ 1666 1667 /* 1668 * There is no smack_file_permission hook 1669 * 1670 * Should access checks be done on each read or write? 1671 * UNICOS and SELinux say yes. 1672 * Trusted Solaris, Trusted Irix, and just about everyone else says no. 1673 * 1674 * I'll say no for now. Smack does not do the frequent 1675 * label changing that SELinux does. 1676 */ 1677 1678 /** 1679 * smack_file_alloc_security - assign a file security blob 1680 * @file: the object 1681 * 1682 * The security blob for a file is a pointer to the master 1683 * label list, so no allocation is done. 1684 * 1685 * f_security is the owner security information. It 1686 * isn't used on file access checks, it's for send_sigio. 1687 * 1688 * Returns 0 1689 */ 1690 static int smack_file_alloc_security(struct file *file) 1691 { 1692 struct smack_known **blob = smack_file(file); 1693 1694 *blob = smk_of_current(); 1695 return 0; 1696 } 1697 1698 /** 1699 * smack_file_ioctl - Smack check on ioctls 1700 * @file: the object 1701 * @cmd: what to do 1702 * @arg: unused 1703 * 1704 * Relies heavily on the correct use of the ioctl command conventions. 1705 * 1706 * Returns 0 if allowed, error code otherwise 1707 */ 1708 static int smack_file_ioctl(struct file *file, unsigned int cmd, 1709 unsigned long arg) 1710 { 1711 int rc = 0; 1712 struct smk_audit_info ad; 1713 struct inode *inode = file_inode(file); 1714 1715 if (unlikely(IS_PRIVATE(inode))) 1716 return 0; 1717 1718 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH); 1719 smk_ad_setfield_u_fs_path(&ad, file->f_path); 1720 1721 if (_IOC_DIR(cmd) & _IOC_WRITE) { 1722 rc = smk_curacc(smk_of_inode(inode), MAY_WRITE, &ad); 1723 rc = smk_bu_file(file, MAY_WRITE, rc); 1724 } 1725 1726 if (rc == 0 && (_IOC_DIR(cmd) & _IOC_READ)) { 1727 rc = smk_curacc(smk_of_inode(inode), MAY_READ, &ad); 1728 rc = smk_bu_file(file, MAY_READ, rc); 1729 } 1730 1731 return rc; 1732 } 1733 1734 /** 1735 * smack_file_lock - Smack check on file locking 1736 * @file: the object 1737 * @cmd: unused 1738 * 1739 * Returns 0 if current has lock access, error code otherwise 1740 */ 1741 static int smack_file_lock(struct file *file, unsigned int cmd) 1742 { 1743 struct smk_audit_info ad; 1744 int rc; 1745 struct inode *inode = file_inode(file); 1746 1747 if (unlikely(IS_PRIVATE(inode))) 1748 return 0; 1749 1750 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH); 1751 smk_ad_setfield_u_fs_path(&ad, file->f_path); 1752 rc = smk_curacc(smk_of_inode(inode), MAY_LOCK, &ad); 1753 rc = smk_bu_file(file, MAY_LOCK, rc); 1754 return rc; 1755 } 1756 1757 /** 1758 * smack_file_fcntl - Smack check on fcntl 1759 * @file: the object 1760 * @cmd: what action to check 1761 * @arg: unused 1762 * 1763 * Generally these operations are harmless. 1764 * File locking operations present an obvious mechanism 1765 * for passing information, so they require write access. 1766 * 1767 * Returns 0 if current has access, error code otherwise 1768 */ 1769 static int smack_file_fcntl(struct file *file, unsigned int cmd, 1770 unsigned long arg) 1771 { 1772 struct smk_audit_info ad; 1773 int rc = 0; 1774 struct inode *inode = file_inode(file); 1775 1776 if (unlikely(IS_PRIVATE(inode))) 1777 return 0; 1778 1779 switch (cmd) { 1780 case F_GETLK: 1781 break; 1782 case F_SETLK: 1783 case F_SETLKW: 1784 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH); 1785 smk_ad_setfield_u_fs_path(&ad, file->f_path); 1786 rc = smk_curacc(smk_of_inode(inode), MAY_LOCK, &ad); 1787 rc = smk_bu_file(file, MAY_LOCK, rc); 1788 break; 1789 case F_SETOWN: 1790 case F_SETSIG: 1791 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH); 1792 smk_ad_setfield_u_fs_path(&ad, file->f_path); 1793 rc = smk_curacc(smk_of_inode(inode), MAY_WRITE, &ad); 1794 rc = smk_bu_file(file, MAY_WRITE, rc); 1795 break; 1796 default: 1797 break; 1798 } 1799 1800 return rc; 1801 } 1802 1803 /** 1804 * smack_mmap_file - Check permissions for a mmap operation. 1805 * @file: contains the file structure for file to map (may be NULL). 1806 * @reqprot: contains the protection requested by the application. 1807 * @prot: contains the protection that will be applied by the kernel. 1808 * @flags: contains the operational flags. 1809 * 1810 * The @file may be NULL, e.g. if mapping anonymous memory. 1811 * 1812 * Return 0 if permission is granted. 1813 */ 1814 static int smack_mmap_file(struct file *file, 1815 unsigned long reqprot, unsigned long prot, 1816 unsigned long flags) 1817 { 1818 struct smack_known *skp; 1819 struct smack_known *mkp; 1820 struct smack_rule *srp; 1821 struct task_smack *tsp; 1822 struct smack_known *okp; 1823 struct inode_smack *isp; 1824 struct superblock_smack *sbsp; 1825 int may; 1826 int mmay; 1827 int tmay; 1828 int rc; 1829 1830 if (file == NULL) 1831 return 0; 1832 1833 if (unlikely(IS_PRIVATE(file_inode(file)))) 1834 return 0; 1835 1836 isp = smack_inode(file_inode(file)); 1837 if (isp->smk_mmap == NULL) 1838 return 0; 1839 sbsp = smack_superblock(file_inode(file)->i_sb); 1840 if (sbsp->smk_flags & SMK_SB_UNTRUSTED && 1841 isp->smk_mmap != sbsp->smk_root) 1842 return -EACCES; 1843 mkp = isp->smk_mmap; 1844 1845 tsp = smack_cred(current_cred()); 1846 skp = smk_of_current(); 1847 rc = 0; 1848 1849 rcu_read_lock(); 1850 /* 1851 * For each Smack rule associated with the subject 1852 * label verify that the SMACK64MMAP also has access 1853 * to that rule's object label. 1854 */ 1855 list_for_each_entry_rcu(srp, &skp->smk_rules, list) { 1856 okp = srp->smk_object; 1857 /* 1858 * Matching labels always allows access. 1859 */ 1860 if (mkp->smk_known == okp->smk_known) 1861 continue; 1862 /* 1863 * If there is a matching local rule take 1864 * that into account as well. 1865 */ 1866 may = smk_access_entry(srp->smk_subject->smk_known, 1867 okp->smk_known, 1868 &tsp->smk_rules); 1869 if (may == -ENOENT) 1870 may = srp->smk_access; 1871 else 1872 may &= srp->smk_access; 1873 /* 1874 * If may is zero the SMACK64MMAP subject can't 1875 * possibly have less access. 1876 */ 1877 if (may == 0) 1878 continue; 1879 1880 /* 1881 * Fetch the global list entry. 1882 * If there isn't one a SMACK64MMAP subject 1883 * can't have as much access as current. 1884 */ 1885 mmay = smk_access_entry(mkp->smk_known, okp->smk_known, 1886 &mkp->smk_rules); 1887 if (mmay == -ENOENT) { 1888 rc = -EACCES; 1889 break; 1890 } 1891 /* 1892 * If there is a local entry it modifies the 1893 * potential access, too. 1894 */ 1895 tmay = smk_access_entry(mkp->smk_known, okp->smk_known, 1896 &tsp->smk_rules); 1897 if (tmay != -ENOENT) 1898 mmay &= tmay; 1899 1900 /* 1901 * If there is any access available to current that is 1902 * not available to a SMACK64MMAP subject 1903 * deny access. 1904 */ 1905 if ((may | mmay) != mmay) { 1906 rc = -EACCES; 1907 break; 1908 } 1909 } 1910 1911 rcu_read_unlock(); 1912 1913 return rc; 1914 } 1915 1916 /** 1917 * smack_file_set_fowner - set the file security blob value 1918 * @file: object in question 1919 * 1920 */ 1921 static void smack_file_set_fowner(struct file *file) 1922 { 1923 struct smack_known **blob = smack_file(file); 1924 1925 *blob = smk_of_current(); 1926 } 1927 1928 /** 1929 * smack_file_send_sigiotask - Smack on sigio 1930 * @tsk: The target task 1931 * @fown: the object the signal come from 1932 * @signum: unused 1933 * 1934 * Allow a privileged task to get signals even if it shouldn't 1935 * 1936 * Returns 0 if a subject with the object's smack could 1937 * write to the task, an error code otherwise. 1938 */ 1939 static int smack_file_send_sigiotask(struct task_struct *tsk, 1940 struct fown_struct *fown, int signum) 1941 { 1942 struct smack_known **blob; 1943 struct smack_known *skp; 1944 struct smack_known *tkp = smk_of_task(smack_cred(tsk->cred)); 1945 const struct cred *tcred; 1946 struct file *file; 1947 int rc; 1948 struct smk_audit_info ad; 1949 1950 /* 1951 * struct fown_struct is never outside the context of a struct file 1952 */ 1953 file = fown->file; 1954 1955 /* we don't log here as rc can be overriden */ 1956 blob = smack_file(file); 1957 skp = *blob; 1958 rc = smk_access(skp, tkp, MAY_DELIVER, NULL); 1959 rc = smk_bu_note("sigiotask", skp, tkp, MAY_DELIVER, rc); 1960 1961 rcu_read_lock(); 1962 tcred = __task_cred(tsk); 1963 if (rc != 0 && smack_privileged_cred(CAP_MAC_OVERRIDE, tcred)) 1964 rc = 0; 1965 rcu_read_unlock(); 1966 1967 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK); 1968 smk_ad_setfield_u_tsk(&ad, tsk); 1969 smack_log(skp->smk_known, tkp->smk_known, MAY_DELIVER, rc, &ad); 1970 return rc; 1971 } 1972 1973 /** 1974 * smack_file_receive - Smack file receive check 1975 * @file: the object 1976 * 1977 * Returns 0 if current has access, error code otherwise 1978 */ 1979 static int smack_file_receive(struct file *file) 1980 { 1981 int rc; 1982 int may = 0; 1983 struct smk_audit_info ad; 1984 struct inode *inode = file_inode(file); 1985 struct socket *sock; 1986 struct task_smack *tsp; 1987 struct socket_smack *ssp; 1988 1989 if (unlikely(IS_PRIVATE(inode))) 1990 return 0; 1991 1992 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH); 1993 smk_ad_setfield_u_fs_path(&ad, file->f_path); 1994 1995 if (inode->i_sb->s_magic == SOCKFS_MAGIC) { 1996 sock = SOCKET_I(inode); 1997 ssp = smack_sock(sock->sk); 1998 tsp = smack_cred(current_cred()); 1999 /* 2000 * If the receiving process can't write to the 2001 * passed socket or if the passed socket can't 2002 * write to the receiving process don't accept 2003 * the passed socket. 2004 */ 2005 rc = smk_access(tsp->smk_task, ssp->smk_out, MAY_WRITE, &ad); 2006 rc = smk_bu_file(file, may, rc); 2007 if (rc < 0) 2008 return rc; 2009 rc = smk_access(ssp->smk_in, tsp->smk_task, MAY_WRITE, &ad); 2010 rc = smk_bu_file(file, may, rc); 2011 return rc; 2012 } 2013 /* 2014 * This code relies on bitmasks. 2015 */ 2016 if (file->f_mode & FMODE_READ) 2017 may = MAY_READ; 2018 if (file->f_mode & FMODE_WRITE) 2019 may |= MAY_WRITE; 2020 2021 rc = smk_curacc(smk_of_inode(inode), may, &ad); 2022 rc = smk_bu_file(file, may, rc); 2023 return rc; 2024 } 2025 2026 /** 2027 * smack_file_open - Smack dentry open processing 2028 * @file: the object 2029 * 2030 * Set the security blob in the file structure. 2031 * Allow the open only if the task has read access. There are 2032 * many read operations (e.g. fstat) that you can do with an 2033 * fd even if you have the file open write-only. 2034 * 2035 * Returns 0 if current has access, error code otherwise 2036 */ 2037 static int smack_file_open(struct file *file) 2038 { 2039 struct task_smack *tsp = smack_cred(file->f_cred); 2040 struct inode *inode = file_inode(file); 2041 struct smk_audit_info ad; 2042 int rc; 2043 2044 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH); 2045 smk_ad_setfield_u_fs_path(&ad, file->f_path); 2046 rc = smk_tskacc(tsp, smk_of_inode(inode), MAY_READ, &ad); 2047 rc = smk_bu_credfile(file->f_cred, file, MAY_READ, rc); 2048 2049 return rc; 2050 } 2051 2052 /* 2053 * Task hooks 2054 */ 2055 2056 /** 2057 * smack_cred_alloc_blank - "allocate" blank task-level security credentials 2058 * @cred: the new credentials 2059 * @gfp: the atomicity of any memory allocations 2060 * 2061 * Prepare a blank set of credentials for modification. This must allocate all 2062 * the memory the LSM module might require such that cred_transfer() can 2063 * complete without error. 2064 */ 2065 static int smack_cred_alloc_blank(struct cred *cred, gfp_t gfp) 2066 { 2067 init_task_smack(smack_cred(cred), NULL, NULL); 2068 return 0; 2069 } 2070 2071 2072 /** 2073 * smack_cred_free - "free" task-level security credentials 2074 * @cred: the credentials in question 2075 * 2076 */ 2077 static void smack_cred_free(struct cred *cred) 2078 { 2079 struct task_smack *tsp = smack_cred(cred); 2080 struct smack_rule *rp; 2081 struct list_head *l; 2082 struct list_head *n; 2083 2084 smk_destroy_label_list(&tsp->smk_relabel); 2085 2086 list_for_each_safe(l, n, &tsp->smk_rules) { 2087 rp = list_entry(l, struct smack_rule, list); 2088 list_del(&rp->list); 2089 kmem_cache_free(smack_rule_cache, rp); 2090 } 2091 } 2092 2093 /** 2094 * smack_cred_prepare - prepare new set of credentials for modification 2095 * @new: the new credentials 2096 * @old: the original credentials 2097 * @gfp: the atomicity of any memory allocations 2098 * 2099 * Prepare a new set of credentials for modification. 2100 */ 2101 static int smack_cred_prepare(struct cred *new, const struct cred *old, 2102 gfp_t gfp) 2103 { 2104 struct task_smack *old_tsp = smack_cred(old); 2105 struct task_smack *new_tsp = smack_cred(new); 2106 int rc; 2107 2108 init_task_smack(new_tsp, old_tsp->smk_task, old_tsp->smk_task); 2109 2110 rc = smk_copy_rules(&new_tsp->smk_rules, &old_tsp->smk_rules, gfp); 2111 if (rc != 0) 2112 return rc; 2113 2114 rc = smk_copy_relabel(&new_tsp->smk_relabel, &old_tsp->smk_relabel, 2115 gfp); 2116 return rc; 2117 } 2118 2119 /** 2120 * smack_cred_transfer - Transfer the old credentials to the new credentials 2121 * @new: the new credentials 2122 * @old: the original credentials 2123 * 2124 * Fill in a set of blank credentials from another set of credentials. 2125 */ 2126 static void smack_cred_transfer(struct cred *new, const struct cred *old) 2127 { 2128 struct task_smack *old_tsp = smack_cred(old); 2129 struct task_smack *new_tsp = smack_cred(new); 2130 2131 init_task_smack(new_tsp, old_tsp->smk_task, old_tsp->smk_task); 2132 } 2133 2134 /** 2135 * smack_cred_getsecid - get the secid corresponding to a creds structure 2136 * @cred: the object creds 2137 * @secid: where to put the result 2138 * 2139 * Sets the secid to contain a u32 version of the smack label. 2140 */ 2141 static void smack_cred_getsecid(const struct cred *cred, u32 *secid) 2142 { 2143 struct smack_known *skp; 2144 2145 rcu_read_lock(); 2146 skp = smk_of_task(smack_cred(cred)); 2147 *secid = skp->smk_secid; 2148 rcu_read_unlock(); 2149 } 2150 2151 /** 2152 * smack_kernel_act_as - Set the subjective context in a set of credentials 2153 * @new: points to the set of credentials to be modified. 2154 * @secid: specifies the security ID to be set 2155 * 2156 * Set the security data for a kernel service. 2157 */ 2158 static int smack_kernel_act_as(struct cred *new, u32 secid) 2159 { 2160 struct task_smack *new_tsp = smack_cred(new); 2161 2162 new_tsp->smk_task = smack_from_secid(secid); 2163 return 0; 2164 } 2165 2166 /** 2167 * smack_kernel_create_files_as - Set the file creation label in a set of creds 2168 * @new: points to the set of credentials to be modified 2169 * @inode: points to the inode to use as a reference 2170 * 2171 * Set the file creation context in a set of credentials to the same 2172 * as the objective context of the specified inode 2173 */ 2174 static int smack_kernel_create_files_as(struct cred *new, 2175 struct inode *inode) 2176 { 2177 struct inode_smack *isp = smack_inode(inode); 2178 struct task_smack *tsp = smack_cred(new); 2179 2180 tsp->smk_forked = isp->smk_inode; 2181 tsp->smk_task = tsp->smk_forked; 2182 return 0; 2183 } 2184 2185 /** 2186 * smk_curacc_on_task - helper to log task related access 2187 * @p: the task object 2188 * @access: the access requested 2189 * @caller: name of the calling function for audit 2190 * 2191 * Return 0 if access is permitted 2192 */ 2193 static int smk_curacc_on_task(struct task_struct *p, int access, 2194 const char *caller) 2195 { 2196 struct smk_audit_info ad; 2197 struct smack_known *skp = smk_of_task_struct_obj(p); 2198 int rc; 2199 2200 smk_ad_init(&ad, caller, LSM_AUDIT_DATA_TASK); 2201 smk_ad_setfield_u_tsk(&ad, p); 2202 rc = smk_curacc(skp, access, &ad); 2203 rc = smk_bu_task(p, access, rc); 2204 return rc; 2205 } 2206 2207 /** 2208 * smack_task_setpgid - Smack check on setting pgid 2209 * @p: the task object 2210 * @pgid: unused 2211 * 2212 * Return 0 if write access is permitted 2213 */ 2214 static int smack_task_setpgid(struct task_struct *p, pid_t pgid) 2215 { 2216 return smk_curacc_on_task(p, MAY_WRITE, __func__); 2217 } 2218 2219 /** 2220 * smack_task_getpgid - Smack access check for getpgid 2221 * @p: the object task 2222 * 2223 * Returns 0 if current can read the object task, error code otherwise 2224 */ 2225 static int smack_task_getpgid(struct task_struct *p) 2226 { 2227 return smk_curacc_on_task(p, MAY_READ, __func__); 2228 } 2229 2230 /** 2231 * smack_task_getsid - Smack access check for getsid 2232 * @p: the object task 2233 * 2234 * Returns 0 if current can read the object task, error code otherwise 2235 */ 2236 static int smack_task_getsid(struct task_struct *p) 2237 { 2238 return smk_curacc_on_task(p, MAY_READ, __func__); 2239 } 2240 2241 /** 2242 * smack_current_getsecid_subj - get the subjective secid of the current task 2243 * @secid: where to put the result 2244 * 2245 * Sets the secid to contain a u32 version of the task's subjective smack label. 2246 */ 2247 static void smack_current_getsecid_subj(u32 *secid) 2248 { 2249 struct smack_known *skp = smk_of_current(); 2250 2251 *secid = skp->smk_secid; 2252 } 2253 2254 /** 2255 * smack_task_getsecid_obj - get the objective secid of the task 2256 * @p: the task 2257 * @secid: where to put the result 2258 * 2259 * Sets the secid to contain a u32 version of the task's objective smack label. 2260 */ 2261 static void smack_task_getsecid_obj(struct task_struct *p, u32 *secid) 2262 { 2263 struct smack_known *skp = smk_of_task_struct_obj(p); 2264 2265 *secid = skp->smk_secid; 2266 } 2267 2268 /** 2269 * smack_task_setnice - Smack check on setting nice 2270 * @p: the task object 2271 * @nice: unused 2272 * 2273 * Return 0 if write access is permitted 2274 */ 2275 static int smack_task_setnice(struct task_struct *p, int nice) 2276 { 2277 return smk_curacc_on_task(p, MAY_WRITE, __func__); 2278 } 2279 2280 /** 2281 * smack_task_setioprio - Smack check on setting ioprio 2282 * @p: the task object 2283 * @ioprio: unused 2284 * 2285 * Return 0 if write access is permitted 2286 */ 2287 static int smack_task_setioprio(struct task_struct *p, int ioprio) 2288 { 2289 return smk_curacc_on_task(p, MAY_WRITE, __func__); 2290 } 2291 2292 /** 2293 * smack_task_getioprio - Smack check on reading ioprio 2294 * @p: the task object 2295 * 2296 * Return 0 if read access is permitted 2297 */ 2298 static int smack_task_getioprio(struct task_struct *p) 2299 { 2300 return smk_curacc_on_task(p, MAY_READ, __func__); 2301 } 2302 2303 /** 2304 * smack_task_setscheduler - Smack check on setting scheduler 2305 * @p: the task object 2306 * 2307 * Return 0 if read access is permitted 2308 */ 2309 static int smack_task_setscheduler(struct task_struct *p) 2310 { 2311 return smk_curacc_on_task(p, MAY_WRITE, __func__); 2312 } 2313 2314 /** 2315 * smack_task_getscheduler - Smack check on reading scheduler 2316 * @p: the task object 2317 * 2318 * Return 0 if read access is permitted 2319 */ 2320 static int smack_task_getscheduler(struct task_struct *p) 2321 { 2322 return smk_curacc_on_task(p, MAY_READ, __func__); 2323 } 2324 2325 /** 2326 * smack_task_movememory - Smack check on moving memory 2327 * @p: the task object 2328 * 2329 * Return 0 if write access is permitted 2330 */ 2331 static int smack_task_movememory(struct task_struct *p) 2332 { 2333 return smk_curacc_on_task(p, MAY_WRITE, __func__); 2334 } 2335 2336 /** 2337 * smack_task_kill - Smack check on signal delivery 2338 * @p: the task object 2339 * @info: unused 2340 * @sig: unused 2341 * @cred: identifies the cred to use in lieu of current's 2342 * 2343 * Return 0 if write access is permitted 2344 * 2345 */ 2346 static int smack_task_kill(struct task_struct *p, struct kernel_siginfo *info, 2347 int sig, const struct cred *cred) 2348 { 2349 struct smk_audit_info ad; 2350 struct smack_known *skp; 2351 struct smack_known *tkp = smk_of_task_struct_obj(p); 2352 int rc; 2353 2354 if (!sig) 2355 return 0; /* null signal; existence test */ 2356 2357 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK); 2358 smk_ad_setfield_u_tsk(&ad, p); 2359 /* 2360 * Sending a signal requires that the sender 2361 * can write the receiver. 2362 */ 2363 if (cred == NULL) { 2364 rc = smk_curacc(tkp, MAY_DELIVER, &ad); 2365 rc = smk_bu_task(p, MAY_DELIVER, rc); 2366 return rc; 2367 } 2368 /* 2369 * If the cred isn't NULL we're dealing with some USB IO 2370 * specific behavior. This is not clean. For one thing 2371 * we can't take privilege into account. 2372 */ 2373 skp = smk_of_task(smack_cred(cred)); 2374 rc = smk_access(skp, tkp, MAY_DELIVER, &ad); 2375 rc = smk_bu_note("USB signal", skp, tkp, MAY_DELIVER, rc); 2376 return rc; 2377 } 2378 2379 /** 2380 * smack_task_to_inode - copy task smack into the inode blob 2381 * @p: task to copy from 2382 * @inode: inode to copy to 2383 * 2384 * Sets the smack pointer in the inode security blob 2385 */ 2386 static void smack_task_to_inode(struct task_struct *p, struct inode *inode) 2387 { 2388 struct inode_smack *isp = smack_inode(inode); 2389 struct smack_known *skp = smk_of_task_struct_obj(p); 2390 2391 isp->smk_inode = skp; 2392 isp->smk_flags |= SMK_INODE_INSTANT; 2393 } 2394 2395 /* 2396 * Socket hooks. 2397 */ 2398 2399 /** 2400 * smack_sk_alloc_security - Allocate a socket blob 2401 * @sk: the socket 2402 * @family: unused 2403 * @gfp_flags: memory allocation flags 2404 * 2405 * Assign Smack pointers to current 2406 * 2407 * Returns 0 on success, -ENOMEM is there's no memory 2408 */ 2409 static int smack_sk_alloc_security(struct sock *sk, int family, gfp_t gfp_flags) 2410 { 2411 struct smack_known *skp = smk_of_current(); 2412 struct socket_smack *ssp = smack_sock(sk); 2413 2414 /* 2415 * Sockets created by kernel threads receive web label. 2416 */ 2417 if (unlikely(current->flags & PF_KTHREAD)) { 2418 ssp->smk_in = &smack_known_web; 2419 ssp->smk_out = &smack_known_web; 2420 } else { 2421 ssp->smk_in = skp; 2422 ssp->smk_out = skp; 2423 } 2424 ssp->smk_packet = NULL; 2425 2426 return 0; 2427 } 2428 2429 #ifdef SMACK_IPV6_PORT_LABELING 2430 /** 2431 * smack_sk_free_security - Free a socket blob 2432 * @sk: the socket 2433 * 2434 * Clears the blob pointer 2435 */ 2436 static void smack_sk_free_security(struct sock *sk) 2437 { 2438 struct smk_port_label *spp; 2439 2440 if (sk->sk_family == PF_INET6) { 2441 rcu_read_lock(); 2442 list_for_each_entry_rcu(spp, &smk_ipv6_port_list, list) { 2443 if (spp->smk_sock != sk) 2444 continue; 2445 spp->smk_can_reuse = 1; 2446 break; 2447 } 2448 rcu_read_unlock(); 2449 } 2450 } 2451 #endif 2452 2453 /** 2454 * smack_sk_clone_security - Copy security context 2455 * @sk: the old socket 2456 * @newsk: the new socket 2457 * 2458 * Copy the security context of the old socket pointer to the cloned 2459 */ 2460 static void smack_sk_clone_security(const struct sock *sk, struct sock *newsk) 2461 { 2462 struct socket_smack *ssp_old = smack_sock(sk); 2463 struct socket_smack *ssp_new = smack_sock(newsk); 2464 2465 *ssp_new = *ssp_old; 2466 } 2467 2468 /** 2469 * smack_ipv4host_label - check host based restrictions 2470 * @sip: the object end 2471 * 2472 * looks for host based access restrictions 2473 * 2474 * This version will only be appropriate for really small sets of single label 2475 * hosts. The caller is responsible for ensuring that the RCU read lock is 2476 * taken before calling this function. 2477 * 2478 * Returns the label of the far end or NULL if it's not special. 2479 */ 2480 static struct smack_known *smack_ipv4host_label(struct sockaddr_in *sip) 2481 { 2482 struct smk_net4addr *snp; 2483 struct in_addr *siap = &sip->sin_addr; 2484 2485 if (siap->s_addr == 0) 2486 return NULL; 2487 2488 list_for_each_entry_rcu(snp, &smk_net4addr_list, list) 2489 /* 2490 * we break after finding the first match because 2491 * the list is sorted from longest to shortest mask 2492 * so we have found the most specific match 2493 */ 2494 if (snp->smk_host.s_addr == 2495 (siap->s_addr & snp->smk_mask.s_addr)) 2496 return snp->smk_label; 2497 2498 return NULL; 2499 } 2500 2501 /* 2502 * smk_ipv6_localhost - Check for local ipv6 host address 2503 * @sip: the address 2504 * 2505 * Returns boolean true if this is the localhost address 2506 */ 2507 static bool smk_ipv6_localhost(struct sockaddr_in6 *sip) 2508 { 2509 __be16 *be16p = (__be16 *)&sip->sin6_addr; 2510 __be32 *be32p = (__be32 *)&sip->sin6_addr; 2511 2512 if (be32p[0] == 0 && be32p[1] == 0 && be32p[2] == 0 && be16p[6] == 0 && 2513 ntohs(be16p[7]) == 1) 2514 return true; 2515 return false; 2516 } 2517 2518 /** 2519 * smack_ipv6host_label - check host based restrictions 2520 * @sip: the object end 2521 * 2522 * looks for host based access restrictions 2523 * 2524 * This version will only be appropriate for really small sets of single label 2525 * hosts. The caller is responsible for ensuring that the RCU read lock is 2526 * taken before calling this function. 2527 * 2528 * Returns the label of the far end or NULL if it's not special. 2529 */ 2530 static struct smack_known *smack_ipv6host_label(struct sockaddr_in6 *sip) 2531 { 2532 struct smk_net6addr *snp; 2533 struct in6_addr *sap = &sip->sin6_addr; 2534 int i; 2535 int found = 0; 2536 2537 /* 2538 * It's local. Don't look for a host label. 2539 */ 2540 if (smk_ipv6_localhost(sip)) 2541 return NULL; 2542 2543 list_for_each_entry_rcu(snp, &smk_net6addr_list, list) { 2544 /* 2545 * If the label is NULL the entry has 2546 * been renounced. Ignore it. 2547 */ 2548 if (snp->smk_label == NULL) 2549 continue; 2550 /* 2551 * we break after finding the first match because 2552 * the list is sorted from longest to shortest mask 2553 * so we have found the most specific match 2554 */ 2555 for (found = 1, i = 0; i < 8; i++) { 2556 if ((sap->s6_addr16[i] & snp->smk_mask.s6_addr16[i]) != 2557 snp->smk_host.s6_addr16[i]) { 2558 found = 0; 2559 break; 2560 } 2561 } 2562 if (found) 2563 return snp->smk_label; 2564 } 2565 2566 return NULL; 2567 } 2568 2569 /** 2570 * smack_netlbl_add - Set the secattr on a socket 2571 * @sk: the socket 2572 * 2573 * Attach the outbound smack value (smk_out) to the socket. 2574 * 2575 * Returns 0 on success or an error code 2576 */ 2577 static int smack_netlbl_add(struct sock *sk) 2578 { 2579 struct socket_smack *ssp = smack_sock(sk); 2580 struct smack_known *skp = ssp->smk_out; 2581 int rc; 2582 2583 local_bh_disable(); 2584 bh_lock_sock_nested(sk); 2585 2586 rc = netlbl_sock_setattr(sk, sk->sk_family, &skp->smk_netlabel, 2587 netlbl_sk_lock_check(sk)); 2588 switch (rc) { 2589 case 0: 2590 ssp->smk_state = SMK_NETLBL_LABELED; 2591 break; 2592 case -EDESTADDRREQ: 2593 ssp->smk_state = SMK_NETLBL_REQSKB; 2594 rc = 0; 2595 break; 2596 } 2597 2598 bh_unlock_sock(sk); 2599 local_bh_enable(); 2600 2601 return rc; 2602 } 2603 2604 /** 2605 * smack_netlbl_delete - Remove the secattr from a socket 2606 * @sk: the socket 2607 * 2608 * Remove the outbound smack value from a socket 2609 */ 2610 static void smack_netlbl_delete(struct sock *sk) 2611 { 2612 struct socket_smack *ssp = smack_sock(sk); 2613 2614 /* 2615 * Take the label off the socket if one is set. 2616 */ 2617 if (ssp->smk_state != SMK_NETLBL_LABELED) 2618 return; 2619 2620 local_bh_disable(); 2621 bh_lock_sock_nested(sk); 2622 netlbl_sock_delattr(sk); 2623 bh_unlock_sock(sk); 2624 local_bh_enable(); 2625 ssp->smk_state = SMK_NETLBL_UNLABELED; 2626 } 2627 2628 /** 2629 * smk_ipv4_check - Perform IPv4 host access checks 2630 * @sk: the socket 2631 * @sap: the destination address 2632 * 2633 * Set the correct secattr for the given socket based on the destination 2634 * address and perform any outbound access checks needed. 2635 * 2636 * Returns 0 on success or an error code. 2637 * 2638 */ 2639 static int smk_ipv4_check(struct sock *sk, struct sockaddr_in *sap) 2640 { 2641 struct smack_known *skp; 2642 int rc = 0; 2643 struct smack_known *hkp; 2644 struct socket_smack *ssp = smack_sock(sk); 2645 struct smk_audit_info ad; 2646 2647 rcu_read_lock(); 2648 hkp = smack_ipv4host_label(sap); 2649 if (hkp != NULL) { 2650 #ifdef CONFIG_AUDIT 2651 struct lsm_network_audit net; 2652 2653 smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net); 2654 ad.a.u.net->family = sap->sin_family; 2655 ad.a.u.net->dport = sap->sin_port; 2656 ad.a.u.net->v4info.daddr = sap->sin_addr.s_addr; 2657 #endif 2658 skp = ssp->smk_out; 2659 rc = smk_access(skp, hkp, MAY_WRITE, &ad); 2660 rc = smk_bu_note("IPv4 host check", skp, hkp, MAY_WRITE, rc); 2661 /* 2662 * Clear the socket netlabel if it's set. 2663 */ 2664 if (!rc) 2665 smack_netlbl_delete(sk); 2666 } 2667 rcu_read_unlock(); 2668 2669 return rc; 2670 } 2671 2672 /** 2673 * smk_ipv6_check - check Smack access 2674 * @subject: subject Smack label 2675 * @object: object Smack label 2676 * @address: address 2677 * @act: the action being taken 2678 * 2679 * Check an IPv6 access 2680 */ 2681 static int smk_ipv6_check(struct smack_known *subject, 2682 struct smack_known *object, 2683 struct sockaddr_in6 *address, int act) 2684 { 2685 #ifdef CONFIG_AUDIT 2686 struct lsm_network_audit net; 2687 #endif 2688 struct smk_audit_info ad; 2689 int rc; 2690 2691 #ifdef CONFIG_AUDIT 2692 smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net); 2693 ad.a.u.net->family = PF_INET6; 2694 ad.a.u.net->dport = address->sin6_port; 2695 if (act == SMK_RECEIVING) 2696 ad.a.u.net->v6info.saddr = address->sin6_addr; 2697 else 2698 ad.a.u.net->v6info.daddr = address->sin6_addr; 2699 #endif 2700 rc = smk_access(subject, object, MAY_WRITE, &ad); 2701 rc = smk_bu_note("IPv6 check", subject, object, MAY_WRITE, rc); 2702 return rc; 2703 } 2704 2705 #ifdef SMACK_IPV6_PORT_LABELING 2706 /** 2707 * smk_ipv6_port_label - Smack port access table management 2708 * @sock: socket 2709 * @address: address 2710 * 2711 * Create or update the port list entry 2712 */ 2713 static void smk_ipv6_port_label(struct socket *sock, struct sockaddr *address) 2714 { 2715 struct sock *sk = sock->sk; 2716 struct sockaddr_in6 *addr6; 2717 struct socket_smack *ssp = smack_sock(sock->sk); 2718 struct smk_port_label *spp; 2719 unsigned short port = 0; 2720 2721 if (address == NULL) { 2722 /* 2723 * This operation is changing the Smack information 2724 * on the bound socket. Take the changes to the port 2725 * as well. 2726 */ 2727 rcu_read_lock(); 2728 list_for_each_entry_rcu(spp, &smk_ipv6_port_list, list) { 2729 if (sk != spp->smk_sock) 2730 continue; 2731 spp->smk_in = ssp->smk_in; 2732 spp->smk_out = ssp->smk_out; 2733 rcu_read_unlock(); 2734 return; 2735 } 2736 /* 2737 * A NULL address is only used for updating existing 2738 * bound entries. If there isn't one, it's OK. 2739 */ 2740 rcu_read_unlock(); 2741 return; 2742 } 2743 2744 addr6 = (struct sockaddr_in6 *)address; 2745 port = ntohs(addr6->sin6_port); 2746 /* 2747 * This is a special case that is safely ignored. 2748 */ 2749 if (port == 0) 2750 return; 2751 2752 /* 2753 * Look for an existing port list entry. 2754 * This is an indication that a port is getting reused. 2755 */ 2756 rcu_read_lock(); 2757 list_for_each_entry_rcu(spp, &smk_ipv6_port_list, list) { 2758 if (spp->smk_port != port || spp->smk_sock_type != sock->type) 2759 continue; 2760 if (spp->smk_can_reuse != 1) { 2761 rcu_read_unlock(); 2762 return; 2763 } 2764 spp->smk_port = port; 2765 spp->smk_sock = sk; 2766 spp->smk_in = ssp->smk_in; 2767 spp->smk_out = ssp->smk_out; 2768 spp->smk_can_reuse = 0; 2769 rcu_read_unlock(); 2770 return; 2771 } 2772 rcu_read_unlock(); 2773 /* 2774 * A new port entry is required. 2775 */ 2776 spp = kzalloc(sizeof(*spp), GFP_KERNEL); 2777 if (spp == NULL) 2778 return; 2779 2780 spp->smk_port = port; 2781 spp->smk_sock = sk; 2782 spp->smk_in = ssp->smk_in; 2783 spp->smk_out = ssp->smk_out; 2784 spp->smk_sock_type = sock->type; 2785 spp->smk_can_reuse = 0; 2786 2787 mutex_lock(&smack_ipv6_lock); 2788 list_add_rcu(&spp->list, &smk_ipv6_port_list); 2789 mutex_unlock(&smack_ipv6_lock); 2790 return; 2791 } 2792 2793 /** 2794 * smk_ipv6_port_check - check Smack port access 2795 * @sk: socket 2796 * @address: address 2797 * @act: the action being taken 2798 * 2799 * Create or update the port list entry 2800 */ 2801 static int smk_ipv6_port_check(struct sock *sk, struct sockaddr_in6 *address, 2802 int act) 2803 { 2804 struct smk_port_label *spp; 2805 struct socket_smack *ssp = smack_sock(sk); 2806 struct smack_known *skp = NULL; 2807 unsigned short port; 2808 struct smack_known *object; 2809 2810 if (act == SMK_RECEIVING) { 2811 skp = smack_ipv6host_label(address); 2812 object = ssp->smk_in; 2813 } else { 2814 skp = ssp->smk_out; 2815 object = smack_ipv6host_label(address); 2816 } 2817 2818 /* 2819 * The other end is a single label host. 2820 */ 2821 if (skp != NULL && object != NULL) 2822 return smk_ipv6_check(skp, object, address, act); 2823 if (skp == NULL) 2824 skp = smack_net_ambient; 2825 if (object == NULL) 2826 object = smack_net_ambient; 2827 2828 /* 2829 * It's remote, so port lookup does no good. 2830 */ 2831 if (!smk_ipv6_localhost(address)) 2832 return smk_ipv6_check(skp, object, address, act); 2833 2834 /* 2835 * It's local so the send check has to have passed. 2836 */ 2837 if (act == SMK_RECEIVING) 2838 return 0; 2839 2840 port = ntohs(address->sin6_port); 2841 rcu_read_lock(); 2842 list_for_each_entry_rcu(spp, &smk_ipv6_port_list, list) { 2843 if (spp->smk_port != port || spp->smk_sock_type != sk->sk_type) 2844 continue; 2845 object = spp->smk_in; 2846 if (act == SMK_CONNECTING) 2847 ssp->smk_packet = spp->smk_out; 2848 break; 2849 } 2850 rcu_read_unlock(); 2851 2852 return smk_ipv6_check(skp, object, address, act); 2853 } 2854 #endif 2855 2856 /** 2857 * smack_inode_setsecurity - set smack xattrs 2858 * @inode: the object 2859 * @name: attribute name 2860 * @value: attribute value 2861 * @size: size of the attribute 2862 * @flags: unused 2863 * 2864 * Sets the named attribute in the appropriate blob 2865 * 2866 * Returns 0 on success, or an error code 2867 */ 2868 static int smack_inode_setsecurity(struct inode *inode, const char *name, 2869 const void *value, size_t size, int flags) 2870 { 2871 struct smack_known *skp; 2872 struct inode_smack *nsp = smack_inode(inode); 2873 struct socket_smack *ssp; 2874 struct socket *sock; 2875 int rc = 0; 2876 2877 if (value == NULL || size > SMK_LONGLABEL || size == 0) 2878 return -EINVAL; 2879 2880 if (strcmp(name, XATTR_SMACK_TRANSMUTE) == 0) { 2881 if (!S_ISDIR(inode->i_mode) || size != TRANS_TRUE_SIZE || 2882 strncmp(value, TRANS_TRUE, TRANS_TRUE_SIZE) != 0) 2883 return -EINVAL; 2884 2885 nsp->smk_flags |= SMK_INODE_TRANSMUTE; 2886 return 0; 2887 } 2888 2889 skp = smk_import_entry(value, size); 2890 if (IS_ERR(skp)) 2891 return PTR_ERR(skp); 2892 2893 if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) { 2894 nsp->smk_inode = skp; 2895 nsp->smk_flags |= SMK_INODE_INSTANT; 2896 return 0; 2897 } 2898 /* 2899 * The rest of the Smack xattrs are only on sockets. 2900 */ 2901 if (inode->i_sb->s_magic != SOCKFS_MAGIC) 2902 return -EOPNOTSUPP; 2903 2904 sock = SOCKET_I(inode); 2905 if (sock == NULL || sock->sk == NULL) 2906 return -EOPNOTSUPP; 2907 2908 ssp = smack_sock(sock->sk); 2909 2910 if (strcmp(name, XATTR_SMACK_IPIN) == 0) 2911 ssp->smk_in = skp; 2912 else if (strcmp(name, XATTR_SMACK_IPOUT) == 0) { 2913 ssp->smk_out = skp; 2914 if (sock->sk->sk_family == PF_INET) { 2915 rc = smack_netlbl_add(sock->sk); 2916 if (rc != 0) 2917 printk(KERN_WARNING 2918 "Smack: \"%s\" netlbl error %d.\n", 2919 __func__, -rc); 2920 } 2921 } else 2922 return -EOPNOTSUPP; 2923 2924 #ifdef SMACK_IPV6_PORT_LABELING 2925 if (sock->sk->sk_family == PF_INET6) 2926 smk_ipv6_port_label(sock, NULL); 2927 #endif 2928 2929 return 0; 2930 } 2931 2932 /** 2933 * smack_socket_post_create - finish socket setup 2934 * @sock: the socket 2935 * @family: protocol family 2936 * @type: unused 2937 * @protocol: unused 2938 * @kern: unused 2939 * 2940 * Sets the netlabel information on the socket 2941 * 2942 * Returns 0 on success, and error code otherwise 2943 */ 2944 static int smack_socket_post_create(struct socket *sock, int family, 2945 int type, int protocol, int kern) 2946 { 2947 struct socket_smack *ssp; 2948 2949 if (sock->sk == NULL) 2950 return 0; 2951 2952 /* 2953 * Sockets created by kernel threads receive web label. 2954 */ 2955 if (unlikely(current->flags & PF_KTHREAD)) { 2956 ssp = smack_sock(sock->sk); 2957 ssp->smk_in = &smack_known_web; 2958 ssp->smk_out = &smack_known_web; 2959 } 2960 2961 if (family != PF_INET) 2962 return 0; 2963 /* 2964 * Set the outbound netlbl. 2965 */ 2966 return smack_netlbl_add(sock->sk); 2967 } 2968 2969 /** 2970 * smack_socket_socketpair - create socket pair 2971 * @socka: one socket 2972 * @sockb: another socket 2973 * 2974 * Cross reference the peer labels for SO_PEERSEC 2975 * 2976 * Returns 0 2977 */ 2978 static int smack_socket_socketpair(struct socket *socka, 2979 struct socket *sockb) 2980 { 2981 struct socket_smack *asp = smack_sock(socka->sk); 2982 struct socket_smack *bsp = smack_sock(sockb->sk); 2983 2984 asp->smk_packet = bsp->smk_out; 2985 bsp->smk_packet = asp->smk_out; 2986 2987 return 0; 2988 } 2989 2990 #ifdef SMACK_IPV6_PORT_LABELING 2991 /** 2992 * smack_socket_bind - record port binding information. 2993 * @sock: the socket 2994 * @address: the port address 2995 * @addrlen: size of the address 2996 * 2997 * Records the label bound to a port. 2998 * 2999 * Returns 0 on success, and error code otherwise 3000 */ 3001 static int smack_socket_bind(struct socket *sock, struct sockaddr *address, 3002 int addrlen) 3003 { 3004 if (sock->sk != NULL && sock->sk->sk_family == PF_INET6) { 3005 if (addrlen < SIN6_LEN_RFC2133 || 3006 address->sa_family != AF_INET6) 3007 return -EINVAL; 3008 smk_ipv6_port_label(sock, address); 3009 } 3010 return 0; 3011 } 3012 #endif /* SMACK_IPV6_PORT_LABELING */ 3013 3014 /** 3015 * smack_socket_connect - connect access check 3016 * @sock: the socket 3017 * @sap: the other end 3018 * @addrlen: size of sap 3019 * 3020 * Verifies that a connection may be possible 3021 * 3022 * Returns 0 on success, and error code otherwise 3023 */ 3024 static int smack_socket_connect(struct socket *sock, struct sockaddr *sap, 3025 int addrlen) 3026 { 3027 int rc = 0; 3028 3029 if (sock->sk == NULL) 3030 return 0; 3031 if (sock->sk->sk_family != PF_INET && 3032 (!IS_ENABLED(CONFIG_IPV6) || sock->sk->sk_family != PF_INET6)) 3033 return 0; 3034 if (addrlen < offsetofend(struct sockaddr, sa_family)) 3035 return 0; 3036 if (IS_ENABLED(CONFIG_IPV6) && sap->sa_family == AF_INET6) { 3037 struct sockaddr_in6 *sip = (struct sockaddr_in6 *)sap; 3038 struct smack_known *rsp = NULL; 3039 3040 if (addrlen < SIN6_LEN_RFC2133) 3041 return 0; 3042 if (__is_defined(SMACK_IPV6_SECMARK_LABELING)) 3043 rsp = smack_ipv6host_label(sip); 3044 if (rsp != NULL) { 3045 struct socket_smack *ssp = smack_sock(sock->sk); 3046 3047 rc = smk_ipv6_check(ssp->smk_out, rsp, sip, 3048 SMK_CONNECTING); 3049 } 3050 #ifdef SMACK_IPV6_PORT_LABELING 3051 rc = smk_ipv6_port_check(sock->sk, sip, SMK_CONNECTING); 3052 #endif 3053 3054 return rc; 3055 } 3056 if (sap->sa_family != AF_INET || addrlen < sizeof(struct sockaddr_in)) 3057 return 0; 3058 rc = smk_ipv4_check(sock->sk, (struct sockaddr_in *)sap); 3059 return rc; 3060 } 3061 3062 /** 3063 * smack_flags_to_may - convert S_ to MAY_ values 3064 * @flags: the S_ value 3065 * 3066 * Returns the equivalent MAY_ value 3067 */ 3068 static int smack_flags_to_may(int flags) 3069 { 3070 int may = 0; 3071 3072 if (flags & S_IRUGO) 3073 may |= MAY_READ; 3074 if (flags & S_IWUGO) 3075 may |= MAY_WRITE; 3076 if (flags & S_IXUGO) 3077 may |= MAY_EXEC; 3078 3079 return may; 3080 } 3081 3082 /** 3083 * smack_msg_msg_alloc_security - Set the security blob for msg_msg 3084 * @msg: the object 3085 * 3086 * Returns 0 3087 */ 3088 static int smack_msg_msg_alloc_security(struct msg_msg *msg) 3089 { 3090 struct smack_known **blob = smack_msg_msg(msg); 3091 3092 *blob = smk_of_current(); 3093 return 0; 3094 } 3095 3096 /** 3097 * smack_of_ipc - the smack pointer for the ipc 3098 * @isp: the object 3099 * 3100 * Returns a pointer to the smack value 3101 */ 3102 static struct smack_known *smack_of_ipc(struct kern_ipc_perm *isp) 3103 { 3104 struct smack_known **blob = smack_ipc(isp); 3105 3106 return *blob; 3107 } 3108 3109 /** 3110 * smack_ipc_alloc_security - Set the security blob for ipc 3111 * @isp: the object 3112 * 3113 * Returns 0 3114 */ 3115 static int smack_ipc_alloc_security(struct kern_ipc_perm *isp) 3116 { 3117 struct smack_known **blob = smack_ipc(isp); 3118 3119 *blob = smk_of_current(); 3120 return 0; 3121 } 3122 3123 /** 3124 * smk_curacc_shm : check if current has access on shm 3125 * @isp : the object 3126 * @access : access requested 3127 * 3128 * Returns 0 if current has the requested access, error code otherwise 3129 */ 3130 static int smk_curacc_shm(struct kern_ipc_perm *isp, int access) 3131 { 3132 struct smack_known *ssp = smack_of_ipc(isp); 3133 struct smk_audit_info ad; 3134 int rc; 3135 3136 #ifdef CONFIG_AUDIT 3137 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC); 3138 ad.a.u.ipc_id = isp->id; 3139 #endif 3140 rc = smk_curacc(ssp, access, &ad); 3141 rc = smk_bu_current("shm", ssp, access, rc); 3142 return rc; 3143 } 3144 3145 /** 3146 * smack_shm_associate - Smack access check for shm 3147 * @isp: the object 3148 * @shmflg: access requested 3149 * 3150 * Returns 0 if current has the requested access, error code otherwise 3151 */ 3152 static int smack_shm_associate(struct kern_ipc_perm *isp, int shmflg) 3153 { 3154 int may; 3155 3156 may = smack_flags_to_may(shmflg); 3157 return smk_curacc_shm(isp, may); 3158 } 3159 3160 /** 3161 * smack_shm_shmctl - Smack access check for shm 3162 * @isp: the object 3163 * @cmd: what it wants to do 3164 * 3165 * Returns 0 if current has the requested access, error code otherwise 3166 */ 3167 static int smack_shm_shmctl(struct kern_ipc_perm *isp, int cmd) 3168 { 3169 int may; 3170 3171 switch (cmd) { 3172 case IPC_STAT: 3173 case SHM_STAT: 3174 case SHM_STAT_ANY: 3175 may = MAY_READ; 3176 break; 3177 case IPC_SET: 3178 case SHM_LOCK: 3179 case SHM_UNLOCK: 3180 case IPC_RMID: 3181 may = MAY_READWRITE; 3182 break; 3183 case IPC_INFO: 3184 case SHM_INFO: 3185 /* 3186 * System level information. 3187 */ 3188 return 0; 3189 default: 3190 return -EINVAL; 3191 } 3192 return smk_curacc_shm(isp, may); 3193 } 3194 3195 /** 3196 * smack_shm_shmat - Smack access for shmat 3197 * @isp: the object 3198 * @shmaddr: unused 3199 * @shmflg: access requested 3200 * 3201 * Returns 0 if current has the requested access, error code otherwise 3202 */ 3203 static int smack_shm_shmat(struct kern_ipc_perm *isp, char __user *shmaddr, 3204 int shmflg) 3205 { 3206 int may; 3207 3208 may = smack_flags_to_may(shmflg); 3209 return smk_curacc_shm(isp, may); 3210 } 3211 3212 /** 3213 * smk_curacc_sem : check if current has access on sem 3214 * @isp : the object 3215 * @access : access requested 3216 * 3217 * Returns 0 if current has the requested access, error code otherwise 3218 */ 3219 static int smk_curacc_sem(struct kern_ipc_perm *isp, int access) 3220 { 3221 struct smack_known *ssp = smack_of_ipc(isp); 3222 struct smk_audit_info ad; 3223 int rc; 3224 3225 #ifdef CONFIG_AUDIT 3226 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC); 3227 ad.a.u.ipc_id = isp->id; 3228 #endif 3229 rc = smk_curacc(ssp, access, &ad); 3230 rc = smk_bu_current("sem", ssp, access, rc); 3231 return rc; 3232 } 3233 3234 /** 3235 * smack_sem_associate - Smack access check for sem 3236 * @isp: the object 3237 * @semflg: access requested 3238 * 3239 * Returns 0 if current has the requested access, error code otherwise 3240 */ 3241 static int smack_sem_associate(struct kern_ipc_perm *isp, int semflg) 3242 { 3243 int may; 3244 3245 may = smack_flags_to_may(semflg); 3246 return smk_curacc_sem(isp, may); 3247 } 3248 3249 /** 3250 * smack_sem_semctl - Smack access check for sem 3251 * @isp: the object 3252 * @cmd: what it wants to do 3253 * 3254 * Returns 0 if current has the requested access, error code otherwise 3255 */ 3256 static int smack_sem_semctl(struct kern_ipc_perm *isp, int cmd) 3257 { 3258 int may; 3259 3260 switch (cmd) { 3261 case GETPID: 3262 case GETNCNT: 3263 case GETZCNT: 3264 case GETVAL: 3265 case GETALL: 3266 case IPC_STAT: 3267 case SEM_STAT: 3268 case SEM_STAT_ANY: 3269 may = MAY_READ; 3270 break; 3271 case SETVAL: 3272 case SETALL: 3273 case IPC_RMID: 3274 case IPC_SET: 3275 may = MAY_READWRITE; 3276 break; 3277 case IPC_INFO: 3278 case SEM_INFO: 3279 /* 3280 * System level information 3281 */ 3282 return 0; 3283 default: 3284 return -EINVAL; 3285 } 3286 3287 return smk_curacc_sem(isp, may); 3288 } 3289 3290 /** 3291 * smack_sem_semop - Smack checks of semaphore operations 3292 * @isp: the object 3293 * @sops: unused 3294 * @nsops: unused 3295 * @alter: unused 3296 * 3297 * Treated as read and write in all cases. 3298 * 3299 * Returns 0 if access is allowed, error code otherwise 3300 */ 3301 static int smack_sem_semop(struct kern_ipc_perm *isp, struct sembuf *sops, 3302 unsigned nsops, int alter) 3303 { 3304 return smk_curacc_sem(isp, MAY_READWRITE); 3305 } 3306 3307 /** 3308 * smk_curacc_msq : helper to check if current has access on msq 3309 * @isp : the msq 3310 * @access : access requested 3311 * 3312 * return 0 if current has access, error otherwise 3313 */ 3314 static int smk_curacc_msq(struct kern_ipc_perm *isp, int access) 3315 { 3316 struct smack_known *msp = smack_of_ipc(isp); 3317 struct smk_audit_info ad; 3318 int rc; 3319 3320 #ifdef CONFIG_AUDIT 3321 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC); 3322 ad.a.u.ipc_id = isp->id; 3323 #endif 3324 rc = smk_curacc(msp, access, &ad); 3325 rc = smk_bu_current("msq", msp, access, rc); 3326 return rc; 3327 } 3328 3329 /** 3330 * smack_msg_queue_associate - Smack access check for msg_queue 3331 * @isp: the object 3332 * @msqflg: access requested 3333 * 3334 * Returns 0 if current has the requested access, error code otherwise 3335 */ 3336 static int smack_msg_queue_associate(struct kern_ipc_perm *isp, int msqflg) 3337 { 3338 int may; 3339 3340 may = smack_flags_to_may(msqflg); 3341 return smk_curacc_msq(isp, may); 3342 } 3343 3344 /** 3345 * smack_msg_queue_msgctl - Smack access check for msg_queue 3346 * @isp: the object 3347 * @cmd: what it wants to do 3348 * 3349 * Returns 0 if current has the requested access, error code otherwise 3350 */ 3351 static int smack_msg_queue_msgctl(struct kern_ipc_perm *isp, int cmd) 3352 { 3353 int may; 3354 3355 switch (cmd) { 3356 case IPC_STAT: 3357 case MSG_STAT: 3358 case MSG_STAT_ANY: 3359 may = MAY_READ; 3360 break; 3361 case IPC_SET: 3362 case IPC_RMID: 3363 may = MAY_READWRITE; 3364 break; 3365 case IPC_INFO: 3366 case MSG_INFO: 3367 /* 3368 * System level information 3369 */ 3370 return 0; 3371 default: 3372 return -EINVAL; 3373 } 3374 3375 return smk_curacc_msq(isp, may); 3376 } 3377 3378 /** 3379 * smack_msg_queue_msgsnd - Smack access check for msg_queue 3380 * @isp: the object 3381 * @msg: unused 3382 * @msqflg: access requested 3383 * 3384 * Returns 0 if current has the requested access, error code otherwise 3385 */ 3386 static int smack_msg_queue_msgsnd(struct kern_ipc_perm *isp, struct msg_msg *msg, 3387 int msqflg) 3388 { 3389 int may; 3390 3391 may = smack_flags_to_may(msqflg); 3392 return smk_curacc_msq(isp, may); 3393 } 3394 3395 /** 3396 * smack_msg_queue_msgrcv - Smack access check for msg_queue 3397 * @isp: the object 3398 * @msg: unused 3399 * @target: unused 3400 * @type: unused 3401 * @mode: unused 3402 * 3403 * Returns 0 if current has read and write access, error code otherwise 3404 */ 3405 static int smack_msg_queue_msgrcv(struct kern_ipc_perm *isp, 3406 struct msg_msg *msg, 3407 struct task_struct *target, long type, 3408 int mode) 3409 { 3410 return smk_curacc_msq(isp, MAY_READWRITE); 3411 } 3412 3413 /** 3414 * smack_ipc_permission - Smack access for ipc_permission() 3415 * @ipp: the object permissions 3416 * @flag: access requested 3417 * 3418 * Returns 0 if current has read and write access, error code otherwise 3419 */ 3420 static int smack_ipc_permission(struct kern_ipc_perm *ipp, short flag) 3421 { 3422 struct smack_known **blob = smack_ipc(ipp); 3423 struct smack_known *iskp = *blob; 3424 int may = smack_flags_to_may(flag); 3425 struct smk_audit_info ad; 3426 int rc; 3427 3428 #ifdef CONFIG_AUDIT 3429 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC); 3430 ad.a.u.ipc_id = ipp->id; 3431 #endif 3432 rc = smk_curacc(iskp, may, &ad); 3433 rc = smk_bu_current("svipc", iskp, may, rc); 3434 return rc; 3435 } 3436 3437 /** 3438 * smack_ipc_getsecid - Extract smack security id 3439 * @ipp: the object permissions 3440 * @secid: where result will be saved 3441 */ 3442 static void smack_ipc_getsecid(struct kern_ipc_perm *ipp, u32 *secid) 3443 { 3444 struct smack_known **blob = smack_ipc(ipp); 3445 struct smack_known *iskp = *blob; 3446 3447 *secid = iskp->smk_secid; 3448 } 3449 3450 /** 3451 * smack_d_instantiate - Make sure the blob is correct on an inode 3452 * @opt_dentry: dentry where inode will be attached 3453 * @inode: the object 3454 * 3455 * Set the inode's security blob if it hasn't been done already. 3456 */ 3457 static void smack_d_instantiate(struct dentry *opt_dentry, struct inode *inode) 3458 { 3459 struct super_block *sbp; 3460 struct superblock_smack *sbsp; 3461 struct inode_smack *isp; 3462 struct smack_known *skp; 3463 struct smack_known *ckp = smk_of_current(); 3464 struct smack_known *final; 3465 char trattr[TRANS_TRUE_SIZE]; 3466 int transflag = 0; 3467 int rc; 3468 struct dentry *dp; 3469 3470 if (inode == NULL) 3471 return; 3472 3473 isp = smack_inode(inode); 3474 3475 /* 3476 * If the inode is already instantiated 3477 * take the quick way out 3478 */ 3479 if (isp->smk_flags & SMK_INODE_INSTANT) 3480 return; 3481 3482 sbp = inode->i_sb; 3483 sbsp = smack_superblock(sbp); 3484 /* 3485 * We're going to use the superblock default label 3486 * if there's no label on the file. 3487 */ 3488 final = sbsp->smk_default; 3489 3490 /* 3491 * If this is the root inode the superblock 3492 * may be in the process of initialization. 3493 * If that is the case use the root value out 3494 * of the superblock. 3495 */ 3496 if (opt_dentry->d_parent == opt_dentry) { 3497 switch (sbp->s_magic) { 3498 case CGROUP_SUPER_MAGIC: 3499 case CGROUP2_SUPER_MAGIC: 3500 /* 3501 * The cgroup filesystem is never mounted, 3502 * so there's no opportunity to set the mount 3503 * options. 3504 */ 3505 sbsp->smk_root = &smack_known_star; 3506 sbsp->smk_default = &smack_known_star; 3507 isp->smk_inode = sbsp->smk_root; 3508 break; 3509 case TMPFS_MAGIC: 3510 /* 3511 * What about shmem/tmpfs anonymous files with dentry 3512 * obtained from d_alloc_pseudo()? 3513 */ 3514 isp->smk_inode = smk_of_current(); 3515 break; 3516 case PIPEFS_MAGIC: 3517 isp->smk_inode = smk_of_current(); 3518 break; 3519 case SOCKFS_MAGIC: 3520 /* 3521 * Socket access is controlled by the socket 3522 * structures associated with the task involved. 3523 */ 3524 isp->smk_inode = &smack_known_star; 3525 break; 3526 default: 3527 isp->smk_inode = sbsp->smk_root; 3528 break; 3529 } 3530 isp->smk_flags |= SMK_INODE_INSTANT; 3531 return; 3532 } 3533 3534 /* 3535 * This is pretty hackish. 3536 * Casey says that we shouldn't have to do 3537 * file system specific code, but it does help 3538 * with keeping it simple. 3539 */ 3540 switch (sbp->s_magic) { 3541 case SMACK_MAGIC: 3542 case CGROUP_SUPER_MAGIC: 3543 case CGROUP2_SUPER_MAGIC: 3544 /* 3545 * Casey says that it's a little embarrassing 3546 * that the smack file system doesn't do 3547 * extended attributes. 3548 * 3549 * Cgroupfs is special 3550 */ 3551 final = &smack_known_star; 3552 break; 3553 case DEVPTS_SUPER_MAGIC: 3554 /* 3555 * devpts seems content with the label of the task. 3556 * Programs that change smack have to treat the 3557 * pty with respect. 3558 */ 3559 final = ckp; 3560 break; 3561 case PROC_SUPER_MAGIC: 3562 /* 3563 * Casey says procfs appears not to care. 3564 * The superblock default suffices. 3565 */ 3566 break; 3567 case TMPFS_MAGIC: 3568 /* 3569 * Device labels should come from the filesystem, 3570 * but watch out, because they're volitile, 3571 * getting recreated on every reboot. 3572 */ 3573 final = &smack_known_star; 3574 /* 3575 * If a smack value has been set we want to use it, 3576 * but since tmpfs isn't giving us the opportunity 3577 * to set mount options simulate setting the 3578 * superblock default. 3579 */ 3580 fallthrough; 3581 default: 3582 /* 3583 * This isn't an understood special case. 3584 * Get the value from the xattr. 3585 */ 3586 3587 /* 3588 * UNIX domain sockets use lower level socket data. 3589 */ 3590 if (S_ISSOCK(inode->i_mode)) { 3591 final = &smack_known_star; 3592 break; 3593 } 3594 /* 3595 * No xattr support means, alas, no SMACK label. 3596 * Use the aforeapplied default. 3597 * It would be curious if the label of the task 3598 * does not match that assigned. 3599 */ 3600 if (!(inode->i_opflags & IOP_XATTR)) 3601 break; 3602 /* 3603 * Get the dentry for xattr. 3604 */ 3605 dp = dget(opt_dentry); 3606 skp = smk_fetch(XATTR_NAME_SMACK, inode, dp); 3607 if (!IS_ERR_OR_NULL(skp)) 3608 final = skp; 3609 3610 /* 3611 * Transmuting directory 3612 */ 3613 if (S_ISDIR(inode->i_mode)) { 3614 /* 3615 * If this is a new directory and the label was 3616 * transmuted when the inode was initialized 3617 * set the transmute attribute on the directory 3618 * and mark the inode. 3619 * 3620 * If there is a transmute attribute on the 3621 * directory mark the inode. 3622 */ 3623 rc = __vfs_getxattr(dp, inode, 3624 XATTR_NAME_SMACKTRANSMUTE, trattr, 3625 TRANS_TRUE_SIZE); 3626 if (rc >= 0 && strncmp(trattr, TRANS_TRUE, 3627 TRANS_TRUE_SIZE) != 0) 3628 rc = -EINVAL; 3629 if (rc >= 0) 3630 transflag = SMK_INODE_TRANSMUTE; 3631 } 3632 /* 3633 * Don't let the exec or mmap label be "*" or "@". 3634 */ 3635 skp = smk_fetch(XATTR_NAME_SMACKEXEC, inode, dp); 3636 if (IS_ERR(skp) || skp == &smack_known_star || 3637 skp == &smack_known_web) 3638 skp = NULL; 3639 isp->smk_task = skp; 3640 3641 skp = smk_fetch(XATTR_NAME_SMACKMMAP, inode, dp); 3642 if (IS_ERR(skp) || skp == &smack_known_star || 3643 skp == &smack_known_web) 3644 skp = NULL; 3645 isp->smk_mmap = skp; 3646 3647 dput(dp); 3648 break; 3649 } 3650 3651 if (final == NULL) 3652 isp->smk_inode = ckp; 3653 else 3654 isp->smk_inode = final; 3655 3656 isp->smk_flags |= (SMK_INODE_INSTANT | transflag); 3657 3658 return; 3659 } 3660 3661 /** 3662 * smack_getselfattr - Smack current process attribute 3663 * @attr: which attribute to fetch 3664 * @ctx: buffer to receive the result 3665 * @size: available size in, actual size out 3666 * @flags: unused 3667 * 3668 * Fill the passed user space @ctx with the details of the requested 3669 * attribute. 3670 * 3671 * Returns the number of attributes on success, an error code otherwise. 3672 * There will only ever be one attribute. 3673 */ 3674 static int smack_getselfattr(unsigned int attr, struct lsm_ctx __user *ctx, 3675 u32 *size, u32 flags) 3676 { 3677 int rc; 3678 struct smack_known *skp; 3679 3680 if (attr != LSM_ATTR_CURRENT) 3681 return -EOPNOTSUPP; 3682 3683 skp = smk_of_current(); 3684 rc = lsm_fill_user_ctx(ctx, size, 3685 skp->smk_known, strlen(skp->smk_known) + 1, 3686 LSM_ID_SMACK, 0); 3687 return (!rc ? 1 : rc); 3688 } 3689 3690 /** 3691 * smack_getprocattr - Smack process attribute access 3692 * @p: the object task 3693 * @name: the name of the attribute in /proc/.../attr 3694 * @value: where to put the result 3695 * 3696 * Places a copy of the task Smack into value 3697 * 3698 * Returns the length of the smack label or an error code 3699 */ 3700 static int smack_getprocattr(struct task_struct *p, const char *name, char **value) 3701 { 3702 struct smack_known *skp = smk_of_task_struct_obj(p); 3703 char *cp; 3704 int slen; 3705 3706 if (strcmp(name, "current") != 0) 3707 return -EINVAL; 3708 3709 cp = kstrdup(skp->smk_known, GFP_KERNEL); 3710 if (cp == NULL) 3711 return -ENOMEM; 3712 3713 slen = strlen(cp); 3714 *value = cp; 3715 return slen; 3716 } 3717 3718 /** 3719 * do_setattr - Smack process attribute setting 3720 * @attr: the ID of the attribute 3721 * @value: the value to set 3722 * @size: the size of the value 3723 * 3724 * Sets the Smack value of the task. Only setting self 3725 * is permitted and only with privilege 3726 * 3727 * Returns the length of the smack label or an error code 3728 */ 3729 static int do_setattr(u64 attr, void *value, size_t size) 3730 { 3731 struct task_smack *tsp = smack_cred(current_cred()); 3732 struct cred *new; 3733 struct smack_known *skp; 3734 struct smack_known_list_elem *sklep; 3735 int rc; 3736 3737 if (!smack_privileged(CAP_MAC_ADMIN) && list_empty(&tsp->smk_relabel)) 3738 return -EPERM; 3739 3740 if (value == NULL || size == 0 || size >= SMK_LONGLABEL) 3741 return -EINVAL; 3742 3743 if (attr != LSM_ATTR_CURRENT) 3744 return -EOPNOTSUPP; 3745 3746 skp = smk_import_entry(value, size); 3747 if (IS_ERR(skp)) 3748 return PTR_ERR(skp); 3749 3750 /* 3751 * No process is ever allowed the web ("@") label 3752 * and the star ("*") label. 3753 */ 3754 if (skp == &smack_known_web || skp == &smack_known_star) 3755 return -EINVAL; 3756 3757 if (!smack_privileged(CAP_MAC_ADMIN)) { 3758 rc = -EPERM; 3759 list_for_each_entry(sklep, &tsp->smk_relabel, list) 3760 if (sklep->smk_label == skp) { 3761 rc = 0; 3762 break; 3763 } 3764 if (rc) 3765 return rc; 3766 } 3767 3768 new = prepare_creds(); 3769 if (new == NULL) 3770 return -ENOMEM; 3771 3772 tsp = smack_cred(new); 3773 tsp->smk_task = skp; 3774 /* 3775 * process can change its label only once 3776 */ 3777 smk_destroy_label_list(&tsp->smk_relabel); 3778 3779 commit_creds(new); 3780 return size; 3781 } 3782 3783 /** 3784 * smack_setselfattr - Set a Smack process attribute 3785 * @attr: which attribute to set 3786 * @ctx: buffer containing the data 3787 * @size: size of @ctx 3788 * @flags: unused 3789 * 3790 * Fill the passed user space @ctx with the details of the requested 3791 * attribute. 3792 * 3793 * Returns 0 on success, an error code otherwise. 3794 */ 3795 static int smack_setselfattr(unsigned int attr, struct lsm_ctx *ctx, 3796 u32 size, u32 flags) 3797 { 3798 int rc; 3799 3800 rc = do_setattr(attr, ctx->ctx, ctx->ctx_len); 3801 if (rc > 0) 3802 return 0; 3803 return rc; 3804 } 3805 3806 /** 3807 * smack_setprocattr - Smack process attribute setting 3808 * @name: the name of the attribute in /proc/.../attr 3809 * @value: the value to set 3810 * @size: the size of the value 3811 * 3812 * Sets the Smack value of the task. Only setting self 3813 * is permitted and only with privilege 3814 * 3815 * Returns the length of the smack label or an error code 3816 */ 3817 static int smack_setprocattr(const char *name, void *value, size_t size) 3818 { 3819 int attr = lsm_name_to_attr(name); 3820 3821 if (attr != LSM_ATTR_UNDEF) 3822 return do_setattr(attr, value, size); 3823 return -EINVAL; 3824 } 3825 3826 /** 3827 * smack_unix_stream_connect - Smack access on UDS 3828 * @sock: one sock 3829 * @other: the other sock 3830 * @newsk: unused 3831 * 3832 * Return 0 if a subject with the smack of sock could access 3833 * an object with the smack of other, otherwise an error code 3834 */ 3835 static int smack_unix_stream_connect(struct sock *sock, 3836 struct sock *other, struct sock *newsk) 3837 { 3838 struct smack_known *skp; 3839 struct smack_known *okp; 3840 struct socket_smack *ssp = smack_sock(sock); 3841 struct socket_smack *osp = smack_sock(other); 3842 struct socket_smack *nsp = smack_sock(newsk); 3843 struct smk_audit_info ad; 3844 int rc = 0; 3845 #ifdef CONFIG_AUDIT 3846 struct lsm_network_audit net; 3847 #endif 3848 3849 if (!smack_privileged(CAP_MAC_OVERRIDE)) { 3850 skp = ssp->smk_out; 3851 okp = osp->smk_in; 3852 #ifdef CONFIG_AUDIT 3853 smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net); 3854 smk_ad_setfield_u_net_sk(&ad, other); 3855 #endif 3856 rc = smk_access(skp, okp, MAY_WRITE, &ad); 3857 rc = smk_bu_note("UDS connect", skp, okp, MAY_WRITE, rc); 3858 if (rc == 0) { 3859 okp = osp->smk_out; 3860 skp = ssp->smk_in; 3861 rc = smk_access(okp, skp, MAY_WRITE, &ad); 3862 rc = smk_bu_note("UDS connect", okp, skp, 3863 MAY_WRITE, rc); 3864 } 3865 } 3866 3867 if (rc == 0) { 3868 /* 3869 * Cross reference the peer labels for SO_PEERSEC. 3870 */ 3871 nsp->smk_packet = ssp->smk_out; 3872 ssp->smk_packet = osp->smk_out; 3873 3874 /* 3875 * new/child/established socket must inherit listening socket labels 3876 */ 3877 nsp->smk_out = osp->smk_out; 3878 nsp->smk_in = osp->smk_in; 3879 } 3880 3881 return rc; 3882 } 3883 3884 /** 3885 * smack_unix_may_send - Smack access on UDS 3886 * @sock: one socket 3887 * @other: the other socket 3888 * 3889 * Return 0 if a subject with the smack of sock could access 3890 * an object with the smack of other, otherwise an error code 3891 */ 3892 static int smack_unix_may_send(struct socket *sock, struct socket *other) 3893 { 3894 struct socket_smack *ssp = smack_sock(sock->sk); 3895 struct socket_smack *osp = smack_sock(other->sk); 3896 struct smk_audit_info ad; 3897 int rc; 3898 3899 #ifdef CONFIG_AUDIT 3900 struct lsm_network_audit net; 3901 3902 smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net); 3903 smk_ad_setfield_u_net_sk(&ad, other->sk); 3904 #endif 3905 3906 if (smack_privileged(CAP_MAC_OVERRIDE)) 3907 return 0; 3908 3909 rc = smk_access(ssp->smk_out, osp->smk_in, MAY_WRITE, &ad); 3910 rc = smk_bu_note("UDS send", ssp->smk_out, osp->smk_in, MAY_WRITE, rc); 3911 return rc; 3912 } 3913 3914 /** 3915 * smack_socket_sendmsg - Smack check based on destination host 3916 * @sock: the socket 3917 * @msg: the message 3918 * @size: the size of the message 3919 * 3920 * Return 0 if the current subject can write to the destination host. 3921 * For IPv4 this is only a question if the destination is a single label host. 3922 * For IPv6 this is a check against the label of the port. 3923 */ 3924 static int smack_socket_sendmsg(struct socket *sock, struct msghdr *msg, 3925 int size) 3926 { 3927 struct sockaddr_in *sip = (struct sockaddr_in *) msg->msg_name; 3928 #if IS_ENABLED(CONFIG_IPV6) 3929 struct sockaddr_in6 *sap = (struct sockaddr_in6 *) msg->msg_name; 3930 #endif 3931 #ifdef SMACK_IPV6_SECMARK_LABELING 3932 struct socket_smack *ssp = smack_sock(sock->sk); 3933 struct smack_known *rsp; 3934 #endif 3935 int rc = 0; 3936 3937 /* 3938 * Perfectly reasonable for this to be NULL 3939 */ 3940 if (sip == NULL) 3941 return 0; 3942 3943 switch (sock->sk->sk_family) { 3944 case AF_INET: 3945 if (msg->msg_namelen < sizeof(struct sockaddr_in) || 3946 sip->sin_family != AF_INET) 3947 return -EINVAL; 3948 rc = smk_ipv4_check(sock->sk, sip); 3949 break; 3950 #if IS_ENABLED(CONFIG_IPV6) 3951 case AF_INET6: 3952 if (msg->msg_namelen < SIN6_LEN_RFC2133 || 3953 sap->sin6_family != AF_INET6) 3954 return -EINVAL; 3955 #ifdef SMACK_IPV6_SECMARK_LABELING 3956 rsp = smack_ipv6host_label(sap); 3957 if (rsp != NULL) 3958 rc = smk_ipv6_check(ssp->smk_out, rsp, sap, 3959 SMK_CONNECTING); 3960 #endif 3961 #ifdef SMACK_IPV6_PORT_LABELING 3962 rc = smk_ipv6_port_check(sock->sk, sap, SMK_SENDING); 3963 #endif 3964 #endif /* IS_ENABLED(CONFIG_IPV6) */ 3965 break; 3966 } 3967 return rc; 3968 } 3969 3970 /** 3971 * smack_from_secattr - Convert a netlabel attr.mls.lvl/attr.mls.cat pair to smack 3972 * @sap: netlabel secattr 3973 * @ssp: socket security information 3974 * 3975 * Returns a pointer to a Smack label entry found on the label list. 3976 */ 3977 static struct smack_known *smack_from_secattr(struct netlbl_lsm_secattr *sap, 3978 struct socket_smack *ssp) 3979 { 3980 struct smack_known *skp; 3981 int found = 0; 3982 int acat; 3983 int kcat; 3984 3985 /* 3986 * Netlabel found it in the cache. 3987 */ 3988 if ((sap->flags & NETLBL_SECATTR_CACHE) != 0) 3989 return (struct smack_known *)sap->cache->data; 3990 3991 if ((sap->flags & NETLBL_SECATTR_SECID) != 0) 3992 /* 3993 * Looks like a fallback, which gives us a secid. 3994 */ 3995 return smack_from_secid(sap->attr.secid); 3996 3997 if ((sap->flags & NETLBL_SECATTR_MLS_LVL) != 0) { 3998 /* 3999 * Looks like a CIPSO packet. 4000 * If there are flags but no level netlabel isn't 4001 * behaving the way we expect it to. 4002 * 4003 * Look it up in the label table 4004 * Without guidance regarding the smack value 4005 * for the packet fall back on the network 4006 * ambient value. 4007 */ 4008 rcu_read_lock(); 4009 list_for_each_entry_rcu(skp, &smack_known_list, list) { 4010 if (sap->attr.mls.lvl != skp->smk_netlabel.attr.mls.lvl) 4011 continue; 4012 /* 4013 * Compare the catsets. Use the netlbl APIs. 4014 */ 4015 if ((sap->flags & NETLBL_SECATTR_MLS_CAT) == 0) { 4016 if ((skp->smk_netlabel.flags & 4017 NETLBL_SECATTR_MLS_CAT) == 0) 4018 found = 1; 4019 break; 4020 } 4021 for (acat = -1, kcat = -1; acat == kcat; ) { 4022 acat = netlbl_catmap_walk(sap->attr.mls.cat, 4023 acat + 1); 4024 kcat = netlbl_catmap_walk( 4025 skp->smk_netlabel.attr.mls.cat, 4026 kcat + 1); 4027 if (acat < 0 || kcat < 0) 4028 break; 4029 } 4030 if (acat == kcat) { 4031 found = 1; 4032 break; 4033 } 4034 } 4035 rcu_read_unlock(); 4036 4037 if (found) 4038 return skp; 4039 4040 if (ssp != NULL && ssp->smk_in == &smack_known_star) 4041 return &smack_known_web; 4042 return &smack_known_star; 4043 } 4044 /* 4045 * Without guidance regarding the smack value 4046 * for the packet fall back on the network 4047 * ambient value. 4048 */ 4049 return smack_net_ambient; 4050 } 4051 4052 #if IS_ENABLED(CONFIG_IPV6) 4053 static int smk_skb_to_addr_ipv6(struct sk_buff *skb, struct sockaddr_in6 *sip) 4054 { 4055 u8 nexthdr; 4056 int offset; 4057 int proto = -EINVAL; 4058 struct ipv6hdr _ipv6h; 4059 struct ipv6hdr *ip6; 4060 __be16 frag_off; 4061 struct tcphdr _tcph, *th; 4062 struct udphdr _udph, *uh; 4063 struct dccp_hdr _dccph, *dh; 4064 4065 sip->sin6_port = 0; 4066 4067 offset = skb_network_offset(skb); 4068 ip6 = skb_header_pointer(skb, offset, sizeof(_ipv6h), &_ipv6h); 4069 if (ip6 == NULL) 4070 return -EINVAL; 4071 sip->sin6_addr = ip6->saddr; 4072 4073 nexthdr = ip6->nexthdr; 4074 offset += sizeof(_ipv6h); 4075 offset = ipv6_skip_exthdr(skb, offset, &nexthdr, &frag_off); 4076 if (offset < 0) 4077 return -EINVAL; 4078 4079 proto = nexthdr; 4080 switch (proto) { 4081 case IPPROTO_TCP: 4082 th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph); 4083 if (th != NULL) 4084 sip->sin6_port = th->source; 4085 break; 4086 case IPPROTO_UDP: 4087 case IPPROTO_UDPLITE: 4088 uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph); 4089 if (uh != NULL) 4090 sip->sin6_port = uh->source; 4091 break; 4092 case IPPROTO_DCCP: 4093 dh = skb_header_pointer(skb, offset, sizeof(_dccph), &_dccph); 4094 if (dh != NULL) 4095 sip->sin6_port = dh->dccph_sport; 4096 break; 4097 } 4098 return proto; 4099 } 4100 #endif /* CONFIG_IPV6 */ 4101 4102 /** 4103 * smack_from_skb - Smack data from the secmark in an skb 4104 * @skb: packet 4105 * 4106 * Returns smack_known of the secmark or NULL if that won't work. 4107 */ 4108 #ifdef CONFIG_NETWORK_SECMARK 4109 static struct smack_known *smack_from_skb(struct sk_buff *skb) 4110 { 4111 if (skb == NULL || skb->secmark == 0) 4112 return NULL; 4113 4114 return smack_from_secid(skb->secmark); 4115 } 4116 #else 4117 static inline struct smack_known *smack_from_skb(struct sk_buff *skb) 4118 { 4119 return NULL; 4120 } 4121 #endif 4122 4123 /** 4124 * smack_from_netlbl - Smack data from the IP options in an skb 4125 * @sk: socket data came in on 4126 * @family: address family 4127 * @skb: packet 4128 * 4129 * Find the Smack label in the IP options. If it hasn't been 4130 * added to the netlabel cache, add it here. 4131 * 4132 * Returns smack_known of the IP options or NULL if that won't work. 4133 */ 4134 static struct smack_known *smack_from_netlbl(const struct sock *sk, u16 family, 4135 struct sk_buff *skb) 4136 { 4137 struct netlbl_lsm_secattr secattr; 4138 struct socket_smack *ssp = NULL; 4139 struct smack_known *skp = NULL; 4140 4141 netlbl_secattr_init(&secattr); 4142 4143 if (sk) 4144 ssp = smack_sock(sk); 4145 4146 if (netlbl_skbuff_getattr(skb, family, &secattr) == 0) { 4147 skp = smack_from_secattr(&secattr, ssp); 4148 if (secattr.flags & NETLBL_SECATTR_CACHEABLE) 4149 netlbl_cache_add(skb, family, &skp->smk_netlabel); 4150 } 4151 4152 netlbl_secattr_destroy(&secattr); 4153 4154 return skp; 4155 } 4156 4157 /** 4158 * smack_socket_sock_rcv_skb - Smack packet delivery access check 4159 * @sk: socket 4160 * @skb: packet 4161 * 4162 * Returns 0 if the packet should be delivered, an error code otherwise 4163 */ 4164 static int smack_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb) 4165 { 4166 struct socket_smack *ssp = smack_sock(sk); 4167 struct smack_known *skp = NULL; 4168 int rc = 0; 4169 struct smk_audit_info ad; 4170 u16 family = sk->sk_family; 4171 #ifdef CONFIG_AUDIT 4172 struct lsm_network_audit net; 4173 #endif 4174 #if IS_ENABLED(CONFIG_IPV6) 4175 struct sockaddr_in6 sadd; 4176 int proto; 4177 4178 if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP)) 4179 family = PF_INET; 4180 #endif /* CONFIG_IPV6 */ 4181 4182 switch (family) { 4183 case PF_INET: 4184 /* 4185 * If there is a secmark use it rather than the CIPSO label. 4186 * If there is no secmark fall back to CIPSO. 4187 * The secmark is assumed to reflect policy better. 4188 */ 4189 skp = smack_from_skb(skb); 4190 if (skp == NULL) { 4191 skp = smack_from_netlbl(sk, family, skb); 4192 if (skp == NULL) 4193 skp = smack_net_ambient; 4194 } 4195 4196 #ifdef CONFIG_AUDIT 4197 smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net); 4198 ad.a.u.net->family = family; 4199 ad.a.u.net->netif = skb->skb_iif; 4200 ipv4_skb_to_auditdata(skb, &ad.a, NULL); 4201 #endif 4202 /* 4203 * Receiving a packet requires that the other end 4204 * be able to write here. Read access is not required. 4205 * This is the simplist possible security model 4206 * for networking. 4207 */ 4208 rc = smk_access(skp, ssp->smk_in, MAY_WRITE, &ad); 4209 rc = smk_bu_note("IPv4 delivery", skp, ssp->smk_in, 4210 MAY_WRITE, rc); 4211 if (rc != 0) 4212 netlbl_skbuff_err(skb, family, rc, 0); 4213 break; 4214 #if IS_ENABLED(CONFIG_IPV6) 4215 case PF_INET6: 4216 proto = smk_skb_to_addr_ipv6(skb, &sadd); 4217 if (proto != IPPROTO_UDP && proto != IPPROTO_UDPLITE && 4218 proto != IPPROTO_TCP && proto != IPPROTO_DCCP) 4219 break; 4220 #ifdef SMACK_IPV6_SECMARK_LABELING 4221 skp = smack_from_skb(skb); 4222 if (skp == NULL) { 4223 if (smk_ipv6_localhost(&sadd)) 4224 break; 4225 skp = smack_ipv6host_label(&sadd); 4226 if (skp == NULL) 4227 skp = smack_net_ambient; 4228 } 4229 #ifdef CONFIG_AUDIT 4230 smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net); 4231 ad.a.u.net->family = family; 4232 ad.a.u.net->netif = skb->skb_iif; 4233 ipv6_skb_to_auditdata(skb, &ad.a, NULL); 4234 #endif /* CONFIG_AUDIT */ 4235 rc = smk_access(skp, ssp->smk_in, MAY_WRITE, &ad); 4236 rc = smk_bu_note("IPv6 delivery", skp, ssp->smk_in, 4237 MAY_WRITE, rc); 4238 #endif /* SMACK_IPV6_SECMARK_LABELING */ 4239 #ifdef SMACK_IPV6_PORT_LABELING 4240 rc = smk_ipv6_port_check(sk, &sadd, SMK_RECEIVING); 4241 #endif /* SMACK_IPV6_PORT_LABELING */ 4242 if (rc != 0) 4243 icmpv6_send(skb, ICMPV6_DEST_UNREACH, 4244 ICMPV6_ADM_PROHIBITED, 0); 4245 break; 4246 #endif /* CONFIG_IPV6 */ 4247 } 4248 4249 return rc; 4250 } 4251 4252 /** 4253 * smack_socket_getpeersec_stream - pull in packet label 4254 * @sock: the socket 4255 * @optval: user's destination 4256 * @optlen: size thereof 4257 * @len: max thereof 4258 * 4259 * returns zero on success, an error code otherwise 4260 */ 4261 static int smack_socket_getpeersec_stream(struct socket *sock, 4262 sockptr_t optval, sockptr_t optlen, 4263 unsigned int len) 4264 { 4265 struct socket_smack *ssp; 4266 char *rcp = ""; 4267 u32 slen = 1; 4268 int rc = 0; 4269 4270 ssp = smack_sock(sock->sk); 4271 if (ssp->smk_packet != NULL) { 4272 rcp = ssp->smk_packet->smk_known; 4273 slen = strlen(rcp) + 1; 4274 } 4275 if (slen > len) { 4276 rc = -ERANGE; 4277 goto out_len; 4278 } 4279 4280 if (copy_to_sockptr(optval, rcp, slen)) 4281 rc = -EFAULT; 4282 out_len: 4283 if (copy_to_sockptr(optlen, &slen, sizeof(slen))) 4284 rc = -EFAULT; 4285 return rc; 4286 } 4287 4288 4289 /** 4290 * smack_socket_getpeersec_dgram - pull in packet label 4291 * @sock: the peer socket 4292 * @skb: packet data 4293 * @secid: pointer to where to put the secid of the packet 4294 * 4295 * Sets the netlabel socket state on sk from parent 4296 */ 4297 static int smack_socket_getpeersec_dgram(struct socket *sock, 4298 struct sk_buff *skb, u32 *secid) 4299 4300 { 4301 struct socket_smack *ssp = NULL; 4302 struct smack_known *skp; 4303 struct sock *sk = NULL; 4304 int family = PF_UNSPEC; 4305 u32 s = 0; /* 0 is the invalid secid */ 4306 4307 if (skb != NULL) { 4308 if (skb->protocol == htons(ETH_P_IP)) 4309 family = PF_INET; 4310 #if IS_ENABLED(CONFIG_IPV6) 4311 else if (skb->protocol == htons(ETH_P_IPV6)) 4312 family = PF_INET6; 4313 #endif /* CONFIG_IPV6 */ 4314 } 4315 if (family == PF_UNSPEC && sock != NULL) 4316 family = sock->sk->sk_family; 4317 4318 switch (family) { 4319 case PF_UNIX: 4320 ssp = smack_sock(sock->sk); 4321 s = ssp->smk_out->smk_secid; 4322 break; 4323 case PF_INET: 4324 skp = smack_from_skb(skb); 4325 if (skp) { 4326 s = skp->smk_secid; 4327 break; 4328 } 4329 /* 4330 * Translate what netlabel gave us. 4331 */ 4332 if (sock != NULL) 4333 sk = sock->sk; 4334 skp = smack_from_netlbl(sk, family, skb); 4335 if (skp != NULL) 4336 s = skp->smk_secid; 4337 break; 4338 case PF_INET6: 4339 #ifdef SMACK_IPV6_SECMARK_LABELING 4340 skp = smack_from_skb(skb); 4341 if (skp) 4342 s = skp->smk_secid; 4343 #endif 4344 break; 4345 } 4346 *secid = s; 4347 if (s == 0) 4348 return -EINVAL; 4349 return 0; 4350 } 4351 4352 /** 4353 * smack_sock_graft - Initialize a newly created socket with an existing sock 4354 * @sk: child sock 4355 * @parent: parent socket 4356 * 4357 * Set the smk_{in,out} state of an existing sock based on the process that 4358 * is creating the new socket. 4359 */ 4360 static void smack_sock_graft(struct sock *sk, struct socket *parent) 4361 { 4362 struct socket_smack *ssp; 4363 struct smack_known *skp = smk_of_current(); 4364 4365 if (sk == NULL || 4366 (sk->sk_family != PF_INET && sk->sk_family != PF_INET6)) 4367 return; 4368 4369 ssp = smack_sock(sk); 4370 ssp->smk_in = skp; 4371 ssp->smk_out = skp; 4372 /* cssp->smk_packet is already set in smack_inet_csk_clone() */ 4373 } 4374 4375 /** 4376 * smack_inet_conn_request - Smack access check on connect 4377 * @sk: socket involved 4378 * @skb: packet 4379 * @req: unused 4380 * 4381 * Returns 0 if a task with the packet label could write to 4382 * the socket, otherwise an error code 4383 */ 4384 static int smack_inet_conn_request(const struct sock *sk, struct sk_buff *skb, 4385 struct request_sock *req) 4386 { 4387 u16 family = sk->sk_family; 4388 struct smack_known *skp; 4389 struct socket_smack *ssp = smack_sock(sk); 4390 struct sockaddr_in addr; 4391 struct iphdr *hdr; 4392 struct smack_known *hskp; 4393 int rc; 4394 struct smk_audit_info ad; 4395 #ifdef CONFIG_AUDIT 4396 struct lsm_network_audit net; 4397 #endif 4398 4399 #if IS_ENABLED(CONFIG_IPV6) 4400 if (family == PF_INET6) { 4401 /* 4402 * Handle mapped IPv4 packets arriving 4403 * via IPv6 sockets. Don't set up netlabel 4404 * processing on IPv6. 4405 */ 4406 if (skb->protocol == htons(ETH_P_IP)) 4407 family = PF_INET; 4408 else 4409 return 0; 4410 } 4411 #endif /* CONFIG_IPV6 */ 4412 4413 /* 4414 * If there is a secmark use it rather than the CIPSO label. 4415 * If there is no secmark fall back to CIPSO. 4416 * The secmark is assumed to reflect policy better. 4417 */ 4418 skp = smack_from_skb(skb); 4419 if (skp == NULL) { 4420 skp = smack_from_netlbl(sk, family, skb); 4421 if (skp == NULL) 4422 skp = &smack_known_huh; 4423 } 4424 4425 #ifdef CONFIG_AUDIT 4426 smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net); 4427 ad.a.u.net->family = family; 4428 ad.a.u.net->netif = skb->skb_iif; 4429 ipv4_skb_to_auditdata(skb, &ad.a, NULL); 4430 #endif 4431 /* 4432 * Receiving a packet requires that the other end be able to write 4433 * here. Read access is not required. 4434 */ 4435 rc = smk_access(skp, ssp->smk_in, MAY_WRITE, &ad); 4436 rc = smk_bu_note("IPv4 connect", skp, ssp->smk_in, MAY_WRITE, rc); 4437 if (rc != 0) 4438 return rc; 4439 4440 /* 4441 * Save the peer's label in the request_sock so we can later setup 4442 * smk_packet in the child socket so that SO_PEERCRED can report it. 4443 */ 4444 req->peer_secid = skp->smk_secid; 4445 4446 /* 4447 * We need to decide if we want to label the incoming connection here 4448 * if we do we only need to label the request_sock and the stack will 4449 * propagate the wire-label to the sock when it is created. 4450 */ 4451 hdr = ip_hdr(skb); 4452 addr.sin_addr.s_addr = hdr->saddr; 4453 rcu_read_lock(); 4454 hskp = smack_ipv4host_label(&addr); 4455 rcu_read_unlock(); 4456 4457 if (hskp == NULL) 4458 rc = netlbl_req_setattr(req, &ssp->smk_out->smk_netlabel); 4459 else 4460 netlbl_req_delattr(req); 4461 4462 return rc; 4463 } 4464 4465 /** 4466 * smack_inet_csk_clone - Copy the connection information to the new socket 4467 * @sk: the new socket 4468 * @req: the connection's request_sock 4469 * 4470 * Transfer the connection's peer label to the newly created socket. 4471 */ 4472 static void smack_inet_csk_clone(struct sock *sk, 4473 const struct request_sock *req) 4474 { 4475 struct socket_smack *ssp = smack_sock(sk); 4476 struct smack_known *skp; 4477 4478 if (req->peer_secid != 0) { 4479 skp = smack_from_secid(req->peer_secid); 4480 ssp->smk_packet = skp; 4481 } else 4482 ssp->smk_packet = NULL; 4483 } 4484 4485 /* 4486 * Key management security hooks 4487 * 4488 * Casey has not tested key support very heavily. 4489 * The permission check is most likely too restrictive. 4490 * If you care about keys please have a look. 4491 */ 4492 #ifdef CONFIG_KEYS 4493 4494 /** 4495 * smack_key_alloc - Set the key security blob 4496 * @key: object 4497 * @cred: the credentials to use 4498 * @flags: unused 4499 * 4500 * No allocation required 4501 * 4502 * Returns 0 4503 */ 4504 static int smack_key_alloc(struct key *key, const struct cred *cred, 4505 unsigned long flags) 4506 { 4507 struct smack_known **blob = smack_key(key); 4508 struct smack_known *skp = smk_of_task(smack_cred(cred)); 4509 4510 *blob = skp; 4511 return 0; 4512 } 4513 4514 /** 4515 * smack_key_permission - Smack access on a key 4516 * @key_ref: gets to the object 4517 * @cred: the credentials to use 4518 * @need_perm: requested key permission 4519 * 4520 * Return 0 if the task has read and write to the object, 4521 * an error code otherwise 4522 */ 4523 static int smack_key_permission(key_ref_t key_ref, 4524 const struct cred *cred, 4525 enum key_need_perm need_perm) 4526 { 4527 struct smack_known **blob; 4528 struct smack_known *skp; 4529 struct key *keyp; 4530 struct smk_audit_info ad; 4531 struct smack_known *tkp = smk_of_task(smack_cred(cred)); 4532 int request = 0; 4533 int rc; 4534 4535 /* 4536 * Validate requested permissions 4537 */ 4538 switch (need_perm) { 4539 case KEY_NEED_READ: 4540 case KEY_NEED_SEARCH: 4541 case KEY_NEED_VIEW: 4542 request |= MAY_READ; 4543 break; 4544 case KEY_NEED_WRITE: 4545 case KEY_NEED_LINK: 4546 case KEY_NEED_SETATTR: 4547 request |= MAY_WRITE; 4548 break; 4549 case KEY_NEED_UNSPECIFIED: 4550 case KEY_NEED_UNLINK: 4551 case KEY_SYSADMIN_OVERRIDE: 4552 case KEY_AUTHTOKEN_OVERRIDE: 4553 case KEY_DEFER_PERM_CHECK: 4554 return 0; 4555 default: 4556 return -EINVAL; 4557 } 4558 4559 keyp = key_ref_to_ptr(key_ref); 4560 if (keyp == NULL) 4561 return -EINVAL; 4562 /* 4563 * If the key hasn't been initialized give it access so that 4564 * it may do so. 4565 */ 4566 blob = smack_key(keyp); 4567 skp = *blob; 4568 if (skp == NULL) 4569 return 0; 4570 /* 4571 * This should not occur 4572 */ 4573 if (tkp == NULL) 4574 return -EACCES; 4575 4576 if (smack_privileged(CAP_MAC_OVERRIDE)) 4577 return 0; 4578 4579 #ifdef CONFIG_AUDIT 4580 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_KEY); 4581 ad.a.u.key_struct.key = keyp->serial; 4582 ad.a.u.key_struct.key_desc = keyp->description; 4583 #endif 4584 rc = smk_access(tkp, skp, request, &ad); 4585 rc = smk_bu_note("key access", tkp, skp, request, rc); 4586 return rc; 4587 } 4588 4589 /* 4590 * smack_key_getsecurity - Smack label tagging the key 4591 * @key points to the key to be queried 4592 * @_buffer points to a pointer that should be set to point to the 4593 * resulting string (if no label or an error occurs). 4594 * Return the length of the string (including terminating NUL) or -ve if 4595 * an error. 4596 * May also return 0 (and a NULL buffer pointer) if there is no label. 4597 */ 4598 static int smack_key_getsecurity(struct key *key, char **_buffer) 4599 { 4600 struct smack_known **blob = smack_key(key); 4601 struct smack_known *skp = *blob; 4602 size_t length; 4603 char *copy; 4604 4605 if (skp == NULL) { 4606 *_buffer = NULL; 4607 return 0; 4608 } 4609 4610 copy = kstrdup(skp->smk_known, GFP_KERNEL); 4611 if (copy == NULL) 4612 return -ENOMEM; 4613 length = strlen(copy) + 1; 4614 4615 *_buffer = copy; 4616 return length; 4617 } 4618 4619 4620 #ifdef CONFIG_KEY_NOTIFICATIONS 4621 /** 4622 * smack_watch_key - Smack access to watch a key for notifications. 4623 * @key: The key to be watched 4624 * 4625 * Return 0 if the @watch->cred has permission to read from the key object and 4626 * an error otherwise. 4627 */ 4628 static int smack_watch_key(struct key *key) 4629 { 4630 struct smk_audit_info ad; 4631 struct smack_known *tkp = smk_of_current(); 4632 struct smack_known **blob = smack_key(key); 4633 int rc; 4634 4635 /* 4636 * This should not occur 4637 */ 4638 if (tkp == NULL) 4639 return -EACCES; 4640 4641 if (smack_privileged_cred(CAP_MAC_OVERRIDE, current_cred())) 4642 return 0; 4643 4644 #ifdef CONFIG_AUDIT 4645 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_KEY); 4646 ad.a.u.key_struct.key = key->serial; 4647 ad.a.u.key_struct.key_desc = key->description; 4648 #endif 4649 rc = smk_access(tkp, *blob, MAY_READ, &ad); 4650 rc = smk_bu_note("key watch", tkp, *blob, MAY_READ, rc); 4651 return rc; 4652 } 4653 #endif /* CONFIG_KEY_NOTIFICATIONS */ 4654 #endif /* CONFIG_KEYS */ 4655 4656 #ifdef CONFIG_WATCH_QUEUE 4657 /** 4658 * smack_post_notification - Smack access to post a notification to a queue 4659 * @w_cred: The credentials of the watcher. 4660 * @cred: The credentials of the event source (may be NULL). 4661 * @n: The notification message to be posted. 4662 */ 4663 static int smack_post_notification(const struct cred *w_cred, 4664 const struct cred *cred, 4665 struct watch_notification *n) 4666 { 4667 struct smk_audit_info ad; 4668 struct smack_known *subj, *obj; 4669 int rc; 4670 4671 /* Always let maintenance notifications through. */ 4672 if (n->type == WATCH_TYPE_META) 4673 return 0; 4674 4675 if (!cred) 4676 return 0; 4677 subj = smk_of_task(smack_cred(cred)); 4678 obj = smk_of_task(smack_cred(w_cred)); 4679 4680 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_NOTIFICATION); 4681 rc = smk_access(subj, obj, MAY_WRITE, &ad); 4682 rc = smk_bu_note("notification", subj, obj, MAY_WRITE, rc); 4683 return rc; 4684 } 4685 #endif /* CONFIG_WATCH_QUEUE */ 4686 4687 /* 4688 * Smack Audit hooks 4689 * 4690 * Audit requires a unique representation of each Smack specific 4691 * rule. This unique representation is used to distinguish the 4692 * object to be audited from remaining kernel objects and also 4693 * works as a glue between the audit hooks. 4694 * 4695 * Since repository entries are added but never deleted, we'll use 4696 * the smack_known label address related to the given audit rule as 4697 * the needed unique representation. This also better fits the smack 4698 * model where nearly everything is a label. 4699 */ 4700 #ifdef CONFIG_AUDIT 4701 4702 /** 4703 * smack_audit_rule_init - Initialize a smack audit rule 4704 * @field: audit rule fields given from user-space (audit.h) 4705 * @op: required testing operator (=, !=, >, <, ...) 4706 * @rulestr: smack label to be audited 4707 * @vrule: pointer to save our own audit rule representation 4708 * @gfp: type of the memory for the allocation 4709 * 4710 * Prepare to audit cases where (@field @op @rulestr) is true. 4711 * The label to be audited is created if necessay. 4712 */ 4713 static int smack_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule, 4714 gfp_t gfp) 4715 { 4716 struct smack_known *skp; 4717 char **rule = (char **)vrule; 4718 *rule = NULL; 4719 4720 if (field != AUDIT_SUBJ_USER && field != AUDIT_OBJ_USER) 4721 return -EINVAL; 4722 4723 if (op != Audit_equal && op != Audit_not_equal) 4724 return -EINVAL; 4725 4726 skp = smk_import_entry(rulestr, 0); 4727 if (IS_ERR(skp)) 4728 return PTR_ERR(skp); 4729 4730 *rule = skp->smk_known; 4731 4732 return 0; 4733 } 4734 4735 /** 4736 * smack_audit_rule_known - Distinguish Smack audit rules 4737 * @krule: rule of interest, in Audit kernel representation format 4738 * 4739 * This is used to filter Smack rules from remaining Audit ones. 4740 * If it's proved that this rule belongs to us, the 4741 * audit_rule_match hook will be called to do the final judgement. 4742 */ 4743 static int smack_audit_rule_known(struct audit_krule *krule) 4744 { 4745 struct audit_field *f; 4746 int i; 4747 4748 for (i = 0; i < krule->field_count; i++) { 4749 f = &krule->fields[i]; 4750 4751 if (f->type == AUDIT_SUBJ_USER || f->type == AUDIT_OBJ_USER) 4752 return 1; 4753 } 4754 4755 return 0; 4756 } 4757 4758 /** 4759 * smack_audit_rule_match - Audit given object ? 4760 * @secid: security id for identifying the object to test 4761 * @field: audit rule flags given from user-space 4762 * @op: required testing operator 4763 * @vrule: smack internal rule presentation 4764 * 4765 * The core Audit hook. It's used to take the decision of 4766 * whether to audit or not to audit a given object. 4767 */ 4768 static int smack_audit_rule_match(u32 secid, u32 field, u32 op, void *vrule) 4769 { 4770 struct smack_known *skp; 4771 char *rule = vrule; 4772 4773 if (unlikely(!rule)) { 4774 WARN_ONCE(1, "Smack: missing rule\n"); 4775 return -ENOENT; 4776 } 4777 4778 if (field != AUDIT_SUBJ_USER && field != AUDIT_OBJ_USER) 4779 return 0; 4780 4781 skp = smack_from_secid(secid); 4782 4783 /* 4784 * No need to do string comparisons. If a match occurs, 4785 * both pointers will point to the same smack_known 4786 * label. 4787 */ 4788 if (op == Audit_equal) 4789 return (rule == skp->smk_known); 4790 if (op == Audit_not_equal) 4791 return (rule != skp->smk_known); 4792 4793 return 0; 4794 } 4795 4796 /* 4797 * There is no need for a smack_audit_rule_free hook. 4798 * No memory was allocated. 4799 */ 4800 4801 #endif /* CONFIG_AUDIT */ 4802 4803 /** 4804 * smack_ismaclabel - check if xattr @name references a smack MAC label 4805 * @name: Full xattr name to check. 4806 */ 4807 static int smack_ismaclabel(const char *name) 4808 { 4809 return (strcmp(name, XATTR_SMACK_SUFFIX) == 0); 4810 } 4811 4812 4813 /** 4814 * smack_secid_to_secctx - return the smack label for a secid 4815 * @secid: incoming integer 4816 * @secdata: destination 4817 * @seclen: how long it is 4818 * 4819 * Exists for networking code. 4820 */ 4821 static int smack_secid_to_secctx(u32 secid, char **secdata, u32 *seclen) 4822 { 4823 struct smack_known *skp = smack_from_secid(secid); 4824 4825 if (secdata) 4826 *secdata = skp->smk_known; 4827 *seclen = strlen(skp->smk_known); 4828 return 0; 4829 } 4830 4831 /** 4832 * smack_secctx_to_secid - return the secid for a smack label 4833 * @secdata: smack label 4834 * @seclen: how long result is 4835 * @secid: outgoing integer 4836 * 4837 * Exists for audit and networking code. 4838 */ 4839 static int smack_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid) 4840 { 4841 struct smack_known *skp = smk_find_entry(secdata); 4842 4843 if (skp) 4844 *secid = skp->smk_secid; 4845 else 4846 *secid = 0; 4847 return 0; 4848 } 4849 4850 /* 4851 * There used to be a smack_release_secctx hook 4852 * that did nothing back when hooks were in a vector. 4853 * Now that there's a list such a hook adds cost. 4854 */ 4855 4856 static int smack_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen) 4857 { 4858 return smack_inode_setsecurity(inode, XATTR_SMACK_SUFFIX, ctx, 4859 ctxlen, 0); 4860 } 4861 4862 static int smack_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen) 4863 { 4864 return __vfs_setxattr_locked(&nop_mnt_idmap, dentry, XATTR_NAME_SMACK, 4865 ctx, ctxlen, 0, NULL); 4866 } 4867 4868 static int smack_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen) 4869 { 4870 struct smack_known *skp = smk_of_inode(inode); 4871 4872 *ctx = skp->smk_known; 4873 *ctxlen = strlen(skp->smk_known); 4874 return 0; 4875 } 4876 4877 static int smack_inode_copy_up(struct dentry *dentry, struct cred **new) 4878 { 4879 4880 struct task_smack *tsp; 4881 struct smack_known *skp; 4882 struct inode_smack *isp; 4883 struct cred *new_creds = *new; 4884 4885 if (new_creds == NULL) { 4886 new_creds = prepare_creds(); 4887 if (new_creds == NULL) 4888 return -ENOMEM; 4889 } 4890 4891 tsp = smack_cred(new_creds); 4892 4893 /* 4894 * Get label from overlay inode and set it in create_sid 4895 */ 4896 isp = smack_inode(d_inode(dentry)); 4897 skp = isp->smk_inode; 4898 tsp->smk_task = skp; 4899 *new = new_creds; 4900 return 0; 4901 } 4902 4903 static int smack_inode_copy_up_xattr(struct dentry *src, const char *name) 4904 { 4905 /* 4906 * Return -ECANCELED if this is the smack access Smack attribute. 4907 */ 4908 if (!strcmp(name, XATTR_NAME_SMACK)) 4909 return -ECANCELED; 4910 4911 return -EOPNOTSUPP; 4912 } 4913 4914 static int smack_dentry_create_files_as(struct dentry *dentry, int mode, 4915 struct qstr *name, 4916 const struct cred *old, 4917 struct cred *new) 4918 { 4919 struct task_smack *otsp = smack_cred(old); 4920 struct task_smack *ntsp = smack_cred(new); 4921 struct inode_smack *isp; 4922 int may; 4923 4924 /* 4925 * Use the process credential unless all of 4926 * the transmuting criteria are met 4927 */ 4928 ntsp->smk_task = otsp->smk_task; 4929 4930 /* 4931 * the attribute of the containing directory 4932 */ 4933 isp = smack_inode(d_inode(dentry->d_parent)); 4934 4935 if (isp->smk_flags & SMK_INODE_TRANSMUTE) { 4936 rcu_read_lock(); 4937 may = smk_access_entry(otsp->smk_task->smk_known, 4938 isp->smk_inode->smk_known, 4939 &otsp->smk_task->smk_rules); 4940 rcu_read_unlock(); 4941 4942 /* 4943 * If the directory is transmuting and the rule 4944 * providing access is transmuting use the containing 4945 * directory label instead of the process label. 4946 */ 4947 if (may > 0 && (may & MAY_TRANSMUTE)) { 4948 ntsp->smk_task = isp->smk_inode; 4949 ntsp->smk_transmuted = ntsp->smk_task; 4950 } 4951 } 4952 return 0; 4953 } 4954 4955 #ifdef CONFIG_IO_URING 4956 /** 4957 * smack_uring_override_creds - Is io_uring cred override allowed? 4958 * @new: the target creds 4959 * 4960 * Check to see if the current task is allowed to override it's credentials 4961 * to service an io_uring operation. 4962 */ 4963 static int smack_uring_override_creds(const struct cred *new) 4964 { 4965 struct task_smack *tsp = smack_cred(current_cred()); 4966 struct task_smack *nsp = smack_cred(new); 4967 4968 /* 4969 * Allow the degenerate case where the new Smack value is 4970 * the same as the current Smack value. 4971 */ 4972 if (tsp->smk_task == nsp->smk_task) 4973 return 0; 4974 4975 if (smack_privileged_cred(CAP_MAC_OVERRIDE, current_cred())) 4976 return 0; 4977 4978 return -EPERM; 4979 } 4980 4981 /** 4982 * smack_uring_sqpoll - check if a io_uring polling thread can be created 4983 * 4984 * Check to see if the current task is allowed to create a new io_uring 4985 * kernel polling thread. 4986 */ 4987 static int smack_uring_sqpoll(void) 4988 { 4989 if (smack_privileged_cred(CAP_MAC_ADMIN, current_cred())) 4990 return 0; 4991 4992 return -EPERM; 4993 } 4994 4995 /** 4996 * smack_uring_cmd - check on file operations for io_uring 4997 * @ioucmd: the command in question 4998 * 4999 * Make a best guess about whether a io_uring "command" should 5000 * be allowed. Use the same logic used for determining if the 5001 * file could be opened for read in the absence of better criteria. 5002 */ 5003 static int smack_uring_cmd(struct io_uring_cmd *ioucmd) 5004 { 5005 struct file *file = ioucmd->file; 5006 struct smk_audit_info ad; 5007 struct task_smack *tsp; 5008 struct inode *inode; 5009 int rc; 5010 5011 if (!file) 5012 return -EINVAL; 5013 5014 tsp = smack_cred(file->f_cred); 5015 inode = file_inode(file); 5016 5017 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH); 5018 smk_ad_setfield_u_fs_path(&ad, file->f_path); 5019 rc = smk_tskacc(tsp, smk_of_inode(inode), MAY_READ, &ad); 5020 rc = smk_bu_credfile(file->f_cred, file, MAY_READ, rc); 5021 5022 return rc; 5023 } 5024 5025 #endif /* CONFIG_IO_URING */ 5026 5027 struct lsm_blob_sizes smack_blob_sizes __ro_after_init = { 5028 .lbs_cred = sizeof(struct task_smack), 5029 .lbs_file = sizeof(struct smack_known *), 5030 .lbs_inode = sizeof(struct inode_smack), 5031 .lbs_ipc = sizeof(struct smack_known *), 5032 .lbs_key = sizeof(struct smack_known *), 5033 .lbs_msg_msg = sizeof(struct smack_known *), 5034 .lbs_sock = sizeof(struct socket_smack), 5035 .lbs_superblock = sizeof(struct superblock_smack), 5036 .lbs_xattr_count = SMACK_INODE_INIT_XATTRS, 5037 }; 5038 5039 static const struct lsm_id smack_lsmid = { 5040 .name = "smack", 5041 .id = LSM_ID_SMACK, 5042 }; 5043 5044 static struct security_hook_list smack_hooks[] __ro_after_init = { 5045 LSM_HOOK_INIT(ptrace_access_check, smack_ptrace_access_check), 5046 LSM_HOOK_INIT(ptrace_traceme, smack_ptrace_traceme), 5047 LSM_HOOK_INIT(syslog, smack_syslog), 5048 5049 LSM_HOOK_INIT(fs_context_submount, smack_fs_context_submount), 5050 LSM_HOOK_INIT(fs_context_dup, smack_fs_context_dup), 5051 LSM_HOOK_INIT(fs_context_parse_param, smack_fs_context_parse_param), 5052 5053 LSM_HOOK_INIT(sb_alloc_security, smack_sb_alloc_security), 5054 LSM_HOOK_INIT(sb_free_mnt_opts, smack_free_mnt_opts), 5055 LSM_HOOK_INIT(sb_eat_lsm_opts, smack_sb_eat_lsm_opts), 5056 LSM_HOOK_INIT(sb_statfs, smack_sb_statfs), 5057 LSM_HOOK_INIT(sb_set_mnt_opts, smack_set_mnt_opts), 5058 5059 LSM_HOOK_INIT(bprm_creds_for_exec, smack_bprm_creds_for_exec), 5060 5061 LSM_HOOK_INIT(inode_alloc_security, smack_inode_alloc_security), 5062 LSM_HOOK_INIT(inode_init_security, smack_inode_init_security), 5063 LSM_HOOK_INIT(inode_link, smack_inode_link), 5064 LSM_HOOK_INIT(inode_unlink, smack_inode_unlink), 5065 LSM_HOOK_INIT(inode_rmdir, smack_inode_rmdir), 5066 LSM_HOOK_INIT(inode_rename, smack_inode_rename), 5067 LSM_HOOK_INIT(inode_permission, smack_inode_permission), 5068 LSM_HOOK_INIT(inode_setattr, smack_inode_setattr), 5069 LSM_HOOK_INIT(inode_getattr, smack_inode_getattr), 5070 LSM_HOOK_INIT(inode_xattr_skipcap, smack_inode_xattr_skipcap), 5071 LSM_HOOK_INIT(inode_setxattr, smack_inode_setxattr), 5072 LSM_HOOK_INIT(inode_post_setxattr, smack_inode_post_setxattr), 5073 LSM_HOOK_INIT(inode_getxattr, smack_inode_getxattr), 5074 LSM_HOOK_INIT(inode_removexattr, smack_inode_removexattr), 5075 LSM_HOOK_INIT(inode_set_acl, smack_inode_set_acl), 5076 LSM_HOOK_INIT(inode_get_acl, smack_inode_get_acl), 5077 LSM_HOOK_INIT(inode_remove_acl, smack_inode_remove_acl), 5078 LSM_HOOK_INIT(inode_getsecurity, smack_inode_getsecurity), 5079 LSM_HOOK_INIT(inode_setsecurity, smack_inode_setsecurity), 5080 LSM_HOOK_INIT(inode_listsecurity, smack_inode_listsecurity), 5081 LSM_HOOK_INIT(inode_getsecid, smack_inode_getsecid), 5082 5083 LSM_HOOK_INIT(file_alloc_security, smack_file_alloc_security), 5084 LSM_HOOK_INIT(file_ioctl, smack_file_ioctl), 5085 LSM_HOOK_INIT(file_ioctl_compat, smack_file_ioctl), 5086 LSM_HOOK_INIT(file_lock, smack_file_lock), 5087 LSM_HOOK_INIT(file_fcntl, smack_file_fcntl), 5088 LSM_HOOK_INIT(mmap_file, smack_mmap_file), 5089 LSM_HOOK_INIT(mmap_addr, cap_mmap_addr), 5090 LSM_HOOK_INIT(file_set_fowner, smack_file_set_fowner), 5091 LSM_HOOK_INIT(file_send_sigiotask, smack_file_send_sigiotask), 5092 LSM_HOOK_INIT(file_receive, smack_file_receive), 5093 5094 LSM_HOOK_INIT(file_open, smack_file_open), 5095 5096 LSM_HOOK_INIT(cred_alloc_blank, smack_cred_alloc_blank), 5097 LSM_HOOK_INIT(cred_free, smack_cred_free), 5098 LSM_HOOK_INIT(cred_prepare, smack_cred_prepare), 5099 LSM_HOOK_INIT(cred_transfer, smack_cred_transfer), 5100 LSM_HOOK_INIT(cred_getsecid, smack_cred_getsecid), 5101 LSM_HOOK_INIT(kernel_act_as, smack_kernel_act_as), 5102 LSM_HOOK_INIT(kernel_create_files_as, smack_kernel_create_files_as), 5103 LSM_HOOK_INIT(task_setpgid, smack_task_setpgid), 5104 LSM_HOOK_INIT(task_getpgid, smack_task_getpgid), 5105 LSM_HOOK_INIT(task_getsid, smack_task_getsid), 5106 LSM_HOOK_INIT(current_getsecid_subj, smack_current_getsecid_subj), 5107 LSM_HOOK_INIT(task_getsecid_obj, smack_task_getsecid_obj), 5108 LSM_HOOK_INIT(task_setnice, smack_task_setnice), 5109 LSM_HOOK_INIT(task_setioprio, smack_task_setioprio), 5110 LSM_HOOK_INIT(task_getioprio, smack_task_getioprio), 5111 LSM_HOOK_INIT(task_setscheduler, smack_task_setscheduler), 5112 LSM_HOOK_INIT(task_getscheduler, smack_task_getscheduler), 5113 LSM_HOOK_INIT(task_movememory, smack_task_movememory), 5114 LSM_HOOK_INIT(task_kill, smack_task_kill), 5115 LSM_HOOK_INIT(task_to_inode, smack_task_to_inode), 5116 5117 LSM_HOOK_INIT(ipc_permission, smack_ipc_permission), 5118 LSM_HOOK_INIT(ipc_getsecid, smack_ipc_getsecid), 5119 5120 LSM_HOOK_INIT(msg_msg_alloc_security, smack_msg_msg_alloc_security), 5121 5122 LSM_HOOK_INIT(msg_queue_alloc_security, smack_ipc_alloc_security), 5123 LSM_HOOK_INIT(msg_queue_associate, smack_msg_queue_associate), 5124 LSM_HOOK_INIT(msg_queue_msgctl, smack_msg_queue_msgctl), 5125 LSM_HOOK_INIT(msg_queue_msgsnd, smack_msg_queue_msgsnd), 5126 LSM_HOOK_INIT(msg_queue_msgrcv, smack_msg_queue_msgrcv), 5127 5128 LSM_HOOK_INIT(shm_alloc_security, smack_ipc_alloc_security), 5129 LSM_HOOK_INIT(shm_associate, smack_shm_associate), 5130 LSM_HOOK_INIT(shm_shmctl, smack_shm_shmctl), 5131 LSM_HOOK_INIT(shm_shmat, smack_shm_shmat), 5132 5133 LSM_HOOK_INIT(sem_alloc_security, smack_ipc_alloc_security), 5134 LSM_HOOK_INIT(sem_associate, smack_sem_associate), 5135 LSM_HOOK_INIT(sem_semctl, smack_sem_semctl), 5136 LSM_HOOK_INIT(sem_semop, smack_sem_semop), 5137 5138 LSM_HOOK_INIT(d_instantiate, smack_d_instantiate), 5139 5140 LSM_HOOK_INIT(getselfattr, smack_getselfattr), 5141 LSM_HOOK_INIT(setselfattr, smack_setselfattr), 5142 LSM_HOOK_INIT(getprocattr, smack_getprocattr), 5143 LSM_HOOK_INIT(setprocattr, smack_setprocattr), 5144 5145 LSM_HOOK_INIT(unix_stream_connect, smack_unix_stream_connect), 5146 LSM_HOOK_INIT(unix_may_send, smack_unix_may_send), 5147 5148 LSM_HOOK_INIT(socket_post_create, smack_socket_post_create), 5149 LSM_HOOK_INIT(socket_socketpair, smack_socket_socketpair), 5150 #ifdef SMACK_IPV6_PORT_LABELING 5151 LSM_HOOK_INIT(socket_bind, smack_socket_bind), 5152 #endif 5153 LSM_HOOK_INIT(socket_connect, smack_socket_connect), 5154 LSM_HOOK_INIT(socket_sendmsg, smack_socket_sendmsg), 5155 LSM_HOOK_INIT(socket_sock_rcv_skb, smack_socket_sock_rcv_skb), 5156 LSM_HOOK_INIT(socket_getpeersec_stream, smack_socket_getpeersec_stream), 5157 LSM_HOOK_INIT(socket_getpeersec_dgram, smack_socket_getpeersec_dgram), 5158 LSM_HOOK_INIT(sk_alloc_security, smack_sk_alloc_security), 5159 #ifdef SMACK_IPV6_PORT_LABELING 5160 LSM_HOOK_INIT(sk_free_security, smack_sk_free_security), 5161 #endif 5162 LSM_HOOK_INIT(sk_clone_security, smack_sk_clone_security), 5163 LSM_HOOK_INIT(sock_graft, smack_sock_graft), 5164 LSM_HOOK_INIT(inet_conn_request, smack_inet_conn_request), 5165 LSM_HOOK_INIT(inet_csk_clone, smack_inet_csk_clone), 5166 5167 /* key management security hooks */ 5168 #ifdef CONFIG_KEYS 5169 LSM_HOOK_INIT(key_alloc, smack_key_alloc), 5170 LSM_HOOK_INIT(key_permission, smack_key_permission), 5171 LSM_HOOK_INIT(key_getsecurity, smack_key_getsecurity), 5172 #ifdef CONFIG_KEY_NOTIFICATIONS 5173 LSM_HOOK_INIT(watch_key, smack_watch_key), 5174 #endif 5175 #endif /* CONFIG_KEYS */ 5176 5177 #ifdef CONFIG_WATCH_QUEUE 5178 LSM_HOOK_INIT(post_notification, smack_post_notification), 5179 #endif 5180 5181 /* Audit hooks */ 5182 #ifdef CONFIG_AUDIT 5183 LSM_HOOK_INIT(audit_rule_init, smack_audit_rule_init), 5184 LSM_HOOK_INIT(audit_rule_known, smack_audit_rule_known), 5185 LSM_HOOK_INIT(audit_rule_match, smack_audit_rule_match), 5186 #endif /* CONFIG_AUDIT */ 5187 5188 LSM_HOOK_INIT(ismaclabel, smack_ismaclabel), 5189 LSM_HOOK_INIT(secid_to_secctx, smack_secid_to_secctx), 5190 LSM_HOOK_INIT(secctx_to_secid, smack_secctx_to_secid), 5191 LSM_HOOK_INIT(inode_notifysecctx, smack_inode_notifysecctx), 5192 LSM_HOOK_INIT(inode_setsecctx, smack_inode_setsecctx), 5193 LSM_HOOK_INIT(inode_getsecctx, smack_inode_getsecctx), 5194 LSM_HOOK_INIT(inode_copy_up, smack_inode_copy_up), 5195 LSM_HOOK_INIT(inode_copy_up_xattr, smack_inode_copy_up_xattr), 5196 LSM_HOOK_INIT(dentry_create_files_as, smack_dentry_create_files_as), 5197 #ifdef CONFIG_IO_URING 5198 LSM_HOOK_INIT(uring_override_creds, smack_uring_override_creds), 5199 LSM_HOOK_INIT(uring_sqpoll, smack_uring_sqpoll), 5200 LSM_HOOK_INIT(uring_cmd, smack_uring_cmd), 5201 #endif 5202 }; 5203 5204 5205 static __init void init_smack_known_list(void) 5206 { 5207 /* 5208 * Initialize rule list locks 5209 */ 5210 mutex_init(&smack_known_huh.smk_rules_lock); 5211 mutex_init(&smack_known_hat.smk_rules_lock); 5212 mutex_init(&smack_known_floor.smk_rules_lock); 5213 mutex_init(&smack_known_star.smk_rules_lock); 5214 mutex_init(&smack_known_web.smk_rules_lock); 5215 /* 5216 * Initialize rule lists 5217 */ 5218 INIT_LIST_HEAD(&smack_known_huh.smk_rules); 5219 INIT_LIST_HEAD(&smack_known_hat.smk_rules); 5220 INIT_LIST_HEAD(&smack_known_star.smk_rules); 5221 INIT_LIST_HEAD(&smack_known_floor.smk_rules); 5222 INIT_LIST_HEAD(&smack_known_web.smk_rules); 5223 /* 5224 * Create the known labels list 5225 */ 5226 smk_insert_entry(&smack_known_huh); 5227 smk_insert_entry(&smack_known_hat); 5228 smk_insert_entry(&smack_known_star); 5229 smk_insert_entry(&smack_known_floor); 5230 smk_insert_entry(&smack_known_web); 5231 } 5232 5233 /** 5234 * smack_init - initialize the smack system 5235 * 5236 * Returns 0 on success, -ENOMEM is there's no memory 5237 */ 5238 static __init int smack_init(void) 5239 { 5240 struct cred *cred = (struct cred *) current->cred; 5241 struct task_smack *tsp; 5242 5243 smack_rule_cache = KMEM_CACHE(smack_rule, 0); 5244 if (!smack_rule_cache) 5245 return -ENOMEM; 5246 5247 /* 5248 * Set the security state for the initial task. 5249 */ 5250 tsp = smack_cred(cred); 5251 init_task_smack(tsp, &smack_known_floor, &smack_known_floor); 5252 5253 /* 5254 * Register with LSM 5255 */ 5256 security_add_hooks(smack_hooks, ARRAY_SIZE(smack_hooks), &smack_lsmid); 5257 smack_enabled = 1; 5258 5259 pr_info("Smack: Initializing.\n"); 5260 #ifdef CONFIG_SECURITY_SMACK_NETFILTER 5261 pr_info("Smack: Netfilter enabled.\n"); 5262 #endif 5263 #ifdef SMACK_IPV6_PORT_LABELING 5264 pr_info("Smack: IPv6 port labeling enabled.\n"); 5265 #endif 5266 #ifdef SMACK_IPV6_SECMARK_LABELING 5267 pr_info("Smack: IPv6 Netfilter enabled.\n"); 5268 #endif 5269 5270 /* initialize the smack_known_list */ 5271 init_smack_known_list(); 5272 5273 return 0; 5274 } 5275 5276 /* 5277 * Smack requires early initialization in order to label 5278 * all processes and objects when they are created. 5279 */ 5280 DEFINE_LSM(smack) = { 5281 .name = "smack", 5282 .flags = LSM_FLAG_LEGACY_MAJOR | LSM_FLAG_EXCLUSIVE, 5283 .blobs = &smack_blob_sizes, 5284 .init = smack_init, 5285 }; 5286