1 /* 2 * AppArmor security module 3 * 4 * This file contains AppArmor LSM hooks. 5 * 6 * Copyright (C) 1998-2008 Novell/SUSE 7 * Copyright 2009-2010 Canonical Ltd. 8 * 9 * This program is free software; you can redistribute it and/or 10 * modify it under the terms of the GNU General Public License as 11 * published by the Free Software Foundation, version 2 of the 12 * License. 13 */ 14 15 #include <linux/security.h> 16 #include <linux/moduleparam.h> 17 #include <linux/mm.h> 18 #include <linux/mman.h> 19 #include <linux/mount.h> 20 #include <linux/namei.h> 21 #include <linux/ptrace.h> 22 #include <linux/ctype.h> 23 #include <linux/sysctl.h> 24 #include <linux/audit.h> 25 #include <linux/user_namespace.h> 26 #include <net/sock.h> 27 28 #include "include/apparmor.h" 29 #include "include/apparmorfs.h" 30 #include "include/audit.h" 31 #include "include/capability.h" 32 #include "include/context.h" 33 #include "include/file.h" 34 #include "include/ipc.h" 35 #include "include/path.h" 36 #include "include/policy.h" 37 #include "include/procattr.h" 38 39 /* Flag indicating whether initialization completed */ 40 int apparmor_initialized __initdata; 41 42 /* 43 * LSM hook functions 44 */ 45 46 /* 47 * free the associated aa_task_cxt and put its profiles 48 */ 49 static void apparmor_cred_free(struct cred *cred) 50 { 51 aa_free_task_context(cred->security); 52 cred->security = NULL; 53 } 54 55 /* 56 * allocate the apparmor part of blank credentials 57 */ 58 static int apparmor_cred_alloc_blank(struct cred *cred, gfp_t gfp) 59 { 60 /* freed by apparmor_cred_free */ 61 struct aa_task_cxt *cxt = aa_alloc_task_context(gfp); 62 if (!cxt) 63 return -ENOMEM; 64 65 cred->security = cxt; 66 return 0; 67 } 68 69 /* 70 * prepare new aa_task_cxt for modification by prepare_cred block 71 */ 72 static int apparmor_cred_prepare(struct cred *new, const struct cred *old, 73 gfp_t gfp) 74 { 75 /* freed by apparmor_cred_free */ 76 struct aa_task_cxt *cxt = aa_alloc_task_context(gfp); 77 if (!cxt) 78 return -ENOMEM; 79 80 aa_dup_task_context(cxt, old->security); 81 new->security = cxt; 82 return 0; 83 } 84 85 /* 86 * transfer the apparmor data to a blank set of creds 87 */ 88 static void apparmor_cred_transfer(struct cred *new, const struct cred *old) 89 { 90 const struct aa_task_cxt *old_cxt = old->security; 91 struct aa_task_cxt *new_cxt = new->security; 92 93 aa_dup_task_context(new_cxt, old_cxt); 94 } 95 96 static int apparmor_ptrace_access_check(struct task_struct *child, 97 unsigned int mode) 98 { 99 int error = cap_ptrace_access_check(child, mode); 100 if (error) 101 return error; 102 103 return aa_ptrace(current, child, mode); 104 } 105 106 static int apparmor_ptrace_traceme(struct task_struct *parent) 107 { 108 int error = cap_ptrace_traceme(parent); 109 if (error) 110 return error; 111 112 return aa_ptrace(parent, current, PTRACE_MODE_ATTACH); 113 } 114 115 /* Derived from security/commoncap.c:cap_capget */ 116 static int apparmor_capget(struct task_struct *target, kernel_cap_t *effective, 117 kernel_cap_t *inheritable, kernel_cap_t *permitted) 118 { 119 struct aa_profile *profile; 120 const struct cred *cred; 121 122 rcu_read_lock(); 123 cred = __task_cred(target); 124 profile = aa_cred_profile(cred); 125 126 *effective = cred->cap_effective; 127 *inheritable = cred->cap_inheritable; 128 *permitted = cred->cap_permitted; 129 130 if (!unconfined(profile) && !COMPLAIN_MODE(profile)) { 131 *effective = cap_intersect(*effective, profile->caps.allow); 132 *permitted = cap_intersect(*permitted, profile->caps.allow); 133 } 134 rcu_read_unlock(); 135 136 return 0; 137 } 138 139 static int apparmor_capable(const struct cred *cred, struct user_namespace *ns, 140 int cap, int audit) 141 { 142 struct aa_profile *profile; 143 /* cap_capable returns 0 on success, else -EPERM */ 144 int error = cap_capable(cred, ns, cap, audit); 145 if (!error) { 146 profile = aa_cred_profile(cred); 147 if (!unconfined(profile)) 148 error = aa_capable(current, profile, cap, audit); 149 } 150 return error; 151 } 152 153 /** 154 * common_perm - basic common permission check wrapper fn for paths 155 * @op: operation being checked 156 * @path: path to check permission of (NOT NULL) 157 * @mask: requested permissions mask 158 * @cond: conditional info for the permission request (NOT NULL) 159 * 160 * Returns: %0 else error code if error or permission denied 161 */ 162 static int common_perm(int op, struct path *path, u32 mask, 163 struct path_cond *cond) 164 { 165 struct aa_profile *profile; 166 int error = 0; 167 168 profile = __aa_current_profile(); 169 if (!unconfined(profile)) 170 error = aa_path_perm(op, profile, path, 0, mask, cond); 171 172 return error; 173 } 174 175 /** 176 * common_perm_dir_dentry - common permission wrapper when path is dir, dentry 177 * @op: operation being checked 178 * @dir: directory of the dentry (NOT NULL) 179 * @dentry: dentry to check (NOT NULL) 180 * @mask: requested permissions mask 181 * @cond: conditional info for the permission request (NOT NULL) 182 * 183 * Returns: %0 else error code if error or permission denied 184 */ 185 static int common_perm_dir_dentry(int op, struct path *dir, 186 struct dentry *dentry, u32 mask, 187 struct path_cond *cond) 188 { 189 struct path path = { dir->mnt, dentry }; 190 191 return common_perm(op, &path, mask, cond); 192 } 193 194 /** 195 * common_perm_mnt_dentry - common permission wrapper when mnt, dentry 196 * @op: operation being checked 197 * @mnt: mount point of dentry (NOT NULL) 198 * @dentry: dentry to check (NOT NULL) 199 * @mask: requested permissions mask 200 * 201 * Returns: %0 else error code if error or permission denied 202 */ 203 static int common_perm_mnt_dentry(int op, struct vfsmount *mnt, 204 struct dentry *dentry, u32 mask) 205 { 206 struct path path = { mnt, dentry }; 207 struct path_cond cond = { dentry->d_inode->i_uid, 208 dentry->d_inode->i_mode 209 }; 210 211 return common_perm(op, &path, mask, &cond); 212 } 213 214 /** 215 * common_perm_rm - common permission wrapper for operations doing rm 216 * @op: operation being checked 217 * @dir: directory that the dentry is in (NOT NULL) 218 * @dentry: dentry being rm'd (NOT NULL) 219 * @mask: requested permission mask 220 * 221 * Returns: %0 else error code if error or permission denied 222 */ 223 static int common_perm_rm(int op, struct path *dir, 224 struct dentry *dentry, u32 mask) 225 { 226 struct inode *inode = dentry->d_inode; 227 struct path_cond cond = { }; 228 229 if (!inode || !dir->mnt || !mediated_filesystem(inode)) 230 return 0; 231 232 cond.uid = inode->i_uid; 233 cond.mode = inode->i_mode; 234 235 return common_perm_dir_dentry(op, dir, dentry, mask, &cond); 236 } 237 238 /** 239 * common_perm_create - common permission wrapper for operations doing create 240 * @op: operation being checked 241 * @dir: directory that dentry will be created in (NOT NULL) 242 * @dentry: dentry to create (NOT NULL) 243 * @mask: request permission mask 244 * @mode: created file mode 245 * 246 * Returns: %0 else error code if error or permission denied 247 */ 248 static int common_perm_create(int op, struct path *dir, struct dentry *dentry, 249 u32 mask, umode_t mode) 250 { 251 struct path_cond cond = { current_fsuid(), mode }; 252 253 if (!dir->mnt || !mediated_filesystem(dir->dentry->d_inode)) 254 return 0; 255 256 return common_perm_dir_dentry(op, dir, dentry, mask, &cond); 257 } 258 259 static int apparmor_path_unlink(struct path *dir, struct dentry *dentry) 260 { 261 return common_perm_rm(OP_UNLINK, dir, dentry, AA_MAY_DELETE); 262 } 263 264 static int apparmor_path_mkdir(struct path *dir, struct dentry *dentry, 265 umode_t mode) 266 { 267 return common_perm_create(OP_MKDIR, dir, dentry, AA_MAY_CREATE, 268 S_IFDIR); 269 } 270 271 static int apparmor_path_rmdir(struct path *dir, struct dentry *dentry) 272 { 273 return common_perm_rm(OP_RMDIR, dir, dentry, AA_MAY_DELETE); 274 } 275 276 static int apparmor_path_mknod(struct path *dir, struct dentry *dentry, 277 umode_t mode, unsigned int dev) 278 { 279 return common_perm_create(OP_MKNOD, dir, dentry, AA_MAY_CREATE, mode); 280 } 281 282 static int apparmor_path_truncate(struct path *path) 283 { 284 struct path_cond cond = { path->dentry->d_inode->i_uid, 285 path->dentry->d_inode->i_mode 286 }; 287 288 if (!path->mnt || !mediated_filesystem(path->dentry->d_inode)) 289 return 0; 290 291 return common_perm(OP_TRUNC, path, MAY_WRITE | AA_MAY_META_WRITE, 292 &cond); 293 } 294 295 static int apparmor_path_symlink(struct path *dir, struct dentry *dentry, 296 const char *old_name) 297 { 298 return common_perm_create(OP_SYMLINK, dir, dentry, AA_MAY_CREATE, 299 S_IFLNK); 300 } 301 302 static int apparmor_path_link(struct dentry *old_dentry, struct path *new_dir, 303 struct dentry *new_dentry) 304 { 305 struct aa_profile *profile; 306 int error = 0; 307 308 if (!mediated_filesystem(old_dentry->d_inode)) 309 return 0; 310 311 profile = aa_current_profile(); 312 if (!unconfined(profile)) 313 error = aa_path_link(profile, old_dentry, new_dir, new_dentry); 314 return error; 315 } 316 317 static int apparmor_path_rename(struct path *old_dir, struct dentry *old_dentry, 318 struct path *new_dir, struct dentry *new_dentry) 319 { 320 struct aa_profile *profile; 321 int error = 0; 322 323 if (!mediated_filesystem(old_dentry->d_inode)) 324 return 0; 325 326 profile = aa_current_profile(); 327 if (!unconfined(profile)) { 328 struct path old_path = { old_dir->mnt, old_dentry }; 329 struct path new_path = { new_dir->mnt, new_dentry }; 330 struct path_cond cond = { old_dentry->d_inode->i_uid, 331 old_dentry->d_inode->i_mode 332 }; 333 334 error = aa_path_perm(OP_RENAME_SRC, profile, &old_path, 0, 335 MAY_READ | AA_MAY_META_READ | MAY_WRITE | 336 AA_MAY_META_WRITE | AA_MAY_DELETE, 337 &cond); 338 if (!error) 339 error = aa_path_perm(OP_RENAME_DEST, profile, &new_path, 340 0, MAY_WRITE | AA_MAY_META_WRITE | 341 AA_MAY_CREATE, &cond); 342 343 } 344 return error; 345 } 346 347 static int apparmor_path_chmod(struct path *path, umode_t mode) 348 { 349 if (!mediated_filesystem(path->dentry->d_inode)) 350 return 0; 351 352 return common_perm_mnt_dentry(OP_CHMOD, path->mnt, path->dentry, AA_MAY_CHMOD); 353 } 354 355 static int apparmor_path_chown(struct path *path, uid_t uid, gid_t gid) 356 { 357 struct path_cond cond = { path->dentry->d_inode->i_uid, 358 path->dentry->d_inode->i_mode 359 }; 360 361 if (!mediated_filesystem(path->dentry->d_inode)) 362 return 0; 363 364 return common_perm(OP_CHOWN, path, AA_MAY_CHOWN, &cond); 365 } 366 367 static int apparmor_inode_getattr(struct vfsmount *mnt, struct dentry *dentry) 368 { 369 if (!mediated_filesystem(dentry->d_inode)) 370 return 0; 371 372 return common_perm_mnt_dentry(OP_GETATTR, mnt, dentry, 373 AA_MAY_META_READ); 374 } 375 376 static int apparmor_dentry_open(struct file *file, const struct cred *cred) 377 { 378 struct aa_file_cxt *fcxt = file->f_security; 379 struct aa_profile *profile; 380 int error = 0; 381 382 if (!mediated_filesystem(file->f_path.dentry->d_inode)) 383 return 0; 384 385 /* If in exec, permission is handled by bprm hooks. 386 * Cache permissions granted by the previous exec check, with 387 * implicit read and executable mmap which are required to 388 * actually execute the image. 389 */ 390 if (current->in_execve) { 391 fcxt->allow = MAY_EXEC | MAY_READ | AA_EXEC_MMAP; 392 return 0; 393 } 394 395 profile = aa_cred_profile(cred); 396 if (!unconfined(profile)) { 397 struct inode *inode = file->f_path.dentry->d_inode; 398 struct path_cond cond = { inode->i_uid, inode->i_mode }; 399 400 error = aa_path_perm(OP_OPEN, profile, &file->f_path, 0, 401 aa_map_file_to_perms(file), &cond); 402 /* todo cache full allowed permissions set and state */ 403 fcxt->allow = aa_map_file_to_perms(file); 404 } 405 406 return error; 407 } 408 409 static int apparmor_file_alloc_security(struct file *file) 410 { 411 /* freed by apparmor_file_free_security */ 412 file->f_security = aa_alloc_file_context(GFP_KERNEL); 413 if (!file->f_security) 414 return -ENOMEM; 415 return 0; 416 417 } 418 419 static void apparmor_file_free_security(struct file *file) 420 { 421 struct aa_file_cxt *cxt = file->f_security; 422 423 aa_free_file_context(cxt); 424 } 425 426 static int common_file_perm(int op, struct file *file, u32 mask) 427 { 428 struct aa_file_cxt *fcxt = file->f_security; 429 struct aa_profile *profile, *fprofile = aa_cred_profile(file->f_cred); 430 int error = 0; 431 432 BUG_ON(!fprofile); 433 434 if (!file->f_path.mnt || 435 !mediated_filesystem(file->f_path.dentry->d_inode)) 436 return 0; 437 438 profile = __aa_current_profile(); 439 440 /* revalidate access, if task is unconfined, or the cached cred 441 * doesn't match or if the request is for more permissions than 442 * was granted. 443 * 444 * Note: the test for !unconfined(fprofile) is to handle file 445 * delegation from unconfined tasks 446 */ 447 if (!unconfined(profile) && !unconfined(fprofile) && 448 ((fprofile != profile) || (mask & ~fcxt->allow))) 449 error = aa_file_perm(op, profile, file, mask); 450 451 return error; 452 } 453 454 static int apparmor_file_permission(struct file *file, int mask) 455 { 456 return common_file_perm(OP_FPERM, file, mask); 457 } 458 459 static int apparmor_file_lock(struct file *file, unsigned int cmd) 460 { 461 u32 mask = AA_MAY_LOCK; 462 463 if (cmd == F_WRLCK) 464 mask |= MAY_WRITE; 465 466 return common_file_perm(OP_FLOCK, file, mask); 467 } 468 469 static int common_mmap(int op, struct file *file, unsigned long prot, 470 unsigned long flags) 471 { 472 struct dentry *dentry; 473 int mask = 0; 474 475 if (!file || !file->f_security) 476 return 0; 477 478 if (prot & PROT_READ) 479 mask |= MAY_READ; 480 /* 481 * Private mappings don't require write perms since they don't 482 * write back to the files 483 */ 484 if ((prot & PROT_WRITE) && !(flags & MAP_PRIVATE)) 485 mask |= MAY_WRITE; 486 if (prot & PROT_EXEC) 487 mask |= AA_EXEC_MMAP; 488 489 dentry = file->f_path.dentry; 490 return common_file_perm(op, file, mask); 491 } 492 493 static int apparmor_file_mmap(struct file *file, unsigned long reqprot, 494 unsigned long prot, unsigned long flags, 495 unsigned long addr, unsigned long addr_only) 496 { 497 int rc = 0; 498 499 /* do DAC check */ 500 rc = cap_file_mmap(file, reqprot, prot, flags, addr, addr_only); 501 if (rc || addr_only) 502 return rc; 503 504 return common_mmap(OP_FMMAP, file, prot, flags); 505 } 506 507 static int apparmor_file_mprotect(struct vm_area_struct *vma, 508 unsigned long reqprot, unsigned long prot) 509 { 510 return common_mmap(OP_FMPROT, vma->vm_file, prot, 511 !(vma->vm_flags & VM_SHARED) ? MAP_PRIVATE : 0); 512 } 513 514 static int apparmor_getprocattr(struct task_struct *task, char *name, 515 char **value) 516 { 517 int error = -ENOENT; 518 struct aa_profile *profile; 519 /* released below */ 520 const struct cred *cred = get_task_cred(task); 521 struct aa_task_cxt *cxt = cred->security; 522 profile = aa_cred_profile(cred); 523 524 if (strcmp(name, "current") == 0) 525 error = aa_getprocattr(aa_newest_version(cxt->profile), 526 value); 527 else if (strcmp(name, "prev") == 0 && cxt->previous) 528 error = aa_getprocattr(aa_newest_version(cxt->previous), 529 value); 530 else if (strcmp(name, "exec") == 0 && cxt->onexec) 531 error = aa_getprocattr(aa_newest_version(cxt->onexec), 532 value); 533 else 534 error = -EINVAL; 535 536 put_cred(cred); 537 538 return error; 539 } 540 541 static int apparmor_setprocattr(struct task_struct *task, char *name, 542 void *value, size_t size) 543 { 544 char *command, *args = value; 545 size_t arg_size; 546 int error; 547 548 if (size == 0) 549 return -EINVAL; 550 /* args points to a PAGE_SIZE buffer, AppArmor requires that 551 * the buffer must be null terminated or have size <= PAGE_SIZE -1 552 * so that AppArmor can null terminate them 553 */ 554 if (args[size - 1] != '\0') { 555 if (size == PAGE_SIZE) 556 return -EINVAL; 557 args[size] = '\0'; 558 } 559 560 /* task can only write its own attributes */ 561 if (current != task) 562 return -EACCES; 563 564 args = value; 565 args = strim(args); 566 command = strsep(&args, " "); 567 if (!args) 568 return -EINVAL; 569 args = skip_spaces(args); 570 if (!*args) 571 return -EINVAL; 572 573 arg_size = size - (args - (char *) value); 574 if (strcmp(name, "current") == 0) { 575 if (strcmp(command, "changehat") == 0) { 576 error = aa_setprocattr_changehat(args, arg_size, 577 !AA_DO_TEST); 578 } else if (strcmp(command, "permhat") == 0) { 579 error = aa_setprocattr_changehat(args, arg_size, 580 AA_DO_TEST); 581 } else if (strcmp(command, "changeprofile") == 0) { 582 error = aa_setprocattr_changeprofile(args, !AA_ONEXEC, 583 !AA_DO_TEST); 584 } else if (strcmp(command, "permprofile") == 0) { 585 error = aa_setprocattr_changeprofile(args, !AA_ONEXEC, 586 AA_DO_TEST); 587 } else if (strcmp(command, "permipc") == 0) { 588 error = aa_setprocattr_permipc(args); 589 } else { 590 struct common_audit_data sa; 591 COMMON_AUDIT_DATA_INIT(&sa, NONE); 592 sa.aad.op = OP_SETPROCATTR; 593 sa.aad.info = name; 594 sa.aad.error = -EINVAL; 595 return aa_audit(AUDIT_APPARMOR_DENIED, 596 __aa_current_profile(), GFP_KERNEL, 597 &sa, NULL); 598 } 599 } else if (strcmp(name, "exec") == 0) { 600 error = aa_setprocattr_changeprofile(args, AA_ONEXEC, 601 !AA_DO_TEST); 602 } else { 603 /* only support the "current" and "exec" process attributes */ 604 return -EINVAL; 605 } 606 if (!error) 607 error = size; 608 return error; 609 } 610 611 static int apparmor_task_setrlimit(struct task_struct *task, 612 unsigned int resource, struct rlimit *new_rlim) 613 { 614 struct aa_profile *profile = __aa_current_profile(); 615 int error = 0; 616 617 if (!unconfined(profile)) 618 error = aa_task_setrlimit(profile, task, resource, new_rlim); 619 620 return error; 621 } 622 623 static struct security_operations apparmor_ops = { 624 .name = "apparmor", 625 626 .ptrace_access_check = apparmor_ptrace_access_check, 627 .ptrace_traceme = apparmor_ptrace_traceme, 628 .capget = apparmor_capget, 629 .capable = apparmor_capable, 630 631 .path_link = apparmor_path_link, 632 .path_unlink = apparmor_path_unlink, 633 .path_symlink = apparmor_path_symlink, 634 .path_mkdir = apparmor_path_mkdir, 635 .path_rmdir = apparmor_path_rmdir, 636 .path_mknod = apparmor_path_mknod, 637 .path_rename = apparmor_path_rename, 638 .path_chmod = apparmor_path_chmod, 639 .path_chown = apparmor_path_chown, 640 .path_truncate = apparmor_path_truncate, 641 .dentry_open = apparmor_dentry_open, 642 .inode_getattr = apparmor_inode_getattr, 643 644 .file_permission = apparmor_file_permission, 645 .file_alloc_security = apparmor_file_alloc_security, 646 .file_free_security = apparmor_file_free_security, 647 .file_mmap = apparmor_file_mmap, 648 .file_mprotect = apparmor_file_mprotect, 649 .file_lock = apparmor_file_lock, 650 651 .getprocattr = apparmor_getprocattr, 652 .setprocattr = apparmor_setprocattr, 653 654 .cred_alloc_blank = apparmor_cred_alloc_blank, 655 .cred_free = apparmor_cred_free, 656 .cred_prepare = apparmor_cred_prepare, 657 .cred_transfer = apparmor_cred_transfer, 658 659 .bprm_set_creds = apparmor_bprm_set_creds, 660 .bprm_committing_creds = apparmor_bprm_committing_creds, 661 .bprm_committed_creds = apparmor_bprm_committed_creds, 662 .bprm_secureexec = apparmor_bprm_secureexec, 663 664 .task_setrlimit = apparmor_task_setrlimit, 665 }; 666 667 /* 668 * AppArmor sysfs module parameters 669 */ 670 671 static int param_set_aabool(const char *val, const struct kernel_param *kp); 672 static int param_get_aabool(char *buffer, const struct kernel_param *kp); 673 #define param_check_aabool param_check_bool 674 static struct kernel_param_ops param_ops_aabool = { 675 .set = param_set_aabool, 676 .get = param_get_aabool 677 }; 678 679 static int param_set_aauint(const char *val, const struct kernel_param *kp); 680 static int param_get_aauint(char *buffer, const struct kernel_param *kp); 681 #define param_check_aauint param_check_uint 682 static struct kernel_param_ops param_ops_aauint = { 683 .set = param_set_aauint, 684 .get = param_get_aauint 685 }; 686 687 static int param_set_aalockpolicy(const char *val, const struct kernel_param *kp); 688 static int param_get_aalockpolicy(char *buffer, const struct kernel_param *kp); 689 #define param_check_aalockpolicy param_check_bool 690 static struct kernel_param_ops param_ops_aalockpolicy = { 691 .set = param_set_aalockpolicy, 692 .get = param_get_aalockpolicy 693 }; 694 695 static int param_set_audit(const char *val, struct kernel_param *kp); 696 static int param_get_audit(char *buffer, struct kernel_param *kp); 697 698 static int param_set_mode(const char *val, struct kernel_param *kp); 699 static int param_get_mode(char *buffer, struct kernel_param *kp); 700 701 /* Flag values, also controllable via /sys/module/apparmor/parameters 702 * We define special types as we want to do additional mediation. 703 */ 704 705 /* AppArmor global enforcement switch - complain, enforce, kill */ 706 enum profile_mode aa_g_profile_mode = APPARMOR_ENFORCE; 707 module_param_call(mode, param_set_mode, param_get_mode, 708 &aa_g_profile_mode, S_IRUSR | S_IWUSR); 709 710 /* Debug mode */ 711 bool aa_g_debug; 712 module_param_named(debug, aa_g_debug, aabool, S_IRUSR | S_IWUSR); 713 714 /* Audit mode */ 715 enum audit_mode aa_g_audit; 716 module_param_call(audit, param_set_audit, param_get_audit, 717 &aa_g_audit, S_IRUSR | S_IWUSR); 718 719 /* Determines if audit header is included in audited messages. This 720 * provides more context if the audit daemon is not running 721 */ 722 bool aa_g_audit_header = 1; 723 module_param_named(audit_header, aa_g_audit_header, aabool, 724 S_IRUSR | S_IWUSR); 725 726 /* lock out loading/removal of policy 727 * TODO: add in at boot loading of policy, which is the only way to 728 * load policy, if lock_policy is set 729 */ 730 bool aa_g_lock_policy; 731 module_param_named(lock_policy, aa_g_lock_policy, aalockpolicy, 732 S_IRUSR | S_IWUSR); 733 734 /* Syscall logging mode */ 735 bool aa_g_logsyscall; 736 module_param_named(logsyscall, aa_g_logsyscall, aabool, S_IRUSR | S_IWUSR); 737 738 /* Maximum pathname length before accesses will start getting rejected */ 739 unsigned int aa_g_path_max = 2 * PATH_MAX; 740 module_param_named(path_max, aa_g_path_max, aauint, S_IRUSR | S_IWUSR); 741 742 /* Determines how paranoid loading of policy is and how much verification 743 * on the loaded policy is done. 744 */ 745 bool aa_g_paranoid_load = 1; 746 module_param_named(paranoid_load, aa_g_paranoid_load, aabool, 747 S_IRUSR | S_IWUSR); 748 749 /* Boot time disable flag */ 750 static bool apparmor_enabled = CONFIG_SECURITY_APPARMOR_BOOTPARAM_VALUE; 751 module_param_named(enabled, apparmor_enabled, aabool, S_IRUSR); 752 753 static int __init apparmor_enabled_setup(char *str) 754 { 755 unsigned long enabled; 756 int error = strict_strtoul(str, 0, &enabled); 757 if (!error) 758 apparmor_enabled = enabled ? 1 : 0; 759 return 1; 760 } 761 762 __setup("apparmor=", apparmor_enabled_setup); 763 764 /* set global flag turning off the ability to load policy */ 765 static int param_set_aalockpolicy(const char *val, const struct kernel_param *kp) 766 { 767 if (!capable(CAP_MAC_ADMIN)) 768 return -EPERM; 769 if (aa_g_lock_policy) 770 return -EACCES; 771 return param_set_bool(val, kp); 772 } 773 774 static int param_get_aalockpolicy(char *buffer, const struct kernel_param *kp) 775 { 776 if (!capable(CAP_MAC_ADMIN)) 777 return -EPERM; 778 return param_get_bool(buffer, kp); 779 } 780 781 static int param_set_aabool(const char *val, const struct kernel_param *kp) 782 { 783 if (!capable(CAP_MAC_ADMIN)) 784 return -EPERM; 785 return param_set_bool(val, kp); 786 } 787 788 static int param_get_aabool(char *buffer, const struct kernel_param *kp) 789 { 790 if (!capable(CAP_MAC_ADMIN)) 791 return -EPERM; 792 return param_get_bool(buffer, kp); 793 } 794 795 static int param_set_aauint(const char *val, const struct kernel_param *kp) 796 { 797 if (!capable(CAP_MAC_ADMIN)) 798 return -EPERM; 799 return param_set_uint(val, kp); 800 } 801 802 static int param_get_aauint(char *buffer, const struct kernel_param *kp) 803 { 804 if (!capable(CAP_MAC_ADMIN)) 805 return -EPERM; 806 return param_get_uint(buffer, kp); 807 } 808 809 static int param_get_audit(char *buffer, struct kernel_param *kp) 810 { 811 if (!capable(CAP_MAC_ADMIN)) 812 return -EPERM; 813 814 if (!apparmor_enabled) 815 return -EINVAL; 816 817 return sprintf(buffer, "%s", audit_mode_names[aa_g_audit]); 818 } 819 820 static int param_set_audit(const char *val, struct kernel_param *kp) 821 { 822 int i; 823 if (!capable(CAP_MAC_ADMIN)) 824 return -EPERM; 825 826 if (!apparmor_enabled) 827 return -EINVAL; 828 829 if (!val) 830 return -EINVAL; 831 832 for (i = 0; i < AUDIT_MAX_INDEX; i++) { 833 if (strcmp(val, audit_mode_names[i]) == 0) { 834 aa_g_audit = i; 835 return 0; 836 } 837 } 838 839 return -EINVAL; 840 } 841 842 static int param_get_mode(char *buffer, struct kernel_param *kp) 843 { 844 if (!capable(CAP_MAC_ADMIN)) 845 return -EPERM; 846 847 if (!apparmor_enabled) 848 return -EINVAL; 849 850 return sprintf(buffer, "%s", profile_mode_names[aa_g_profile_mode]); 851 } 852 853 static int param_set_mode(const char *val, struct kernel_param *kp) 854 { 855 int i; 856 if (!capable(CAP_MAC_ADMIN)) 857 return -EPERM; 858 859 if (!apparmor_enabled) 860 return -EINVAL; 861 862 if (!val) 863 return -EINVAL; 864 865 for (i = 0; i < APPARMOR_NAMES_MAX_INDEX; i++) { 866 if (strcmp(val, profile_mode_names[i]) == 0) { 867 aa_g_profile_mode = i; 868 return 0; 869 } 870 } 871 872 return -EINVAL; 873 } 874 875 /* 876 * AppArmor init functions 877 */ 878 879 /** 880 * set_init_cxt - set a task context and profile on the first task. 881 * 882 * TODO: allow setting an alternate profile than unconfined 883 */ 884 static int __init set_init_cxt(void) 885 { 886 struct cred *cred = (struct cred *)current->real_cred; 887 struct aa_task_cxt *cxt; 888 889 cxt = aa_alloc_task_context(GFP_KERNEL); 890 if (!cxt) 891 return -ENOMEM; 892 893 cxt->profile = aa_get_profile(root_ns->unconfined); 894 cred->security = cxt; 895 896 return 0; 897 } 898 899 static int __init apparmor_init(void) 900 { 901 int error; 902 903 if (!apparmor_enabled || !security_module_enable(&apparmor_ops)) { 904 aa_info_message("AppArmor disabled by boot time parameter"); 905 apparmor_enabled = 0; 906 return 0; 907 } 908 909 error = aa_alloc_root_ns(); 910 if (error) { 911 AA_ERROR("Unable to allocate default profile namespace\n"); 912 goto alloc_out; 913 } 914 915 error = set_init_cxt(); 916 if (error) { 917 AA_ERROR("Failed to set context on init task\n"); 918 goto register_security_out; 919 } 920 921 error = register_security(&apparmor_ops); 922 if (error) { 923 AA_ERROR("Unable to register AppArmor\n"); 924 goto set_init_cxt_out; 925 } 926 927 /* Report that AppArmor successfully initialized */ 928 apparmor_initialized = 1; 929 if (aa_g_profile_mode == APPARMOR_COMPLAIN) 930 aa_info_message("AppArmor initialized: complain mode enabled"); 931 else if (aa_g_profile_mode == APPARMOR_KILL) 932 aa_info_message("AppArmor initialized: kill mode enabled"); 933 else 934 aa_info_message("AppArmor initialized"); 935 936 return error; 937 938 set_init_cxt_out: 939 aa_free_task_context(current->real_cred->security); 940 941 register_security_out: 942 aa_free_root_ns(); 943 944 alloc_out: 945 aa_destroy_aafs(); 946 947 apparmor_enabled = 0; 948 return error; 949 } 950 951 security_initcall(apparmor_init); 952