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/lsm_hooks.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 <linux/netfilter_ipv4.h> 27 #include <linux/netfilter_ipv6.h> 28 #include <net/sock.h> 29 #include <uapi/linux/mount.h> 30 31 #include "include/apparmor.h" 32 #include "include/apparmorfs.h" 33 #include "include/audit.h" 34 #include "include/capability.h" 35 #include "include/cred.h" 36 #include "include/file.h" 37 #include "include/ipc.h" 38 #include "include/net.h" 39 #include "include/path.h" 40 #include "include/label.h" 41 #include "include/policy.h" 42 #include "include/policy_ns.h" 43 #include "include/procattr.h" 44 #include "include/mount.h" 45 #include "include/secid.h" 46 47 /* Flag indicating whether initialization completed */ 48 int apparmor_initialized; 49 50 DEFINE_PER_CPU(struct aa_buffers, aa_buffers); 51 52 53 /* 54 * LSM hook functions 55 */ 56 57 /* 58 * put the associated labels 59 */ 60 static void apparmor_cred_free(struct cred *cred) 61 { 62 aa_put_label(cred_label(cred)); 63 cred_label(cred) = NULL; 64 } 65 66 /* 67 * allocate the apparmor part of blank credentials 68 */ 69 static int apparmor_cred_alloc_blank(struct cred *cred, gfp_t gfp) 70 { 71 cred_label(cred) = NULL; 72 return 0; 73 } 74 75 /* 76 * prepare new cred label for modification by prepare_cred block 77 */ 78 static int apparmor_cred_prepare(struct cred *new, const struct cred *old, 79 gfp_t gfp) 80 { 81 cred_label(new) = aa_get_newest_label(cred_label(old)); 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 cred_label(new) = aa_get_newest_label(cred_label(old)); 91 } 92 93 static void apparmor_task_free(struct task_struct *task) 94 { 95 96 aa_free_task_ctx(task_ctx(task)); 97 task_ctx(task) = NULL; 98 } 99 100 static int apparmor_task_alloc(struct task_struct *task, 101 unsigned long clone_flags) 102 { 103 struct aa_task_ctx *new = aa_alloc_task_ctx(GFP_KERNEL); 104 105 if (!new) 106 return -ENOMEM; 107 108 aa_dup_task_ctx(new, task_ctx(current)); 109 task_ctx(task) = new; 110 111 return 0; 112 } 113 114 static int apparmor_ptrace_access_check(struct task_struct *child, 115 unsigned int mode) 116 { 117 struct aa_label *tracer, *tracee; 118 int error; 119 120 tracer = __begin_current_label_crit_section(); 121 tracee = aa_get_task_label(child); 122 error = aa_may_ptrace(tracer, tracee, 123 (mode & PTRACE_MODE_READ) ? AA_PTRACE_READ 124 : AA_PTRACE_TRACE); 125 aa_put_label(tracee); 126 __end_current_label_crit_section(tracer); 127 128 return error; 129 } 130 131 static int apparmor_ptrace_traceme(struct task_struct *parent) 132 { 133 struct aa_label *tracer, *tracee; 134 int error; 135 136 tracee = __begin_current_label_crit_section(); 137 tracer = aa_get_task_label(parent); 138 error = aa_may_ptrace(tracer, tracee, AA_PTRACE_TRACE); 139 aa_put_label(tracer); 140 __end_current_label_crit_section(tracee); 141 142 return error; 143 } 144 145 /* Derived from security/commoncap.c:cap_capget */ 146 static int apparmor_capget(struct task_struct *target, kernel_cap_t *effective, 147 kernel_cap_t *inheritable, kernel_cap_t *permitted) 148 { 149 struct aa_label *label; 150 const struct cred *cred; 151 152 rcu_read_lock(); 153 cred = __task_cred(target); 154 label = aa_get_newest_cred_label(cred); 155 156 /* 157 * cap_capget is stacked ahead of this and will 158 * initialize effective and permitted. 159 */ 160 if (!unconfined(label)) { 161 struct aa_profile *profile; 162 struct label_it i; 163 164 label_for_each_confined(i, label, profile) { 165 if (COMPLAIN_MODE(profile)) 166 continue; 167 *effective = cap_intersect(*effective, 168 profile->caps.allow); 169 *permitted = cap_intersect(*permitted, 170 profile->caps.allow); 171 } 172 } 173 rcu_read_unlock(); 174 aa_put_label(label); 175 176 return 0; 177 } 178 179 static int apparmor_capable(const struct cred *cred, struct user_namespace *ns, 180 int cap, int audit) 181 { 182 struct aa_label *label; 183 int error = 0; 184 185 label = aa_get_newest_cred_label(cred); 186 if (!unconfined(label)) 187 error = aa_capable(label, cap, audit); 188 aa_put_label(label); 189 190 return error; 191 } 192 193 /** 194 * common_perm - basic common permission check wrapper fn for paths 195 * @op: operation being checked 196 * @path: path to check permission of (NOT NULL) 197 * @mask: requested permissions mask 198 * @cond: conditional info for the permission request (NOT NULL) 199 * 200 * Returns: %0 else error code if error or permission denied 201 */ 202 static int common_perm(const char *op, const struct path *path, u32 mask, 203 struct path_cond *cond) 204 { 205 struct aa_label *label; 206 int error = 0; 207 208 label = __begin_current_label_crit_section(); 209 if (!unconfined(label)) 210 error = aa_path_perm(op, label, path, 0, mask, cond); 211 __end_current_label_crit_section(label); 212 213 return error; 214 } 215 216 /** 217 * common_perm_cond - common permission wrapper around inode cond 218 * @op: operation being checked 219 * @path: location to check (NOT NULL) 220 * @mask: requested permissions mask 221 * 222 * Returns: %0 else error code if error or permission denied 223 */ 224 static int common_perm_cond(const char *op, const struct path *path, u32 mask) 225 { 226 struct path_cond cond = { d_backing_inode(path->dentry)->i_uid, 227 d_backing_inode(path->dentry)->i_mode 228 }; 229 230 if (!path_mediated_fs(path->dentry)) 231 return 0; 232 233 return common_perm(op, path, mask, &cond); 234 } 235 236 /** 237 * common_perm_dir_dentry - common permission wrapper when path is dir, dentry 238 * @op: operation being checked 239 * @dir: directory of the dentry (NOT NULL) 240 * @dentry: dentry to check (NOT NULL) 241 * @mask: requested permissions mask 242 * @cond: conditional info for the permission request (NOT NULL) 243 * 244 * Returns: %0 else error code if error or permission denied 245 */ 246 static int common_perm_dir_dentry(const char *op, const struct path *dir, 247 struct dentry *dentry, u32 mask, 248 struct path_cond *cond) 249 { 250 struct path path = { .mnt = dir->mnt, .dentry = dentry }; 251 252 return common_perm(op, &path, mask, cond); 253 } 254 255 /** 256 * common_perm_rm - common permission wrapper for operations doing rm 257 * @op: operation being checked 258 * @dir: directory that the dentry is in (NOT NULL) 259 * @dentry: dentry being rm'd (NOT NULL) 260 * @mask: requested permission mask 261 * 262 * Returns: %0 else error code if error or permission denied 263 */ 264 static int common_perm_rm(const char *op, const struct path *dir, 265 struct dentry *dentry, u32 mask) 266 { 267 struct inode *inode = d_backing_inode(dentry); 268 struct path_cond cond = { }; 269 270 if (!inode || !path_mediated_fs(dentry)) 271 return 0; 272 273 cond.uid = inode->i_uid; 274 cond.mode = inode->i_mode; 275 276 return common_perm_dir_dentry(op, dir, dentry, mask, &cond); 277 } 278 279 /** 280 * common_perm_create - common permission wrapper for operations doing create 281 * @op: operation being checked 282 * @dir: directory that dentry will be created in (NOT NULL) 283 * @dentry: dentry to create (NOT NULL) 284 * @mask: request permission mask 285 * @mode: created file mode 286 * 287 * Returns: %0 else error code if error or permission denied 288 */ 289 static int common_perm_create(const char *op, const struct path *dir, 290 struct dentry *dentry, u32 mask, umode_t mode) 291 { 292 struct path_cond cond = { current_fsuid(), mode }; 293 294 if (!path_mediated_fs(dir->dentry)) 295 return 0; 296 297 return common_perm_dir_dentry(op, dir, dentry, mask, &cond); 298 } 299 300 static int apparmor_path_unlink(const struct path *dir, struct dentry *dentry) 301 { 302 return common_perm_rm(OP_UNLINK, dir, dentry, AA_MAY_DELETE); 303 } 304 305 static int apparmor_path_mkdir(const struct path *dir, struct dentry *dentry, 306 umode_t mode) 307 { 308 return common_perm_create(OP_MKDIR, dir, dentry, AA_MAY_CREATE, 309 S_IFDIR); 310 } 311 312 static int apparmor_path_rmdir(const struct path *dir, struct dentry *dentry) 313 { 314 return common_perm_rm(OP_RMDIR, dir, dentry, AA_MAY_DELETE); 315 } 316 317 static int apparmor_path_mknod(const struct path *dir, struct dentry *dentry, 318 umode_t mode, unsigned int dev) 319 { 320 return common_perm_create(OP_MKNOD, dir, dentry, AA_MAY_CREATE, mode); 321 } 322 323 static int apparmor_path_truncate(const struct path *path) 324 { 325 return common_perm_cond(OP_TRUNC, path, MAY_WRITE | AA_MAY_SETATTR); 326 } 327 328 static int apparmor_path_symlink(const struct path *dir, struct dentry *dentry, 329 const char *old_name) 330 { 331 return common_perm_create(OP_SYMLINK, dir, dentry, AA_MAY_CREATE, 332 S_IFLNK); 333 } 334 335 static int apparmor_path_link(struct dentry *old_dentry, const struct path *new_dir, 336 struct dentry *new_dentry) 337 { 338 struct aa_label *label; 339 int error = 0; 340 341 if (!path_mediated_fs(old_dentry)) 342 return 0; 343 344 label = begin_current_label_crit_section(); 345 if (!unconfined(label)) 346 error = aa_path_link(label, old_dentry, new_dir, new_dentry); 347 end_current_label_crit_section(label); 348 349 return error; 350 } 351 352 static int apparmor_path_rename(const struct path *old_dir, struct dentry *old_dentry, 353 const struct path *new_dir, struct dentry *new_dentry) 354 { 355 struct aa_label *label; 356 int error = 0; 357 358 if (!path_mediated_fs(old_dentry)) 359 return 0; 360 361 label = begin_current_label_crit_section(); 362 if (!unconfined(label)) { 363 struct path old_path = { .mnt = old_dir->mnt, 364 .dentry = old_dentry }; 365 struct path new_path = { .mnt = new_dir->mnt, 366 .dentry = new_dentry }; 367 struct path_cond cond = { d_backing_inode(old_dentry)->i_uid, 368 d_backing_inode(old_dentry)->i_mode 369 }; 370 371 error = aa_path_perm(OP_RENAME_SRC, label, &old_path, 0, 372 MAY_READ | AA_MAY_GETATTR | MAY_WRITE | 373 AA_MAY_SETATTR | AA_MAY_DELETE, 374 &cond); 375 if (!error) 376 error = aa_path_perm(OP_RENAME_DEST, label, &new_path, 377 0, MAY_WRITE | AA_MAY_SETATTR | 378 AA_MAY_CREATE, &cond); 379 380 } 381 end_current_label_crit_section(label); 382 383 return error; 384 } 385 386 static int apparmor_path_chmod(const struct path *path, umode_t mode) 387 { 388 return common_perm_cond(OP_CHMOD, path, AA_MAY_CHMOD); 389 } 390 391 static int apparmor_path_chown(const struct path *path, kuid_t uid, kgid_t gid) 392 { 393 return common_perm_cond(OP_CHOWN, path, AA_MAY_CHOWN); 394 } 395 396 static int apparmor_inode_getattr(const struct path *path) 397 { 398 return common_perm_cond(OP_GETATTR, path, AA_MAY_GETATTR); 399 } 400 401 static int apparmor_file_open(struct file *file) 402 { 403 struct aa_file_ctx *fctx = file_ctx(file); 404 struct aa_label *label; 405 int error = 0; 406 407 if (!path_mediated_fs(file->f_path.dentry)) 408 return 0; 409 410 /* If in exec, permission is handled by bprm hooks. 411 * Cache permissions granted by the previous exec check, with 412 * implicit read and executable mmap which are required to 413 * actually execute the image. 414 */ 415 if (current->in_execve) { 416 fctx->allow = MAY_EXEC | MAY_READ | AA_EXEC_MMAP; 417 return 0; 418 } 419 420 label = aa_get_newest_cred_label(file->f_cred); 421 if (!unconfined(label)) { 422 struct inode *inode = file_inode(file); 423 struct path_cond cond = { inode->i_uid, inode->i_mode }; 424 425 error = aa_path_perm(OP_OPEN, label, &file->f_path, 0, 426 aa_map_file_to_perms(file), &cond); 427 /* todo cache full allowed permissions set and state */ 428 fctx->allow = aa_map_file_to_perms(file); 429 } 430 aa_put_label(label); 431 432 return error; 433 } 434 435 static int apparmor_file_alloc_security(struct file *file) 436 { 437 int error = 0; 438 439 /* freed by apparmor_file_free_security */ 440 struct aa_label *label = begin_current_label_crit_section(); 441 file->f_security = aa_alloc_file_ctx(label, GFP_KERNEL); 442 if (!file_ctx(file)) 443 error = -ENOMEM; 444 end_current_label_crit_section(label); 445 446 return error; 447 } 448 449 static void apparmor_file_free_security(struct file *file) 450 { 451 aa_free_file_ctx(file_ctx(file)); 452 } 453 454 static int common_file_perm(const char *op, struct file *file, u32 mask) 455 { 456 struct aa_label *label; 457 int error = 0; 458 459 /* don't reaudit files closed during inheritance */ 460 if (file->f_path.dentry == aa_null.dentry) 461 return -EACCES; 462 463 label = __begin_current_label_crit_section(); 464 error = aa_file_perm(op, label, file, mask); 465 __end_current_label_crit_section(label); 466 467 return error; 468 } 469 470 static int apparmor_file_receive(struct file *file) 471 { 472 return common_file_perm(OP_FRECEIVE, file, aa_map_file_to_perms(file)); 473 } 474 475 static int apparmor_file_permission(struct file *file, int mask) 476 { 477 return common_file_perm(OP_FPERM, file, mask); 478 } 479 480 static int apparmor_file_lock(struct file *file, unsigned int cmd) 481 { 482 u32 mask = AA_MAY_LOCK; 483 484 if (cmd == F_WRLCK) 485 mask |= MAY_WRITE; 486 487 return common_file_perm(OP_FLOCK, file, mask); 488 } 489 490 static int common_mmap(const char *op, struct file *file, unsigned long prot, 491 unsigned long flags) 492 { 493 int mask = 0; 494 495 if (!file || !file_ctx(file)) 496 return 0; 497 498 if (prot & PROT_READ) 499 mask |= MAY_READ; 500 /* 501 * Private mappings don't require write perms since they don't 502 * write back to the files 503 */ 504 if ((prot & PROT_WRITE) && !(flags & MAP_PRIVATE)) 505 mask |= MAY_WRITE; 506 if (prot & PROT_EXEC) 507 mask |= AA_EXEC_MMAP; 508 509 return common_file_perm(op, file, mask); 510 } 511 512 static int apparmor_mmap_file(struct file *file, unsigned long reqprot, 513 unsigned long prot, unsigned long flags) 514 { 515 return common_mmap(OP_FMMAP, file, prot, flags); 516 } 517 518 static int apparmor_file_mprotect(struct vm_area_struct *vma, 519 unsigned long reqprot, unsigned long prot) 520 { 521 return common_mmap(OP_FMPROT, vma->vm_file, prot, 522 !(vma->vm_flags & VM_SHARED) ? MAP_PRIVATE : 0); 523 } 524 525 static int apparmor_sb_mount(const char *dev_name, const struct path *path, 526 const char *type, unsigned long flags, void *data) 527 { 528 struct aa_label *label; 529 int error = 0; 530 531 /* Discard magic */ 532 if ((flags & MS_MGC_MSK) == MS_MGC_VAL) 533 flags &= ~MS_MGC_MSK; 534 535 flags &= ~AA_MS_IGNORE_MASK; 536 537 label = __begin_current_label_crit_section(); 538 if (!unconfined(label)) { 539 if (flags & MS_REMOUNT) 540 error = aa_remount(label, path, flags, data); 541 else if (flags & MS_BIND) 542 error = aa_bind_mount(label, path, dev_name, flags); 543 else if (flags & (MS_SHARED | MS_PRIVATE | MS_SLAVE | 544 MS_UNBINDABLE)) 545 error = aa_mount_change_type(label, path, flags); 546 else if (flags & MS_MOVE) 547 error = aa_move_mount(label, path, dev_name); 548 else 549 error = aa_new_mount(label, dev_name, path, type, 550 flags, data); 551 } 552 __end_current_label_crit_section(label); 553 554 return error; 555 } 556 557 static int apparmor_sb_umount(struct vfsmount *mnt, int flags) 558 { 559 struct aa_label *label; 560 int error = 0; 561 562 label = __begin_current_label_crit_section(); 563 if (!unconfined(label)) 564 error = aa_umount(label, mnt, flags); 565 __end_current_label_crit_section(label); 566 567 return error; 568 } 569 570 static int apparmor_sb_pivotroot(const struct path *old_path, 571 const struct path *new_path) 572 { 573 struct aa_label *label; 574 int error = 0; 575 576 label = aa_get_current_label(); 577 if (!unconfined(label)) 578 error = aa_pivotroot(label, old_path, new_path); 579 aa_put_label(label); 580 581 return error; 582 } 583 584 static int apparmor_getprocattr(struct task_struct *task, char *name, 585 char **value) 586 { 587 int error = -ENOENT; 588 /* released below */ 589 const struct cred *cred = get_task_cred(task); 590 struct aa_task_ctx *ctx = task_ctx(current); 591 struct aa_label *label = NULL; 592 593 if (strcmp(name, "current") == 0) 594 label = aa_get_newest_label(cred_label(cred)); 595 else if (strcmp(name, "prev") == 0 && ctx->previous) 596 label = aa_get_newest_label(ctx->previous); 597 else if (strcmp(name, "exec") == 0 && ctx->onexec) 598 label = aa_get_newest_label(ctx->onexec); 599 else 600 error = -EINVAL; 601 602 if (label) 603 error = aa_getprocattr(label, value); 604 605 aa_put_label(label); 606 put_cred(cred); 607 608 return error; 609 } 610 611 static int apparmor_setprocattr(const char *name, void *value, 612 size_t size) 613 { 614 char *command, *largs = NULL, *args = value; 615 size_t arg_size; 616 int error; 617 DEFINE_AUDIT_DATA(sa, LSM_AUDIT_DATA_NONE, OP_SETPROCATTR); 618 619 if (size == 0) 620 return -EINVAL; 621 622 /* AppArmor requires that the buffer must be null terminated atm */ 623 if (args[size - 1] != '\0') { 624 /* null terminate */ 625 largs = args = kmalloc(size + 1, GFP_KERNEL); 626 if (!args) 627 return -ENOMEM; 628 memcpy(args, value, size); 629 args[size] = '\0'; 630 } 631 632 error = -EINVAL; 633 args = strim(args); 634 command = strsep(&args, " "); 635 if (!args) 636 goto out; 637 args = skip_spaces(args); 638 if (!*args) 639 goto out; 640 641 arg_size = size - (args - (largs ? largs : (char *) value)); 642 if (strcmp(name, "current") == 0) { 643 if (strcmp(command, "changehat") == 0) { 644 error = aa_setprocattr_changehat(args, arg_size, 645 AA_CHANGE_NOFLAGS); 646 } else if (strcmp(command, "permhat") == 0) { 647 error = aa_setprocattr_changehat(args, arg_size, 648 AA_CHANGE_TEST); 649 } else if (strcmp(command, "changeprofile") == 0) { 650 error = aa_change_profile(args, AA_CHANGE_NOFLAGS); 651 } else if (strcmp(command, "permprofile") == 0) { 652 error = aa_change_profile(args, AA_CHANGE_TEST); 653 } else if (strcmp(command, "stack") == 0) { 654 error = aa_change_profile(args, AA_CHANGE_STACK); 655 } else 656 goto fail; 657 } else if (strcmp(name, "exec") == 0) { 658 if (strcmp(command, "exec") == 0) 659 error = aa_change_profile(args, AA_CHANGE_ONEXEC); 660 else if (strcmp(command, "stack") == 0) 661 error = aa_change_profile(args, (AA_CHANGE_ONEXEC | 662 AA_CHANGE_STACK)); 663 else 664 goto fail; 665 } else 666 /* only support the "current" and "exec" process attributes */ 667 goto fail; 668 669 if (!error) 670 error = size; 671 out: 672 kfree(largs); 673 return error; 674 675 fail: 676 aad(&sa)->label = begin_current_label_crit_section(); 677 aad(&sa)->info = name; 678 aad(&sa)->error = error = -EINVAL; 679 aa_audit_msg(AUDIT_APPARMOR_DENIED, &sa, NULL); 680 end_current_label_crit_section(aad(&sa)->label); 681 goto out; 682 } 683 684 /** 685 * apparmor_bprm_committing_creds - do task cleanup on committing new creds 686 * @bprm: binprm for the exec (NOT NULL) 687 */ 688 static void apparmor_bprm_committing_creds(struct linux_binprm *bprm) 689 { 690 struct aa_label *label = aa_current_raw_label(); 691 struct aa_label *new_label = cred_label(bprm->cred); 692 693 /* bail out if unconfined or not changing profile */ 694 if ((new_label->proxy == label->proxy) || 695 (unconfined(new_label))) 696 return; 697 698 aa_inherit_files(bprm->cred, current->files); 699 700 current->pdeath_signal = 0; 701 702 /* reset soft limits and set hard limits for the new label */ 703 __aa_transition_rlimits(label, new_label); 704 } 705 706 /** 707 * apparmor_bprm_committed_cred - do cleanup after new creds committed 708 * @bprm: binprm for the exec (NOT NULL) 709 */ 710 static void apparmor_bprm_committed_creds(struct linux_binprm *bprm) 711 { 712 /* clear out temporary/transitional state from the context */ 713 aa_clear_task_ctx_trans(task_ctx(current)); 714 715 return; 716 } 717 718 static void apparmor_task_getsecid(struct task_struct *p, u32 *secid) 719 { 720 struct aa_label *label = aa_get_task_label(p); 721 *secid = label->secid; 722 aa_put_label(label); 723 } 724 725 static int apparmor_task_setrlimit(struct task_struct *task, 726 unsigned int resource, struct rlimit *new_rlim) 727 { 728 struct aa_label *label = __begin_current_label_crit_section(); 729 int error = 0; 730 731 if (!unconfined(label)) 732 error = aa_task_setrlimit(label, task, resource, new_rlim); 733 __end_current_label_crit_section(label); 734 735 return error; 736 } 737 738 static int apparmor_task_kill(struct task_struct *target, struct kernel_siginfo *info, 739 int sig, const struct cred *cred) 740 { 741 struct aa_label *cl, *tl; 742 int error; 743 744 if (cred) { 745 /* 746 * Dealing with USB IO specific behavior 747 */ 748 cl = aa_get_newest_cred_label(cred); 749 tl = aa_get_task_label(target); 750 error = aa_may_signal(cl, tl, sig); 751 aa_put_label(cl); 752 aa_put_label(tl); 753 return error; 754 } 755 756 cl = __begin_current_label_crit_section(); 757 tl = aa_get_task_label(target); 758 error = aa_may_signal(cl, tl, sig); 759 aa_put_label(tl); 760 __end_current_label_crit_section(cl); 761 762 return error; 763 } 764 765 /** 766 * apparmor_sk_alloc_security - allocate and attach the sk_security field 767 */ 768 static int apparmor_sk_alloc_security(struct sock *sk, int family, gfp_t flags) 769 { 770 struct aa_sk_ctx *ctx; 771 772 ctx = kzalloc(sizeof(*ctx), flags); 773 if (!ctx) 774 return -ENOMEM; 775 776 SK_CTX(sk) = ctx; 777 778 return 0; 779 } 780 781 /** 782 * apparmor_sk_free_security - free the sk_security field 783 */ 784 static void apparmor_sk_free_security(struct sock *sk) 785 { 786 struct aa_sk_ctx *ctx = SK_CTX(sk); 787 788 SK_CTX(sk) = NULL; 789 aa_put_label(ctx->label); 790 aa_put_label(ctx->peer); 791 kfree(ctx); 792 } 793 794 /** 795 * apparmor_clone_security - clone the sk_security field 796 */ 797 static void apparmor_sk_clone_security(const struct sock *sk, 798 struct sock *newsk) 799 { 800 struct aa_sk_ctx *ctx = SK_CTX(sk); 801 struct aa_sk_ctx *new = SK_CTX(newsk); 802 803 new->label = aa_get_label(ctx->label); 804 new->peer = aa_get_label(ctx->peer); 805 } 806 807 /** 808 * apparmor_socket_create - check perms before creating a new socket 809 */ 810 static int apparmor_socket_create(int family, int type, int protocol, int kern) 811 { 812 struct aa_label *label; 813 int error = 0; 814 815 AA_BUG(in_interrupt()); 816 817 label = begin_current_label_crit_section(); 818 if (!(kern || unconfined(label))) 819 error = af_select(family, 820 create_perm(label, family, type, protocol), 821 aa_af_perm(label, OP_CREATE, AA_MAY_CREATE, 822 family, type, protocol)); 823 end_current_label_crit_section(label); 824 825 return error; 826 } 827 828 /** 829 * apparmor_socket_post_create - setup the per-socket security struct 830 * 831 * Note: 832 * - kernel sockets currently labeled unconfined but we may want to 833 * move to a special kernel label 834 * - socket may not have sk here if created with sock_create_lite or 835 * sock_alloc. These should be accept cases which will be handled in 836 * sock_graft. 837 */ 838 static int apparmor_socket_post_create(struct socket *sock, int family, 839 int type, int protocol, int kern) 840 { 841 struct aa_label *label; 842 843 if (kern) { 844 struct aa_ns *ns = aa_get_current_ns(); 845 846 label = aa_get_label(ns_unconfined(ns)); 847 aa_put_ns(ns); 848 } else 849 label = aa_get_current_label(); 850 851 if (sock->sk) { 852 struct aa_sk_ctx *ctx = SK_CTX(sock->sk); 853 854 aa_put_label(ctx->label); 855 ctx->label = aa_get_label(label); 856 } 857 aa_put_label(label); 858 859 return 0; 860 } 861 862 /** 863 * apparmor_socket_bind - check perms before bind addr to socket 864 */ 865 static int apparmor_socket_bind(struct socket *sock, 866 struct sockaddr *address, int addrlen) 867 { 868 AA_BUG(!sock); 869 AA_BUG(!sock->sk); 870 AA_BUG(!address); 871 AA_BUG(in_interrupt()); 872 873 return af_select(sock->sk->sk_family, 874 bind_perm(sock, address, addrlen), 875 aa_sk_perm(OP_BIND, AA_MAY_BIND, sock->sk)); 876 } 877 878 /** 879 * apparmor_socket_connect - check perms before connecting @sock to @address 880 */ 881 static int apparmor_socket_connect(struct socket *sock, 882 struct sockaddr *address, int addrlen) 883 { 884 AA_BUG(!sock); 885 AA_BUG(!sock->sk); 886 AA_BUG(!address); 887 AA_BUG(in_interrupt()); 888 889 return af_select(sock->sk->sk_family, 890 connect_perm(sock, address, addrlen), 891 aa_sk_perm(OP_CONNECT, AA_MAY_CONNECT, sock->sk)); 892 } 893 894 /** 895 * apparmor_socket_list - check perms before allowing listen 896 */ 897 static int apparmor_socket_listen(struct socket *sock, int backlog) 898 { 899 AA_BUG(!sock); 900 AA_BUG(!sock->sk); 901 AA_BUG(in_interrupt()); 902 903 return af_select(sock->sk->sk_family, 904 listen_perm(sock, backlog), 905 aa_sk_perm(OP_LISTEN, AA_MAY_LISTEN, sock->sk)); 906 } 907 908 /** 909 * apparmor_socket_accept - check perms before accepting a new connection. 910 * 911 * Note: while @newsock is created and has some information, the accept 912 * has not been done. 913 */ 914 static int apparmor_socket_accept(struct socket *sock, struct socket *newsock) 915 { 916 AA_BUG(!sock); 917 AA_BUG(!sock->sk); 918 AA_BUG(!newsock); 919 AA_BUG(in_interrupt()); 920 921 return af_select(sock->sk->sk_family, 922 accept_perm(sock, newsock), 923 aa_sk_perm(OP_ACCEPT, AA_MAY_ACCEPT, sock->sk)); 924 } 925 926 static int aa_sock_msg_perm(const char *op, u32 request, struct socket *sock, 927 struct msghdr *msg, int size) 928 { 929 AA_BUG(!sock); 930 AA_BUG(!sock->sk); 931 AA_BUG(!msg); 932 AA_BUG(in_interrupt()); 933 934 return af_select(sock->sk->sk_family, 935 msg_perm(op, request, sock, msg, size), 936 aa_sk_perm(op, request, sock->sk)); 937 } 938 939 /** 940 * apparmor_socket_sendmsg - check perms before sending msg to another socket 941 */ 942 static int apparmor_socket_sendmsg(struct socket *sock, 943 struct msghdr *msg, int size) 944 { 945 return aa_sock_msg_perm(OP_SENDMSG, AA_MAY_SEND, sock, msg, size); 946 } 947 948 /** 949 * apparmor_socket_recvmsg - check perms before receiving a message 950 */ 951 static int apparmor_socket_recvmsg(struct socket *sock, 952 struct msghdr *msg, int size, int flags) 953 { 954 return aa_sock_msg_perm(OP_RECVMSG, AA_MAY_RECEIVE, sock, msg, size); 955 } 956 957 /* revaliation, get/set attr, shutdown */ 958 static int aa_sock_perm(const char *op, u32 request, struct socket *sock) 959 { 960 AA_BUG(!sock); 961 AA_BUG(!sock->sk); 962 AA_BUG(in_interrupt()); 963 964 return af_select(sock->sk->sk_family, 965 sock_perm(op, request, sock), 966 aa_sk_perm(op, request, sock->sk)); 967 } 968 969 /** 970 * apparmor_socket_getsockname - check perms before getting the local address 971 */ 972 static int apparmor_socket_getsockname(struct socket *sock) 973 { 974 return aa_sock_perm(OP_GETSOCKNAME, AA_MAY_GETATTR, sock); 975 } 976 977 /** 978 * apparmor_socket_getpeername - check perms before getting remote address 979 */ 980 static int apparmor_socket_getpeername(struct socket *sock) 981 { 982 return aa_sock_perm(OP_GETPEERNAME, AA_MAY_GETATTR, sock); 983 } 984 985 /* revaliation, get/set attr, opt */ 986 static int aa_sock_opt_perm(const char *op, u32 request, struct socket *sock, 987 int level, int optname) 988 { 989 AA_BUG(!sock); 990 AA_BUG(!sock->sk); 991 AA_BUG(in_interrupt()); 992 993 return af_select(sock->sk->sk_family, 994 opt_perm(op, request, sock, level, optname), 995 aa_sk_perm(op, request, sock->sk)); 996 } 997 998 /** 999 * apparmor_getsockopt - check perms before getting socket options 1000 */ 1001 static int apparmor_socket_getsockopt(struct socket *sock, int level, 1002 int optname) 1003 { 1004 return aa_sock_opt_perm(OP_GETSOCKOPT, AA_MAY_GETOPT, sock, 1005 level, optname); 1006 } 1007 1008 /** 1009 * apparmor_setsockopt - check perms before setting socket options 1010 */ 1011 static int apparmor_socket_setsockopt(struct socket *sock, int level, 1012 int optname) 1013 { 1014 return aa_sock_opt_perm(OP_SETSOCKOPT, AA_MAY_SETOPT, sock, 1015 level, optname); 1016 } 1017 1018 /** 1019 * apparmor_socket_shutdown - check perms before shutting down @sock conn 1020 */ 1021 static int apparmor_socket_shutdown(struct socket *sock, int how) 1022 { 1023 return aa_sock_perm(OP_SHUTDOWN, AA_MAY_SHUTDOWN, sock); 1024 } 1025 1026 #ifdef CONFIG_NETWORK_SECMARK 1027 /** 1028 * apparmor_socket_sock_recv_skb - check perms before associating skb to sk 1029 * 1030 * Note: can not sleep may be called with locks held 1031 * 1032 * dont want protocol specific in __skb_recv_datagram() 1033 * to deny an incoming connection socket_sock_rcv_skb() 1034 */ 1035 static int apparmor_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb) 1036 { 1037 struct aa_sk_ctx *ctx = SK_CTX(sk); 1038 1039 if (!skb->secmark) 1040 return 0; 1041 1042 return apparmor_secmark_check(ctx->label, OP_RECVMSG, AA_MAY_RECEIVE, 1043 skb->secmark, sk); 1044 } 1045 #endif 1046 1047 1048 static struct aa_label *sk_peer_label(struct sock *sk) 1049 { 1050 struct aa_sk_ctx *ctx = SK_CTX(sk); 1051 1052 if (ctx->peer) 1053 return ctx->peer; 1054 1055 return ERR_PTR(-ENOPROTOOPT); 1056 } 1057 1058 /** 1059 * apparmor_socket_getpeersec_stream - get security context of peer 1060 * 1061 * Note: for tcp only valid if using ipsec or cipso on lan 1062 */ 1063 static int apparmor_socket_getpeersec_stream(struct socket *sock, 1064 char __user *optval, 1065 int __user *optlen, 1066 unsigned int len) 1067 { 1068 char *name; 1069 int slen, error = 0; 1070 struct aa_label *label; 1071 struct aa_label *peer; 1072 1073 label = begin_current_label_crit_section(); 1074 peer = sk_peer_label(sock->sk); 1075 if (IS_ERR(peer)) { 1076 error = PTR_ERR(peer); 1077 goto done; 1078 } 1079 slen = aa_label_asxprint(&name, labels_ns(label), peer, 1080 FLAG_SHOW_MODE | FLAG_VIEW_SUBNS | 1081 FLAG_HIDDEN_UNCONFINED, GFP_KERNEL); 1082 /* don't include terminating \0 in slen, it breaks some apps */ 1083 if (slen < 0) { 1084 error = -ENOMEM; 1085 } else { 1086 if (slen > len) { 1087 error = -ERANGE; 1088 } else if (copy_to_user(optval, name, slen)) { 1089 error = -EFAULT; 1090 goto out; 1091 } 1092 if (put_user(slen, optlen)) 1093 error = -EFAULT; 1094 out: 1095 kfree(name); 1096 1097 } 1098 1099 done: 1100 end_current_label_crit_section(label); 1101 1102 return error; 1103 } 1104 1105 /** 1106 * apparmor_socket_getpeersec_dgram - get security label of packet 1107 * @sock: the peer socket 1108 * @skb: packet data 1109 * @secid: pointer to where to put the secid of the packet 1110 * 1111 * Sets the netlabel socket state on sk from parent 1112 */ 1113 static int apparmor_socket_getpeersec_dgram(struct socket *sock, 1114 struct sk_buff *skb, u32 *secid) 1115 1116 { 1117 /* TODO: requires secid support */ 1118 return -ENOPROTOOPT; 1119 } 1120 1121 /** 1122 * apparmor_sock_graft - Initialize newly created socket 1123 * @sk: child sock 1124 * @parent: parent socket 1125 * 1126 * Note: could set off of SOCK_CTX(parent) but need to track inode and we can 1127 * just set sk security information off of current creating process label 1128 * Labeling of sk for accept case - probably should be sock based 1129 * instead of task, because of the case where an implicitly labeled 1130 * socket is shared by different tasks. 1131 */ 1132 static void apparmor_sock_graft(struct sock *sk, struct socket *parent) 1133 { 1134 struct aa_sk_ctx *ctx = SK_CTX(sk); 1135 1136 if (!ctx->label) 1137 ctx->label = aa_get_current_label(); 1138 } 1139 1140 #ifdef CONFIG_NETWORK_SECMARK 1141 static int apparmor_inet_conn_request(struct sock *sk, struct sk_buff *skb, 1142 struct request_sock *req) 1143 { 1144 struct aa_sk_ctx *ctx = SK_CTX(sk); 1145 1146 if (!skb->secmark) 1147 return 0; 1148 1149 return apparmor_secmark_check(ctx->label, OP_CONNECT, AA_MAY_CONNECT, 1150 skb->secmark, sk); 1151 } 1152 #endif 1153 1154 static struct security_hook_list apparmor_hooks[] __lsm_ro_after_init = { 1155 LSM_HOOK_INIT(ptrace_access_check, apparmor_ptrace_access_check), 1156 LSM_HOOK_INIT(ptrace_traceme, apparmor_ptrace_traceme), 1157 LSM_HOOK_INIT(capget, apparmor_capget), 1158 LSM_HOOK_INIT(capable, apparmor_capable), 1159 1160 LSM_HOOK_INIT(sb_mount, apparmor_sb_mount), 1161 LSM_HOOK_INIT(sb_umount, apparmor_sb_umount), 1162 LSM_HOOK_INIT(sb_pivotroot, apparmor_sb_pivotroot), 1163 1164 LSM_HOOK_INIT(path_link, apparmor_path_link), 1165 LSM_HOOK_INIT(path_unlink, apparmor_path_unlink), 1166 LSM_HOOK_INIT(path_symlink, apparmor_path_symlink), 1167 LSM_HOOK_INIT(path_mkdir, apparmor_path_mkdir), 1168 LSM_HOOK_INIT(path_rmdir, apparmor_path_rmdir), 1169 LSM_HOOK_INIT(path_mknod, apparmor_path_mknod), 1170 LSM_HOOK_INIT(path_rename, apparmor_path_rename), 1171 LSM_HOOK_INIT(path_chmod, apparmor_path_chmod), 1172 LSM_HOOK_INIT(path_chown, apparmor_path_chown), 1173 LSM_HOOK_INIT(path_truncate, apparmor_path_truncate), 1174 LSM_HOOK_INIT(inode_getattr, apparmor_inode_getattr), 1175 1176 LSM_HOOK_INIT(file_open, apparmor_file_open), 1177 LSM_HOOK_INIT(file_receive, apparmor_file_receive), 1178 LSM_HOOK_INIT(file_permission, apparmor_file_permission), 1179 LSM_HOOK_INIT(file_alloc_security, apparmor_file_alloc_security), 1180 LSM_HOOK_INIT(file_free_security, apparmor_file_free_security), 1181 LSM_HOOK_INIT(mmap_file, apparmor_mmap_file), 1182 LSM_HOOK_INIT(file_mprotect, apparmor_file_mprotect), 1183 LSM_HOOK_INIT(file_lock, apparmor_file_lock), 1184 1185 LSM_HOOK_INIT(getprocattr, apparmor_getprocattr), 1186 LSM_HOOK_INIT(setprocattr, apparmor_setprocattr), 1187 1188 LSM_HOOK_INIT(sk_alloc_security, apparmor_sk_alloc_security), 1189 LSM_HOOK_INIT(sk_free_security, apparmor_sk_free_security), 1190 LSM_HOOK_INIT(sk_clone_security, apparmor_sk_clone_security), 1191 1192 LSM_HOOK_INIT(socket_create, apparmor_socket_create), 1193 LSM_HOOK_INIT(socket_post_create, apparmor_socket_post_create), 1194 LSM_HOOK_INIT(socket_bind, apparmor_socket_bind), 1195 LSM_HOOK_INIT(socket_connect, apparmor_socket_connect), 1196 LSM_HOOK_INIT(socket_listen, apparmor_socket_listen), 1197 LSM_HOOK_INIT(socket_accept, apparmor_socket_accept), 1198 LSM_HOOK_INIT(socket_sendmsg, apparmor_socket_sendmsg), 1199 LSM_HOOK_INIT(socket_recvmsg, apparmor_socket_recvmsg), 1200 LSM_HOOK_INIT(socket_getsockname, apparmor_socket_getsockname), 1201 LSM_HOOK_INIT(socket_getpeername, apparmor_socket_getpeername), 1202 LSM_HOOK_INIT(socket_getsockopt, apparmor_socket_getsockopt), 1203 LSM_HOOK_INIT(socket_setsockopt, apparmor_socket_setsockopt), 1204 LSM_HOOK_INIT(socket_shutdown, apparmor_socket_shutdown), 1205 #ifdef CONFIG_NETWORK_SECMARK 1206 LSM_HOOK_INIT(socket_sock_rcv_skb, apparmor_socket_sock_rcv_skb), 1207 #endif 1208 LSM_HOOK_INIT(socket_getpeersec_stream, 1209 apparmor_socket_getpeersec_stream), 1210 LSM_HOOK_INIT(socket_getpeersec_dgram, 1211 apparmor_socket_getpeersec_dgram), 1212 LSM_HOOK_INIT(sock_graft, apparmor_sock_graft), 1213 #ifdef CONFIG_NETWORK_SECMARK 1214 LSM_HOOK_INIT(inet_conn_request, apparmor_inet_conn_request), 1215 #endif 1216 1217 LSM_HOOK_INIT(cred_alloc_blank, apparmor_cred_alloc_blank), 1218 LSM_HOOK_INIT(cred_free, apparmor_cred_free), 1219 LSM_HOOK_INIT(cred_prepare, apparmor_cred_prepare), 1220 LSM_HOOK_INIT(cred_transfer, apparmor_cred_transfer), 1221 1222 LSM_HOOK_INIT(bprm_set_creds, apparmor_bprm_set_creds), 1223 LSM_HOOK_INIT(bprm_committing_creds, apparmor_bprm_committing_creds), 1224 LSM_HOOK_INIT(bprm_committed_creds, apparmor_bprm_committed_creds), 1225 1226 LSM_HOOK_INIT(task_free, apparmor_task_free), 1227 LSM_HOOK_INIT(task_alloc, apparmor_task_alloc), 1228 LSM_HOOK_INIT(task_getsecid, apparmor_task_getsecid), 1229 LSM_HOOK_INIT(task_setrlimit, apparmor_task_setrlimit), 1230 LSM_HOOK_INIT(task_kill, apparmor_task_kill), 1231 1232 #ifdef CONFIG_AUDIT 1233 LSM_HOOK_INIT(audit_rule_init, aa_audit_rule_init), 1234 LSM_HOOK_INIT(audit_rule_known, aa_audit_rule_known), 1235 LSM_HOOK_INIT(audit_rule_match, aa_audit_rule_match), 1236 LSM_HOOK_INIT(audit_rule_free, aa_audit_rule_free), 1237 #endif 1238 1239 LSM_HOOK_INIT(secid_to_secctx, apparmor_secid_to_secctx), 1240 LSM_HOOK_INIT(secctx_to_secid, apparmor_secctx_to_secid), 1241 LSM_HOOK_INIT(release_secctx, apparmor_release_secctx), 1242 }; 1243 1244 /* 1245 * AppArmor sysfs module parameters 1246 */ 1247 1248 static int param_set_aabool(const char *val, const struct kernel_param *kp); 1249 static int param_get_aabool(char *buffer, const struct kernel_param *kp); 1250 #define param_check_aabool param_check_bool 1251 static const struct kernel_param_ops param_ops_aabool = { 1252 .flags = KERNEL_PARAM_OPS_FL_NOARG, 1253 .set = param_set_aabool, 1254 .get = param_get_aabool 1255 }; 1256 1257 static int param_set_aauint(const char *val, const struct kernel_param *kp); 1258 static int param_get_aauint(char *buffer, const struct kernel_param *kp); 1259 #define param_check_aauint param_check_uint 1260 static const struct kernel_param_ops param_ops_aauint = { 1261 .set = param_set_aauint, 1262 .get = param_get_aauint 1263 }; 1264 1265 static int param_set_aalockpolicy(const char *val, const struct kernel_param *kp); 1266 static int param_get_aalockpolicy(char *buffer, const struct kernel_param *kp); 1267 #define param_check_aalockpolicy param_check_bool 1268 static const struct kernel_param_ops param_ops_aalockpolicy = { 1269 .flags = KERNEL_PARAM_OPS_FL_NOARG, 1270 .set = param_set_aalockpolicy, 1271 .get = param_get_aalockpolicy 1272 }; 1273 1274 static int param_set_audit(const char *val, const struct kernel_param *kp); 1275 static int param_get_audit(char *buffer, const struct kernel_param *kp); 1276 1277 static int param_set_mode(const char *val, const struct kernel_param *kp); 1278 static int param_get_mode(char *buffer, const struct kernel_param *kp); 1279 1280 /* Flag values, also controllable via /sys/module/apparmor/parameters 1281 * We define special types as we want to do additional mediation. 1282 */ 1283 1284 /* AppArmor global enforcement switch - complain, enforce, kill */ 1285 enum profile_mode aa_g_profile_mode = APPARMOR_ENFORCE; 1286 module_param_call(mode, param_set_mode, param_get_mode, 1287 &aa_g_profile_mode, S_IRUSR | S_IWUSR); 1288 1289 /* whether policy verification hashing is enabled */ 1290 bool aa_g_hash_policy = IS_ENABLED(CONFIG_SECURITY_APPARMOR_HASH_DEFAULT); 1291 #ifdef CONFIG_SECURITY_APPARMOR_HASH 1292 module_param_named(hash_policy, aa_g_hash_policy, aabool, S_IRUSR | S_IWUSR); 1293 #endif 1294 1295 /* Debug mode */ 1296 bool aa_g_debug = IS_ENABLED(CONFIG_SECURITY_APPARMOR_DEBUG_MESSAGES); 1297 module_param_named(debug, aa_g_debug, aabool, S_IRUSR | S_IWUSR); 1298 1299 /* Audit mode */ 1300 enum audit_mode aa_g_audit; 1301 module_param_call(audit, param_set_audit, param_get_audit, 1302 &aa_g_audit, S_IRUSR | S_IWUSR); 1303 1304 /* Determines if audit header is included in audited messages. This 1305 * provides more context if the audit daemon is not running 1306 */ 1307 bool aa_g_audit_header = true; 1308 module_param_named(audit_header, aa_g_audit_header, aabool, 1309 S_IRUSR | S_IWUSR); 1310 1311 /* lock out loading/removal of policy 1312 * TODO: add in at boot loading of policy, which is the only way to 1313 * load policy, if lock_policy is set 1314 */ 1315 bool aa_g_lock_policy; 1316 module_param_named(lock_policy, aa_g_lock_policy, aalockpolicy, 1317 S_IRUSR | S_IWUSR); 1318 1319 /* Syscall logging mode */ 1320 bool aa_g_logsyscall; 1321 module_param_named(logsyscall, aa_g_logsyscall, aabool, S_IRUSR | S_IWUSR); 1322 1323 /* Maximum pathname length before accesses will start getting rejected */ 1324 unsigned int aa_g_path_max = 2 * PATH_MAX; 1325 module_param_named(path_max, aa_g_path_max, aauint, S_IRUSR); 1326 1327 /* Determines how paranoid loading of policy is and how much verification 1328 * on the loaded policy is done. 1329 * DEPRECATED: read only as strict checking of load is always done now 1330 * that none root users (user namespaces) can load policy. 1331 */ 1332 bool aa_g_paranoid_load = true; 1333 module_param_named(paranoid_load, aa_g_paranoid_load, aabool, S_IRUGO); 1334 1335 /* Boot time disable flag */ 1336 static bool apparmor_enabled = CONFIG_SECURITY_APPARMOR_BOOTPARAM_VALUE; 1337 module_param_named(enabled, apparmor_enabled, bool, S_IRUGO); 1338 1339 static int __init apparmor_enabled_setup(char *str) 1340 { 1341 unsigned long enabled; 1342 int error = kstrtoul(str, 0, &enabled); 1343 if (!error) 1344 apparmor_enabled = enabled ? 1 : 0; 1345 return 1; 1346 } 1347 1348 __setup("apparmor=", apparmor_enabled_setup); 1349 1350 /* set global flag turning off the ability to load policy */ 1351 static int param_set_aalockpolicy(const char *val, const struct kernel_param *kp) 1352 { 1353 if (!apparmor_enabled) 1354 return -EINVAL; 1355 if (apparmor_initialized && !policy_admin_capable(NULL)) 1356 return -EPERM; 1357 return param_set_bool(val, kp); 1358 } 1359 1360 static int param_get_aalockpolicy(char *buffer, const struct kernel_param *kp) 1361 { 1362 if (!apparmor_enabled) 1363 return -EINVAL; 1364 if (apparmor_initialized && !policy_view_capable(NULL)) 1365 return -EPERM; 1366 return param_get_bool(buffer, kp); 1367 } 1368 1369 static int param_set_aabool(const char *val, const struct kernel_param *kp) 1370 { 1371 if (!apparmor_enabled) 1372 return -EINVAL; 1373 if (apparmor_initialized && !policy_admin_capable(NULL)) 1374 return -EPERM; 1375 return param_set_bool(val, kp); 1376 } 1377 1378 static int param_get_aabool(char *buffer, const struct kernel_param *kp) 1379 { 1380 if (!apparmor_enabled) 1381 return -EINVAL; 1382 if (apparmor_initialized && !policy_view_capable(NULL)) 1383 return -EPERM; 1384 return param_get_bool(buffer, kp); 1385 } 1386 1387 static int param_set_aauint(const char *val, const struct kernel_param *kp) 1388 { 1389 int error; 1390 1391 if (!apparmor_enabled) 1392 return -EINVAL; 1393 /* file is ro but enforce 2nd line check */ 1394 if (apparmor_initialized) 1395 return -EPERM; 1396 1397 error = param_set_uint(val, kp); 1398 pr_info("AppArmor: buffer size set to %d bytes\n", aa_g_path_max); 1399 1400 return error; 1401 } 1402 1403 static int param_get_aauint(char *buffer, const struct kernel_param *kp) 1404 { 1405 if (!apparmor_enabled) 1406 return -EINVAL; 1407 if (apparmor_initialized && !policy_view_capable(NULL)) 1408 return -EPERM; 1409 return param_get_uint(buffer, kp); 1410 } 1411 1412 static int param_get_audit(char *buffer, const struct kernel_param *kp) 1413 { 1414 if (!apparmor_enabled) 1415 return -EINVAL; 1416 if (apparmor_initialized && !policy_view_capable(NULL)) 1417 return -EPERM; 1418 return sprintf(buffer, "%s", audit_mode_names[aa_g_audit]); 1419 } 1420 1421 static int param_set_audit(const char *val, const struct kernel_param *kp) 1422 { 1423 int i; 1424 1425 if (!apparmor_enabled) 1426 return -EINVAL; 1427 if (!val) 1428 return -EINVAL; 1429 if (apparmor_initialized && !policy_admin_capable(NULL)) 1430 return -EPERM; 1431 1432 i = match_string(audit_mode_names, AUDIT_MAX_INDEX, val); 1433 if (i < 0) 1434 return -EINVAL; 1435 1436 aa_g_audit = i; 1437 return 0; 1438 } 1439 1440 static int param_get_mode(char *buffer, const struct kernel_param *kp) 1441 { 1442 if (!apparmor_enabled) 1443 return -EINVAL; 1444 if (apparmor_initialized && !policy_view_capable(NULL)) 1445 return -EPERM; 1446 1447 return sprintf(buffer, "%s", aa_profile_mode_names[aa_g_profile_mode]); 1448 } 1449 1450 static int param_set_mode(const char *val, const struct kernel_param *kp) 1451 { 1452 int i; 1453 1454 if (!apparmor_enabled) 1455 return -EINVAL; 1456 if (!val) 1457 return -EINVAL; 1458 if (apparmor_initialized && !policy_admin_capable(NULL)) 1459 return -EPERM; 1460 1461 i = match_string(aa_profile_mode_names, APPARMOR_MODE_NAMES_MAX_INDEX, 1462 val); 1463 if (i < 0) 1464 return -EINVAL; 1465 1466 aa_g_profile_mode = i; 1467 return 0; 1468 } 1469 1470 /* 1471 * AppArmor init functions 1472 */ 1473 1474 /** 1475 * set_init_ctx - set a task context and profile on the first task. 1476 * 1477 * TODO: allow setting an alternate profile than unconfined 1478 */ 1479 static int __init set_init_ctx(void) 1480 { 1481 struct cred *cred = (struct cred *)current->real_cred; 1482 struct aa_task_ctx *ctx; 1483 1484 ctx = aa_alloc_task_ctx(GFP_KERNEL); 1485 if (!ctx) 1486 return -ENOMEM; 1487 1488 cred_label(cred) = aa_get_label(ns_unconfined(root_ns)); 1489 task_ctx(current) = ctx; 1490 1491 return 0; 1492 } 1493 1494 static void destroy_buffers(void) 1495 { 1496 u32 i, j; 1497 1498 for_each_possible_cpu(i) { 1499 for_each_cpu_buffer(j) { 1500 kfree(per_cpu(aa_buffers, i).buf[j]); 1501 per_cpu(aa_buffers, i).buf[j] = NULL; 1502 } 1503 } 1504 } 1505 1506 static int __init alloc_buffers(void) 1507 { 1508 u32 i, j; 1509 1510 for_each_possible_cpu(i) { 1511 for_each_cpu_buffer(j) { 1512 char *buffer; 1513 1514 if (cpu_to_node(i) > num_online_nodes()) 1515 /* fallback to kmalloc for offline nodes */ 1516 buffer = kmalloc(aa_g_path_max, GFP_KERNEL); 1517 else 1518 buffer = kmalloc_node(aa_g_path_max, GFP_KERNEL, 1519 cpu_to_node(i)); 1520 if (!buffer) { 1521 destroy_buffers(); 1522 return -ENOMEM; 1523 } 1524 per_cpu(aa_buffers, i).buf[j] = buffer; 1525 } 1526 } 1527 1528 return 0; 1529 } 1530 1531 #ifdef CONFIG_SYSCTL 1532 static int apparmor_dointvec(struct ctl_table *table, int write, 1533 void __user *buffer, size_t *lenp, loff_t *ppos) 1534 { 1535 if (!policy_admin_capable(NULL)) 1536 return -EPERM; 1537 if (!apparmor_enabled) 1538 return -EINVAL; 1539 1540 return proc_dointvec(table, write, buffer, lenp, ppos); 1541 } 1542 1543 static struct ctl_path apparmor_sysctl_path[] = { 1544 { .procname = "kernel", }, 1545 { } 1546 }; 1547 1548 static struct ctl_table apparmor_sysctl_table[] = { 1549 { 1550 .procname = "unprivileged_userns_apparmor_policy", 1551 .data = &unprivileged_userns_apparmor_policy, 1552 .maxlen = sizeof(int), 1553 .mode = 0600, 1554 .proc_handler = apparmor_dointvec, 1555 }, 1556 { } 1557 }; 1558 1559 static int __init apparmor_init_sysctl(void) 1560 { 1561 return register_sysctl_paths(apparmor_sysctl_path, 1562 apparmor_sysctl_table) ? 0 : -ENOMEM; 1563 } 1564 #else 1565 static inline int apparmor_init_sysctl(void) 1566 { 1567 return 0; 1568 } 1569 #endif /* CONFIG_SYSCTL */ 1570 1571 #if defined(CONFIG_NETFILTER) && defined(CONFIG_NETWORK_SECMARK) 1572 static unsigned int apparmor_ip_postroute(void *priv, 1573 struct sk_buff *skb, 1574 const struct nf_hook_state *state) 1575 { 1576 struct aa_sk_ctx *ctx; 1577 struct sock *sk; 1578 1579 if (!skb->secmark) 1580 return NF_ACCEPT; 1581 1582 sk = skb_to_full_sk(skb); 1583 if (sk == NULL) 1584 return NF_ACCEPT; 1585 1586 ctx = SK_CTX(sk); 1587 if (!apparmor_secmark_check(ctx->label, OP_SENDMSG, AA_MAY_SEND, 1588 skb->secmark, sk)) 1589 return NF_ACCEPT; 1590 1591 return NF_DROP_ERR(-ECONNREFUSED); 1592 1593 } 1594 1595 static unsigned int apparmor_ipv4_postroute(void *priv, 1596 struct sk_buff *skb, 1597 const struct nf_hook_state *state) 1598 { 1599 return apparmor_ip_postroute(priv, skb, state); 1600 } 1601 1602 static unsigned int apparmor_ipv6_postroute(void *priv, 1603 struct sk_buff *skb, 1604 const struct nf_hook_state *state) 1605 { 1606 return apparmor_ip_postroute(priv, skb, state); 1607 } 1608 1609 static const struct nf_hook_ops apparmor_nf_ops[] = { 1610 { 1611 .hook = apparmor_ipv4_postroute, 1612 .pf = NFPROTO_IPV4, 1613 .hooknum = NF_INET_POST_ROUTING, 1614 .priority = NF_IP_PRI_SELINUX_FIRST, 1615 }, 1616 #if IS_ENABLED(CONFIG_IPV6) 1617 { 1618 .hook = apparmor_ipv6_postroute, 1619 .pf = NFPROTO_IPV6, 1620 .hooknum = NF_INET_POST_ROUTING, 1621 .priority = NF_IP6_PRI_SELINUX_FIRST, 1622 }, 1623 #endif 1624 }; 1625 1626 static int __net_init apparmor_nf_register(struct net *net) 1627 { 1628 int ret; 1629 1630 ret = nf_register_net_hooks(net, apparmor_nf_ops, 1631 ARRAY_SIZE(apparmor_nf_ops)); 1632 return ret; 1633 } 1634 1635 static void __net_exit apparmor_nf_unregister(struct net *net) 1636 { 1637 nf_unregister_net_hooks(net, apparmor_nf_ops, 1638 ARRAY_SIZE(apparmor_nf_ops)); 1639 } 1640 1641 static struct pernet_operations apparmor_net_ops = { 1642 .init = apparmor_nf_register, 1643 .exit = apparmor_nf_unregister, 1644 }; 1645 1646 static int __init apparmor_nf_ip_init(void) 1647 { 1648 int err; 1649 1650 if (!apparmor_enabled) 1651 return 0; 1652 1653 err = register_pernet_subsys(&apparmor_net_ops); 1654 if (err) 1655 panic("Apparmor: register_pernet_subsys: error %d\n", err); 1656 1657 return 0; 1658 } 1659 __initcall(apparmor_nf_ip_init); 1660 #endif 1661 1662 static int __init apparmor_init(void) 1663 { 1664 int error; 1665 1666 if (!apparmor_enabled || !security_module_enable("apparmor")) { 1667 aa_info_message("AppArmor disabled by boot time parameter"); 1668 apparmor_enabled = false; 1669 return 0; 1670 } 1671 1672 aa_secids_init(); 1673 1674 error = aa_setup_dfa_engine(); 1675 if (error) { 1676 AA_ERROR("Unable to setup dfa engine\n"); 1677 goto alloc_out; 1678 } 1679 1680 error = aa_alloc_root_ns(); 1681 if (error) { 1682 AA_ERROR("Unable to allocate default profile namespace\n"); 1683 goto alloc_out; 1684 } 1685 1686 error = apparmor_init_sysctl(); 1687 if (error) { 1688 AA_ERROR("Unable to register sysctls\n"); 1689 goto alloc_out; 1690 1691 } 1692 1693 error = alloc_buffers(); 1694 if (error) { 1695 AA_ERROR("Unable to allocate work buffers\n"); 1696 goto buffers_out; 1697 } 1698 1699 error = set_init_ctx(); 1700 if (error) { 1701 AA_ERROR("Failed to set context on init task\n"); 1702 aa_free_root_ns(); 1703 goto buffers_out; 1704 } 1705 security_add_hooks(apparmor_hooks, ARRAY_SIZE(apparmor_hooks), 1706 "apparmor"); 1707 1708 /* Report that AppArmor successfully initialized */ 1709 apparmor_initialized = 1; 1710 if (aa_g_profile_mode == APPARMOR_COMPLAIN) 1711 aa_info_message("AppArmor initialized: complain mode enabled"); 1712 else if (aa_g_profile_mode == APPARMOR_KILL) 1713 aa_info_message("AppArmor initialized: kill mode enabled"); 1714 else 1715 aa_info_message("AppArmor initialized"); 1716 1717 return error; 1718 1719 buffers_out: 1720 destroy_buffers(); 1721 1722 alloc_out: 1723 aa_destroy_aafs(); 1724 aa_teardown_dfa_engine(); 1725 1726 apparmor_enabled = false; 1727 return error; 1728 } 1729 1730 DEFINE_LSM(apparmor) = { 1731 .name = "apparmor", 1732 .init = apparmor_init, 1733 }; 1734