diff options
Diffstat (limited to 'security/apparmor/lsm.c')
| -rw-r--r-- | security/apparmor/lsm.c | 938 |
1 files changed, 938 insertions, 0 deletions
diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c new file mode 100644 index 00000000000..8db33a8b50c --- /dev/null +++ b/security/apparmor/lsm.c | |||
| @@ -0,0 +1,938 @@ | |||
| 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 <net/sock.h> | ||
| 26 | |||
| 27 | #include "include/apparmor.h" | ||
| 28 | #include "include/apparmorfs.h" | ||
| 29 | #include "include/audit.h" | ||
| 30 | #include "include/capability.h" | ||
| 31 | #include "include/context.h" | ||
| 32 | #include "include/file.h" | ||
| 33 | #include "include/ipc.h" | ||
| 34 | #include "include/path.h" | ||
| 35 | #include "include/policy.h" | ||
| 36 | #include "include/procattr.h" | ||
| 37 | |||
| 38 | /* Flag indicating whether initialization completed */ | ||
| 39 | int apparmor_initialized __initdata; | ||
| 40 | |||
| 41 | /* | ||
| 42 | * LSM hook functions | ||
| 43 | */ | ||
| 44 | |||
| 45 | /* | ||
| 46 | * free the associated aa_task_cxt and put its profiles | ||
| 47 | */ | ||
| 48 | static void apparmor_cred_free(struct cred *cred) | ||
| 49 | { | ||
| 50 | aa_free_task_context(cred->security); | ||
| 51 | cred->security = NULL; | ||
| 52 | } | ||
| 53 | |||
| 54 | /* | ||
| 55 | * allocate the apparmor part of blank credentials | ||
| 56 | */ | ||
| 57 | static int apparmor_cred_alloc_blank(struct cred *cred, gfp_t gfp) | ||
| 58 | { | ||
| 59 | /* freed by apparmor_cred_free */ | ||
| 60 | struct aa_task_cxt *cxt = aa_alloc_task_context(gfp); | ||
| 61 | if (!cxt) | ||
| 62 | return -ENOMEM; | ||
| 63 | |||
| 64 | cred->security = cxt; | ||
| 65 | return 0; | ||
| 66 | } | ||
| 67 | |||
| 68 | /* | ||
| 69 | * prepare new aa_task_cxt for modification by prepare_cred block | ||
| 70 | */ | ||
| 71 | static int apparmor_cred_prepare(struct cred *new, const struct cred *old, | ||
| 72 | gfp_t gfp) | ||
| 73 | { | ||
| 74 | /* freed by apparmor_cred_free */ | ||
| 75 | struct aa_task_cxt *cxt = aa_alloc_task_context(gfp); | ||
| 76 | if (!cxt) | ||
| 77 | return -ENOMEM; | ||
| 78 | |||
| 79 | aa_dup_task_context(cxt, old->security); | ||
| 80 | new->security = cxt; | ||
| 81 | return 0; | ||
| 82 | } | ||
| 83 | |||
| 84 | /* | ||
| 85 | * transfer the apparmor data to a blank set of creds | ||
| 86 | */ | ||
| 87 | static void apparmor_cred_transfer(struct cred *new, const struct cred *old) | ||
| 88 | { | ||
| 89 | const struct aa_task_cxt *old_cxt = old->security; | ||
| 90 | struct aa_task_cxt *new_cxt = new->security; | ||
| 91 | |||
| 92 | aa_dup_task_context(new_cxt, old_cxt); | ||
| 93 | } | ||
| 94 | |||
| 95 | static int apparmor_ptrace_access_check(struct task_struct *child, | ||
| 96 | unsigned int mode) | ||
| 97 | { | ||
| 98 | int error = cap_ptrace_access_check(child, mode); | ||
| 99 | if (error) | ||
| 100 | return error; | ||
| 101 | |||
| 102 | return aa_ptrace(current, child, mode); | ||
| 103 | } | ||
| 104 | |||
| 105 | static int apparmor_ptrace_traceme(struct task_struct *parent) | ||
| 106 | { | ||
| 107 | int error = cap_ptrace_traceme(parent); | ||
| 108 | if (error) | ||
| 109 | return error; | ||
| 110 | |||
| 111 | return aa_ptrace(parent, current, PTRACE_MODE_ATTACH); | ||
| 112 | } | ||
| 113 | |||
| 114 | /* Derived from security/commoncap.c:cap_capget */ | ||
| 115 | static int apparmor_capget(struct task_struct *target, kernel_cap_t *effective, | ||
| 116 | kernel_cap_t *inheritable, kernel_cap_t *permitted) | ||
| 117 | { | ||
| 118 | struct aa_profile *profile; | ||
| 119 | const struct cred *cred; | ||
| 120 | |||
| 121 | rcu_read_lock(); | ||
| 122 | cred = __task_cred(target); | ||
| 123 | profile = aa_cred_profile(cred); | ||
| 124 | |||
| 125 | *effective = cred->cap_effective; | ||
| 126 | *inheritable = cred->cap_inheritable; | ||
| 127 | *permitted = cred->cap_permitted; | ||
| 128 | |||
| 129 | if (!unconfined(profile)) { | ||
| 130 | *effective = cap_intersect(*effective, profile->caps.allow); | ||
| 131 | *permitted = cap_intersect(*permitted, profile->caps.allow); | ||
| 132 | } | ||
| 133 | rcu_read_unlock(); | ||
| 134 | |||
| 135 | return 0; | ||
| 136 | } | ||
| 137 | |||
| 138 | static int apparmor_capable(struct task_struct *task, const struct cred *cred, | ||
| 139 | int cap, int audit) | ||
| 140 | { | ||
| 141 | struct aa_profile *profile; | ||
| 142 | /* cap_capable returns 0 on success, else -EPERM */ | ||
| 143 | int error = cap_capable(task, cred, cap, audit); | ||
| 144 | if (!error) { | ||
| 145 | profile = aa_cred_profile(cred); | ||
| 146 | if (!unconfined(profile)) | ||
| 147 | error = aa_capable(task, profile, cap, audit); | ||
| 148 | } | ||
| 149 | return error; | ||
| 150 | } | ||
| 151 | |||
| 152 | /** | ||
| 153 | * common_perm - basic common permission check wrapper fn for paths | ||
| 154 | * @op: operation being checked | ||
| 155 | * @path: path to check permission of (NOT NULL) | ||
| 156 | * @mask: requested permissions mask | ||
| 157 | * @cond: conditional info for the permission request (NOT NULL) | ||
| 158 | * | ||
| 159 | * Returns: %0 else error code if error or permission denied | ||
| 160 | */ | ||
| 161 | static int common_perm(int op, struct path *path, u32 mask, | ||
| 162 | struct path_cond *cond) | ||
| 163 | { | ||
| 164 | struct aa_profile *profile; | ||
| 165 | int error = 0; | ||
| 166 | |||
| 167 | profile = __aa_current_profile(); | ||
| 168 | if (!unconfined(profile)) | ||
| 169 | error = aa_path_perm(op, profile, path, 0, mask, cond); | ||
| 170 | |||
| 171 | return error; | ||
| 172 | } | ||
| 173 | |||
| 174 | /** | ||
| 175 | * common_perm_dir_dentry - common permission wrapper when path is dir, dentry | ||
| 176 | * @op: operation being checked | ||
| 177 | * @dir: directory of the dentry (NOT NULL) | ||
| 178 | * @dentry: dentry to check (NOT NULL) | ||
| 179 | * @mask: requested permissions mask | ||
| 180 | * @cond: conditional info for the permission request (NOT NULL) | ||
| 181 | * | ||
| 182 | * Returns: %0 else error code if error or permission denied | ||
| 183 | */ | ||
| 184 | static int common_perm_dir_dentry(int op, struct path *dir, | ||
| 185 | struct dentry *dentry, u32 mask, | ||
| 186 | struct path_cond *cond) | ||
| 187 | { | ||
| 188 | struct path path = { dir->mnt, dentry }; | ||
| 189 | |||
| 190 | return common_perm(op, &path, mask, cond); | ||
| 191 | } | ||
| 192 | |||
| 193 | /** | ||
| 194 | * common_perm_mnt_dentry - common permission wrapper when mnt, dentry | ||
| 195 | * @op: operation being checked | ||
| 196 | * @mnt: mount point of dentry (NOT NULL) | ||
| 197 | * @dentry: dentry to check (NOT NULL) | ||
| 198 | * @mask: requested permissions mask | ||
| 199 | * | ||
| 200 | * Returns: %0 else error code if error or permission denied | ||
| 201 | */ | ||
| 202 | static int common_perm_mnt_dentry(int op, struct vfsmount *mnt, | ||
| 203 | struct dentry *dentry, u32 mask) | ||
| 204 | { | ||
| 205 | struct path path = { mnt, dentry }; | ||
| 206 | struct path_cond cond = { dentry->d_inode->i_uid, | ||
| 207 | dentry->d_inode->i_mode | ||
| 208 | }; | ||
| 209 | |||
| 210 | return common_perm(op, &path, mask, &cond); | ||
| 211 | } | ||
| 212 | |||
| 213 | /** | ||
| 214 | * common_perm_rm - common permission wrapper for operations doing rm | ||
| 215 | * @op: operation being checked | ||
| 216 | * @dir: directory that the dentry is in (NOT NULL) | ||
| 217 | * @dentry: dentry being rm'd (NOT NULL) | ||
| 218 | * @mask: requested permission mask | ||
| 219 | * | ||
| 220 | * Returns: %0 else error code if error or permission denied | ||
| 221 | */ | ||
| 222 | static int common_perm_rm(int op, struct path *dir, | ||
| 223 | struct dentry *dentry, u32 mask) | ||
| 224 | { | ||
| 225 | struct inode *inode = dentry->d_inode; | ||
| 226 | struct path_cond cond = { }; | ||
| 227 | |||
| 228 | if (!inode || !dir->mnt || !mediated_filesystem(inode)) | ||
| 229 | return 0; | ||
| 230 | |||
| 231 | cond.uid = inode->i_uid; | ||
| 232 | cond.mode = inode->i_mode; | ||
| 233 | |||
| 234 | return common_perm_dir_dentry(op, dir, dentry, mask, &cond); | ||
| 235 | } | ||
| 236 | |||
| 237 | /** | ||
| 238 | * common_perm_create - common permission wrapper for operations doing create | ||
| 239 | * @op: operation being checked | ||
| 240 | * @dir: directory that dentry will be created in (NOT NULL) | ||
| 241 | * @dentry: dentry to create (NOT NULL) | ||
| 242 | * @mask: request permission mask | ||
| 243 | * @mode: created file mode | ||
| 244 | * | ||
| 245 | * Returns: %0 else error code if error or permission denied | ||
| 246 | */ | ||
| 247 | static int common_perm_create(int op, struct path *dir, struct dentry *dentry, | ||
| 248 | u32 mask, umode_t mode) | ||
| 249 | { | ||
| 250 | struct path_cond cond = { current_fsuid(), mode }; | ||
| 251 | |||
| 252 | if (!dir->mnt || !mediated_filesystem(dir->dentry->d_inode)) | ||
| 253 | return 0; | ||
| 254 | |||
| 255 | return common_perm_dir_dentry(op, dir, dentry, mask, &cond); | ||
| 256 | } | ||
| 257 | |||
| 258 | static int apparmor_path_unlink(struct path *dir, struct dentry *dentry) | ||
| 259 | { | ||
| 260 | return common_perm_rm(OP_UNLINK, dir, dentry, AA_MAY_DELETE); | ||
| 261 | } | ||
| 262 | |||
| 263 | static int apparmor_path_mkdir(struct path *dir, struct dentry *dentry, | ||
| 264 | int mode) | ||
| 265 | { | ||
| 266 | return common_perm_create(OP_MKDIR, dir, dentry, AA_MAY_CREATE, | ||
| 267 | S_IFDIR); | ||
| 268 | } | ||
| 269 | |||
| 270 | static int apparmor_path_rmdir(struct path *dir, struct dentry *dentry) | ||
| 271 | { | ||
| 272 | return common_perm_rm(OP_RMDIR, dir, dentry, AA_MAY_DELETE); | ||
| 273 | } | ||
| 274 | |||
| 275 | static int apparmor_path_mknod(struct path *dir, struct dentry *dentry, | ||
| 276 | int mode, unsigned int dev) | ||
| 277 | { | ||
| 278 | return common_perm_create(OP_MKNOD, dir, dentry, AA_MAY_CREATE, mode); | ||
| 279 | } | ||
| 280 | |||
| 281 | static int apparmor_path_truncate(struct path *path) | ||
| 282 | { | ||
| 283 | struct path_cond cond = { path->dentry->d_inode->i_uid, | ||
| 284 | path->dentry->d_inode->i_mode | ||
| 285 | }; | ||
| 286 | |||
| 287 | if (!path->mnt || !mediated_filesystem(path->dentry->d_inode)) | ||
| 288 | return 0; | ||
| 289 | |||
| 290 | return common_perm(OP_TRUNC, path, MAY_WRITE | AA_MAY_META_WRITE, | ||
| 291 | &cond); | ||
| 292 | } | ||
| 293 | |||
| 294 | static int apparmor_path_symlink(struct path *dir, struct dentry *dentry, | ||
| 295 | const char *old_name) | ||
| 296 | { | ||
| 297 | return common_perm_create(OP_SYMLINK, dir, dentry, AA_MAY_CREATE, | ||
| 298 | S_IFLNK); | ||
| 299 | } | ||
| 300 | |||
| 301 | static int apparmor_path_link(struct dentry *old_dentry, struct path *new_dir, | ||
| 302 | struct dentry *new_dentry) | ||
| 303 | { | ||
| 304 | struct aa_profile *profile; | ||
| 305 | int error = 0; | ||
| 306 | |||
| 307 | if (!mediated_filesystem(old_dentry->d_inode)) | ||
| 308 | return 0; | ||
| 309 | |||
| 310 | profile = aa_current_profile(); | ||
| 311 | if (!unconfined(profile)) | ||
| 312 | error = aa_path_link(profile, old_dentry, new_dir, new_dentry); | ||
| 313 | return error; | ||
| 314 | } | ||
| 315 | |||
| 316 | static int apparmor_path_rename(struct path *old_dir, struct dentry *old_dentry, | ||
| 317 | struct path *new_dir, struct dentry *new_dentry) | ||
| 318 | { | ||
| 319 | struct aa_profile *profile; | ||
| 320 | int error = 0; | ||
| 321 | |||
| 322 | if (!mediated_filesystem(old_dentry->d_inode)) | ||
| 323 | return 0; | ||
| 324 | |||
| 325 | profile = aa_current_profile(); | ||
| 326 | if (!unconfined(profile)) { | ||
| 327 | struct path old_path = { old_dir->mnt, old_dentry }; | ||
| 328 | struct path new_path = { new_dir->mnt, new_dentry }; | ||
| 329 | struct path_cond cond = { old_dentry->d_inode->i_uid, | ||
| 330 | old_dentry->d_inode->i_mode | ||
| 331 | }; | ||
| 332 | |||
| 333 | error = aa_path_perm(OP_RENAME_SRC, profile, &old_path, 0, | ||
| 334 | MAY_READ | AA_MAY_META_READ | MAY_WRITE | | ||
| 335 | AA_MAY_META_WRITE | AA_MAY_DELETE, | ||
| 336 | &cond); | ||
| 337 | if (!error) | ||
| 338 | error = aa_path_perm(OP_RENAME_DEST, profile, &new_path, | ||
| 339 | 0, MAY_WRITE | AA_MAY_META_WRITE | | ||
| 340 | AA_MAY_CREATE, &cond); | ||
| 341 | |||
| 342 | } | ||
| 343 | return error; | ||
| 344 | } | ||
| 345 | |||
| 346 | static int apparmor_path_chmod(struct dentry *dentry, struct vfsmount *mnt, | ||
| 347 | mode_t mode) | ||
| 348 | { | ||
| 349 | if (!mediated_filesystem(dentry->d_inode)) | ||
| 350 | return 0; | ||
| 351 | |||
| 352 | return common_perm_mnt_dentry(OP_CHMOD, mnt, 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, NULL, GFP_KERNEL, | ||
| 596 | &sa, NULL); | ||
| 597 | } | ||
| 598 | } else if (strcmp(name, "exec") == 0) { | ||
| 599 | error = aa_setprocattr_changeprofile(args, AA_ONEXEC, | ||
| 600 | !AA_DO_TEST); | ||
| 601 | } else { | ||
| 602 | /* only support the "current" and "exec" process attributes */ | ||
| 603 | return -EINVAL; | ||
| 604 | } | ||
| 605 | if (!error) | ||
| 606 | error = size; | ||
| 607 | return error; | ||
| 608 | } | ||
| 609 | |||
| 610 | static int apparmor_task_setrlimit(unsigned int resource, | ||
| 611 | struct rlimit *new_rlim) | ||
| 612 | { | ||
| 613 | struct aa_profile *profile = aa_current_profile(); | ||
| 614 | int error = 0; | ||
| 615 | |||
| 616 | if (!unconfined(profile)) | ||
| 617 | error = aa_task_setrlimit(profile, resource, new_rlim); | ||
| 618 | |||
| 619 | return error; | ||
| 620 | } | ||
| 621 | |||
| 622 | static struct security_operations apparmor_ops = { | ||
| 623 | .name = "apparmor", | ||
| 624 | |||
| 625 | .ptrace_access_check = apparmor_ptrace_access_check, | ||
| 626 | .ptrace_traceme = apparmor_ptrace_traceme, | ||
| 627 | .capget = apparmor_capget, | ||
| 628 | .capable = apparmor_capable, | ||
| 629 | |||
| 630 | .path_link = apparmor_path_link, | ||
| 631 | .path_unlink = apparmor_path_unlink, | ||
| 632 | .path_symlink = apparmor_path_symlink, | ||
| 633 | .path_mkdir = apparmor_path_mkdir, | ||
| 634 | .path_rmdir = apparmor_path_rmdir, | ||
| 635 | .path_mknod = apparmor_path_mknod, | ||
| 636 | .path_rename = apparmor_path_rename, | ||
| 637 | .path_chmod = apparmor_path_chmod, | ||
| 638 | .path_chown = apparmor_path_chown, | ||
| 639 | .path_truncate = apparmor_path_truncate, | ||
| 640 | .dentry_open = apparmor_dentry_open, | ||
| 641 | .inode_getattr = apparmor_inode_getattr, | ||
| 642 | |||
| 643 | .file_permission = apparmor_file_permission, | ||
| 644 | .file_alloc_security = apparmor_file_alloc_security, | ||
| 645 | .file_free_security = apparmor_file_free_security, | ||
| 646 | .file_mmap = apparmor_file_mmap, | ||
| 647 | .file_mprotect = apparmor_file_mprotect, | ||
| 648 | .file_lock = apparmor_file_lock, | ||
| 649 | |||
| 650 | .getprocattr = apparmor_getprocattr, | ||
| 651 | .setprocattr = apparmor_setprocattr, | ||
| 652 | |||
| 653 | .cred_alloc_blank = apparmor_cred_alloc_blank, | ||
| 654 | .cred_free = apparmor_cred_free, | ||
| 655 | .cred_prepare = apparmor_cred_prepare, | ||
| 656 | .cred_transfer = apparmor_cred_transfer, | ||
| 657 | |||
| 658 | .bprm_set_creds = apparmor_bprm_set_creds, | ||
| 659 | .bprm_committing_creds = apparmor_bprm_committing_creds, | ||
| 660 | .bprm_committed_creds = apparmor_bprm_committed_creds, | ||
| 661 | .bprm_secureexec = apparmor_bprm_secureexec, | ||
| 662 | |||
| 663 | .task_setrlimit = apparmor_task_setrlimit, | ||
| 664 | }; | ||
| 665 | |||
| 666 | /* | ||
| 667 | * AppArmor sysfs module parameters | ||
| 668 | */ | ||
| 669 | |||
| 670 | static int param_set_aabool(const char *val, struct kernel_param *kp); | ||
| 671 | static int param_get_aabool(char *buffer, struct kernel_param *kp); | ||
| 672 | #define param_check_aabool(name, p) __param_check(name, p, int) | ||
| 673 | |||
| 674 | static int param_set_aauint(const char *val, struct kernel_param *kp); | ||
| 675 | static int param_get_aauint(char *buffer, struct kernel_param *kp); | ||
| 676 | #define param_check_aauint(name, p) __param_check(name, p, int) | ||
| 677 | |||
| 678 | static int param_set_aalockpolicy(const char *val, struct kernel_param *kp); | ||
| 679 | static int param_get_aalockpolicy(char *buffer, struct kernel_param *kp); | ||
| 680 | #define param_check_aalockpolicy(name, p) __param_check(name, p, int) | ||
| 681 | |||
| 682 | static int param_set_audit(const char *val, struct kernel_param *kp); | ||
| 683 | static int param_get_audit(char *buffer, struct kernel_param *kp); | ||
| 684 | #define param_check_audit(name, p) __param_check(name, p, int) | ||
| 685 | |||
| 686 | static int param_set_mode(const char *val, struct kernel_param *kp); | ||
| 687 | static int param_get_mode(char *buffer, struct kernel_param *kp); | ||
| 688 | #define param_check_mode(name, p) __param_check(name, p, int) | ||
| 689 | |||
| 690 | /* Flag values, also controllable via /sys/module/apparmor/parameters | ||
| 691 | * We define special types as we want to do additional mediation. | ||
| 692 | */ | ||
| 693 | |||
| 694 | /* AppArmor global enforcement switch - complain, enforce, kill */ | ||
| 695 | enum profile_mode aa_g_profile_mode = APPARMOR_ENFORCE; | ||
| 696 | module_param_call(mode, param_set_mode, param_get_mode, | ||
| 697 | &aa_g_profile_mode, S_IRUSR | S_IWUSR); | ||
| 698 | |||
| 699 | /* Debug mode */ | ||
| 700 | int aa_g_debug; | ||
| 701 | module_param_named(debug, aa_g_debug, aabool, S_IRUSR | S_IWUSR); | ||
| 702 | |||
| 703 | /* Audit mode */ | ||
| 704 | enum audit_mode aa_g_audit; | ||
| 705 | module_param_call(audit, param_set_audit, param_get_audit, | ||
| 706 | &aa_g_audit, S_IRUSR | S_IWUSR); | ||
| 707 | |||
| 708 | /* Determines if audit header is included in audited messages. This | ||
| 709 | * provides more context if the audit daemon is not running | ||
| 710 | */ | ||
| 711 | int aa_g_audit_header = 1; | ||
| 712 | module_param_named(audit_header, aa_g_audit_header, aabool, | ||
| 713 | S_IRUSR | S_IWUSR); | ||
| 714 | |||
| 715 | /* lock out loading/removal of policy | ||
| 716 | * TODO: add in at boot loading of policy, which is the only way to | ||
| 717 | * load policy, if lock_policy is set | ||
| 718 | */ | ||
| 719 | int aa_g_lock_policy; | ||
| 720 | module_param_named(lock_policy, aa_g_lock_policy, aalockpolicy, | ||
| 721 | S_IRUSR | S_IWUSR); | ||
| 722 | |||
| 723 | /* Syscall logging mode */ | ||
| 724 | int aa_g_logsyscall; | ||
| 725 | module_param_named(logsyscall, aa_g_logsyscall, aabool, S_IRUSR | S_IWUSR); | ||
| 726 | |||
| 727 | /* Maximum pathname length before accesses will start getting rejected */ | ||
| 728 | unsigned int aa_g_path_max = 2 * PATH_MAX; | ||
| 729 | module_param_named(path_max, aa_g_path_max, aauint, S_IRUSR | S_IWUSR); | ||
| 730 | |||
| 731 | /* Determines how paranoid loading of policy is and how much verification | ||
| 732 | * on the loaded policy is done. | ||
| 733 | */ | ||
| 734 | int aa_g_paranoid_load = 1; | ||
| 735 | module_param_named(paranoid_load, aa_g_paranoid_load, aabool, | ||
| 736 | S_IRUSR | S_IWUSR); | ||
| 737 | |||
| 738 | /* Boot time disable flag */ | ||
| 739 | static unsigned int apparmor_enabled = CONFIG_SECURITY_APPARMOR_BOOTPARAM_VALUE; | ||
| 740 | module_param_named(enabled, apparmor_enabled, aabool, S_IRUSR); | ||
| 741 | |||
| 742 | static int __init apparmor_enabled_setup(char *str) | ||
| 743 | { | ||
| 744 | unsigned long enabled; | ||
| 745 | int error = strict_strtoul(str, 0, &enabled); | ||
| 746 | if (!error) | ||
| 747 | apparmor_enabled = enabled ? 1 : 0; | ||
| 748 | return 1; | ||
| 749 | } | ||
| 750 | |||
| 751 | __setup("apparmor=", apparmor_enabled_setup); | ||
| 752 | |||
| 753 | /* set global flag turning off the ability to load policy */ | ||
| 754 | static int param_set_aalockpolicy(const char *val, struct kernel_param *kp) | ||
| 755 | { | ||
| 756 | if (!capable(CAP_MAC_ADMIN)) | ||
| 757 | return -EPERM; | ||
| 758 | if (aa_g_lock_policy) | ||
| 759 | return -EACCES; | ||
| 760 | return param_set_bool(val, kp); | ||
| 761 | } | ||
| 762 | |||
| 763 | static int param_get_aalockpolicy(char *buffer, struct kernel_param *kp) | ||
| 764 | { | ||
| 765 | if (!capable(CAP_MAC_ADMIN)) | ||
| 766 | return -EPERM; | ||
| 767 | return param_get_bool(buffer, kp); | ||
| 768 | } | ||
| 769 | |||
| 770 | static int param_set_aabool(const char *val, struct kernel_param *kp) | ||
| 771 | { | ||
| 772 | if (!capable(CAP_MAC_ADMIN)) | ||
| 773 | return -EPERM; | ||
| 774 | return param_set_bool(val, kp); | ||
| 775 | } | ||
| 776 | |||
| 777 | static int param_get_aabool(char *buffer, struct kernel_param *kp) | ||
| 778 | { | ||
| 779 | if (!capable(CAP_MAC_ADMIN)) | ||
| 780 | return -EPERM; | ||
| 781 | return param_get_bool(buffer, kp); | ||
| 782 | } | ||
| 783 | |||
| 784 | static int param_set_aauint(const char *val, struct kernel_param *kp) | ||
| 785 | { | ||
| 786 | if (!capable(CAP_MAC_ADMIN)) | ||
| 787 | return -EPERM; | ||
| 788 | return param_set_uint(val, kp); | ||
| 789 | } | ||
| 790 | |||
| 791 | static int param_get_aauint(char *buffer, struct kernel_param *kp) | ||
| 792 | { | ||
| 793 | if (!capable(CAP_MAC_ADMIN)) | ||
| 794 | return -EPERM; | ||
| 795 | return param_get_uint(buffer, kp); | ||
| 796 | } | ||
| 797 | |||
| 798 | static int param_get_audit(char *buffer, struct kernel_param *kp) | ||
| 799 | { | ||
| 800 | if (!capable(CAP_MAC_ADMIN)) | ||
| 801 | return -EPERM; | ||
| 802 | |||
| 803 | if (!apparmor_enabled) | ||
| 804 | return -EINVAL; | ||
| 805 | |||
| 806 | return sprintf(buffer, "%s", audit_mode_names[aa_g_audit]); | ||
| 807 | } | ||
| 808 | |||
| 809 | static int param_set_audit(const char *val, struct kernel_param *kp) | ||
| 810 | { | ||
| 811 | int i; | ||
| 812 | if (!capable(CAP_MAC_ADMIN)) | ||
| 813 | return -EPERM; | ||
| 814 | |||
| 815 | if (!apparmor_enabled) | ||
| 816 | return -EINVAL; | ||
| 817 | |||
| 818 | if (!val) | ||
| 819 | return -EINVAL; | ||
| 820 | |||
| 821 | for (i = 0; i < AUDIT_MAX_INDEX; i++) { | ||
| 822 | if (strcmp(val, audit_mode_names[i]) == 0) { | ||
| 823 | aa_g_audit = i; | ||
| 824 | return 0; | ||
| 825 | } | ||
| 826 | } | ||
| 827 | |||
| 828 | return -EINVAL; | ||
| 829 | } | ||
| 830 | |||
| 831 | static int param_get_mode(char *buffer, struct kernel_param *kp) | ||
| 832 | { | ||
| 833 | if (!capable(CAP_MAC_ADMIN)) | ||
| 834 | return -EPERM; | ||
| 835 | |||
| 836 | if (!apparmor_enabled) | ||
| 837 | return -EINVAL; | ||
| 838 | |||
| 839 | return sprintf(buffer, "%s", profile_mode_names[aa_g_profile_mode]); | ||
| 840 | } | ||
| 841 | |||
| 842 | static int param_set_mode(const char *val, struct kernel_param *kp) | ||
| 843 | { | ||
| 844 | int i; | ||
| 845 | if (!capable(CAP_MAC_ADMIN)) | ||
| 846 | return -EPERM; | ||
| 847 | |||
| 848 | if (!apparmor_enabled) | ||
| 849 | return -EINVAL; | ||
| 850 | |||
| 851 | if (!val) | ||
| 852 | return -EINVAL; | ||
| 853 | |||
| 854 | for (i = 0; i < APPARMOR_NAMES_MAX_INDEX; i++) { | ||
| 855 | if (strcmp(val, profile_mode_names[i]) == 0) { | ||
| 856 | aa_g_profile_mode = i; | ||
| 857 | return 0; | ||
| 858 | } | ||
| 859 | } | ||
| 860 | |||
| 861 | return -EINVAL; | ||
| 862 | } | ||
| 863 | |||
| 864 | /* | ||
| 865 | * AppArmor init functions | ||
| 866 | */ | ||
| 867 | |||
| 868 | /** | ||
| 869 | * set_init_cxt - set a task context and profile on the first task. | ||
| 870 | * | ||
| 871 | * TODO: allow setting an alternate profile than unconfined | ||
| 872 | */ | ||
| 873 | static int __init set_init_cxt(void) | ||
| 874 | { | ||
| 875 | struct cred *cred = (struct cred *)current->real_cred; | ||
| 876 | struct aa_task_cxt *cxt; | ||
| 877 | |||
| 878 | cxt = aa_alloc_task_context(GFP_KERNEL); | ||
| 879 | if (!cxt) | ||
| 880 | return -ENOMEM; | ||
| 881 | |||
| 882 | cxt->profile = aa_get_profile(root_ns->unconfined); | ||
| 883 | cred->security = cxt; | ||
| 884 | |||
| 885 | return 0; | ||
| 886 | } | ||
| 887 | |||
| 888 | static int __init apparmor_init(void) | ||
| 889 | { | ||
| 890 | int error; | ||
| 891 | |||
| 892 | if (!apparmor_enabled || !security_module_enable(&apparmor_ops)) { | ||
| 893 | aa_info_message("AppArmor disabled by boot time parameter"); | ||
| 894 | apparmor_enabled = 0; | ||
| 895 | return 0; | ||
| 896 | } | ||
| 897 | |||
| 898 | error = aa_alloc_root_ns(); | ||
| 899 | if (error) { | ||
| 900 | AA_ERROR("Unable to allocate default profile namespace\n"); | ||
| 901 | goto alloc_out; | ||
| 902 | } | ||
| 903 | |||
| 904 | error = set_init_cxt(); | ||
| 905 | if (error) { | ||
| 906 | AA_ERROR("Failed to set context on init task\n"); | ||
| 907 | goto register_security_out; | ||
| 908 | } | ||
| 909 | |||
| 910 | error = register_security(&apparmor_ops); | ||
| 911 | if (error) { | ||
| 912 | AA_ERROR("Unable to register AppArmor\n"); | ||
| 913 | goto register_security_out; | ||
| 914 | } | ||
| 915 | |||
| 916 | /* Report that AppArmor successfully initialized */ | ||
| 917 | apparmor_initialized = 1; | ||
| 918 | if (aa_g_profile_mode == APPARMOR_COMPLAIN) | ||
| 919 | aa_info_message("AppArmor initialized: complain mode enabled"); | ||
| 920 | else if (aa_g_profile_mode == APPARMOR_KILL) | ||
| 921 | aa_info_message("AppArmor initialized: kill mode enabled"); | ||
| 922 | else | ||
| 923 | aa_info_message("AppArmor initialized"); | ||
| 924 | |||
| 925 | return error; | ||
| 926 | |||
| 927 | register_security_out: | ||
| 928 | aa_free_root_ns(); | ||
| 929 | |||
| 930 | alloc_out: | ||
| 931 | aa_destroy_aafs(); | ||
| 932 | |||
| 933 | apparmor_enabled = 0; | ||
| 934 | return error; | ||
| 935 | |||
| 936 | } | ||
| 937 | |||
| 938 | security_initcall(apparmor_init); | ||
