1 /* 2 * security/tomoyo/tomoyo.c 3 * 4 * Copyright (C) 2005-2011 NTT DATA CORPORATION 5 */ 6 7 #include <linux/lsm_hooks.h> 8 #include "common.h" 9 10 /** 11 * tomoyo_cred_alloc_blank - Target for security_cred_alloc_blank(). 12 * 13 * @new: Pointer to "struct cred". 14 * @gfp: Memory allocation flags. 15 * 16 * Returns 0. 17 */ 18 static int tomoyo_cred_alloc_blank(struct cred *new, gfp_t gfp) 19 { 20 new->security = NULL; 21 return 0; 22 } 23 24 /** 25 * tomoyo_cred_prepare - Target for security_prepare_creds(). 26 * 27 * @new: Pointer to "struct cred". 28 * @old: Pointer to "struct cred". 29 * @gfp: Memory allocation flags. 30 * 31 * Returns 0. 32 */ 33 static int tomoyo_cred_prepare(struct cred *new, const struct cred *old, 34 gfp_t gfp) 35 { 36 struct tomoyo_domain_info *domain = old->security; 37 new->security = domain; 38 if (domain) 39 atomic_inc(&domain->users); 40 return 0; 41 } 42 43 /** 44 * tomoyo_cred_transfer - Target for security_transfer_creds(). 45 * 46 * @new: Pointer to "struct cred". 47 * @old: Pointer to "struct cred". 48 */ 49 static void tomoyo_cred_transfer(struct cred *new, const struct cred *old) 50 { 51 tomoyo_cred_prepare(new, old, 0); 52 } 53 54 /** 55 * tomoyo_cred_free - Target for security_cred_free(). 56 * 57 * @cred: Pointer to "struct cred". 58 */ 59 static void tomoyo_cred_free(struct cred *cred) 60 { 61 struct tomoyo_domain_info *domain = cred->security; 62 if (domain) 63 atomic_dec(&domain->users); 64 } 65 66 /** 67 * tomoyo_bprm_set_creds - Target for security_bprm_set_creds(). 68 * 69 * @bprm: Pointer to "struct linux_binprm". 70 * 71 * Returns 0 on success, negative value otherwise. 72 */ 73 static int tomoyo_bprm_set_creds(struct linux_binprm *bprm) 74 { 75 /* 76 * Do only if this function is called for the first time of an execve 77 * operation. 78 */ 79 if (bprm->cred_prepared) 80 return 0; 81 #ifndef CONFIG_SECURITY_TOMOYO_OMIT_USERSPACE_LOADER 82 /* 83 * Load policy if /sbin/tomoyo-init exists and /sbin/init is requested 84 * for the first time. 85 */ 86 if (!tomoyo_policy_loaded) 87 tomoyo_load_policy(bprm->filename); 88 #endif 89 /* 90 * Release reference to "struct tomoyo_domain_info" stored inside 91 * "bprm->cred->security". New reference to "struct tomoyo_domain_info" 92 * stored inside "bprm->cred->security" will be acquired later inside 93 * tomoyo_find_next_domain(). 94 */ 95 atomic_dec(&((struct tomoyo_domain_info *) 96 bprm->cred->security)->users); 97 /* 98 * Tell tomoyo_bprm_check_security() is called for the first time of an 99 * execve operation. 100 */ 101 bprm->cred->security = NULL; 102 return 0; 103 } 104 105 /** 106 * tomoyo_bprm_check_security - Target for security_bprm_check(). 107 * 108 * @bprm: Pointer to "struct linux_binprm". 109 * 110 * Returns 0 on success, negative value otherwise. 111 */ 112 static int tomoyo_bprm_check_security(struct linux_binprm *bprm) 113 { 114 struct tomoyo_domain_info *domain = bprm->cred->security; 115 116 /* 117 * Execute permission is checked against pathname passed to do_execve() 118 * using current domain. 119 */ 120 if (!domain) { 121 const int idx = tomoyo_read_lock(); 122 const int err = tomoyo_find_next_domain(bprm); 123 tomoyo_read_unlock(idx); 124 return err; 125 } 126 /* 127 * Read permission is checked against interpreters using next domain. 128 */ 129 return tomoyo_check_open_permission(domain, &bprm->file->f_path, 130 O_RDONLY); 131 } 132 133 /** 134 * tomoyo_inode_getattr - Target for security_inode_getattr(). 135 * 136 * @mnt: Pointer to "struct vfsmount". 137 * @dentry: Pointer to "struct dentry". 138 * 139 * Returns 0 on success, negative value otherwise. 140 */ 141 static int tomoyo_inode_getattr(const struct path *path) 142 { 143 return tomoyo_path_perm(TOMOYO_TYPE_GETATTR, path, NULL); 144 } 145 146 /** 147 * tomoyo_path_truncate - Target for security_path_truncate(). 148 * 149 * @path: Pointer to "struct path". 150 * 151 * Returns 0 on success, negative value otherwise. 152 */ 153 static int tomoyo_path_truncate(const struct path *path) 154 { 155 return tomoyo_path_perm(TOMOYO_TYPE_TRUNCATE, path, NULL); 156 } 157 158 /** 159 * tomoyo_path_unlink - Target for security_path_unlink(). 160 * 161 * @parent: Pointer to "struct path". 162 * @dentry: Pointer to "struct dentry". 163 * 164 * Returns 0 on success, negative value otherwise. 165 */ 166 static int tomoyo_path_unlink(const struct path *parent, struct dentry *dentry) 167 { 168 struct path path = { parent->mnt, dentry }; 169 return tomoyo_path_perm(TOMOYO_TYPE_UNLINK, &path, NULL); 170 } 171 172 /** 173 * tomoyo_path_mkdir - Target for security_path_mkdir(). 174 * 175 * @parent: Pointer to "struct path". 176 * @dentry: Pointer to "struct dentry". 177 * @mode: DAC permission mode. 178 * 179 * Returns 0 on success, negative value otherwise. 180 */ 181 static int tomoyo_path_mkdir(const struct path *parent, struct dentry *dentry, 182 umode_t mode) 183 { 184 struct path path = { parent->mnt, dentry }; 185 return tomoyo_path_number_perm(TOMOYO_TYPE_MKDIR, &path, 186 mode & S_IALLUGO); 187 } 188 189 /** 190 * tomoyo_path_rmdir - Target for security_path_rmdir(). 191 * 192 * @parent: Pointer to "struct path". 193 * @dentry: Pointer to "struct dentry". 194 * 195 * Returns 0 on success, negative value otherwise. 196 */ 197 static int tomoyo_path_rmdir(const struct path *parent, struct dentry *dentry) 198 { 199 struct path path = { parent->mnt, dentry }; 200 return tomoyo_path_perm(TOMOYO_TYPE_RMDIR, &path, NULL); 201 } 202 203 /** 204 * tomoyo_path_symlink - Target for security_path_symlink(). 205 * 206 * @parent: Pointer to "struct path". 207 * @dentry: Pointer to "struct dentry". 208 * @old_name: Symlink's content. 209 * 210 * Returns 0 on success, negative value otherwise. 211 */ 212 static int tomoyo_path_symlink(const struct path *parent, struct dentry *dentry, 213 const char *old_name) 214 { 215 struct path path = { parent->mnt, dentry }; 216 return tomoyo_path_perm(TOMOYO_TYPE_SYMLINK, &path, old_name); 217 } 218 219 /** 220 * tomoyo_path_mknod - Target for security_path_mknod(). 221 * 222 * @parent: Pointer to "struct path". 223 * @dentry: Pointer to "struct dentry". 224 * @mode: DAC permission mode. 225 * @dev: Device attributes. 226 * 227 * Returns 0 on success, negative value otherwise. 228 */ 229 static int tomoyo_path_mknod(const struct path *parent, struct dentry *dentry, 230 umode_t mode, unsigned int dev) 231 { 232 struct path path = { parent->mnt, dentry }; 233 int type = TOMOYO_TYPE_CREATE; 234 const unsigned int perm = mode & S_IALLUGO; 235 236 switch (mode & S_IFMT) { 237 case S_IFCHR: 238 type = TOMOYO_TYPE_MKCHAR; 239 break; 240 case S_IFBLK: 241 type = TOMOYO_TYPE_MKBLOCK; 242 break; 243 default: 244 goto no_dev; 245 } 246 return tomoyo_mkdev_perm(type, &path, perm, dev); 247 no_dev: 248 switch (mode & S_IFMT) { 249 case S_IFIFO: 250 type = TOMOYO_TYPE_MKFIFO; 251 break; 252 case S_IFSOCK: 253 type = TOMOYO_TYPE_MKSOCK; 254 break; 255 } 256 return tomoyo_path_number_perm(type, &path, perm); 257 } 258 259 /** 260 * tomoyo_path_link - Target for security_path_link(). 261 * 262 * @old_dentry: Pointer to "struct dentry". 263 * @new_dir: Pointer to "struct path". 264 * @new_dentry: Pointer to "struct dentry". 265 * 266 * Returns 0 on success, negative value otherwise. 267 */ 268 static int tomoyo_path_link(struct dentry *old_dentry, const struct path *new_dir, 269 struct dentry *new_dentry) 270 { 271 struct path path1 = { new_dir->mnt, old_dentry }; 272 struct path path2 = { new_dir->mnt, new_dentry }; 273 return tomoyo_path2_perm(TOMOYO_TYPE_LINK, &path1, &path2); 274 } 275 276 /** 277 * tomoyo_path_rename - Target for security_path_rename(). 278 * 279 * @old_parent: Pointer to "struct path". 280 * @old_dentry: Pointer to "struct dentry". 281 * @new_parent: Pointer to "struct path". 282 * @new_dentry: Pointer to "struct dentry". 283 * 284 * Returns 0 on success, negative value otherwise. 285 */ 286 static int tomoyo_path_rename(const struct path *old_parent, 287 struct dentry *old_dentry, 288 const struct path *new_parent, 289 struct dentry *new_dentry) 290 { 291 struct path path1 = { old_parent->mnt, old_dentry }; 292 struct path path2 = { new_parent->mnt, new_dentry }; 293 return tomoyo_path2_perm(TOMOYO_TYPE_RENAME, &path1, &path2); 294 } 295 296 /** 297 * tomoyo_file_fcntl - Target for security_file_fcntl(). 298 * 299 * @file: Pointer to "struct file". 300 * @cmd: Command for fcntl(). 301 * @arg: Argument for @cmd. 302 * 303 * Returns 0 on success, negative value otherwise. 304 */ 305 static int tomoyo_file_fcntl(struct file *file, unsigned int cmd, 306 unsigned long arg) 307 { 308 if (!(cmd == F_SETFL && ((arg ^ file->f_flags) & O_APPEND))) 309 return 0; 310 return tomoyo_check_open_permission(tomoyo_domain(), &file->f_path, 311 O_WRONLY | (arg & O_APPEND)); 312 } 313 314 /** 315 * tomoyo_file_open - Target for security_file_open(). 316 * 317 * @f: Pointer to "struct file". 318 * @cred: Pointer to "struct cred". 319 * 320 * Returns 0 on success, negative value otherwise. 321 */ 322 static int tomoyo_file_open(struct file *f, const struct cred *cred) 323 { 324 int flags = f->f_flags; 325 /* Don't check read permission here if called from do_execve(). */ 326 if (current->in_execve) 327 return 0; 328 return tomoyo_check_open_permission(tomoyo_domain(), &f->f_path, flags); 329 } 330 331 /** 332 * tomoyo_file_ioctl - Target for security_file_ioctl(). 333 * 334 * @file: Pointer to "struct file". 335 * @cmd: Command for ioctl(). 336 * @arg: Argument for @cmd. 337 * 338 * Returns 0 on success, negative value otherwise. 339 */ 340 static int tomoyo_file_ioctl(struct file *file, unsigned int cmd, 341 unsigned long arg) 342 { 343 return tomoyo_path_number_perm(TOMOYO_TYPE_IOCTL, &file->f_path, cmd); 344 } 345 346 /** 347 * tomoyo_path_chmod - Target for security_path_chmod(). 348 * 349 * @path: Pointer to "struct path". 350 * @mode: DAC permission mode. 351 * 352 * Returns 0 on success, negative value otherwise. 353 */ 354 static int tomoyo_path_chmod(const struct path *path, umode_t mode) 355 { 356 return tomoyo_path_number_perm(TOMOYO_TYPE_CHMOD, path, 357 mode & S_IALLUGO); 358 } 359 360 /** 361 * tomoyo_path_chown - Target for security_path_chown(). 362 * 363 * @path: Pointer to "struct path". 364 * @uid: Owner ID. 365 * @gid: Group ID. 366 * 367 * Returns 0 on success, negative value otherwise. 368 */ 369 static int tomoyo_path_chown(const struct path *path, kuid_t uid, kgid_t gid) 370 { 371 int error = 0; 372 if (uid_valid(uid)) 373 error = tomoyo_path_number_perm(TOMOYO_TYPE_CHOWN, path, 374 from_kuid(&init_user_ns, uid)); 375 if (!error && gid_valid(gid)) 376 error = tomoyo_path_number_perm(TOMOYO_TYPE_CHGRP, path, 377 from_kgid(&init_user_ns, gid)); 378 return error; 379 } 380 381 /** 382 * tomoyo_path_chroot - Target for security_path_chroot(). 383 * 384 * @path: Pointer to "struct path". 385 * 386 * Returns 0 on success, negative value otherwise. 387 */ 388 static int tomoyo_path_chroot(const struct path *path) 389 { 390 return tomoyo_path_perm(TOMOYO_TYPE_CHROOT, path, NULL); 391 } 392 393 /** 394 * tomoyo_sb_mount - Target for security_sb_mount(). 395 * 396 * @dev_name: Name of device file. Maybe NULL. 397 * @path: Pointer to "struct path". 398 * @type: Name of filesystem type. Maybe NULL. 399 * @flags: Mount options. 400 * @data: Optional data. Maybe NULL. 401 * 402 * Returns 0 on success, negative value otherwise. 403 */ 404 static int tomoyo_sb_mount(const char *dev_name, const struct path *path, 405 const char *type, unsigned long flags, void *data) 406 { 407 return tomoyo_mount_permission(dev_name, path, type, flags, data); 408 } 409 410 /** 411 * tomoyo_sb_umount - Target for security_sb_umount(). 412 * 413 * @mnt: Pointer to "struct vfsmount". 414 * @flags: Unmount options. 415 * 416 * Returns 0 on success, negative value otherwise. 417 */ 418 static int tomoyo_sb_umount(struct vfsmount *mnt, int flags) 419 { 420 struct path path = { mnt, mnt->mnt_root }; 421 return tomoyo_path_perm(TOMOYO_TYPE_UMOUNT, &path, NULL); 422 } 423 424 /** 425 * tomoyo_sb_pivotroot - Target for security_sb_pivotroot(). 426 * 427 * @old_path: Pointer to "struct path". 428 * @new_path: Pointer to "struct path". 429 * 430 * Returns 0 on success, negative value otherwise. 431 */ 432 static int tomoyo_sb_pivotroot(const struct path *old_path, const struct path *new_path) 433 { 434 return tomoyo_path2_perm(TOMOYO_TYPE_PIVOT_ROOT, new_path, old_path); 435 } 436 437 /** 438 * tomoyo_socket_listen - Check permission for listen(). 439 * 440 * @sock: Pointer to "struct socket". 441 * @backlog: Backlog parameter. 442 * 443 * Returns 0 on success, negative value otherwise. 444 */ 445 static int tomoyo_socket_listen(struct socket *sock, int backlog) 446 { 447 return tomoyo_socket_listen_permission(sock); 448 } 449 450 /** 451 * tomoyo_socket_connect - Check permission for connect(). 452 * 453 * @sock: Pointer to "struct socket". 454 * @addr: Pointer to "struct sockaddr". 455 * @addr_len: Size of @addr. 456 * 457 * Returns 0 on success, negative value otherwise. 458 */ 459 static int tomoyo_socket_connect(struct socket *sock, struct sockaddr *addr, 460 int addr_len) 461 { 462 return tomoyo_socket_connect_permission(sock, addr, addr_len); 463 } 464 465 /** 466 * tomoyo_socket_bind - Check permission for bind(). 467 * 468 * @sock: Pointer to "struct socket". 469 * @addr: Pointer to "struct sockaddr". 470 * @addr_len: Size of @addr. 471 * 472 * Returns 0 on success, negative value otherwise. 473 */ 474 static int tomoyo_socket_bind(struct socket *sock, struct sockaddr *addr, 475 int addr_len) 476 { 477 return tomoyo_socket_bind_permission(sock, addr, addr_len); 478 } 479 480 /** 481 * tomoyo_socket_sendmsg - Check permission for sendmsg(). 482 * 483 * @sock: Pointer to "struct socket". 484 * @msg: Pointer to "struct msghdr". 485 * @size: Size of message. 486 * 487 * Returns 0 on success, negative value otherwise. 488 */ 489 static int tomoyo_socket_sendmsg(struct socket *sock, struct msghdr *msg, 490 int size) 491 { 492 return tomoyo_socket_sendmsg_permission(sock, msg, size); 493 } 494 495 /* 496 * tomoyo_security_ops is a "struct security_operations" which is used for 497 * registering TOMOYO. 498 */ 499 static struct security_hook_list tomoyo_hooks[] = { 500 LSM_HOOK_INIT(cred_alloc_blank, tomoyo_cred_alloc_blank), 501 LSM_HOOK_INIT(cred_prepare, tomoyo_cred_prepare), 502 LSM_HOOK_INIT(cred_transfer, tomoyo_cred_transfer), 503 LSM_HOOK_INIT(cred_free, tomoyo_cred_free), 504 LSM_HOOK_INIT(bprm_set_creds, tomoyo_bprm_set_creds), 505 LSM_HOOK_INIT(bprm_check_security, tomoyo_bprm_check_security), 506 LSM_HOOK_INIT(file_fcntl, tomoyo_file_fcntl), 507 LSM_HOOK_INIT(file_open, tomoyo_file_open), 508 LSM_HOOK_INIT(path_truncate, tomoyo_path_truncate), 509 LSM_HOOK_INIT(path_unlink, tomoyo_path_unlink), 510 LSM_HOOK_INIT(path_mkdir, tomoyo_path_mkdir), 511 LSM_HOOK_INIT(path_rmdir, tomoyo_path_rmdir), 512 LSM_HOOK_INIT(path_symlink, tomoyo_path_symlink), 513 LSM_HOOK_INIT(path_mknod, tomoyo_path_mknod), 514 LSM_HOOK_INIT(path_link, tomoyo_path_link), 515 LSM_HOOK_INIT(path_rename, tomoyo_path_rename), 516 LSM_HOOK_INIT(inode_getattr, tomoyo_inode_getattr), 517 LSM_HOOK_INIT(file_ioctl, tomoyo_file_ioctl), 518 LSM_HOOK_INIT(path_chmod, tomoyo_path_chmod), 519 LSM_HOOK_INIT(path_chown, tomoyo_path_chown), 520 LSM_HOOK_INIT(path_chroot, tomoyo_path_chroot), 521 LSM_HOOK_INIT(sb_mount, tomoyo_sb_mount), 522 LSM_HOOK_INIT(sb_umount, tomoyo_sb_umount), 523 LSM_HOOK_INIT(sb_pivotroot, tomoyo_sb_pivotroot), 524 LSM_HOOK_INIT(socket_bind, tomoyo_socket_bind), 525 LSM_HOOK_INIT(socket_connect, tomoyo_socket_connect), 526 LSM_HOOK_INIT(socket_listen, tomoyo_socket_listen), 527 LSM_HOOK_INIT(socket_sendmsg, tomoyo_socket_sendmsg), 528 }; 529 530 /* Lock for GC. */ 531 DEFINE_SRCU(tomoyo_ss); 532 533 /** 534 * tomoyo_init - Register TOMOYO Linux as a LSM module. 535 * 536 * Returns 0. 537 */ 538 static int __init tomoyo_init(void) 539 { 540 struct cred *cred = (struct cred *) current_cred(); 541 542 if (!security_module_enable("tomoyo")) 543 return 0; 544 /* register ourselves with the security framework */ 545 security_add_hooks(tomoyo_hooks, ARRAY_SIZE(tomoyo_hooks)); 546 printk(KERN_INFO "TOMOYO Linux initialized\n"); 547 cred->security = &tomoyo_kernel_domain; 548 tomoyo_mm_init(); 549 return 0; 550 } 551 552 security_initcall(tomoyo_init); 553