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1 /*
2 * security/tomoyo/tomoyo.c
3 *
4 * Copyright (C) 2005-2011 NTT DATA CORPORATION
5 */
6
7 #include <linux/security.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 int rc;
76
77 rc = cap_bprm_set_creds(bprm);
78 if (rc)
79 return rc;
80
81 /*
82 * Do only if this function is called for the first time of an execve
83 * operation.
84 */
85 if (bprm->cred_prepared)
86 return 0;
87 #ifndef CONFIG_SECURITY_TOMOYO_OMIT_USERSPACE_LOADER
88 /*
89 * Load policy if /sbin/tomoyo-init exists and /sbin/init is requested
90 * for the first time.
91 */
92 if (!tomoyo_policy_loaded)
93 tomoyo_load_policy(bprm->filename);
94 #endif
95 /*
96 * Release reference to "struct tomoyo_domain_info" stored inside
97 * "bprm->cred->security". New reference to "struct tomoyo_domain_info"
98 * stored inside "bprm->cred->security" will be acquired later inside
99 * tomoyo_find_next_domain().
100 */
101 atomic_dec(&((struct tomoyo_domain_info *)
102 bprm->cred->security)->users);
103 /*
104 * Tell tomoyo_bprm_check_security() is called for the first time of an
105 * execve operation.
106 */
107 bprm->cred->security = NULL;
108 return 0;
109 }
110
111 /**
112 * tomoyo_bprm_check_security - Target for security_bprm_check().
113 *
114 * @bprm: Pointer to "struct linux_binprm".
115 *
116 * Returns 0 on success, negative value otherwise.
117 */
118 static int tomoyo_bprm_check_security(struct linux_binprm *bprm)
119 {
120 struct tomoyo_domain_info *domain = bprm->cred->security;
121
122 /*
123 * Execute permission is checked against pathname passed to do_execve()
124 * using current domain.
125 */
126 if (!domain) {
127 const int idx = tomoyo_read_lock();
128 const int err = tomoyo_find_next_domain(bprm);
129 tomoyo_read_unlock(idx);
130 return err;
131 }
132 /*
133 * Read permission is checked against interpreters using next domain.
134 */
135 return tomoyo_check_open_permission(domain, &bprm->file->f_path,
136 O_RDONLY);
137 }
138
139 /**
140 * tomoyo_inode_getattr - Target for security_inode_getattr().
141 *
142 * @mnt: Pointer to "struct vfsmount".
143 * @dentry: Pointer to "struct dentry".
144 *
145 * Returns 0 on success, negative value otherwise.
146 */
147 static int tomoyo_inode_getattr(const struct path *path)
148 {
149 return tomoyo_path_perm(TOMOYO_TYPE_GETATTR, path, NULL);
150 }
151
152 /**
153 * tomoyo_path_truncate - Target for security_path_truncate().
154 *
155 * @path: Pointer to "struct path".
156 *
157 * Returns 0 on success, negative value otherwise.
158 */
159 static int tomoyo_path_truncate(struct path *path)
160 {
161 return tomoyo_path_perm(TOMOYO_TYPE_TRUNCATE, path, NULL);
162 }
163
164 /**
165 * tomoyo_path_unlink - Target for security_path_unlink().
166 *
167 * @parent: Pointer to "struct path".
168 * @dentry: Pointer to "struct dentry".
169 *
170 * Returns 0 on success, negative value otherwise.
171 */
172 static int tomoyo_path_unlink(struct path *parent, struct dentry *dentry)
173 {
174 struct path path = { parent->mnt, dentry };
175 return tomoyo_path_perm(TOMOYO_TYPE_UNLINK, &path, NULL);
176 }
177
178 /**
179 * tomoyo_path_mkdir - Target for security_path_mkdir().
180 *
181 * @parent: Pointer to "struct path".
182 * @dentry: Pointer to "struct dentry".
183 * @mode: DAC permission mode.
184 *
185 * Returns 0 on success, negative value otherwise.
186 */
187 static int tomoyo_path_mkdir(struct path *parent, struct dentry *dentry,
188 umode_t mode)
189 {
190 struct path path = { parent->mnt, dentry };
191 return tomoyo_path_number_perm(TOMOYO_TYPE_MKDIR, &path,
192 mode & S_IALLUGO);
193 }
194
195 /**
196 * tomoyo_path_rmdir - Target for security_path_rmdir().
197 *
198 * @parent: Pointer to "struct path".
199 * @dentry: Pointer to "struct dentry".
200 *
201 * Returns 0 on success, negative value otherwise.
202 */
203 static int tomoyo_path_rmdir(struct path *parent, struct dentry *dentry)
204 {
205 struct path path = { parent->mnt, dentry };
206 return tomoyo_path_perm(TOMOYO_TYPE_RMDIR, &path, NULL);
207 }
208
209 /**
210 * tomoyo_path_symlink - Target for security_path_symlink().
211 *
212 * @parent: Pointer to "struct path".
213 * @dentry: Pointer to "struct dentry".
214 * @old_name: Symlink's content.
215 *
216 * Returns 0 on success, negative value otherwise.
217 */
218 static int tomoyo_path_symlink(struct path *parent, struct dentry *dentry,
219 const char *old_name)
220 {
221 struct path path = { parent->mnt, dentry };
222 return tomoyo_path_perm(TOMOYO_TYPE_SYMLINK, &path, old_name);
223 }
224
225 /**
226 * tomoyo_path_mknod - Target for security_path_mknod().
227 *
228 * @parent: Pointer to "struct path".
229 * @dentry: Pointer to "struct dentry".
230 * @mode: DAC permission mode.
231 * @dev: Device attributes.
232 *
233 * Returns 0 on success, negative value otherwise.
234 */
235 static int tomoyo_path_mknod(struct path *parent, struct dentry *dentry,
236 umode_t mode, unsigned int dev)
237 {
238 struct path path = { parent->mnt, dentry };
239 int type = TOMOYO_TYPE_CREATE;
240 const unsigned int perm = mode & S_IALLUGO;
241
242 switch (mode & S_IFMT) {
243 case S_IFCHR:
244 type = TOMOYO_TYPE_MKCHAR;
245 break;
246 case S_IFBLK:
247 type = TOMOYO_TYPE_MKBLOCK;
248 break;
249 default:
250 goto no_dev;
251 }
252 return tomoyo_mkdev_perm(type, &path, perm, dev);
253 no_dev:
254 switch (mode & S_IFMT) {
255 case S_IFIFO:
256 type = TOMOYO_TYPE_MKFIFO;
257 break;
258 case S_IFSOCK:
259 type = TOMOYO_TYPE_MKSOCK;
260 break;
261 }
262 return tomoyo_path_number_perm(type, &path, perm);
263 }
264
265 /**
266 * tomoyo_path_link - Target for security_path_link().
267 *
268 * @old_dentry: Pointer to "struct dentry".
269 * @new_dir: Pointer to "struct path".
270 * @new_dentry: Pointer to "struct dentry".
271 *
272 * Returns 0 on success, negative value otherwise.
273 */
274 static int tomoyo_path_link(struct dentry *old_dentry, struct path *new_dir,
275 struct dentry *new_dentry)
276 {
277 struct path path1 = { new_dir->mnt, old_dentry };
278 struct path path2 = { new_dir->mnt, new_dentry };
279 return tomoyo_path2_perm(TOMOYO_TYPE_LINK, &path1, &path2);
280 }
281
282 /**
283 * tomoyo_path_rename - Target for security_path_rename().
284 *
285 * @old_parent: Pointer to "struct path".
286 * @old_dentry: Pointer to "struct dentry".
287 * @new_parent: Pointer to "struct path".
288 * @new_dentry: Pointer to "struct dentry".
289 *
290 * Returns 0 on success, negative value otherwise.
291 */
292 static int tomoyo_path_rename(struct path *old_parent,
293 struct dentry *old_dentry,
294 struct path *new_parent,
295 struct dentry *new_dentry)
296 {
297 struct path path1 = { old_parent->mnt, old_dentry };
298 struct path path2 = { new_parent->mnt, new_dentry };
299 return tomoyo_path2_perm(TOMOYO_TYPE_RENAME, &path1, &path2);
300 }
301
302 /**
303 * tomoyo_file_fcntl - Target for security_file_fcntl().
304 *
305 * @file: Pointer to "struct file".
306 * @cmd: Command for fcntl().
307 * @arg: Argument for @cmd.
308 *
309 * Returns 0 on success, negative value otherwise.
310 */
311 static int tomoyo_file_fcntl(struct file *file, unsigned int cmd,
312 unsigned long arg)
313 {
314 if (!(cmd == F_SETFL && ((arg ^ file->f_flags) & O_APPEND)))
315 return 0;
316 return tomoyo_check_open_permission(tomoyo_domain(), &file->f_path,
317 O_WRONLY | (arg & O_APPEND));
318 }
319
320 /**
321 * tomoyo_file_open - Target for security_file_open().
322 *
323 * @f: Pointer to "struct file".
324 * @cred: Pointer to "struct cred".
325 *
326 * Returns 0 on success, negative value otherwise.
327 */
328 static int tomoyo_file_open(struct file *f, const struct cred *cred)
329 {
330 int flags = f->f_flags;
331 /* Don't check read permission here if called from do_execve(). */
332 if (current->in_execve)
333 return 0;
334 return tomoyo_check_open_permission(tomoyo_domain(), &f->f_path, flags);
335 }
336
337 /**
338 * tomoyo_file_ioctl - Target for security_file_ioctl().
339 *
340 * @file: Pointer to "struct file".
341 * @cmd: Command for ioctl().
342 * @arg: Argument for @cmd.
343 *
344 * Returns 0 on success, negative value otherwise.
345 */
346 static int tomoyo_file_ioctl(struct file *file, unsigned int cmd,
347 unsigned long arg)
348 {
349 return tomoyo_path_number_perm(TOMOYO_TYPE_IOCTL, &file->f_path, cmd);
350 }
351
352 /**
353 * tomoyo_path_chmod - Target for security_path_chmod().
354 *
355 * @path: Pointer to "struct path".
356 * @mode: DAC permission mode.
357 *
358 * Returns 0 on success, negative value otherwise.
359 */
360 static int tomoyo_path_chmod(struct path *path, umode_t mode)
361 {
362 return tomoyo_path_number_perm(TOMOYO_TYPE_CHMOD, path,
363 mode & S_IALLUGO);
364 }
365
366 /**
367 * tomoyo_path_chown - Target for security_path_chown().
368 *
369 * @path: Pointer to "struct path".
370 * @uid: Owner ID.
371 * @gid: Group ID.
372 *
373 * Returns 0 on success, negative value otherwise.
374 */
375 static int tomoyo_path_chown(struct path *path, kuid_t uid, kgid_t gid)
376 {
377 int error = 0;
378 if (uid_valid(uid))
379 error = tomoyo_path_number_perm(TOMOYO_TYPE_CHOWN, path,
380 from_kuid(&init_user_ns, uid));
381 if (!error && gid_valid(gid))
382 error = tomoyo_path_number_perm(TOMOYO_TYPE_CHGRP, path,
383 from_kgid(&init_user_ns, gid));
384 return error;
385 }
386
387 /**
388 * tomoyo_path_chroot - Target for security_path_chroot().
389 *
390 * @path: Pointer to "struct path".
391 *
392 * Returns 0 on success, negative value otherwise.
393 */
394 static int tomoyo_path_chroot(struct path *path)
395 {
396 return tomoyo_path_perm(TOMOYO_TYPE_CHROOT, path, NULL);
397 }
398
399 /**
400 * tomoyo_sb_mount - Target for security_sb_mount().
401 *
402 * @dev_name: Name of device file. Maybe NULL.
403 * @path: Pointer to "struct path".
404 * @type: Name of filesystem type. Maybe NULL.
405 * @flags: Mount options.
406 * @data: Optional data. Maybe NULL.
407 *
408 * Returns 0 on success, negative value otherwise.
409 */
410 static int tomoyo_sb_mount(const char *dev_name, struct path *path,
411 const char *type, unsigned long flags, void *data)
412 {
413 return tomoyo_mount_permission(dev_name, path, type, flags, data);
414 }
415
416 /**
417 * tomoyo_sb_umount - Target for security_sb_umount().
418 *
419 * @mnt: Pointer to "struct vfsmount".
420 * @flags: Unmount options.
421 *
422 * Returns 0 on success, negative value otherwise.
423 */
424 static int tomoyo_sb_umount(struct vfsmount *mnt, int flags)
425 {
426 struct path path = { mnt, mnt->mnt_root };
427 return tomoyo_path_perm(TOMOYO_TYPE_UMOUNT, &path, NULL);
428 }
429
430 /**
431 * tomoyo_sb_pivotroot - Target for security_sb_pivotroot().
432 *
433 * @old_path: Pointer to "struct path".
434 * @new_path: Pointer to "struct path".
435 *
436 * Returns 0 on success, negative value otherwise.
437 */
438 static int tomoyo_sb_pivotroot(struct path *old_path, struct path *new_path)
439 {
440 return tomoyo_path2_perm(TOMOYO_TYPE_PIVOT_ROOT, new_path, old_path);
441 }
442
443 /**
444 * tomoyo_socket_listen - Check permission for listen().
445 *
446 * @sock: Pointer to "struct socket".
447 * @backlog: Backlog parameter.
448 *
449 * Returns 0 on success, negative value otherwise.
450 */
451 static int tomoyo_socket_listen(struct socket *sock, int backlog)
452 {
453 return tomoyo_socket_listen_permission(sock);
454 }
455
456 /**
457 * tomoyo_socket_connect - Check permission for connect().
458 *
459 * @sock: Pointer to "struct socket".
460 * @addr: Pointer to "struct sockaddr".
461 * @addr_len: Size of @addr.
462 *
463 * Returns 0 on success, negative value otherwise.
464 */
465 static int tomoyo_socket_connect(struct socket *sock, struct sockaddr *addr,
466 int addr_len)
467 {
468 return tomoyo_socket_connect_permission(sock, addr, addr_len);
469 }
470
471 /**
472 * tomoyo_socket_bind - Check permission for bind().
473 *
474 * @sock: Pointer to "struct socket".
475 * @addr: Pointer to "struct sockaddr".
476 * @addr_len: Size of @addr.
477 *
478 * Returns 0 on success, negative value otherwise.
479 */
480 static int tomoyo_socket_bind(struct socket *sock, struct sockaddr *addr,
481 int addr_len)
482 {
483 return tomoyo_socket_bind_permission(sock, addr, addr_len);
484 }
485
486 /**
487 * tomoyo_socket_sendmsg - Check permission for sendmsg().
488 *
489 * @sock: Pointer to "struct socket".
490 * @msg: Pointer to "struct msghdr".
491 * @size: Size of message.
492 *
493 * Returns 0 on success, negative value otherwise.
494 */
495 static int tomoyo_socket_sendmsg(struct socket *sock, struct msghdr *msg,
496 int size)
497 {
498 return tomoyo_socket_sendmsg_permission(sock, msg, size);
499 }
500
501 /*
502 * tomoyo_security_ops is a "struct security_operations" which is used for
503 * registering TOMOYO.
504 */
505 static struct security_operations tomoyo_security_ops = {
506 .name = "tomoyo",
507 .cred_alloc_blank = tomoyo_cred_alloc_blank,
508 .cred_prepare = tomoyo_cred_prepare,
509 .cred_transfer = tomoyo_cred_transfer,
510 .cred_free = tomoyo_cred_free,
511 .bprm_set_creds = tomoyo_bprm_set_creds,
512 .bprm_check_security = tomoyo_bprm_check_security,
513 .file_fcntl = tomoyo_file_fcntl,
514 .file_open = tomoyo_file_open,
515 .path_truncate = tomoyo_path_truncate,
516 .path_unlink = tomoyo_path_unlink,
517 .path_mkdir = tomoyo_path_mkdir,
518 .path_rmdir = tomoyo_path_rmdir,
519 .path_symlink = tomoyo_path_symlink,
520 .path_mknod = tomoyo_path_mknod,
521 .path_link = tomoyo_path_link,
522 .path_rename = tomoyo_path_rename,
523 .inode_getattr = tomoyo_inode_getattr,
524 .file_ioctl = tomoyo_file_ioctl,
525 .path_chmod = tomoyo_path_chmod,
526 .path_chown = tomoyo_path_chown,
527 .path_chroot = tomoyo_path_chroot,
528 .sb_mount = tomoyo_sb_mount,
529 .sb_umount = tomoyo_sb_umount,
530 .sb_pivotroot = tomoyo_sb_pivotroot,
531 .socket_bind = tomoyo_socket_bind,
532 .socket_connect = tomoyo_socket_connect,
533 .socket_listen = tomoyo_socket_listen,
534 .socket_sendmsg = tomoyo_socket_sendmsg,
535 };
536
537 /* Lock for GC. */
538 DEFINE_SRCU(tomoyo_ss);
539
540 /**
541 * tomoyo_init - Register TOMOYO Linux as a LSM module.
542 *
543 * Returns 0.
544 */
545 static int __init tomoyo_init(void)
546 {
547 struct cred *cred = (struct cred *) current_cred();
548
549 if (!security_module_enable(&tomoyo_security_ops))
550 return 0;
551 /* register ourselves with the security framework */
552 if (register_security(&tomoyo_security_ops))
553 panic("Failure registering TOMOYO Linux");
554 printk(KERN_INFO "TOMOYO Linux initialized\n");
555 cred->security = &tomoyo_kernel_domain;
556 tomoyo_mm_init();
557 return 0;
558 }
559
560 security_initcall(tomoyo_init);