aboutsummaryrefslogtreecommitdiff
path: root/security/tomoyo/tomoyo.c
blob: 716c92ec941adc595c1887995afd897a77d8ab26 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
// SPDX-License-Identifier: GPL-2.0
/*
 * security/tomoyo/tomoyo.c
 *
 * Copyright (C) 2005-2011  NTT DATA CORPORATION
 */

#include <linux/lsm_hooks.h>
#include "common.h"

/**
 * tomoyo_domain - Get "struct tomoyo_domain_info" for current thread.
 *
 * Returns pointer to "struct tomoyo_domain_info" for current thread.
 */
struct tomoyo_domain_info *tomoyo_domain(void)
{
	struct tomoyo_task *s = tomoyo_task(current);

	if (s->old_domain_info && !current->in_execve) {
		atomic_dec(&s->old_domain_info->users);
		s->old_domain_info = NULL;
	}
	return s->domain_info;
}

/**
 * tomoyo_cred_prepare - Target for security_prepare_creds().
 *
 * @new: Pointer to "struct cred".
 * @old: Pointer to "struct cred".
 * @gfp: Memory allocation flags.
 *
 * Returns 0.
 */
static int tomoyo_cred_prepare(struct cred *new, const struct cred *old,
			       gfp_t gfp)
{
	/* Restore old_domain_info saved by previous execve() request. */
	struct tomoyo_task *s = tomoyo_task(current);

	if (s->old_domain_info && !current->in_execve) {
		atomic_dec(&s->domain_info->users);
		s->domain_info = s->old_domain_info;
		s->old_domain_info = NULL;
	}
	return 0;
}

/**
 * tomoyo_bprm_committed_creds - Target for security_bprm_committed_creds().
 *
 * @bprm: Pointer to "struct linux_binprm".
 */
static void tomoyo_bprm_committed_creds(struct linux_binprm *bprm)
{
	/* Clear old_domain_info saved by execve() request. */
	struct tomoyo_task *s = tomoyo_task(current);

	atomic_dec(&s->old_domain_info->users);
	s->old_domain_info = NULL;
}

#ifndef CONFIG_SECURITY_TOMOYO_OMIT_USERSPACE_LOADER
/**
 * tomoyo_bprm_set_creds - Target for security_bprm_set_creds().
 *
 * @bprm: Pointer to "struct linux_binprm".
 *
 * Returns 0.
 */
static int tomoyo_bprm_set_creds(struct linux_binprm *bprm)
{
	/*
	 * Do only if this function is called for the first time of an execve
	 * operation.
	 */
	if (bprm->called_set_creds)
		return 0;
	/*
	 * Load policy if /sbin/tomoyo-init exists and /sbin/init is requested
	 * for the first time.
	 */
	if (!tomoyo_policy_loaded)
		tomoyo_load_policy(bprm->filename);
	return 0;
}
#endif

/**
 * tomoyo_bprm_check_security - Target for security_bprm_check().
 *
 * @bprm: Pointer to "struct linux_binprm".
 *
 * Returns 0 on success, negative value otherwise.
 */
static int tomoyo_bprm_check_security(struct linux_binprm *bprm)
{
	struct tomoyo_task *s = tomoyo_task(current);

	/*
	 * Execute permission is checked against pathname passed to do_execve()
	 * using current domain.
	 */
	if (!s->old_domain_info) {
		const int idx = tomoyo_read_lock();
		const int err = tomoyo_find_next_domain(bprm);

		tomoyo_read_unlock(idx);
		return err;
	}
	/*
	 * Read permission is checked against interpreters using next domain.
	 */
	return tomoyo_check_open_permission(s->domain_info,
					    &bprm->file->f_path, O_RDONLY);
}

/**
 * tomoyo_inode_getattr - Target for security_inode_getattr().
 *
 * @mnt:    Pointer to "struct vfsmount".
 * @dentry: Pointer to "struct dentry".
 *
 * Returns 0 on success, negative value otherwise.
 */
static int tomoyo_inode_getattr(const struct path *path)
{
	return tomoyo_path_perm(TOMOYO_TYPE_GETATTR, path, NULL);
}

/**
 * tomoyo_path_truncate - Target for security_path_truncate().
 *
 * @path: Pointer to "struct path".
 *
 * Returns 0 on success, negative value otherwise.
 */
static int tomoyo_path_truncate(const struct path *path)
{
	return tomoyo_path_perm(TOMOYO_TYPE_TRUNCATE, path, NULL);
}

/**
 * tomoyo_path_unlink - Target for security_path_unlink().
 *
 * @parent: Pointer to "struct path".
 * @dentry: Pointer to "struct dentry".
 *
 * Returns 0 on success, negative value otherwise.
 */
static int tomoyo_path_unlink(const struct path *parent, struct dentry *dentry)
{
	struct path path = { .mnt = parent->mnt, .dentry = dentry };

	return tomoyo_path_perm(TOMOYO_TYPE_UNLINK, &path, NULL);
}

/**
 * tomoyo_path_mkdir - Target for security_path_mkdir().
 *
 * @parent: Pointer to "struct path".
 * @dentry: Pointer to "struct dentry".
 * @mode:   DAC permission mode.
 *
 * Returns 0 on success, negative value otherwise.
 */
static int tomoyo_path_mkdir(const struct path *parent, struct dentry *dentry,
			     umode_t mode)
{
	struct path path = { .mnt = parent->mnt, .dentry = dentry };

	return tomoyo_path_number_perm(TOMOYO_TYPE_MKDIR, &path,
				       mode & S_IALLUGO);
}

/**
 * tomoyo_path_rmdir - Target for security_path_rmdir().
 *
 * @parent: Pointer to "struct path".
 * @dentry: Pointer to "struct dentry".
 *
 * Returns 0 on success, negative value otherwise.
 */
static int tomoyo_path_rmdir(const struct path *parent, struct dentry *dentry)
{
	struct path path = { .mnt = parent->mnt, .dentry = dentry };

	return tomoyo_path_perm(TOMOYO_TYPE_RMDIR, &path, NULL);
}

/**
 * tomoyo_path_symlink - Target for security_path_symlink().
 *
 * @parent:   Pointer to "struct path".
 * @dentry:   Pointer to "struct dentry".
 * @old_name: Symlink's content.
 *
 * Returns 0 on success, negative value otherwise.
 */
static int tomoyo_path_symlink(const struct path *parent, struct dentry *dentry,
			       const char *old_name)
{
	struct path path = { .mnt = parent->mnt, .dentry = dentry };

	return tomoyo_path_perm(TOMOYO_TYPE_SYMLINK, &path, old_name);
}

/**
 * tomoyo_path_mknod - Target for security_path_mknod().
 *
 * @parent: Pointer to "struct path".
 * @dentry: Pointer to "struct dentry".
 * @mode:   DAC permission mode.
 * @dev:    Device attributes.
 *
 * Returns 0 on success, negative value otherwise.
 */
static int tomoyo_path_mknod(const struct path *parent, struct dentry *dentry,
			     umode_t mode, unsigned int dev)
{
	struct path path = { .mnt = parent->mnt, .dentry = dentry };
	int type = TOMOYO_TYPE_CREATE;
	const unsigned int perm = mode & S_IALLUGO;

	switch (mode & S_IFMT) {
	case S_IFCHR:
		type = TOMOYO_TYPE_MKCHAR;
		break;
	case S_IFBLK:
		type = TOMOYO_TYPE_MKBLOCK;
		break;
	default:
		goto no_dev;
	}
	return tomoyo_mkdev_perm(type, &path, perm, dev);
 no_dev:
	switch (mode & S_IFMT) {
	case S_IFIFO:
		type = TOMOYO_TYPE_MKFIFO;
		break;
	case S_IFSOCK:
		type = TOMOYO_TYPE_MKSOCK;
		break;
	}
	return tomoyo_path_number_perm(type, &path, perm);
}

/**
 * tomoyo_path_link - Target for security_path_link().
 *
 * @old_dentry: Pointer to "struct dentry".
 * @new_dir:    Pointer to "struct path".
 * @new_dentry: Pointer to "struct dentry".
 *
 * Returns 0 on success, negative value otherwise.
 */
static int tomoyo_path_link(struct dentry *old_dentry, const struct path *new_dir,
			    struct dentry *new_dentry)
{
	struct path path1 = { .mnt = new_dir->mnt, .dentry = old_dentry };
	struct path path2 = { .mnt = new_dir->mnt, .dentry = new_dentry };

	return tomoyo_path2_perm(TOMOYO_TYPE_LINK, &path1, &path2);
}

/**
 * tomoyo_path_rename - Target for security_path_rename().
 *
 * @old_parent: Pointer to "struct path".
 * @old_dentry: Pointer to "struct dentry".
 * @new_parent: Pointer to "struct path".
 * @new_dentry: Pointer to "struct dentry".
 *
 * Returns 0 on success, negative value otherwise.
 */
static int tomoyo_path_rename(const struct path *old_parent,
			      struct dentry *old_dentry,
			      const struct path *new_parent,
			      struct dentry *new_dentry)
{
	struct path path1 = { .mnt = old_parent->mnt, .dentry = old_dentry };
	struct path path2 = { .mnt = new_parent->mnt, .dentry = new_dentry };

	return tomoyo_path2_perm(TOMOYO_TYPE_RENAME, &path1, &path2);
}

/**
 * tomoyo_file_fcntl - Target for security_file_fcntl().
 *
 * @file: Pointer to "struct file".
 * @cmd:  Command for fcntl().
 * @arg:  Argument for @cmd.
 *
 * Returns 0 on success, negative value otherwise.
 */
static int tomoyo_file_fcntl(struct file *file, unsigned int cmd,
			     unsigned long arg)
{
	if (!(cmd == F_SETFL && ((arg ^ file->f_flags) & O_APPEND)))
		return 0;
	return tomoyo_check_open_permission(tomoyo_domain(), &file->f_path,
					    O_WRONLY | (arg & O_APPEND));
}

/**
 * tomoyo_file_open - Target for security_file_open().
 *
 * @f:    Pointer to "struct file".
 * @cred: Pointer to "struct cred".
 *
 * Returns 0 on success, negative value otherwise.
 */
static int tomoyo_file_open(struct file *f)
{
	/* Don't check read permission here if called from do_execve(). */
	if (current->in_execve)
		return 0;
	return tomoyo_check_open_permission(tomoyo_domain(), &f->f_path,
					    f->f_flags);
}

/**
 * tomoyo_file_ioctl - Target for security_file_ioctl().
 *
 * @file: Pointer to "struct file".
 * @cmd:  Command for ioctl().
 * @arg:  Argument for @cmd.
 *
 * Returns 0 on success, negative value otherwise.
 */
static int tomoyo_file_ioctl(struct file *file, unsigned int cmd,
			     unsigned long arg)
{
	return tomoyo_path_number_perm(TOMOYO_TYPE_IOCTL, &file->f_path, cmd);
}

/**
 * tomoyo_path_chmod - Target for security_path_chmod().
 *
 * @path: Pointer to "struct path".
 * @mode: DAC permission mode.
 *
 * Returns 0 on success, negative value otherwise.
 */
static int tomoyo_path_chmod(const struct path *path, umode_t mode)
{
	return tomoyo_path_number_perm(TOMOYO_TYPE_CHMOD, path,
				       mode & S_IALLUGO);
}

/**
 * tomoyo_path_chown - Target for security_path_chown().
 *
 * @path: Pointer to "struct path".
 * @uid:  Owner ID.
 * @gid:  Group ID.
 *
 * Returns 0 on success, negative value otherwise.
 */
static int tomoyo_path_chown(const struct path *path, kuid_t uid, kgid_t gid)
{
	int error = 0;

	if (uid_valid(uid))
		error = tomoyo_path_number_perm(TOMOYO_TYPE_CHOWN, path,
						from_kuid(&init_user_ns, uid));
	if (!error && gid_valid(gid))
		error = tomoyo_path_number_perm(TOMOYO_TYPE_CHGRP, path,
						from_kgid(&init_user_ns, gid));
	return error;
}

/**
 * tomoyo_path_chroot - Target for security_path_chroot().
 *
 * @path: Pointer to "struct path".
 *
 * Returns 0 on success, negative value otherwise.
 */
static int tomoyo_path_chroot(const struct path *path)
{
	return tomoyo_path_perm(TOMOYO_TYPE_CHROOT, path, NULL);
}

/**
 * tomoyo_sb_mount - Target for security_sb_mount().
 *
 * @dev_name: Name of device file. Maybe NULL.
 * @path:     Pointer to "struct path".
 * @type:     Name of filesystem type. Maybe NULL.
 * @flags:    Mount options.
 * @data:     Optional data. Maybe NULL.
 *
 * Returns 0 on success, negative value otherwise.
 */
static int tomoyo_sb_mount(const char *dev_name, const struct path *path,
			   const char *type, unsigned long flags, void *data)
{
	return tomoyo_mount_permission(dev_name, path, type, flags, data);
}

/**
 * tomoyo_sb_umount - Target for security_sb_umount().
 *
 * @mnt:   Pointer to "struct vfsmount".
 * @flags: Unmount options.
 *
 * Returns 0 on success, negative value otherwise.
 */
static int tomoyo_sb_umount(struct vfsmount *mnt, int flags)
{
	struct path path = { .mnt = mnt, .dentry = mnt->mnt_root };

	return tomoyo_path_perm(TOMOYO_TYPE_UMOUNT, &path, NULL);
}

/**
 * tomoyo_sb_pivotroot - Target for security_sb_pivotroot().
 *
 * @old_path: Pointer to "struct path".
 * @new_path: Pointer to "struct path".
 *
 * Returns 0 on success, negative value otherwise.
 */
static int tomoyo_sb_pivotroot(const struct path *old_path, const struct path *new_path)
{
	return tomoyo_path2_perm(TOMOYO_TYPE_PIVOT_ROOT, new_path, old_path);
}

/**
 * tomoyo_socket_listen - Check permission for listen().
 *
 * @sock:    Pointer to "struct socket".
 * @backlog: Backlog parameter.
 *
 * Returns 0 on success, negative value otherwise.
 */
static int tomoyo_socket_listen(struct socket *sock, int backlog)
{
	return tomoyo_socket_listen_permission(sock);
}

/**
 * tomoyo_socket_connect - Check permission for connect().
 *
 * @sock:     Pointer to "struct socket".
 * @addr:     Pointer to "struct sockaddr".
 * @addr_len: Size of @addr.
 *
 * Returns 0 on success, negative value otherwise.
 */
static int tomoyo_socket_connect(struct socket *sock, struct sockaddr *addr,
				 int addr_len)
{
	return tomoyo_socket_connect_permission(sock, addr, addr_len);
}

/**
 * tomoyo_socket_bind - Check permission for bind().
 *
 * @sock:     Pointer to "struct socket".
 * @addr:     Pointer to "struct sockaddr".
 * @addr_len: Size of @addr.
 *
 * Returns 0 on success, negative value otherwise.
 */
static int tomoyo_socket_bind(struct socket *sock, struct sockaddr *addr,
			      int addr_len)
{
	return tomoyo_socket_bind_permission(sock, addr, addr_len);
}

/**
 * tomoyo_socket_sendmsg - Check permission for sendmsg().
 *
 * @sock: Pointer to "struct socket".
 * @msg:  Pointer to "struct msghdr".
 * @size: Size of message.
 *
 * Returns 0 on success, negative value otherwise.
 */
static int tomoyo_socket_sendmsg(struct socket *sock, struct msghdr *msg,
				 int size)
{
	return tomoyo_socket_sendmsg_permission(sock, msg, size);
}

struct lsm_blob_sizes tomoyo_blob_sizes __lsm_ro_after_init = {
	.lbs_task = sizeof(struct tomoyo_task),
};

/**
 * tomoyo_task_alloc - Target for security_task_alloc().
 *
 * @task:  Pointer to "struct task_struct".
 * @flags: clone() flags.
 *
 * Returns 0.
 */
static int tomoyo_task_alloc(struct task_struct *task,
			     unsigned long clone_flags)
{
	struct tomoyo_task *old = tomoyo_task(current);
	struct tomoyo_task *new = tomoyo_task(task);

	new->domain_info = old->domain_info;
	atomic_inc(&new->domain_info->users);
	new->old_domain_info = NULL;
	return 0;
}

/**
 * tomoyo_task_free - Target for security_task_free().
 *
 * @task: Pointer to "struct task_struct".
 */
static void tomoyo_task_free(struct task_struct *task)
{
	struct tomoyo_task *s = tomoyo_task(task);

	if (s->domain_info) {
		atomic_dec(&s->domain_info->users);
		s->domain_info = NULL;
	}
	if (s->old_domain_info) {
		atomic_dec(&s->old_domain_info->users);
		s->old_domain_info = NULL;
	}
}

/*
 * tomoyo_security_ops is a "struct security_operations" which is used for
 * registering TOMOYO.
 */
static struct security_hook_list tomoyo_hooks[] __lsm_ro_after_init = {
	LSM_HOOK_INIT(cred_prepare, tomoyo_cred_prepare),
	LSM_HOOK_INIT(bprm_committed_creds, tomoyo_bprm_committed_creds),
	LSM_HOOK_INIT(task_alloc, tomoyo_task_alloc),
	LSM_HOOK_INIT(task_free, tomoyo_task_free),
#ifndef CONFIG_SECURITY_TOMOYO_OMIT_USERSPACE_LOADER
	LSM_HOOK_INIT(bprm_set_creds, tomoyo_bprm_set_creds),
#endif
	LSM_HOOK_INIT(bprm_check_security, tomoyo_bprm_check_security),
	LSM_HOOK_INIT(file_fcntl, tomoyo_file_fcntl),
	LSM_HOOK_INIT(file_open, tomoyo_file_open),
	LSM_HOOK_INIT(path_truncate, tomoyo_path_truncate),
	LSM_HOOK_INIT(path_unlink, tomoyo_path_unlink),
	LSM_HOOK_INIT(path_mkdir, tomoyo_path_mkdir),
	LSM_HOOK_INIT(path_rmdir, tomoyo_path_rmdir),
	LSM_HOOK_INIT(path_symlink, tomoyo_path_symlink),
	LSM_HOOK_INIT(path_mknod, tomoyo_path_mknod),
	LSM_HOOK_INIT(path_link, tomoyo_path_link),
	LSM_HOOK_INIT(path_rename, tomoyo_path_rename),
	LSM_HOOK_INIT(inode_getattr, tomoyo_inode_getattr),
	LSM_HOOK_INIT(file_ioctl, tomoyo_file_ioctl),
	LSM_HOOK_INIT(path_chmod, tomoyo_path_chmod),
	LSM_HOOK_INIT(path_chown, tomoyo_path_chown),
	LSM_HOOK_INIT(path_chroot, tomoyo_path_chroot),
	LSM_HOOK_INIT(sb_mount, tomoyo_sb_mount),
	LSM_HOOK_INIT(sb_umount, tomoyo_sb_umount),
	LSM_HOOK_INIT(sb_pivotroot, tomoyo_sb_pivotroot),
	LSM_HOOK_INIT(socket_bind, tomoyo_socket_bind),
	LSM_HOOK_INIT(socket_connect, tomoyo_socket_connect),
	LSM_HOOK_INIT(socket_listen, tomoyo_socket_listen),
	LSM_HOOK_INIT(socket_sendmsg, tomoyo_socket_sendmsg),
};

/* Lock for GC. */
DEFINE_SRCU(tomoyo_ss);

int tomoyo_enabled __lsm_ro_after_init = 1;

/**
 * tomoyo_init - Register TOMOYO Linux as a LSM module.
 *
 * Returns 0.
 */
static int __init tomoyo_init(void)
{
	struct tomoyo_task *s = tomoyo_task(current);

	/* register ourselves with the security framework */
	security_add_hooks(tomoyo_hooks, ARRAY_SIZE(tomoyo_hooks), "tomoyo");
	pr_info("TOMOYO Linux initialized\n");
	s->domain_info = &tomoyo_kernel_domain;
	atomic_inc(&tomoyo_kernel_domain.users);
	s->old_domain_info = NULL;
	tomoyo_mm_init();

	return 0;
}

DEFINE_LSM(tomoyo) = {
	.name = "tomoyo",
	.enabled = &tomoyo_enabled,
	.flags = LSM_FLAG_LEGACY_MAJOR,
	.blobs = &tomoyo_blob_sizes,
	.init = tomoyo_init,
};