1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * AppArmor security module
4  *
5  * This file contains AppArmor /sys/kernel/security/apparmor interface functions
6  *
7  * Copyright (C) 1998-2008 Novell/SUSE
8  * Copyright 2009-2010 Canonical Ltd.
9  */
10 
11 #include <linux/ctype.h>
12 #include <linux/security.h>
13 #include <linux/vmalloc.h>
14 #include <linux/init.h>
15 #include <linux/seq_file.h>
16 #include <linux/uaccess.h>
17 #include <linux/mount.h>
18 #include <linux/namei.h>
19 #include <linux/capability.h>
20 #include <linux/rcupdate.h>
21 #include <linux/fs.h>
22 #include <linux/fs_context.h>
23 #include <linux/poll.h>
24 #include <linux/zlib.h>
25 #include <uapi/linux/major.h>
26 #include <uapi/linux/magic.h>
27 
28 #include "include/apparmor.h"
29 #include "include/apparmorfs.h"
30 #include "include/audit.h"
31 #include "include/cred.h"
32 #include "include/crypto.h"
33 #include "include/ipc.h"
34 #include "include/label.h"
35 #include "include/policy.h"
36 #include "include/policy_ns.h"
37 #include "include/resource.h"
38 #include "include/policy_unpack.h"
39 
40 /*
41  * The apparmor filesystem interface used for policy load and introspection
42  * The interface is split into two main components based on their function
43  * a securityfs component:
44  *   used for static files that are always available, and which allows
45  *   userspace to specificy the location of the security filesystem.
46  *
47  *   fns and data are prefixed with
48  *      aa_sfs_
49  *
50  * an apparmorfs component:
51  *   used loaded policy content and introspection. It is not part of  a
52  *   regular mounted filesystem and is available only through the magic
53  *   policy symlink in the root of the securityfs apparmor/ directory.
54  *   Tasks queries will be magically redirected to the correct portion
55  *   of the policy tree based on their confinement.
56  *
57  *   fns and data are prefixed with
58  *      aafs_
59  *
60  * The aa_fs_ prefix is used to indicate the fn is used by both the
61  * securityfs and apparmorfs filesystems.
62  */
63 
64 
65 /*
66  * support fns
67  */
68 
69 struct rawdata_f_data {
70 	struct aa_loaddata *loaddata;
71 };
72 
73 #define RAWDATA_F_DATA_BUF(p) (char *)(p + 1)
74 
75 static void rawdata_f_data_free(struct rawdata_f_data *private)
76 {
77 	if (!private)
78 		return;
79 
80 	aa_put_loaddata(private->loaddata);
81 	kvfree(private);
82 }
83 
84 static struct rawdata_f_data *rawdata_f_data_alloc(size_t size)
85 {
86 	struct rawdata_f_data *ret;
87 
88 	if (size > SIZE_MAX - sizeof(*ret))
89 		return ERR_PTR(-EINVAL);
90 
91 	ret = kvzalloc(sizeof(*ret) + size, GFP_KERNEL);
92 	if (!ret)
93 		return ERR_PTR(-ENOMEM);
94 
95 	return ret;
96 }
97 
98 /**
99  * aa_mangle_name - mangle a profile name to std profile layout form
100  * @name: profile name to mangle  (NOT NULL)
101  * @target: buffer to store mangled name, same length as @name (MAYBE NULL)
102  *
103  * Returns: length of mangled name
104  */
105 static int mangle_name(const char *name, char *target)
106 {
107 	char *t = target;
108 
109 	while (*name == '/' || *name == '.')
110 		name++;
111 
112 	if (target) {
113 		for (; *name; name++) {
114 			if (*name == '/')
115 				*(t)++ = '.';
116 			else if (isspace(*name))
117 				*(t)++ = '_';
118 			else if (isalnum(*name) || strchr("._-", *name))
119 				*(t)++ = *name;
120 		}
121 
122 		*t = 0;
123 	} else {
124 		int len = 0;
125 		for (; *name; name++) {
126 			if (isalnum(*name) || isspace(*name) ||
127 			    strchr("/._-", *name))
128 				len++;
129 		}
130 
131 		return len;
132 	}
133 
134 	return t - target;
135 }
136 
137 
138 /*
139  * aafs - core fns and data for the policy tree
140  */
141 
142 #define AAFS_NAME		"apparmorfs"
143 static struct vfsmount *aafs_mnt;
144 static int aafs_count;
145 
146 
147 static int aafs_show_path(struct seq_file *seq, struct dentry *dentry)
148 {
149 	seq_printf(seq, "%s:[%lu]", AAFS_NAME, d_inode(dentry)->i_ino);
150 	return 0;
151 }
152 
153 static void aafs_free_inode(struct inode *inode)
154 {
155 	if (S_ISLNK(inode->i_mode))
156 		kfree(inode->i_link);
157 	free_inode_nonrcu(inode);
158 }
159 
160 static const struct super_operations aafs_super_ops = {
161 	.statfs = simple_statfs,
162 	.free_inode = aafs_free_inode,
163 	.show_path = aafs_show_path,
164 };
165 
166 static int apparmorfs_fill_super(struct super_block *sb, struct fs_context *fc)
167 {
168 	static struct tree_descr files[] = { {""} };
169 	int error;
170 
171 	error = simple_fill_super(sb, AAFS_MAGIC, files);
172 	if (error)
173 		return error;
174 	sb->s_op = &aafs_super_ops;
175 
176 	return 0;
177 }
178 
179 static int apparmorfs_get_tree(struct fs_context *fc)
180 {
181 	return get_tree_single(fc, apparmorfs_fill_super);
182 }
183 
184 static const struct fs_context_operations apparmorfs_context_ops = {
185 	.get_tree	= apparmorfs_get_tree,
186 };
187 
188 static int apparmorfs_init_fs_context(struct fs_context *fc)
189 {
190 	fc->ops = &apparmorfs_context_ops;
191 	return 0;
192 }
193 
194 static struct file_system_type aafs_ops = {
195 	.owner = THIS_MODULE,
196 	.name = AAFS_NAME,
197 	.init_fs_context = apparmorfs_init_fs_context,
198 	.kill_sb = kill_anon_super,
199 };
200 
201 /**
202  * __aafs_setup_d_inode - basic inode setup for apparmorfs
203  * @dir: parent directory for the dentry
204  * @dentry: dentry we are seting the inode up for
205  * @mode: permissions the file should have
206  * @data: data to store on inode.i_private, available in open()
207  * @link: if symlink, symlink target string
208  * @fops: struct file_operations that should be used
209  * @iops: struct of inode_operations that should be used
210  */
211 static int __aafs_setup_d_inode(struct inode *dir, struct dentry *dentry,
212 			       umode_t mode, void *data, char *link,
213 			       const struct file_operations *fops,
214 			       const struct inode_operations *iops)
215 {
216 	struct inode *inode = new_inode(dir->i_sb);
217 
218 	AA_BUG(!dir);
219 	AA_BUG(!dentry);
220 
221 	if (!inode)
222 		return -ENOMEM;
223 
224 	inode->i_ino = get_next_ino();
225 	inode->i_mode = mode;
226 	inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode);
227 	inode->i_private = data;
228 	if (S_ISDIR(mode)) {
229 		inode->i_op = iops ? iops : &simple_dir_inode_operations;
230 		inode->i_fop = &simple_dir_operations;
231 		inc_nlink(inode);
232 		inc_nlink(dir);
233 	} else if (S_ISLNK(mode)) {
234 		inode->i_op = iops ? iops : &simple_symlink_inode_operations;
235 		inode->i_link = link;
236 	} else {
237 		inode->i_fop = fops;
238 	}
239 	d_instantiate(dentry, inode);
240 	dget(dentry);
241 
242 	return 0;
243 }
244 
245 /**
246  * aafs_create - create a dentry in the apparmorfs filesystem
247  *
248  * @name: name of dentry to create
249  * @mode: permissions the file should have
250  * @parent: parent directory for this dentry
251  * @data: data to store on inode.i_private, available in open()
252  * @link: if symlink, symlink target string
253  * @fops: struct file_operations that should be used for
254  * @iops: struct of inode_operations that should be used
255  *
256  * This is the basic "create a xxx" function for apparmorfs.
257  *
258  * Returns a pointer to a dentry if it succeeds, that must be free with
259  * aafs_remove(). Will return ERR_PTR on failure.
260  */
261 static struct dentry *aafs_create(const char *name, umode_t mode,
262 				  struct dentry *parent, void *data, void *link,
263 				  const struct file_operations *fops,
264 				  const struct inode_operations *iops)
265 {
266 	struct dentry *dentry;
267 	struct inode *dir;
268 	int error;
269 
270 	AA_BUG(!name);
271 	AA_BUG(!parent);
272 
273 	if (!(mode & S_IFMT))
274 		mode = (mode & S_IALLUGO) | S_IFREG;
275 
276 	error = simple_pin_fs(&aafs_ops, &aafs_mnt, &aafs_count);
277 	if (error)
278 		return ERR_PTR(error);
279 
280 	dir = d_inode(parent);
281 
282 	inode_lock(dir);
283 	dentry = lookup_one_len(name, parent, strlen(name));
284 	if (IS_ERR(dentry)) {
285 		error = PTR_ERR(dentry);
286 		goto fail_lock;
287 	}
288 
289 	if (d_really_is_positive(dentry)) {
290 		error = -EEXIST;
291 		goto fail_dentry;
292 	}
293 
294 	error = __aafs_setup_d_inode(dir, dentry, mode, data, link, fops, iops);
295 	if (error)
296 		goto fail_dentry;
297 	inode_unlock(dir);
298 
299 	return dentry;
300 
301 fail_dentry:
302 	dput(dentry);
303 
304 fail_lock:
305 	inode_unlock(dir);
306 	simple_release_fs(&aafs_mnt, &aafs_count);
307 
308 	return ERR_PTR(error);
309 }
310 
311 /**
312  * aafs_create_file - create a file in the apparmorfs filesystem
313  *
314  * @name: name of dentry to create
315  * @mode: permissions the file should have
316  * @parent: parent directory for this dentry
317  * @data: data to store on inode.i_private, available in open()
318  * @fops: struct file_operations that should be used for
319  *
320  * see aafs_create
321  */
322 static struct dentry *aafs_create_file(const char *name, umode_t mode,
323 				       struct dentry *parent, void *data,
324 				       const struct file_operations *fops)
325 {
326 	return aafs_create(name, mode, parent, data, NULL, fops, NULL);
327 }
328 
329 /**
330  * aafs_create_dir - create a directory in the apparmorfs filesystem
331  *
332  * @name: name of dentry to create
333  * @parent: parent directory for this dentry
334  *
335  * see aafs_create
336  */
337 static struct dentry *aafs_create_dir(const char *name, struct dentry *parent)
338 {
339 	return aafs_create(name, S_IFDIR | 0755, parent, NULL, NULL, NULL,
340 			   NULL);
341 }
342 
343 /**
344  * aafs_remove - removes a file or directory from the apparmorfs filesystem
345  *
346  * @dentry: dentry of the file/directory/symlink to removed.
347  */
348 static void aafs_remove(struct dentry *dentry)
349 {
350 	struct inode *dir;
351 
352 	if (!dentry || IS_ERR(dentry))
353 		return;
354 
355 	dir = d_inode(dentry->d_parent);
356 	inode_lock(dir);
357 	if (simple_positive(dentry)) {
358 		if (d_is_dir(dentry))
359 			simple_rmdir(dir, dentry);
360 		else
361 			simple_unlink(dir, dentry);
362 		d_delete(dentry);
363 		dput(dentry);
364 	}
365 	inode_unlock(dir);
366 	simple_release_fs(&aafs_mnt, &aafs_count);
367 }
368 
369 
370 /*
371  * aa_fs - policy load/replace/remove
372  */
373 
374 /**
375  * aa_simple_write_to_buffer - common routine for getting policy from user
376  * @userbuf: user buffer to copy data from  (NOT NULL)
377  * @alloc_size: size of user buffer (REQUIRES: @alloc_size >= @copy_size)
378  * @copy_size: size of data to copy from user buffer
379  * @pos: position write is at in the file (NOT NULL)
380  *
381  * Returns: kernel buffer containing copy of user buffer data or an
382  *          ERR_PTR on failure.
383  */
384 static struct aa_loaddata *aa_simple_write_to_buffer(const char __user *userbuf,
385 						     size_t alloc_size,
386 						     size_t copy_size,
387 						     loff_t *pos)
388 {
389 	struct aa_loaddata *data;
390 
391 	AA_BUG(copy_size > alloc_size);
392 
393 	if (*pos != 0)
394 		/* only writes from pos 0, that is complete writes */
395 		return ERR_PTR(-ESPIPE);
396 
397 	/* freed by caller to simple_write_to_buffer */
398 	data = aa_loaddata_alloc(alloc_size);
399 	if (IS_ERR(data))
400 		return data;
401 
402 	data->size = copy_size;
403 	if (copy_from_user(data->data, userbuf, copy_size)) {
404 		kvfree(data);
405 		return ERR_PTR(-EFAULT);
406 	}
407 
408 	return data;
409 }
410 
411 static ssize_t policy_update(u32 mask, const char __user *buf, size_t size,
412 			     loff_t *pos, struct aa_ns *ns)
413 {
414 	struct aa_loaddata *data;
415 	struct aa_label *label;
416 	ssize_t error;
417 
418 	label = begin_current_label_crit_section();
419 
420 	/* high level check about policy management - fine grained in
421 	 * below after unpack
422 	 */
423 	error = aa_may_manage_policy(label, ns, mask);
424 	if (error)
425 		goto end_section;
426 
427 	data = aa_simple_write_to_buffer(buf, size, size, pos);
428 	error = PTR_ERR(data);
429 	if (!IS_ERR(data)) {
430 		error = aa_replace_profiles(ns, label, mask, data);
431 		aa_put_loaddata(data);
432 	}
433 end_section:
434 	end_current_label_crit_section(label);
435 
436 	return error;
437 }
438 
439 /* .load file hook fn to load policy */
440 static ssize_t profile_load(struct file *f, const char __user *buf, size_t size,
441 			    loff_t *pos)
442 {
443 	struct aa_ns *ns = aa_get_ns(f->f_inode->i_private);
444 	int error = policy_update(AA_MAY_LOAD_POLICY, buf, size, pos, ns);
445 
446 	aa_put_ns(ns);
447 
448 	return error;
449 }
450 
451 static const struct file_operations aa_fs_profile_load = {
452 	.write = profile_load,
453 	.llseek = default_llseek,
454 };
455 
456 /* .replace file hook fn to load and/or replace policy */
457 static ssize_t profile_replace(struct file *f, const char __user *buf,
458 			       size_t size, loff_t *pos)
459 {
460 	struct aa_ns *ns = aa_get_ns(f->f_inode->i_private);
461 	int error = policy_update(AA_MAY_LOAD_POLICY | AA_MAY_REPLACE_POLICY,
462 				  buf, size, pos, ns);
463 	aa_put_ns(ns);
464 
465 	return error;
466 }
467 
468 static const struct file_operations aa_fs_profile_replace = {
469 	.write = profile_replace,
470 	.llseek = default_llseek,
471 };
472 
473 /* .remove file hook fn to remove loaded policy */
474 static ssize_t profile_remove(struct file *f, const char __user *buf,
475 			      size_t size, loff_t *pos)
476 {
477 	struct aa_loaddata *data;
478 	struct aa_label *label;
479 	ssize_t error;
480 	struct aa_ns *ns = aa_get_ns(f->f_inode->i_private);
481 
482 	label = begin_current_label_crit_section();
483 	/* high level check about policy management - fine grained in
484 	 * below after unpack
485 	 */
486 	error = aa_may_manage_policy(label, ns, AA_MAY_REMOVE_POLICY);
487 	if (error)
488 		goto out;
489 
490 	/*
491 	 * aa_remove_profile needs a null terminated string so 1 extra
492 	 * byte is allocated and the copied data is null terminated.
493 	 */
494 	data = aa_simple_write_to_buffer(buf, size + 1, size, pos);
495 
496 	error = PTR_ERR(data);
497 	if (!IS_ERR(data)) {
498 		data->data[size] = 0;
499 		error = aa_remove_profiles(ns, label, data->data, size);
500 		aa_put_loaddata(data);
501 	}
502  out:
503 	end_current_label_crit_section(label);
504 	aa_put_ns(ns);
505 	return error;
506 }
507 
508 static const struct file_operations aa_fs_profile_remove = {
509 	.write = profile_remove,
510 	.llseek = default_llseek,
511 };
512 
513 struct aa_revision {
514 	struct aa_ns *ns;
515 	long last_read;
516 };
517 
518 /* revision file hook fn for policy loads */
519 static int ns_revision_release(struct inode *inode, struct file *file)
520 {
521 	struct aa_revision *rev = file->private_data;
522 
523 	if (rev) {
524 		aa_put_ns(rev->ns);
525 		kfree(rev);
526 	}
527 
528 	return 0;
529 }
530 
531 static ssize_t ns_revision_read(struct file *file, char __user *buf,
532 				size_t size, loff_t *ppos)
533 {
534 	struct aa_revision *rev = file->private_data;
535 	char buffer[32];
536 	long last_read;
537 	int avail;
538 
539 	mutex_lock_nested(&rev->ns->lock, rev->ns->level);
540 	last_read = rev->last_read;
541 	if (last_read == rev->ns->revision) {
542 		mutex_unlock(&rev->ns->lock);
543 		if (file->f_flags & O_NONBLOCK)
544 			return -EAGAIN;
545 		if (wait_event_interruptible(rev->ns->wait,
546 					     last_read !=
547 					     READ_ONCE(rev->ns->revision)))
548 			return -ERESTARTSYS;
549 		mutex_lock_nested(&rev->ns->lock, rev->ns->level);
550 	}
551 
552 	avail = sprintf(buffer, "%ld\n", rev->ns->revision);
553 	if (*ppos + size > avail) {
554 		rev->last_read = rev->ns->revision;
555 		*ppos = 0;
556 	}
557 	mutex_unlock(&rev->ns->lock);
558 
559 	return simple_read_from_buffer(buf, size, ppos, buffer, avail);
560 }
561 
562 static int ns_revision_open(struct inode *inode, struct file *file)
563 {
564 	struct aa_revision *rev = kzalloc(sizeof(*rev), GFP_KERNEL);
565 
566 	if (!rev)
567 		return -ENOMEM;
568 
569 	rev->ns = aa_get_ns(inode->i_private);
570 	if (!rev->ns)
571 		rev->ns = aa_get_current_ns();
572 	file->private_data = rev;
573 
574 	return 0;
575 }
576 
577 static __poll_t ns_revision_poll(struct file *file, poll_table *pt)
578 {
579 	struct aa_revision *rev = file->private_data;
580 	__poll_t mask = 0;
581 
582 	if (rev) {
583 		mutex_lock_nested(&rev->ns->lock, rev->ns->level);
584 		poll_wait(file, &rev->ns->wait, pt);
585 		if (rev->last_read < rev->ns->revision)
586 			mask |= EPOLLIN | EPOLLRDNORM;
587 		mutex_unlock(&rev->ns->lock);
588 	}
589 
590 	return mask;
591 }
592 
593 void __aa_bump_ns_revision(struct aa_ns *ns)
594 {
595 	WRITE_ONCE(ns->revision, READ_ONCE(ns->revision) + 1);
596 	wake_up_interruptible(&ns->wait);
597 }
598 
599 static const struct file_operations aa_fs_ns_revision_fops = {
600 	.owner		= THIS_MODULE,
601 	.open		= ns_revision_open,
602 	.poll		= ns_revision_poll,
603 	.read		= ns_revision_read,
604 	.llseek		= generic_file_llseek,
605 	.release	= ns_revision_release,
606 };
607 
608 static void profile_query_cb(struct aa_profile *profile, struct aa_perms *perms,
609 			     const char *match_str, size_t match_len)
610 {
611 	struct aa_perms tmp = { };
612 	struct aa_dfa *dfa;
613 	unsigned int state = 0;
614 
615 	if (profile_unconfined(profile))
616 		return;
617 	if (profile->file.dfa && *match_str == AA_CLASS_FILE) {
618 		dfa = profile->file.dfa;
619 		state = aa_dfa_match_len(dfa, profile->file.start,
620 					 match_str + 1, match_len - 1);
621 		if (state) {
622 			struct path_cond cond = { };
623 
624 			tmp = aa_compute_fperms(dfa, state, &cond);
625 		}
626 	} else if (profile->policy.dfa) {
627 		if (!PROFILE_MEDIATES(profile, *match_str))
628 			return;	/* no change to current perms */
629 		dfa = profile->policy.dfa;
630 		state = aa_dfa_match_len(dfa, profile->policy.start[0],
631 					 match_str, match_len);
632 		if (state)
633 			aa_compute_perms(dfa, state, &tmp);
634 	}
635 	aa_apply_modes_to_perms(profile, &tmp);
636 	aa_perms_accum_raw(perms, &tmp);
637 }
638 
639 
640 /**
641  * query_data - queries a policy and writes its data to buf
642  * @buf: the resulting data is stored here (NOT NULL)
643  * @buf_len: size of buf
644  * @query: query string used to retrieve data
645  * @query_len: size of query including second NUL byte
646  *
647  * The buffers pointed to by buf and query may overlap. The query buffer is
648  * parsed before buf is written to.
649  *
650  * The query should look like "<LABEL>\0<KEY>\0", where <LABEL> is the name of
651  * the security confinement context and <KEY> is the name of the data to
652  * retrieve. <LABEL> and <KEY> must not be NUL-terminated.
653  *
654  * Don't expect the contents of buf to be preserved on failure.
655  *
656  * Returns: number of characters written to buf or -errno on failure
657  */
658 static ssize_t query_data(char *buf, size_t buf_len,
659 			  char *query, size_t query_len)
660 {
661 	char *out;
662 	const char *key;
663 	struct label_it i;
664 	struct aa_label *label, *curr;
665 	struct aa_profile *profile;
666 	struct aa_data *data;
667 	u32 bytes, blocks;
668 	__le32 outle32;
669 
670 	if (!query_len)
671 		return -EINVAL; /* need a query */
672 
673 	key = query + strnlen(query, query_len) + 1;
674 	if (key + 1 >= query + query_len)
675 		return -EINVAL; /* not enough space for a non-empty key */
676 	if (key + strnlen(key, query + query_len - key) >= query + query_len)
677 		return -EINVAL; /* must end with NUL */
678 
679 	if (buf_len < sizeof(bytes) + sizeof(blocks))
680 		return -EINVAL; /* not enough space */
681 
682 	curr = begin_current_label_crit_section();
683 	label = aa_label_parse(curr, query, GFP_KERNEL, false, false);
684 	end_current_label_crit_section(curr);
685 	if (IS_ERR(label))
686 		return PTR_ERR(label);
687 
688 	/* We are going to leave space for two numbers. The first is the total
689 	 * number of bytes we are writing after the first number. This is so
690 	 * users can read the full output without reallocation.
691 	 *
692 	 * The second number is the number of data blocks we're writing. An
693 	 * application might be confined by multiple policies having data in
694 	 * the same key.
695 	 */
696 	memset(buf, 0, sizeof(bytes) + sizeof(blocks));
697 	out = buf + sizeof(bytes) + sizeof(blocks);
698 
699 	blocks = 0;
700 	label_for_each_confined(i, label, profile) {
701 		if (!profile->data)
702 			continue;
703 
704 		data = rhashtable_lookup_fast(profile->data, &key,
705 					      profile->data->p);
706 
707 		if (data) {
708 			if (out + sizeof(outle32) + data->size > buf +
709 			    buf_len) {
710 				aa_put_label(label);
711 				return -EINVAL; /* not enough space */
712 			}
713 			outle32 = __cpu_to_le32(data->size);
714 			memcpy(out, &outle32, sizeof(outle32));
715 			out += sizeof(outle32);
716 			memcpy(out, data->data, data->size);
717 			out += data->size;
718 			blocks++;
719 		}
720 	}
721 	aa_put_label(label);
722 
723 	outle32 = __cpu_to_le32(out - buf - sizeof(bytes));
724 	memcpy(buf, &outle32, sizeof(outle32));
725 	outle32 = __cpu_to_le32(blocks);
726 	memcpy(buf + sizeof(bytes), &outle32, sizeof(outle32));
727 
728 	return out - buf;
729 }
730 
731 /**
732  * query_label - queries a label and writes permissions to buf
733  * @buf: the resulting permissions string is stored here (NOT NULL)
734  * @buf_len: size of buf
735  * @query: binary query string to match against the dfa
736  * @query_len: size of query
737  * @view_only: only compute for querier's view
738  *
739  * The buffers pointed to by buf and query may overlap. The query buffer is
740  * parsed before buf is written to.
741  *
742  * The query should look like "LABEL_NAME\0DFA_STRING" where LABEL_NAME is
743  * the name of the label, in the current namespace, that is to be queried and
744  * DFA_STRING is a binary string to match against the label(s)'s DFA.
745  *
746  * LABEL_NAME must be NUL terminated. DFA_STRING may contain NUL characters
747  * but must *not* be NUL terminated.
748  *
749  * Returns: number of characters written to buf or -errno on failure
750  */
751 static ssize_t query_label(char *buf, size_t buf_len,
752 			   char *query, size_t query_len, bool view_only)
753 {
754 	struct aa_profile *profile;
755 	struct aa_label *label, *curr;
756 	char *label_name, *match_str;
757 	size_t label_name_len, match_len;
758 	struct aa_perms perms;
759 	struct label_it i;
760 
761 	if (!query_len)
762 		return -EINVAL;
763 
764 	label_name = query;
765 	label_name_len = strnlen(query, query_len);
766 	if (!label_name_len || label_name_len == query_len)
767 		return -EINVAL;
768 
769 	/**
770 	 * The extra byte is to account for the null byte between the
771 	 * profile name and dfa string. profile_name_len is greater
772 	 * than zero and less than query_len, so a byte can be safely
773 	 * added or subtracted.
774 	 */
775 	match_str = label_name + label_name_len + 1;
776 	match_len = query_len - label_name_len - 1;
777 
778 	curr = begin_current_label_crit_section();
779 	label = aa_label_parse(curr, label_name, GFP_KERNEL, false, false);
780 	end_current_label_crit_section(curr);
781 	if (IS_ERR(label))
782 		return PTR_ERR(label);
783 
784 	perms = allperms;
785 	if (view_only) {
786 		label_for_each_in_ns(i, labels_ns(label), label, profile) {
787 			profile_query_cb(profile, &perms, match_str, match_len);
788 		}
789 	} else {
790 		label_for_each(i, label, profile) {
791 			profile_query_cb(profile, &perms, match_str, match_len);
792 		}
793 	}
794 	aa_put_label(label);
795 
796 	return scnprintf(buf, buf_len,
797 		      "allow 0x%08x\ndeny 0x%08x\naudit 0x%08x\nquiet 0x%08x\n",
798 		      perms.allow, perms.deny, perms.audit, perms.quiet);
799 }
800 
801 /*
802  * Transaction based IO.
803  * The file expects a write which triggers the transaction, and then
804  * possibly a read(s) which collects the result - which is stored in a
805  * file-local buffer. Once a new write is performed, a new set of results
806  * are stored in the file-local buffer.
807  */
808 struct multi_transaction {
809 	struct kref count;
810 	ssize_t size;
811 	char data[];
812 };
813 
814 #define MULTI_TRANSACTION_LIMIT (PAGE_SIZE - sizeof(struct multi_transaction))
815 /* TODO: replace with per file lock */
816 static DEFINE_SPINLOCK(multi_transaction_lock);
817 
818 static void multi_transaction_kref(struct kref *kref)
819 {
820 	struct multi_transaction *t;
821 
822 	t = container_of(kref, struct multi_transaction, count);
823 	free_page((unsigned long) t);
824 }
825 
826 static struct multi_transaction *
827 get_multi_transaction(struct multi_transaction *t)
828 {
829 	if  (t)
830 		kref_get(&(t->count));
831 
832 	return t;
833 }
834 
835 static void put_multi_transaction(struct multi_transaction *t)
836 {
837 	if (t)
838 		kref_put(&(t->count), multi_transaction_kref);
839 }
840 
841 /* does not increment @new's count */
842 static void multi_transaction_set(struct file *file,
843 				  struct multi_transaction *new, size_t n)
844 {
845 	struct multi_transaction *old;
846 
847 	AA_BUG(n > MULTI_TRANSACTION_LIMIT);
848 
849 	new->size = n;
850 	spin_lock(&multi_transaction_lock);
851 	old = (struct multi_transaction *) file->private_data;
852 	file->private_data = new;
853 	spin_unlock(&multi_transaction_lock);
854 	put_multi_transaction(old);
855 }
856 
857 static struct multi_transaction *multi_transaction_new(struct file *file,
858 						       const char __user *buf,
859 						       size_t size)
860 {
861 	struct multi_transaction *t;
862 
863 	if (size > MULTI_TRANSACTION_LIMIT - 1)
864 		return ERR_PTR(-EFBIG);
865 
866 	t = (struct multi_transaction *)get_zeroed_page(GFP_KERNEL);
867 	if (!t)
868 		return ERR_PTR(-ENOMEM);
869 	kref_init(&t->count);
870 	if (copy_from_user(t->data, buf, size))
871 		return ERR_PTR(-EFAULT);
872 
873 	return t;
874 }
875 
876 static ssize_t multi_transaction_read(struct file *file, char __user *buf,
877 				       size_t size, loff_t *pos)
878 {
879 	struct multi_transaction *t;
880 	ssize_t ret;
881 
882 	spin_lock(&multi_transaction_lock);
883 	t = get_multi_transaction(file->private_data);
884 	spin_unlock(&multi_transaction_lock);
885 	if (!t)
886 		return 0;
887 
888 	ret = simple_read_from_buffer(buf, size, pos, t->data, t->size);
889 	put_multi_transaction(t);
890 
891 	return ret;
892 }
893 
894 static int multi_transaction_release(struct inode *inode, struct file *file)
895 {
896 	put_multi_transaction(file->private_data);
897 
898 	return 0;
899 }
900 
901 #define QUERY_CMD_LABEL		"label\0"
902 #define QUERY_CMD_LABEL_LEN	6
903 #define QUERY_CMD_PROFILE	"profile\0"
904 #define QUERY_CMD_PROFILE_LEN	8
905 #define QUERY_CMD_LABELALL	"labelall\0"
906 #define QUERY_CMD_LABELALL_LEN	9
907 #define QUERY_CMD_DATA		"data\0"
908 #define QUERY_CMD_DATA_LEN	5
909 
910 /**
911  * aa_write_access - generic permissions and data query
912  * @file: pointer to open apparmorfs/access file
913  * @ubuf: user buffer containing the complete query string (NOT NULL)
914  * @count: size of ubuf
915  * @ppos: position in the file (MUST BE ZERO)
916  *
917  * Allows for one permissions or data query per open(), write(), and read()
918  * sequence. The only queries currently supported are label-based queries for
919  * permissions or data.
920  *
921  * For permissions queries, ubuf must begin with "label\0", followed by the
922  * profile query specific format described in the query_label() function
923  * documentation.
924  *
925  * For data queries, ubuf must have the form "data\0<LABEL>\0<KEY>\0", where
926  * <LABEL> is the name of the security confinement context and <KEY> is the
927  * name of the data to retrieve.
928  *
929  * Returns: number of bytes written or -errno on failure
930  */
931 static ssize_t aa_write_access(struct file *file, const char __user *ubuf,
932 			       size_t count, loff_t *ppos)
933 {
934 	struct multi_transaction *t;
935 	ssize_t len;
936 
937 	if (*ppos)
938 		return -ESPIPE;
939 
940 	t = multi_transaction_new(file, ubuf, count);
941 	if (IS_ERR(t))
942 		return PTR_ERR(t);
943 
944 	if (count > QUERY_CMD_PROFILE_LEN &&
945 	    !memcmp(t->data, QUERY_CMD_PROFILE, QUERY_CMD_PROFILE_LEN)) {
946 		len = query_label(t->data, MULTI_TRANSACTION_LIMIT,
947 				  t->data + QUERY_CMD_PROFILE_LEN,
948 				  count - QUERY_CMD_PROFILE_LEN, true);
949 	} else if (count > QUERY_CMD_LABEL_LEN &&
950 		   !memcmp(t->data, QUERY_CMD_LABEL, QUERY_CMD_LABEL_LEN)) {
951 		len = query_label(t->data, MULTI_TRANSACTION_LIMIT,
952 				  t->data + QUERY_CMD_LABEL_LEN,
953 				  count - QUERY_CMD_LABEL_LEN, true);
954 	} else if (count > QUERY_CMD_LABELALL_LEN &&
955 		   !memcmp(t->data, QUERY_CMD_LABELALL,
956 			   QUERY_CMD_LABELALL_LEN)) {
957 		len = query_label(t->data, MULTI_TRANSACTION_LIMIT,
958 				  t->data + QUERY_CMD_LABELALL_LEN,
959 				  count - QUERY_CMD_LABELALL_LEN, false);
960 	} else if (count > QUERY_CMD_DATA_LEN &&
961 		   !memcmp(t->data, QUERY_CMD_DATA, QUERY_CMD_DATA_LEN)) {
962 		len = query_data(t->data, MULTI_TRANSACTION_LIMIT,
963 				 t->data + QUERY_CMD_DATA_LEN,
964 				 count - QUERY_CMD_DATA_LEN);
965 	} else
966 		len = -EINVAL;
967 
968 	if (len < 0) {
969 		put_multi_transaction(t);
970 		return len;
971 	}
972 
973 	multi_transaction_set(file, t, len);
974 
975 	return count;
976 }
977 
978 static const struct file_operations aa_sfs_access = {
979 	.write		= aa_write_access,
980 	.read		= multi_transaction_read,
981 	.release	= multi_transaction_release,
982 	.llseek		= generic_file_llseek,
983 };
984 
985 static int aa_sfs_seq_show(struct seq_file *seq, void *v)
986 {
987 	struct aa_sfs_entry *fs_file = seq->private;
988 
989 	if (!fs_file)
990 		return 0;
991 
992 	switch (fs_file->v_type) {
993 	case AA_SFS_TYPE_BOOLEAN:
994 		seq_printf(seq, "%s\n", fs_file->v.boolean ? "yes" : "no");
995 		break;
996 	case AA_SFS_TYPE_STRING:
997 		seq_printf(seq, "%s\n", fs_file->v.string);
998 		break;
999 	case AA_SFS_TYPE_U64:
1000 		seq_printf(seq, "%#08lx\n", fs_file->v.u64);
1001 		break;
1002 	default:
1003 		/* Ignore unpritable entry types. */
1004 		break;
1005 	}
1006 
1007 	return 0;
1008 }
1009 
1010 static int aa_sfs_seq_open(struct inode *inode, struct file *file)
1011 {
1012 	return single_open(file, aa_sfs_seq_show, inode->i_private);
1013 }
1014 
1015 const struct file_operations aa_sfs_seq_file_ops = {
1016 	.owner		= THIS_MODULE,
1017 	.open		= aa_sfs_seq_open,
1018 	.read		= seq_read,
1019 	.llseek		= seq_lseek,
1020 	.release	= single_release,
1021 };
1022 
1023 /*
1024  * profile based file operations
1025  *     policy/profiles/XXXX/profiles/ *
1026  */
1027 
1028 #define SEQ_PROFILE_FOPS(NAME)						      \
1029 static int seq_profile_ ##NAME ##_open(struct inode *inode, struct file *file)\
1030 {									      \
1031 	return seq_profile_open(inode, file, seq_profile_ ##NAME ##_show);    \
1032 }									      \
1033 									      \
1034 static const struct file_operations seq_profile_ ##NAME ##_fops = {	      \
1035 	.owner		= THIS_MODULE,					      \
1036 	.open		= seq_profile_ ##NAME ##_open,			      \
1037 	.read		= seq_read,					      \
1038 	.llseek		= seq_lseek,					      \
1039 	.release	= seq_profile_release,				      \
1040 }									      \
1041 
1042 static int seq_profile_open(struct inode *inode, struct file *file,
1043 			    int (*show)(struct seq_file *, void *))
1044 {
1045 	struct aa_proxy *proxy = aa_get_proxy(inode->i_private);
1046 	int error = single_open(file, show, proxy);
1047 
1048 	if (error) {
1049 		file->private_data = NULL;
1050 		aa_put_proxy(proxy);
1051 	}
1052 
1053 	return error;
1054 }
1055 
1056 static int seq_profile_release(struct inode *inode, struct file *file)
1057 {
1058 	struct seq_file *seq = (struct seq_file *) file->private_data;
1059 	if (seq)
1060 		aa_put_proxy(seq->private);
1061 	return single_release(inode, file);
1062 }
1063 
1064 static int seq_profile_name_show(struct seq_file *seq, void *v)
1065 {
1066 	struct aa_proxy *proxy = seq->private;
1067 	struct aa_label *label = aa_get_label_rcu(&proxy->label);
1068 	struct aa_profile *profile = labels_profile(label);
1069 	seq_printf(seq, "%s\n", profile->base.name);
1070 	aa_put_label(label);
1071 
1072 	return 0;
1073 }
1074 
1075 static int seq_profile_mode_show(struct seq_file *seq, void *v)
1076 {
1077 	struct aa_proxy *proxy = seq->private;
1078 	struct aa_label *label = aa_get_label_rcu(&proxy->label);
1079 	struct aa_profile *profile = labels_profile(label);
1080 	seq_printf(seq, "%s\n", aa_profile_mode_names[profile->mode]);
1081 	aa_put_label(label);
1082 
1083 	return 0;
1084 }
1085 
1086 static int seq_profile_attach_show(struct seq_file *seq, void *v)
1087 {
1088 	struct aa_proxy *proxy = seq->private;
1089 	struct aa_label *label = aa_get_label_rcu(&proxy->label);
1090 	struct aa_profile *profile = labels_profile(label);
1091 	if (profile->attach)
1092 		seq_printf(seq, "%s\n", profile->attach);
1093 	else if (profile->xmatch)
1094 		seq_puts(seq, "<unknown>\n");
1095 	else
1096 		seq_printf(seq, "%s\n", profile->base.name);
1097 	aa_put_label(label);
1098 
1099 	return 0;
1100 }
1101 
1102 static int seq_profile_hash_show(struct seq_file *seq, void *v)
1103 {
1104 	struct aa_proxy *proxy = seq->private;
1105 	struct aa_label *label = aa_get_label_rcu(&proxy->label);
1106 	struct aa_profile *profile = labels_profile(label);
1107 	unsigned int i, size = aa_hash_size();
1108 
1109 	if (profile->hash) {
1110 		for (i = 0; i < size; i++)
1111 			seq_printf(seq, "%.2x", profile->hash[i]);
1112 		seq_putc(seq, '\n');
1113 	}
1114 	aa_put_label(label);
1115 
1116 	return 0;
1117 }
1118 
1119 SEQ_PROFILE_FOPS(name);
1120 SEQ_PROFILE_FOPS(mode);
1121 SEQ_PROFILE_FOPS(attach);
1122 SEQ_PROFILE_FOPS(hash);
1123 
1124 /*
1125  * namespace based files
1126  *     several root files and
1127  *     policy/ *
1128  */
1129 
1130 #define SEQ_NS_FOPS(NAME)						      \
1131 static int seq_ns_ ##NAME ##_open(struct inode *inode, struct file *file)     \
1132 {									      \
1133 	return single_open(file, seq_ns_ ##NAME ##_show, inode->i_private);   \
1134 }									      \
1135 									      \
1136 static const struct file_operations seq_ns_ ##NAME ##_fops = {	      \
1137 	.owner		= THIS_MODULE,					      \
1138 	.open		= seq_ns_ ##NAME ##_open,			      \
1139 	.read		= seq_read,					      \
1140 	.llseek		= seq_lseek,					      \
1141 	.release	= single_release,				      \
1142 }									      \
1143 
1144 static int seq_ns_stacked_show(struct seq_file *seq, void *v)
1145 {
1146 	struct aa_label *label;
1147 
1148 	label = begin_current_label_crit_section();
1149 	seq_printf(seq, "%s\n", label->size > 1 ? "yes" : "no");
1150 	end_current_label_crit_section(label);
1151 
1152 	return 0;
1153 }
1154 
1155 static int seq_ns_nsstacked_show(struct seq_file *seq, void *v)
1156 {
1157 	struct aa_label *label;
1158 	struct aa_profile *profile;
1159 	struct label_it it;
1160 	int count = 1;
1161 
1162 	label = begin_current_label_crit_section();
1163 
1164 	if (label->size > 1) {
1165 		label_for_each(it, label, profile)
1166 			if (profile->ns != labels_ns(label)) {
1167 				count++;
1168 				break;
1169 			}
1170 	}
1171 
1172 	seq_printf(seq, "%s\n", count > 1 ? "yes" : "no");
1173 	end_current_label_crit_section(label);
1174 
1175 	return 0;
1176 }
1177 
1178 static int seq_ns_level_show(struct seq_file *seq, void *v)
1179 {
1180 	struct aa_label *label;
1181 
1182 	label = begin_current_label_crit_section();
1183 	seq_printf(seq, "%d\n", labels_ns(label)->level);
1184 	end_current_label_crit_section(label);
1185 
1186 	return 0;
1187 }
1188 
1189 static int seq_ns_name_show(struct seq_file *seq, void *v)
1190 {
1191 	struct aa_label *label = begin_current_label_crit_section();
1192 	seq_printf(seq, "%s\n", labels_ns(label)->base.name);
1193 	end_current_label_crit_section(label);
1194 
1195 	return 0;
1196 }
1197 
1198 SEQ_NS_FOPS(stacked);
1199 SEQ_NS_FOPS(nsstacked);
1200 SEQ_NS_FOPS(level);
1201 SEQ_NS_FOPS(name);
1202 
1203 
1204 /* policy/raw_data/ * file ops */
1205 
1206 #define SEQ_RAWDATA_FOPS(NAME)						      \
1207 static int seq_rawdata_ ##NAME ##_open(struct inode *inode, struct file *file)\
1208 {									      \
1209 	return seq_rawdata_open(inode, file, seq_rawdata_ ##NAME ##_show);    \
1210 }									      \
1211 									      \
1212 static const struct file_operations seq_rawdata_ ##NAME ##_fops = {	      \
1213 	.owner		= THIS_MODULE,					      \
1214 	.open		= seq_rawdata_ ##NAME ##_open,			      \
1215 	.read		= seq_read,					      \
1216 	.llseek		= seq_lseek,					      \
1217 	.release	= seq_rawdata_release,				      \
1218 }									      \
1219 
1220 static int seq_rawdata_open(struct inode *inode, struct file *file,
1221 			    int (*show)(struct seq_file *, void *))
1222 {
1223 	struct aa_loaddata *data = __aa_get_loaddata(inode->i_private);
1224 	int error;
1225 
1226 	if (!data)
1227 		/* lost race this ent is being reaped */
1228 		return -ENOENT;
1229 
1230 	error = single_open(file, show, data);
1231 	if (error) {
1232 		AA_BUG(file->private_data &&
1233 		       ((struct seq_file *)file->private_data)->private);
1234 		aa_put_loaddata(data);
1235 	}
1236 
1237 	return error;
1238 }
1239 
1240 static int seq_rawdata_release(struct inode *inode, struct file *file)
1241 {
1242 	struct seq_file *seq = (struct seq_file *) file->private_data;
1243 
1244 	if (seq)
1245 		aa_put_loaddata(seq->private);
1246 
1247 	return single_release(inode, file);
1248 }
1249 
1250 static int seq_rawdata_abi_show(struct seq_file *seq, void *v)
1251 {
1252 	struct aa_loaddata *data = seq->private;
1253 
1254 	seq_printf(seq, "v%d\n", data->abi);
1255 
1256 	return 0;
1257 }
1258 
1259 static int seq_rawdata_revision_show(struct seq_file *seq, void *v)
1260 {
1261 	struct aa_loaddata *data = seq->private;
1262 
1263 	seq_printf(seq, "%ld\n", data->revision);
1264 
1265 	return 0;
1266 }
1267 
1268 static int seq_rawdata_hash_show(struct seq_file *seq, void *v)
1269 {
1270 	struct aa_loaddata *data = seq->private;
1271 	unsigned int i, size = aa_hash_size();
1272 
1273 	if (data->hash) {
1274 		for (i = 0; i < size; i++)
1275 			seq_printf(seq, "%.2x", data->hash[i]);
1276 		seq_putc(seq, '\n');
1277 	}
1278 
1279 	return 0;
1280 }
1281 
1282 static int seq_rawdata_compressed_size_show(struct seq_file *seq, void *v)
1283 {
1284 	struct aa_loaddata *data = seq->private;
1285 
1286 	seq_printf(seq, "%zu\n", data->compressed_size);
1287 
1288 	return 0;
1289 }
1290 
1291 SEQ_RAWDATA_FOPS(abi);
1292 SEQ_RAWDATA_FOPS(revision);
1293 SEQ_RAWDATA_FOPS(hash);
1294 SEQ_RAWDATA_FOPS(compressed_size);
1295 
1296 static int deflate_decompress(char *src, size_t slen, char *dst, size_t dlen)
1297 {
1298 	int error;
1299 	struct z_stream_s strm;
1300 
1301 	if (aa_g_rawdata_compression_level == 0) {
1302 		if (dlen < slen)
1303 			return -EINVAL;
1304 		memcpy(dst, src, slen);
1305 		return 0;
1306 	}
1307 
1308 	memset(&strm, 0, sizeof(strm));
1309 
1310 	strm.workspace = kvzalloc(zlib_inflate_workspacesize(), GFP_KERNEL);
1311 	if (!strm.workspace)
1312 		return -ENOMEM;
1313 
1314 	strm.next_in = src;
1315 	strm.avail_in = slen;
1316 
1317 	error = zlib_inflateInit(&strm);
1318 	if (error != Z_OK) {
1319 		error = -ENOMEM;
1320 		goto fail_inflate_init;
1321 	}
1322 
1323 	strm.next_out = dst;
1324 	strm.avail_out = dlen;
1325 
1326 	error = zlib_inflate(&strm, Z_FINISH);
1327 	if (error != Z_STREAM_END)
1328 		error = -EINVAL;
1329 	else
1330 		error = 0;
1331 
1332 	zlib_inflateEnd(&strm);
1333 fail_inflate_init:
1334 	kvfree(strm.workspace);
1335 	return error;
1336 }
1337 
1338 static ssize_t rawdata_read(struct file *file, char __user *buf, size_t size,
1339 			    loff_t *ppos)
1340 {
1341 	struct rawdata_f_data *private = file->private_data;
1342 
1343 	return simple_read_from_buffer(buf, size, ppos,
1344 				       RAWDATA_F_DATA_BUF(private),
1345 				       private->loaddata->size);
1346 }
1347 
1348 static int rawdata_release(struct inode *inode, struct file *file)
1349 {
1350 	rawdata_f_data_free(file->private_data);
1351 
1352 	return 0;
1353 }
1354 
1355 static int rawdata_open(struct inode *inode, struct file *file)
1356 {
1357 	int error;
1358 	struct aa_loaddata *loaddata;
1359 	struct rawdata_f_data *private;
1360 
1361 	if (!policy_view_capable(NULL))
1362 		return -EACCES;
1363 
1364 	loaddata = __aa_get_loaddata(inode->i_private);
1365 	if (!loaddata)
1366 		/* lost race: this entry is being reaped */
1367 		return -ENOENT;
1368 
1369 	private = rawdata_f_data_alloc(loaddata->size);
1370 	if (IS_ERR(private)) {
1371 		error = PTR_ERR(private);
1372 		goto fail_private_alloc;
1373 	}
1374 
1375 	private->loaddata = loaddata;
1376 
1377 	error = deflate_decompress(loaddata->data, loaddata->compressed_size,
1378 				   RAWDATA_F_DATA_BUF(private),
1379 				   loaddata->size);
1380 	if (error)
1381 		goto fail_decompress;
1382 
1383 	file->private_data = private;
1384 	return 0;
1385 
1386 fail_decompress:
1387 	rawdata_f_data_free(private);
1388 	return error;
1389 
1390 fail_private_alloc:
1391 	aa_put_loaddata(loaddata);
1392 	return error;
1393 }
1394 
1395 static const struct file_operations rawdata_fops = {
1396 	.open = rawdata_open,
1397 	.read = rawdata_read,
1398 	.llseek = generic_file_llseek,
1399 	.release = rawdata_release,
1400 };
1401 
1402 static void remove_rawdata_dents(struct aa_loaddata *rawdata)
1403 {
1404 	int i;
1405 
1406 	for (i = 0; i < AAFS_LOADDATA_NDENTS; i++) {
1407 		if (!IS_ERR_OR_NULL(rawdata->dents[i])) {
1408 			/* no refcounts on i_private */
1409 			aafs_remove(rawdata->dents[i]);
1410 			rawdata->dents[i] = NULL;
1411 		}
1412 	}
1413 }
1414 
1415 void __aa_fs_remove_rawdata(struct aa_loaddata *rawdata)
1416 {
1417 	AA_BUG(rawdata->ns && !mutex_is_locked(&rawdata->ns->lock));
1418 
1419 	if (rawdata->ns) {
1420 		remove_rawdata_dents(rawdata);
1421 		list_del_init(&rawdata->list);
1422 		aa_put_ns(rawdata->ns);
1423 		rawdata->ns = NULL;
1424 	}
1425 }
1426 
1427 int __aa_fs_create_rawdata(struct aa_ns *ns, struct aa_loaddata *rawdata)
1428 {
1429 	struct dentry *dent, *dir;
1430 
1431 	AA_BUG(!ns);
1432 	AA_BUG(!rawdata);
1433 	AA_BUG(!mutex_is_locked(&ns->lock));
1434 	AA_BUG(!ns_subdata_dir(ns));
1435 
1436 	/*
1437 	 * just use ns revision dir was originally created at. This is
1438 	 * under ns->lock and if load is successful revision will be
1439 	 * bumped and is guaranteed to be unique
1440 	 */
1441 	rawdata->name = kasprintf(GFP_KERNEL, "%ld", ns->revision);
1442 	if (!rawdata->name)
1443 		return -ENOMEM;
1444 
1445 	dir = aafs_create_dir(rawdata->name, ns_subdata_dir(ns));
1446 	if (IS_ERR(dir))
1447 		/* ->name freed when rawdata freed */
1448 		return PTR_ERR(dir);
1449 	rawdata->dents[AAFS_LOADDATA_DIR] = dir;
1450 
1451 	dent = aafs_create_file("abi", S_IFREG | 0444, dir, rawdata,
1452 				      &seq_rawdata_abi_fops);
1453 	if (IS_ERR(dent))
1454 		goto fail;
1455 	rawdata->dents[AAFS_LOADDATA_ABI] = dent;
1456 
1457 	dent = aafs_create_file("revision", S_IFREG | 0444, dir, rawdata,
1458 				      &seq_rawdata_revision_fops);
1459 	if (IS_ERR(dent))
1460 		goto fail;
1461 	rawdata->dents[AAFS_LOADDATA_REVISION] = dent;
1462 
1463 	if (aa_g_hash_policy) {
1464 		dent = aafs_create_file("sha1", S_IFREG | 0444, dir,
1465 					      rawdata, &seq_rawdata_hash_fops);
1466 		if (IS_ERR(dent))
1467 			goto fail;
1468 		rawdata->dents[AAFS_LOADDATA_HASH] = dent;
1469 	}
1470 
1471 	dent = aafs_create_file("compressed_size", S_IFREG | 0444, dir,
1472 				rawdata,
1473 				&seq_rawdata_compressed_size_fops);
1474 	if (IS_ERR(dent))
1475 		goto fail;
1476 	rawdata->dents[AAFS_LOADDATA_COMPRESSED_SIZE] = dent;
1477 
1478 	dent = aafs_create_file("raw_data", S_IFREG | 0444,
1479 				      dir, rawdata, &rawdata_fops);
1480 	if (IS_ERR(dent))
1481 		goto fail;
1482 	rawdata->dents[AAFS_LOADDATA_DATA] = dent;
1483 	d_inode(dent)->i_size = rawdata->size;
1484 
1485 	rawdata->ns = aa_get_ns(ns);
1486 	list_add(&rawdata->list, &ns->rawdata_list);
1487 	/* no refcount on inode rawdata */
1488 
1489 	return 0;
1490 
1491 fail:
1492 	remove_rawdata_dents(rawdata);
1493 
1494 	return PTR_ERR(dent);
1495 }
1496 
1497 /** fns to setup dynamic per profile/namespace files **/
1498 
1499 /**
1500  *
1501  * Requires: @profile->ns->lock held
1502  */
1503 void __aafs_profile_rmdir(struct aa_profile *profile)
1504 {
1505 	struct aa_profile *child;
1506 	int i;
1507 
1508 	if (!profile)
1509 		return;
1510 
1511 	list_for_each_entry(child, &profile->base.profiles, base.list)
1512 		__aafs_profile_rmdir(child);
1513 
1514 	for (i = AAFS_PROF_SIZEOF - 1; i >= 0; --i) {
1515 		struct aa_proxy *proxy;
1516 		if (!profile->dents[i])
1517 			continue;
1518 
1519 		proxy = d_inode(profile->dents[i])->i_private;
1520 		aafs_remove(profile->dents[i]);
1521 		aa_put_proxy(proxy);
1522 		profile->dents[i] = NULL;
1523 	}
1524 }
1525 
1526 /**
1527  *
1528  * Requires: @old->ns->lock held
1529  */
1530 void __aafs_profile_migrate_dents(struct aa_profile *old,
1531 				  struct aa_profile *new)
1532 {
1533 	int i;
1534 
1535 	AA_BUG(!old);
1536 	AA_BUG(!new);
1537 	AA_BUG(!mutex_is_locked(&profiles_ns(old)->lock));
1538 
1539 	for (i = 0; i < AAFS_PROF_SIZEOF; i++) {
1540 		new->dents[i] = old->dents[i];
1541 		if (new->dents[i])
1542 			new->dents[i]->d_inode->i_mtime = current_time(new->dents[i]->d_inode);
1543 		old->dents[i] = NULL;
1544 	}
1545 }
1546 
1547 static struct dentry *create_profile_file(struct dentry *dir, const char *name,
1548 					  struct aa_profile *profile,
1549 					  const struct file_operations *fops)
1550 {
1551 	struct aa_proxy *proxy = aa_get_proxy(profile->label.proxy);
1552 	struct dentry *dent;
1553 
1554 	dent = aafs_create_file(name, S_IFREG | 0444, dir, proxy, fops);
1555 	if (IS_ERR(dent))
1556 		aa_put_proxy(proxy);
1557 
1558 	return dent;
1559 }
1560 
1561 static int profile_depth(struct aa_profile *profile)
1562 {
1563 	int depth = 0;
1564 
1565 	rcu_read_lock();
1566 	for (depth = 0; profile; profile = rcu_access_pointer(profile->parent))
1567 		depth++;
1568 	rcu_read_unlock();
1569 
1570 	return depth;
1571 }
1572 
1573 static char *gen_symlink_name(int depth, const char *dirname, const char *fname)
1574 {
1575 	char *buffer, *s;
1576 	int error;
1577 	int size = depth * 6 + strlen(dirname) + strlen(fname) + 11;
1578 
1579 	s = buffer = kmalloc(size, GFP_KERNEL);
1580 	if (!buffer)
1581 		return ERR_PTR(-ENOMEM);
1582 
1583 	for (; depth > 0; depth--) {
1584 		strcpy(s, "../../");
1585 		s += 6;
1586 		size -= 6;
1587 	}
1588 
1589 	error = snprintf(s, size, "raw_data/%s/%s", dirname, fname);
1590 	if (error >= size || error < 0) {
1591 		kfree(buffer);
1592 		return ERR_PTR(-ENAMETOOLONG);
1593 	}
1594 
1595 	return buffer;
1596 }
1597 
1598 static void rawdata_link_cb(void *arg)
1599 {
1600 	kfree(arg);
1601 }
1602 
1603 static const char *rawdata_get_link_base(struct dentry *dentry,
1604 					 struct inode *inode,
1605 					 struct delayed_call *done,
1606 					 const char *name)
1607 {
1608 	struct aa_proxy *proxy = inode->i_private;
1609 	struct aa_label *label;
1610 	struct aa_profile *profile;
1611 	char *target;
1612 	int depth;
1613 
1614 	if (!dentry)
1615 		return ERR_PTR(-ECHILD);
1616 
1617 	label = aa_get_label_rcu(&proxy->label);
1618 	profile = labels_profile(label);
1619 	depth = profile_depth(profile);
1620 	target = gen_symlink_name(depth, profile->rawdata->name, name);
1621 	aa_put_label(label);
1622 
1623 	if (IS_ERR(target))
1624 		return target;
1625 
1626 	set_delayed_call(done, rawdata_link_cb, target);
1627 
1628 	return target;
1629 }
1630 
1631 static const char *rawdata_get_link_sha1(struct dentry *dentry,
1632 					 struct inode *inode,
1633 					 struct delayed_call *done)
1634 {
1635 	return rawdata_get_link_base(dentry, inode, done, "sha1");
1636 }
1637 
1638 static const char *rawdata_get_link_abi(struct dentry *dentry,
1639 					struct inode *inode,
1640 					struct delayed_call *done)
1641 {
1642 	return rawdata_get_link_base(dentry, inode, done, "abi");
1643 }
1644 
1645 static const char *rawdata_get_link_data(struct dentry *dentry,
1646 					 struct inode *inode,
1647 					 struct delayed_call *done)
1648 {
1649 	return rawdata_get_link_base(dentry, inode, done, "raw_data");
1650 }
1651 
1652 static const struct inode_operations rawdata_link_sha1_iops = {
1653 	.get_link	= rawdata_get_link_sha1,
1654 };
1655 
1656 static const struct inode_operations rawdata_link_abi_iops = {
1657 	.get_link	= rawdata_get_link_abi,
1658 };
1659 static const struct inode_operations rawdata_link_data_iops = {
1660 	.get_link	= rawdata_get_link_data,
1661 };
1662 
1663 
1664 /*
1665  * Requires: @profile->ns->lock held
1666  */
1667 int __aafs_profile_mkdir(struct aa_profile *profile, struct dentry *parent)
1668 {
1669 	struct aa_profile *child;
1670 	struct dentry *dent = NULL, *dir;
1671 	int error;
1672 
1673 	AA_BUG(!profile);
1674 	AA_BUG(!mutex_is_locked(&profiles_ns(profile)->lock));
1675 
1676 	if (!parent) {
1677 		struct aa_profile *p;
1678 		p = aa_deref_parent(profile);
1679 		dent = prof_dir(p);
1680 		/* adding to parent that previously didn't have children */
1681 		dent = aafs_create_dir("profiles", dent);
1682 		if (IS_ERR(dent))
1683 			goto fail;
1684 		prof_child_dir(p) = parent = dent;
1685 	}
1686 
1687 	if (!profile->dirname) {
1688 		int len, id_len;
1689 		len = mangle_name(profile->base.name, NULL);
1690 		id_len = snprintf(NULL, 0, ".%ld", profile->ns->uniq_id);
1691 
1692 		profile->dirname = kmalloc(len + id_len + 1, GFP_KERNEL);
1693 		if (!profile->dirname) {
1694 			error = -ENOMEM;
1695 			goto fail2;
1696 		}
1697 
1698 		mangle_name(profile->base.name, profile->dirname);
1699 		sprintf(profile->dirname + len, ".%ld", profile->ns->uniq_id++);
1700 	}
1701 
1702 	dent = aafs_create_dir(profile->dirname, parent);
1703 	if (IS_ERR(dent))
1704 		goto fail;
1705 	prof_dir(profile) = dir = dent;
1706 
1707 	dent = create_profile_file(dir, "name", profile,
1708 				   &seq_profile_name_fops);
1709 	if (IS_ERR(dent))
1710 		goto fail;
1711 	profile->dents[AAFS_PROF_NAME] = dent;
1712 
1713 	dent = create_profile_file(dir, "mode", profile,
1714 				   &seq_profile_mode_fops);
1715 	if (IS_ERR(dent))
1716 		goto fail;
1717 	profile->dents[AAFS_PROF_MODE] = dent;
1718 
1719 	dent = create_profile_file(dir, "attach", profile,
1720 				   &seq_profile_attach_fops);
1721 	if (IS_ERR(dent))
1722 		goto fail;
1723 	profile->dents[AAFS_PROF_ATTACH] = dent;
1724 
1725 	if (profile->hash) {
1726 		dent = create_profile_file(dir, "sha1", profile,
1727 					   &seq_profile_hash_fops);
1728 		if (IS_ERR(dent))
1729 			goto fail;
1730 		profile->dents[AAFS_PROF_HASH] = dent;
1731 	}
1732 
1733 	if (profile->rawdata) {
1734 		dent = aafs_create("raw_sha1", S_IFLNK | 0444, dir,
1735 				   profile->label.proxy, NULL, NULL,
1736 				   &rawdata_link_sha1_iops);
1737 		if (IS_ERR(dent))
1738 			goto fail;
1739 		aa_get_proxy(profile->label.proxy);
1740 		profile->dents[AAFS_PROF_RAW_HASH] = dent;
1741 
1742 		dent = aafs_create("raw_abi", S_IFLNK | 0444, dir,
1743 				   profile->label.proxy, NULL, NULL,
1744 				   &rawdata_link_abi_iops);
1745 		if (IS_ERR(dent))
1746 			goto fail;
1747 		aa_get_proxy(profile->label.proxy);
1748 		profile->dents[AAFS_PROF_RAW_ABI] = dent;
1749 
1750 		dent = aafs_create("raw_data", S_IFLNK | 0444, dir,
1751 				   profile->label.proxy, NULL, NULL,
1752 				   &rawdata_link_data_iops);
1753 		if (IS_ERR(dent))
1754 			goto fail;
1755 		aa_get_proxy(profile->label.proxy);
1756 		profile->dents[AAFS_PROF_RAW_DATA] = dent;
1757 	}
1758 
1759 	list_for_each_entry(child, &profile->base.profiles, base.list) {
1760 		error = __aafs_profile_mkdir(child, prof_child_dir(profile));
1761 		if (error)
1762 			goto fail2;
1763 	}
1764 
1765 	return 0;
1766 
1767 fail:
1768 	error = PTR_ERR(dent);
1769 
1770 fail2:
1771 	__aafs_profile_rmdir(profile);
1772 
1773 	return error;
1774 }
1775 
1776 static int ns_mkdir_op(struct user_namespace *mnt_userns, struct inode *dir,
1777 		       struct dentry *dentry, umode_t mode)
1778 {
1779 	struct aa_ns *ns, *parent;
1780 	/* TODO: improve permission check */
1781 	struct aa_label *label;
1782 	int error;
1783 
1784 	label = begin_current_label_crit_section();
1785 	error = aa_may_manage_policy(label, NULL, AA_MAY_LOAD_POLICY);
1786 	end_current_label_crit_section(label);
1787 	if (error)
1788 		return error;
1789 
1790 	parent = aa_get_ns(dir->i_private);
1791 	AA_BUG(d_inode(ns_subns_dir(parent)) != dir);
1792 
1793 	/* we have to unlock and then relock to get locking order right
1794 	 * for pin_fs
1795 	 */
1796 	inode_unlock(dir);
1797 	error = simple_pin_fs(&aafs_ops, &aafs_mnt, &aafs_count);
1798 	mutex_lock_nested(&parent->lock, parent->level);
1799 	inode_lock_nested(dir, I_MUTEX_PARENT);
1800 	if (error)
1801 		goto out;
1802 
1803 	error = __aafs_setup_d_inode(dir, dentry, mode | S_IFDIR,  NULL,
1804 				     NULL, NULL, NULL);
1805 	if (error)
1806 		goto out_pin;
1807 
1808 	ns = __aa_find_or_create_ns(parent, READ_ONCE(dentry->d_name.name),
1809 				    dentry);
1810 	if (IS_ERR(ns)) {
1811 		error = PTR_ERR(ns);
1812 		ns = NULL;
1813 	}
1814 
1815 	aa_put_ns(ns);		/* list ref remains */
1816 out_pin:
1817 	if (error)
1818 		simple_release_fs(&aafs_mnt, &aafs_count);
1819 out:
1820 	mutex_unlock(&parent->lock);
1821 	aa_put_ns(parent);
1822 
1823 	return error;
1824 }
1825 
1826 static int ns_rmdir_op(struct inode *dir, struct dentry *dentry)
1827 {
1828 	struct aa_ns *ns, *parent;
1829 	/* TODO: improve permission check */
1830 	struct aa_label *label;
1831 	int error;
1832 
1833 	label = begin_current_label_crit_section();
1834 	error = aa_may_manage_policy(label, NULL, AA_MAY_LOAD_POLICY);
1835 	end_current_label_crit_section(label);
1836 	if (error)
1837 		return error;
1838 
1839 	parent = aa_get_ns(dir->i_private);
1840 	/* rmdir calls the generic securityfs functions to remove files
1841 	 * from the apparmor dir. It is up to the apparmor ns locking
1842 	 * to avoid races.
1843 	 */
1844 	inode_unlock(dir);
1845 	inode_unlock(dentry->d_inode);
1846 
1847 	mutex_lock_nested(&parent->lock, parent->level);
1848 	ns = aa_get_ns(__aa_findn_ns(&parent->sub_ns, dentry->d_name.name,
1849 				     dentry->d_name.len));
1850 	if (!ns) {
1851 		error = -ENOENT;
1852 		goto out;
1853 	}
1854 	AA_BUG(ns_dir(ns) != dentry);
1855 
1856 	__aa_remove_ns(ns);
1857 	aa_put_ns(ns);
1858 
1859 out:
1860 	mutex_unlock(&parent->lock);
1861 	inode_lock_nested(dir, I_MUTEX_PARENT);
1862 	inode_lock(dentry->d_inode);
1863 	aa_put_ns(parent);
1864 
1865 	return error;
1866 }
1867 
1868 static const struct inode_operations ns_dir_inode_operations = {
1869 	.lookup		= simple_lookup,
1870 	.mkdir		= ns_mkdir_op,
1871 	.rmdir		= ns_rmdir_op,
1872 };
1873 
1874 static void __aa_fs_list_remove_rawdata(struct aa_ns *ns)
1875 {
1876 	struct aa_loaddata *ent, *tmp;
1877 
1878 	AA_BUG(!mutex_is_locked(&ns->lock));
1879 
1880 	list_for_each_entry_safe(ent, tmp, &ns->rawdata_list, list)
1881 		__aa_fs_remove_rawdata(ent);
1882 }
1883 
1884 /**
1885  *
1886  * Requires: @ns->lock held
1887  */
1888 void __aafs_ns_rmdir(struct aa_ns *ns)
1889 {
1890 	struct aa_ns *sub;
1891 	struct aa_profile *child;
1892 	int i;
1893 
1894 	if (!ns)
1895 		return;
1896 	AA_BUG(!mutex_is_locked(&ns->lock));
1897 
1898 	list_for_each_entry(child, &ns->base.profiles, base.list)
1899 		__aafs_profile_rmdir(child);
1900 
1901 	list_for_each_entry(sub, &ns->sub_ns, base.list) {
1902 		mutex_lock_nested(&sub->lock, sub->level);
1903 		__aafs_ns_rmdir(sub);
1904 		mutex_unlock(&sub->lock);
1905 	}
1906 
1907 	__aa_fs_list_remove_rawdata(ns);
1908 
1909 	if (ns_subns_dir(ns)) {
1910 		sub = d_inode(ns_subns_dir(ns))->i_private;
1911 		aa_put_ns(sub);
1912 	}
1913 	if (ns_subload(ns)) {
1914 		sub = d_inode(ns_subload(ns))->i_private;
1915 		aa_put_ns(sub);
1916 	}
1917 	if (ns_subreplace(ns)) {
1918 		sub = d_inode(ns_subreplace(ns))->i_private;
1919 		aa_put_ns(sub);
1920 	}
1921 	if (ns_subremove(ns)) {
1922 		sub = d_inode(ns_subremove(ns))->i_private;
1923 		aa_put_ns(sub);
1924 	}
1925 	if (ns_subrevision(ns)) {
1926 		sub = d_inode(ns_subrevision(ns))->i_private;
1927 		aa_put_ns(sub);
1928 	}
1929 
1930 	for (i = AAFS_NS_SIZEOF - 1; i >= 0; --i) {
1931 		aafs_remove(ns->dents[i]);
1932 		ns->dents[i] = NULL;
1933 	}
1934 }
1935 
1936 /* assumes cleanup in caller */
1937 static int __aafs_ns_mkdir_entries(struct aa_ns *ns, struct dentry *dir)
1938 {
1939 	struct dentry *dent;
1940 
1941 	AA_BUG(!ns);
1942 	AA_BUG(!dir);
1943 
1944 	dent = aafs_create_dir("profiles", dir);
1945 	if (IS_ERR(dent))
1946 		return PTR_ERR(dent);
1947 	ns_subprofs_dir(ns) = dent;
1948 
1949 	dent = aafs_create_dir("raw_data", dir);
1950 	if (IS_ERR(dent))
1951 		return PTR_ERR(dent);
1952 	ns_subdata_dir(ns) = dent;
1953 
1954 	dent = aafs_create_file("revision", 0444, dir, ns,
1955 				&aa_fs_ns_revision_fops);
1956 	if (IS_ERR(dent))
1957 		return PTR_ERR(dent);
1958 	aa_get_ns(ns);
1959 	ns_subrevision(ns) = dent;
1960 
1961 	dent = aafs_create_file(".load", 0640, dir, ns,
1962 				      &aa_fs_profile_load);
1963 	if (IS_ERR(dent))
1964 		return PTR_ERR(dent);
1965 	aa_get_ns(ns);
1966 	ns_subload(ns) = dent;
1967 
1968 	dent = aafs_create_file(".replace", 0640, dir, ns,
1969 				      &aa_fs_profile_replace);
1970 	if (IS_ERR(dent))
1971 		return PTR_ERR(dent);
1972 	aa_get_ns(ns);
1973 	ns_subreplace(ns) = dent;
1974 
1975 	dent = aafs_create_file(".remove", 0640, dir, ns,
1976 				      &aa_fs_profile_remove);
1977 	if (IS_ERR(dent))
1978 		return PTR_ERR(dent);
1979 	aa_get_ns(ns);
1980 	ns_subremove(ns) = dent;
1981 
1982 	  /* use create_dentry so we can supply private data */
1983 	dent = aafs_create("namespaces", S_IFDIR | 0755, dir, ns, NULL, NULL,
1984 			   &ns_dir_inode_operations);
1985 	if (IS_ERR(dent))
1986 		return PTR_ERR(dent);
1987 	aa_get_ns(ns);
1988 	ns_subns_dir(ns) = dent;
1989 
1990 	return 0;
1991 }
1992 
1993 /*
1994  * Requires: @ns->lock held
1995  */
1996 int __aafs_ns_mkdir(struct aa_ns *ns, struct dentry *parent, const char *name,
1997 		    struct dentry *dent)
1998 {
1999 	struct aa_ns *sub;
2000 	struct aa_profile *child;
2001 	struct dentry *dir;
2002 	int error;
2003 
2004 	AA_BUG(!ns);
2005 	AA_BUG(!parent);
2006 	AA_BUG(!mutex_is_locked(&ns->lock));
2007 
2008 	if (!name)
2009 		name = ns->base.name;
2010 
2011 	if (!dent) {
2012 		/* create ns dir if it doesn't already exist */
2013 		dent = aafs_create_dir(name, parent);
2014 		if (IS_ERR(dent))
2015 			goto fail;
2016 	} else
2017 		dget(dent);
2018 	ns_dir(ns) = dir = dent;
2019 	error = __aafs_ns_mkdir_entries(ns, dir);
2020 	if (error)
2021 		goto fail2;
2022 
2023 	/* profiles */
2024 	list_for_each_entry(child, &ns->base.profiles, base.list) {
2025 		error = __aafs_profile_mkdir(child, ns_subprofs_dir(ns));
2026 		if (error)
2027 			goto fail2;
2028 	}
2029 
2030 	/* subnamespaces */
2031 	list_for_each_entry(sub, &ns->sub_ns, base.list) {
2032 		mutex_lock_nested(&sub->lock, sub->level);
2033 		error = __aafs_ns_mkdir(sub, ns_subns_dir(ns), NULL, NULL);
2034 		mutex_unlock(&sub->lock);
2035 		if (error)
2036 			goto fail2;
2037 	}
2038 
2039 	return 0;
2040 
2041 fail:
2042 	error = PTR_ERR(dent);
2043 
2044 fail2:
2045 	__aafs_ns_rmdir(ns);
2046 
2047 	return error;
2048 }
2049 
2050 /**
2051  * __next_ns - find the next namespace to list
2052  * @root: root namespace to stop search at (NOT NULL)
2053  * @ns: current ns position (NOT NULL)
2054  *
2055  * Find the next namespace from @ns under @root and handle all locking needed
2056  * while switching current namespace.
2057  *
2058  * Returns: next namespace or NULL if at last namespace under @root
2059  * Requires: ns->parent->lock to be held
2060  * NOTE: will not unlock root->lock
2061  */
2062 static struct aa_ns *__next_ns(struct aa_ns *root, struct aa_ns *ns)
2063 {
2064 	struct aa_ns *parent, *next;
2065 
2066 	AA_BUG(!root);
2067 	AA_BUG(!ns);
2068 	AA_BUG(ns != root && !mutex_is_locked(&ns->parent->lock));
2069 
2070 	/* is next namespace a child */
2071 	if (!list_empty(&ns->sub_ns)) {
2072 		next = list_first_entry(&ns->sub_ns, typeof(*ns), base.list);
2073 		mutex_lock_nested(&next->lock, next->level);
2074 		return next;
2075 	}
2076 
2077 	/* check if the next ns is a sibling, parent, gp, .. */
2078 	parent = ns->parent;
2079 	while (ns != root) {
2080 		mutex_unlock(&ns->lock);
2081 		next = list_next_entry(ns, base.list);
2082 		if (!list_entry_is_head(next, &parent->sub_ns, base.list)) {
2083 			mutex_lock_nested(&next->lock, next->level);
2084 			return next;
2085 		}
2086 		ns = parent;
2087 		parent = parent->parent;
2088 	}
2089 
2090 	return NULL;
2091 }
2092 
2093 /**
2094  * __first_profile - find the first profile in a namespace
2095  * @root: namespace that is root of profiles being displayed (NOT NULL)
2096  * @ns: namespace to start in   (NOT NULL)
2097  *
2098  * Returns: unrefcounted profile or NULL if no profile
2099  * Requires: profile->ns.lock to be held
2100  */
2101 static struct aa_profile *__first_profile(struct aa_ns *root,
2102 					  struct aa_ns *ns)
2103 {
2104 	AA_BUG(!root);
2105 	AA_BUG(ns && !mutex_is_locked(&ns->lock));
2106 
2107 	for (; ns; ns = __next_ns(root, ns)) {
2108 		if (!list_empty(&ns->base.profiles))
2109 			return list_first_entry(&ns->base.profiles,
2110 						struct aa_profile, base.list);
2111 	}
2112 	return NULL;
2113 }
2114 
2115 /**
2116  * __next_profile - step to the next profile in a profile tree
2117  * @profile: current profile in tree (NOT NULL)
2118  *
2119  * Perform a depth first traversal on the profile tree in a namespace
2120  *
2121  * Returns: next profile or NULL if done
2122  * Requires: profile->ns.lock to be held
2123  */
2124 static struct aa_profile *__next_profile(struct aa_profile *p)
2125 {
2126 	struct aa_profile *parent;
2127 	struct aa_ns *ns = p->ns;
2128 
2129 	AA_BUG(!mutex_is_locked(&profiles_ns(p)->lock));
2130 
2131 	/* is next profile a child */
2132 	if (!list_empty(&p->base.profiles))
2133 		return list_first_entry(&p->base.profiles, typeof(*p),
2134 					base.list);
2135 
2136 	/* is next profile a sibling, parent sibling, gp, sibling, .. */
2137 	parent = rcu_dereference_protected(p->parent,
2138 					   mutex_is_locked(&p->ns->lock));
2139 	while (parent) {
2140 		p = list_next_entry(p, base.list);
2141 		if (!list_entry_is_head(p, &parent->base.profiles, base.list))
2142 			return p;
2143 		p = parent;
2144 		parent = rcu_dereference_protected(parent->parent,
2145 					    mutex_is_locked(&parent->ns->lock));
2146 	}
2147 
2148 	/* is next another profile in the namespace */
2149 	p = list_next_entry(p, base.list);
2150 	if (!list_entry_is_head(p, &ns->base.profiles, base.list))
2151 		return p;
2152 
2153 	return NULL;
2154 }
2155 
2156 /**
2157  * next_profile - step to the next profile in where ever it may be
2158  * @root: root namespace  (NOT NULL)
2159  * @profile: current profile  (NOT NULL)
2160  *
2161  * Returns: next profile or NULL if there isn't one
2162  */
2163 static struct aa_profile *next_profile(struct aa_ns *root,
2164 				       struct aa_profile *profile)
2165 {
2166 	struct aa_profile *next = __next_profile(profile);
2167 	if (next)
2168 		return next;
2169 
2170 	/* finished all profiles in namespace move to next namespace */
2171 	return __first_profile(root, __next_ns(root, profile->ns));
2172 }
2173 
2174 /**
2175  * p_start - start a depth first traversal of profile tree
2176  * @f: seq_file to fill
2177  * @pos: current position
2178  *
2179  * Returns: first profile under current namespace or NULL if none found
2180  *
2181  * acquires first ns->lock
2182  */
2183 static void *p_start(struct seq_file *f, loff_t *pos)
2184 {
2185 	struct aa_profile *profile = NULL;
2186 	struct aa_ns *root = aa_get_current_ns();
2187 	loff_t l = *pos;
2188 	f->private = root;
2189 
2190 	/* find the first profile */
2191 	mutex_lock_nested(&root->lock, root->level);
2192 	profile = __first_profile(root, root);
2193 
2194 	/* skip to position */
2195 	for (; profile && l > 0; l--)
2196 		profile = next_profile(root, profile);
2197 
2198 	return profile;
2199 }
2200 
2201 /**
2202  * p_next - read the next profile entry
2203  * @f: seq_file to fill
2204  * @p: profile previously returned
2205  * @pos: current position
2206  *
2207  * Returns: next profile after @p or NULL if none
2208  *
2209  * may acquire/release locks in namespace tree as necessary
2210  */
2211 static void *p_next(struct seq_file *f, void *p, loff_t *pos)
2212 {
2213 	struct aa_profile *profile = p;
2214 	struct aa_ns *ns = f->private;
2215 	(*pos)++;
2216 
2217 	return next_profile(ns, profile);
2218 }
2219 
2220 /**
2221  * p_stop - stop depth first traversal
2222  * @f: seq_file we are filling
2223  * @p: the last profile writen
2224  *
2225  * Release all locking done by p_start/p_next on namespace tree
2226  */
2227 static void p_stop(struct seq_file *f, void *p)
2228 {
2229 	struct aa_profile *profile = p;
2230 	struct aa_ns *root = f->private, *ns;
2231 
2232 	if (profile) {
2233 		for (ns = profile->ns; ns && ns != root; ns = ns->parent)
2234 			mutex_unlock(&ns->lock);
2235 	}
2236 	mutex_unlock(&root->lock);
2237 	aa_put_ns(root);
2238 }
2239 
2240 /**
2241  * seq_show_profile - show a profile entry
2242  * @f: seq_file to file
2243  * @p: current position (profile)    (NOT NULL)
2244  *
2245  * Returns: error on failure
2246  */
2247 static int seq_show_profile(struct seq_file *f, void *p)
2248 {
2249 	struct aa_profile *profile = (struct aa_profile *)p;
2250 	struct aa_ns *root = f->private;
2251 
2252 	aa_label_seq_xprint(f, root, &profile->label,
2253 			    FLAG_SHOW_MODE | FLAG_VIEW_SUBNS, GFP_KERNEL);
2254 	seq_putc(f, '\n');
2255 
2256 	return 0;
2257 }
2258 
2259 static const struct seq_operations aa_sfs_profiles_op = {
2260 	.start = p_start,
2261 	.next = p_next,
2262 	.stop = p_stop,
2263 	.show = seq_show_profile,
2264 };
2265 
2266 static int profiles_open(struct inode *inode, struct file *file)
2267 {
2268 	if (!policy_view_capable(NULL))
2269 		return -EACCES;
2270 
2271 	return seq_open(file, &aa_sfs_profiles_op);
2272 }
2273 
2274 static int profiles_release(struct inode *inode, struct file *file)
2275 {
2276 	return seq_release(inode, file);
2277 }
2278 
2279 static const struct file_operations aa_sfs_profiles_fops = {
2280 	.open = profiles_open,
2281 	.read = seq_read,
2282 	.llseek = seq_lseek,
2283 	.release = profiles_release,
2284 };
2285 
2286 
2287 /** Base file system setup **/
2288 static struct aa_sfs_entry aa_sfs_entry_file[] = {
2289 	AA_SFS_FILE_STRING("mask",
2290 			   "create read write exec append mmap_exec link lock"),
2291 	{ }
2292 };
2293 
2294 static struct aa_sfs_entry aa_sfs_entry_ptrace[] = {
2295 	AA_SFS_FILE_STRING("mask", "read trace"),
2296 	{ }
2297 };
2298 
2299 static struct aa_sfs_entry aa_sfs_entry_signal[] = {
2300 	AA_SFS_FILE_STRING("mask", AA_SFS_SIG_MASK),
2301 	{ }
2302 };
2303 
2304 static struct aa_sfs_entry aa_sfs_entry_attach[] = {
2305 	AA_SFS_FILE_BOOLEAN("xattr", 1),
2306 	{ }
2307 };
2308 static struct aa_sfs_entry aa_sfs_entry_domain[] = {
2309 	AA_SFS_FILE_BOOLEAN("change_hat",	1),
2310 	AA_SFS_FILE_BOOLEAN("change_hatv",	1),
2311 	AA_SFS_FILE_BOOLEAN("change_onexec",	1),
2312 	AA_SFS_FILE_BOOLEAN("change_profile",	1),
2313 	AA_SFS_FILE_BOOLEAN("stack",		1),
2314 	AA_SFS_FILE_BOOLEAN("fix_binfmt_elf_mmap",	1),
2315 	AA_SFS_FILE_BOOLEAN("post_nnp_subset",	1),
2316 	AA_SFS_FILE_BOOLEAN("computed_longest_left",	1),
2317 	AA_SFS_DIR("attach_conditions",		aa_sfs_entry_attach),
2318 	AA_SFS_FILE_STRING("version", "1.2"),
2319 	{ }
2320 };
2321 
2322 static struct aa_sfs_entry aa_sfs_entry_versions[] = {
2323 	AA_SFS_FILE_BOOLEAN("v5",	1),
2324 	AA_SFS_FILE_BOOLEAN("v6",	1),
2325 	AA_SFS_FILE_BOOLEAN("v7",	1),
2326 	AA_SFS_FILE_BOOLEAN("v8",	1),
2327 	{ }
2328 };
2329 
2330 static struct aa_sfs_entry aa_sfs_entry_policy[] = {
2331 	AA_SFS_DIR("versions",			aa_sfs_entry_versions),
2332 	AA_SFS_FILE_BOOLEAN("set_load",		1),
2333 	/* number of out of band transitions supported */
2334 	AA_SFS_FILE_U64("outofband",		MAX_OOB_SUPPORTED),
2335 	{ }
2336 };
2337 
2338 static struct aa_sfs_entry aa_sfs_entry_mount[] = {
2339 	AA_SFS_FILE_STRING("mask", "mount umount pivot_root"),
2340 	{ }
2341 };
2342 
2343 static struct aa_sfs_entry aa_sfs_entry_ns[] = {
2344 	AA_SFS_FILE_BOOLEAN("profile",		1),
2345 	AA_SFS_FILE_BOOLEAN("pivot_root",	0),
2346 	{ }
2347 };
2348 
2349 static struct aa_sfs_entry aa_sfs_entry_query_label[] = {
2350 	AA_SFS_FILE_STRING("perms", "allow deny audit quiet"),
2351 	AA_SFS_FILE_BOOLEAN("data",		1),
2352 	AA_SFS_FILE_BOOLEAN("multi_transaction",	1),
2353 	{ }
2354 };
2355 
2356 static struct aa_sfs_entry aa_sfs_entry_query[] = {
2357 	AA_SFS_DIR("label",			aa_sfs_entry_query_label),
2358 	{ }
2359 };
2360 static struct aa_sfs_entry aa_sfs_entry_features[] = {
2361 	AA_SFS_DIR("policy",			aa_sfs_entry_policy),
2362 	AA_SFS_DIR("domain",			aa_sfs_entry_domain),
2363 	AA_SFS_DIR("file",			aa_sfs_entry_file),
2364 	AA_SFS_DIR("network_v8",		aa_sfs_entry_network),
2365 	AA_SFS_DIR("mount",			aa_sfs_entry_mount),
2366 	AA_SFS_DIR("namespaces",		aa_sfs_entry_ns),
2367 	AA_SFS_FILE_U64("capability",		VFS_CAP_FLAGS_MASK),
2368 	AA_SFS_DIR("rlimit",			aa_sfs_entry_rlimit),
2369 	AA_SFS_DIR("caps",			aa_sfs_entry_caps),
2370 	AA_SFS_DIR("ptrace",			aa_sfs_entry_ptrace),
2371 	AA_SFS_DIR("signal",			aa_sfs_entry_signal),
2372 	AA_SFS_DIR("query",			aa_sfs_entry_query),
2373 	{ }
2374 };
2375 
2376 static struct aa_sfs_entry aa_sfs_entry_apparmor[] = {
2377 	AA_SFS_FILE_FOPS(".access", 0666, &aa_sfs_access),
2378 	AA_SFS_FILE_FOPS(".stacked", 0444, &seq_ns_stacked_fops),
2379 	AA_SFS_FILE_FOPS(".ns_stacked", 0444, &seq_ns_nsstacked_fops),
2380 	AA_SFS_FILE_FOPS(".ns_level", 0444, &seq_ns_level_fops),
2381 	AA_SFS_FILE_FOPS(".ns_name", 0444, &seq_ns_name_fops),
2382 	AA_SFS_FILE_FOPS("profiles", 0444, &aa_sfs_profiles_fops),
2383 	AA_SFS_DIR("features", aa_sfs_entry_features),
2384 	{ }
2385 };
2386 
2387 static struct aa_sfs_entry aa_sfs_entry =
2388 	AA_SFS_DIR("apparmor", aa_sfs_entry_apparmor);
2389 
2390 /**
2391  * entry_create_file - create a file entry in the apparmor securityfs
2392  * @fs_file: aa_sfs_entry to build an entry for (NOT NULL)
2393  * @parent: the parent dentry in the securityfs
2394  *
2395  * Use entry_remove_file to remove entries created with this fn.
2396  */
2397 static int __init entry_create_file(struct aa_sfs_entry *fs_file,
2398 				    struct dentry *parent)
2399 {
2400 	int error = 0;
2401 
2402 	fs_file->dentry = securityfs_create_file(fs_file->name,
2403 						 S_IFREG | fs_file->mode,
2404 						 parent, fs_file,
2405 						 fs_file->file_ops);
2406 	if (IS_ERR(fs_file->dentry)) {
2407 		error = PTR_ERR(fs_file->dentry);
2408 		fs_file->dentry = NULL;
2409 	}
2410 	return error;
2411 }
2412 
2413 static void __init entry_remove_dir(struct aa_sfs_entry *fs_dir);
2414 /**
2415  * entry_create_dir - recursively create a directory entry in the securityfs
2416  * @fs_dir: aa_sfs_entry (and all child entries) to build (NOT NULL)
2417  * @parent: the parent dentry in the securityfs
2418  *
2419  * Use entry_remove_dir to remove entries created with this fn.
2420  */
2421 static int __init entry_create_dir(struct aa_sfs_entry *fs_dir,
2422 				   struct dentry *parent)
2423 {
2424 	struct aa_sfs_entry *fs_file;
2425 	struct dentry *dir;
2426 	int error;
2427 
2428 	dir = securityfs_create_dir(fs_dir->name, parent);
2429 	if (IS_ERR(dir))
2430 		return PTR_ERR(dir);
2431 	fs_dir->dentry = dir;
2432 
2433 	for (fs_file = fs_dir->v.files; fs_file && fs_file->name; ++fs_file) {
2434 		if (fs_file->v_type == AA_SFS_TYPE_DIR)
2435 			error = entry_create_dir(fs_file, fs_dir->dentry);
2436 		else
2437 			error = entry_create_file(fs_file, fs_dir->dentry);
2438 		if (error)
2439 			goto failed;
2440 	}
2441 
2442 	return 0;
2443 
2444 failed:
2445 	entry_remove_dir(fs_dir);
2446 
2447 	return error;
2448 }
2449 
2450 /**
2451  * entry_remove_file - drop a single file entry in the apparmor securityfs
2452  * @fs_file: aa_sfs_entry to detach from the securityfs (NOT NULL)
2453  */
2454 static void __init entry_remove_file(struct aa_sfs_entry *fs_file)
2455 {
2456 	if (!fs_file->dentry)
2457 		return;
2458 
2459 	securityfs_remove(fs_file->dentry);
2460 	fs_file->dentry = NULL;
2461 }
2462 
2463 /**
2464  * entry_remove_dir - recursively drop a directory entry from the securityfs
2465  * @fs_dir: aa_sfs_entry (and all child entries) to detach (NOT NULL)
2466  */
2467 static void __init entry_remove_dir(struct aa_sfs_entry *fs_dir)
2468 {
2469 	struct aa_sfs_entry *fs_file;
2470 
2471 	for (fs_file = fs_dir->v.files; fs_file && fs_file->name; ++fs_file) {
2472 		if (fs_file->v_type == AA_SFS_TYPE_DIR)
2473 			entry_remove_dir(fs_file);
2474 		else
2475 			entry_remove_file(fs_file);
2476 	}
2477 
2478 	entry_remove_file(fs_dir);
2479 }
2480 
2481 /**
2482  * aa_destroy_aafs - cleanup and free aafs
2483  *
2484  * releases dentries allocated by aa_create_aafs
2485  */
2486 void __init aa_destroy_aafs(void)
2487 {
2488 	entry_remove_dir(&aa_sfs_entry);
2489 }
2490 
2491 
2492 #define NULL_FILE_NAME ".null"
2493 struct path aa_null;
2494 
2495 static int aa_mk_null_file(struct dentry *parent)
2496 {
2497 	struct vfsmount *mount = NULL;
2498 	struct dentry *dentry;
2499 	struct inode *inode;
2500 	int count = 0;
2501 	int error = simple_pin_fs(parent->d_sb->s_type, &mount, &count);
2502 
2503 	if (error)
2504 		return error;
2505 
2506 	inode_lock(d_inode(parent));
2507 	dentry = lookup_one_len(NULL_FILE_NAME, parent, strlen(NULL_FILE_NAME));
2508 	if (IS_ERR(dentry)) {
2509 		error = PTR_ERR(dentry);
2510 		goto out;
2511 	}
2512 	inode = new_inode(parent->d_inode->i_sb);
2513 	if (!inode) {
2514 		error = -ENOMEM;
2515 		goto out1;
2516 	}
2517 
2518 	inode->i_ino = get_next_ino();
2519 	inode->i_mode = S_IFCHR | S_IRUGO | S_IWUGO;
2520 	inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode);
2521 	init_special_inode(inode, S_IFCHR | S_IRUGO | S_IWUGO,
2522 			   MKDEV(MEM_MAJOR, 3));
2523 	d_instantiate(dentry, inode);
2524 	aa_null.dentry = dget(dentry);
2525 	aa_null.mnt = mntget(mount);
2526 
2527 	error = 0;
2528 
2529 out1:
2530 	dput(dentry);
2531 out:
2532 	inode_unlock(d_inode(parent));
2533 	simple_release_fs(&mount, &count);
2534 	return error;
2535 }
2536 
2537 
2538 
2539 static const char *policy_get_link(struct dentry *dentry,
2540 				   struct inode *inode,
2541 				   struct delayed_call *done)
2542 {
2543 	struct aa_ns *ns;
2544 	struct path path;
2545 	int error;
2546 
2547 	if (!dentry)
2548 		return ERR_PTR(-ECHILD);
2549 
2550 	ns = aa_get_current_ns();
2551 	path.mnt = mntget(aafs_mnt);
2552 	path.dentry = dget(ns_dir(ns));
2553 	error = nd_jump_link(&path);
2554 	aa_put_ns(ns);
2555 
2556 	return ERR_PTR(error);
2557 }
2558 
2559 static int policy_readlink(struct dentry *dentry, char __user *buffer,
2560 			   int buflen)
2561 {
2562 	char name[32];
2563 	int res;
2564 
2565 	res = snprintf(name, sizeof(name), "%s:[%lu]", AAFS_NAME,
2566 		       d_inode(dentry)->i_ino);
2567 	if (res > 0 && res < sizeof(name))
2568 		res = readlink_copy(buffer, buflen, name);
2569 	else
2570 		res = -ENOENT;
2571 
2572 	return res;
2573 }
2574 
2575 static const struct inode_operations policy_link_iops = {
2576 	.readlink	= policy_readlink,
2577 	.get_link	= policy_get_link,
2578 };
2579 
2580 
2581 /**
2582  * aa_create_aafs - create the apparmor security filesystem
2583  *
2584  * dentries created here are released by aa_destroy_aafs
2585  *
2586  * Returns: error on failure
2587  */
2588 static int __init aa_create_aafs(void)
2589 {
2590 	struct dentry *dent;
2591 	int error;
2592 
2593 	if (!apparmor_initialized)
2594 		return 0;
2595 
2596 	if (aa_sfs_entry.dentry) {
2597 		AA_ERROR("%s: AppArmor securityfs already exists\n", __func__);
2598 		return -EEXIST;
2599 	}
2600 
2601 	/* setup apparmorfs used to virtualize policy/ */
2602 	aafs_mnt = kern_mount(&aafs_ops);
2603 	if (IS_ERR(aafs_mnt))
2604 		panic("can't set apparmorfs up\n");
2605 	aafs_mnt->mnt_sb->s_flags &= ~SB_NOUSER;
2606 
2607 	/* Populate fs tree. */
2608 	error = entry_create_dir(&aa_sfs_entry, NULL);
2609 	if (error)
2610 		goto error;
2611 
2612 	dent = securityfs_create_file(".load", 0666, aa_sfs_entry.dentry,
2613 				      NULL, &aa_fs_profile_load);
2614 	if (IS_ERR(dent))
2615 		goto dent_error;
2616 	ns_subload(root_ns) = dent;
2617 
2618 	dent = securityfs_create_file(".replace", 0666, aa_sfs_entry.dentry,
2619 				      NULL, &aa_fs_profile_replace);
2620 	if (IS_ERR(dent))
2621 		goto dent_error;
2622 	ns_subreplace(root_ns) = dent;
2623 
2624 	dent = securityfs_create_file(".remove", 0666, aa_sfs_entry.dentry,
2625 				      NULL, &aa_fs_profile_remove);
2626 	if (IS_ERR(dent))
2627 		goto dent_error;
2628 	ns_subremove(root_ns) = dent;
2629 
2630 	dent = securityfs_create_file("revision", 0444, aa_sfs_entry.dentry,
2631 				      NULL, &aa_fs_ns_revision_fops);
2632 	if (IS_ERR(dent))
2633 		goto dent_error;
2634 	ns_subrevision(root_ns) = dent;
2635 
2636 	/* policy tree referenced by magic policy symlink */
2637 	mutex_lock_nested(&root_ns->lock, root_ns->level);
2638 	error = __aafs_ns_mkdir(root_ns, aafs_mnt->mnt_root, ".policy",
2639 				aafs_mnt->mnt_root);
2640 	mutex_unlock(&root_ns->lock);
2641 	if (error)
2642 		goto error;
2643 
2644 	/* magic symlink similar to nsfs redirects based on task policy */
2645 	dent = securityfs_create_symlink("policy", aa_sfs_entry.dentry,
2646 					 NULL, &policy_link_iops);
2647 	if (IS_ERR(dent))
2648 		goto dent_error;
2649 
2650 	error = aa_mk_null_file(aa_sfs_entry.dentry);
2651 	if (error)
2652 		goto error;
2653 
2654 	/* TODO: add default profile to apparmorfs */
2655 
2656 	/* Report that AppArmor fs is enabled */
2657 	aa_info_message("AppArmor Filesystem Enabled");
2658 	return 0;
2659 
2660 dent_error:
2661 	error = PTR_ERR(dent);
2662 error:
2663 	aa_destroy_aafs();
2664 	AA_ERROR("Error creating AppArmor securityfs\n");
2665 	return error;
2666 }
2667 
2668 fs_initcall(aa_create_aafs);
2669