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63e2b423 JJ |
1 | /* |
2 | * AppArmor security module | |
3 | * | |
4 | * This file contains AppArmor /sys/kernel/security/apparmor interface functions | |
5 | * | |
6 | * Copyright (C) 1998-2008 Novell/SUSE | |
7 | * Copyright 2009-2010 Canonical Ltd. | |
8 | * | |
9 | * This program is free software; you can redistribute it and/or | |
10 | * modify it under the terms of the GNU General Public License as | |
11 | * published by the Free Software Foundation, version 2 of the | |
12 | * License. | |
13 | */ | |
14 | ||
15 | #include <linux/security.h> | |
16 | #include <linux/vmalloc.h> | |
17 | #include <linux/module.h> | |
18 | #include <linux/seq_file.h> | |
19 | #include <linux/uaccess.h> | |
20 | #include <linux/namei.h> | |
e74abcf3 | 21 | #include <linux/capability.h> |
63e2b423 JJ |
22 | |
23 | #include "include/apparmor.h" | |
24 | #include "include/apparmorfs.h" | |
25 | #include "include/audit.h" | |
26 | #include "include/context.h" | |
27 | #include "include/policy.h" | |
d384b0a1 | 28 | #include "include/resource.h" |
63e2b423 JJ |
29 | |
30 | /** | |
31 | * aa_simple_write_to_buffer - common routine for getting policy from user | |
32 | * @op: operation doing the user buffer copy | |
33 | * @userbuf: user buffer to copy data from (NOT NULL) | |
3ed02ada | 34 | * @alloc_size: size of user buffer (REQUIRES: @alloc_size >= @copy_size) |
63e2b423 JJ |
35 | * @copy_size: size of data to copy from user buffer |
36 | * @pos: position write is at in the file (NOT NULL) | |
37 | * | |
38 | * Returns: kernel buffer containing copy of user buffer data or an | |
39 | * ERR_PTR on failure. | |
40 | */ | |
41 | static char *aa_simple_write_to_buffer(int op, const char __user *userbuf, | |
42 | size_t alloc_size, size_t copy_size, | |
43 | loff_t *pos) | |
44 | { | |
45 | char *data; | |
46 | ||
3ed02ada JJ |
47 | BUG_ON(copy_size > alloc_size); |
48 | ||
63e2b423 JJ |
49 | if (*pos != 0) |
50 | /* only writes from pos 0, that is complete writes */ | |
51 | return ERR_PTR(-ESPIPE); | |
52 | ||
53 | /* | |
54 | * Don't allow profile load/replace/remove from profiles that don't | |
55 | * have CAP_MAC_ADMIN | |
56 | */ | |
57 | if (!aa_may_manage_policy(op)) | |
58 | return ERR_PTR(-EACCES); | |
59 | ||
60 | /* freed by caller to simple_write_to_buffer */ | |
61 | data = kvmalloc(alloc_size); | |
62 | if (data == NULL) | |
63 | return ERR_PTR(-ENOMEM); | |
64 | ||
65 | if (copy_from_user(data, userbuf, copy_size)) { | |
66 | kvfree(data); | |
67 | return ERR_PTR(-EFAULT); | |
68 | } | |
69 | ||
70 | return data; | |
71 | } | |
72 | ||
73 | ||
74 | /* .load file hook fn to load policy */ | |
75 | static ssize_t profile_load(struct file *f, const char __user *buf, size_t size, | |
76 | loff_t *pos) | |
77 | { | |
78 | char *data; | |
79 | ssize_t error; | |
80 | ||
81 | data = aa_simple_write_to_buffer(OP_PROF_LOAD, buf, size, size, pos); | |
82 | ||
83 | error = PTR_ERR(data); | |
84 | if (!IS_ERR(data)) { | |
85 | error = aa_replace_profiles(data, size, PROF_ADD); | |
86 | kvfree(data); | |
87 | } | |
88 | ||
89 | return error; | |
90 | } | |
91 | ||
92 | static const struct file_operations aa_fs_profile_load = { | |
6038f373 AB |
93 | .write = profile_load, |
94 | .llseek = default_llseek, | |
63e2b423 JJ |
95 | }; |
96 | ||
97 | /* .replace file hook fn to load and/or replace policy */ | |
98 | static ssize_t profile_replace(struct file *f, const char __user *buf, | |
99 | size_t size, loff_t *pos) | |
100 | { | |
101 | char *data; | |
102 | ssize_t error; | |
103 | ||
104 | data = aa_simple_write_to_buffer(OP_PROF_REPL, buf, size, size, pos); | |
105 | error = PTR_ERR(data); | |
106 | if (!IS_ERR(data)) { | |
107 | error = aa_replace_profiles(data, size, PROF_REPLACE); | |
108 | kvfree(data); | |
109 | } | |
110 | ||
111 | return error; | |
112 | } | |
113 | ||
114 | static const struct file_operations aa_fs_profile_replace = { | |
6038f373 AB |
115 | .write = profile_replace, |
116 | .llseek = default_llseek, | |
63e2b423 JJ |
117 | }; |
118 | ||
119 | /* .remove file hook fn to remove loaded policy */ | |
120 | static ssize_t profile_remove(struct file *f, const char __user *buf, | |
121 | size_t size, loff_t *pos) | |
122 | { | |
123 | char *data; | |
124 | ssize_t error; | |
125 | ||
126 | /* | |
127 | * aa_remove_profile needs a null terminated string so 1 extra | |
128 | * byte is allocated and the copied data is null terminated. | |
129 | */ | |
130 | data = aa_simple_write_to_buffer(OP_PROF_RM, buf, size + 1, size, pos); | |
131 | ||
132 | error = PTR_ERR(data); | |
133 | if (!IS_ERR(data)) { | |
134 | data[size] = 0; | |
135 | error = aa_remove_profiles(data, size); | |
136 | kvfree(data); | |
137 | } | |
138 | ||
139 | return error; | |
140 | } | |
141 | ||
142 | static const struct file_operations aa_fs_profile_remove = { | |
6038f373 AB |
143 | .write = profile_remove, |
144 | .llseek = default_llseek, | |
63e2b423 JJ |
145 | }; |
146 | ||
e74abcf3 KC |
147 | static int aa_fs_seq_show(struct seq_file *seq, void *v) |
148 | { | |
149 | struct aa_fs_entry *fs_file = seq->private; | |
150 | ||
151 | if (!fs_file) | |
152 | return 0; | |
153 | ||
154 | switch (fs_file->v_type) { | |
155 | case AA_FS_TYPE_BOOLEAN: | |
156 | seq_printf(seq, "%s\n", fs_file->v.boolean ? "yes" : "no"); | |
157 | break; | |
a9bf8e9f KC |
158 | case AA_FS_TYPE_STRING: |
159 | seq_printf(seq, "%s\n", fs_file->v.string); | |
160 | break; | |
e74abcf3 KC |
161 | case AA_FS_TYPE_U64: |
162 | seq_printf(seq, "%#08lx\n", fs_file->v.u64); | |
163 | break; | |
164 | default: | |
165 | /* Ignore unpritable entry types. */ | |
166 | break; | |
167 | } | |
168 | ||
169 | return 0; | |
170 | } | |
171 | ||
172 | static int aa_fs_seq_open(struct inode *inode, struct file *file) | |
173 | { | |
174 | return single_open(file, aa_fs_seq_show, inode->i_private); | |
175 | } | |
176 | ||
177 | const struct file_operations aa_fs_seq_file_ops = { | |
178 | .owner = THIS_MODULE, | |
179 | .open = aa_fs_seq_open, | |
180 | .read = seq_read, | |
181 | .llseek = seq_lseek, | |
182 | .release = single_release, | |
183 | }; | |
184 | ||
63e2b423 JJ |
185 | /** Base file system setup **/ |
186 | ||
a9bf8e9f KC |
187 | static struct aa_fs_entry aa_fs_entry_file[] = { |
188 | AA_FS_FILE_STRING("mask", "create read write exec append mmap_exec " \ | |
189 | "link lock"), | |
190 | { } | |
191 | }; | |
192 | ||
e74abcf3 KC |
193 | static struct aa_fs_entry aa_fs_entry_domain[] = { |
194 | AA_FS_FILE_BOOLEAN("change_hat", 1), | |
195 | AA_FS_FILE_BOOLEAN("change_hatv", 1), | |
196 | AA_FS_FILE_BOOLEAN("change_onexec", 1), | |
197 | AA_FS_FILE_BOOLEAN("change_profile", 1), | |
198 | { } | |
199 | }; | |
200 | ||
201 | static struct aa_fs_entry aa_fs_entry_features[] = { | |
202 | AA_FS_DIR("domain", aa_fs_entry_domain), | |
a9bf8e9f | 203 | AA_FS_DIR("file", aa_fs_entry_file), |
e74abcf3 | 204 | AA_FS_FILE_U64("capability", VFS_CAP_FLAGS_MASK), |
d384b0a1 | 205 | AA_FS_DIR("rlimit", aa_fs_entry_rlimit), |
e74abcf3 KC |
206 | { } |
207 | }; | |
208 | ||
9acd494b KC |
209 | static struct aa_fs_entry aa_fs_entry_apparmor[] = { |
210 | AA_FS_FILE_FOPS(".load", 0640, &aa_fs_profile_load), | |
211 | AA_FS_FILE_FOPS(".replace", 0640, &aa_fs_profile_replace), | |
212 | AA_FS_FILE_FOPS(".remove", 0640, &aa_fs_profile_remove), | |
e74abcf3 | 213 | AA_FS_DIR("features", aa_fs_entry_features), |
9acd494b KC |
214 | { } |
215 | }; | |
63e2b423 | 216 | |
9acd494b KC |
217 | static struct aa_fs_entry aa_fs_entry = |
218 | AA_FS_DIR("apparmor", aa_fs_entry_apparmor); | |
63e2b423 | 219 | |
9acd494b KC |
220 | /** |
221 | * aafs_create_file - create a file entry in the apparmor securityfs | |
222 | * @fs_file: aa_fs_entry to build an entry for (NOT NULL) | |
223 | * @parent: the parent dentry in the securityfs | |
224 | * | |
225 | * Use aafs_remove_file to remove entries created with this fn. | |
226 | */ | |
227 | static int __init aafs_create_file(struct aa_fs_entry *fs_file, | |
228 | struct dentry *parent) | |
229 | { | |
230 | int error = 0; | |
231 | ||
232 | fs_file->dentry = securityfs_create_file(fs_file->name, | |
233 | S_IFREG | fs_file->mode, | |
234 | parent, fs_file, | |
235 | fs_file->file_ops); | |
236 | if (IS_ERR(fs_file->dentry)) { | |
237 | error = PTR_ERR(fs_file->dentry); | |
238 | fs_file->dentry = NULL; | |
63e2b423 | 239 | } |
9acd494b | 240 | return error; |
63e2b423 JJ |
241 | } |
242 | ||
243 | /** | |
9acd494b KC |
244 | * aafs_create_dir - recursively create a directory entry in the securityfs |
245 | * @fs_dir: aa_fs_entry (and all child entries) to build (NOT NULL) | |
246 | * @parent: the parent dentry in the securityfs | |
63e2b423 | 247 | * |
9acd494b | 248 | * Use aafs_remove_dir to remove entries created with this fn. |
63e2b423 | 249 | */ |
9acd494b KC |
250 | static int __init aafs_create_dir(struct aa_fs_entry *fs_dir, |
251 | struct dentry *parent) | |
63e2b423 | 252 | { |
9acd494b KC |
253 | int error; |
254 | struct aa_fs_entry *fs_file; | |
63e2b423 | 255 | |
9acd494b KC |
256 | fs_dir->dentry = securityfs_create_dir(fs_dir->name, parent); |
257 | if (IS_ERR(fs_dir->dentry)) { | |
258 | error = PTR_ERR(fs_dir->dentry); | |
259 | fs_dir->dentry = NULL; | |
260 | goto failed; | |
261 | } | |
63e2b423 | 262 | |
9acd494b KC |
263 | for (fs_file = fs_dir->v.files; fs_file->name; ++fs_file) { |
264 | if (fs_file->v_type == AA_FS_TYPE_DIR) | |
265 | error = aafs_create_dir(fs_file, fs_dir->dentry); | |
266 | else | |
267 | error = aafs_create_file(fs_file, fs_dir->dentry); | |
268 | if (error) | |
269 | goto failed; | |
270 | } | |
271 | ||
272 | return 0; | |
273 | ||
274 | failed: | |
275 | return error; | |
276 | } | |
277 | ||
278 | /** | |
279 | * aafs_remove_file - drop a single file entry in the apparmor securityfs | |
280 | * @fs_file: aa_fs_entry to detach from the securityfs (NOT NULL) | |
281 | */ | |
282 | static void __init aafs_remove_file(struct aa_fs_entry *fs_file) | |
283 | { | |
284 | if (!fs_file->dentry) | |
285 | return; | |
286 | ||
287 | securityfs_remove(fs_file->dentry); | |
288 | fs_file->dentry = NULL; | |
289 | } | |
290 | ||
291 | /** | |
292 | * aafs_remove_dir - recursively drop a directory entry from the securityfs | |
293 | * @fs_dir: aa_fs_entry (and all child entries) to detach (NOT NULL) | |
294 | */ | |
295 | static void __init aafs_remove_dir(struct aa_fs_entry *fs_dir) | |
296 | { | |
297 | struct aa_fs_entry *fs_file; | |
298 | ||
299 | for (fs_file = fs_dir->v.files; fs_file->name; ++fs_file) { | |
300 | if (fs_file->v_type == AA_FS_TYPE_DIR) | |
301 | aafs_remove_dir(fs_file); | |
302 | else | |
303 | aafs_remove_file(fs_file); | |
304 | } | |
305 | ||
306 | aafs_remove_file(fs_dir); | |
63e2b423 JJ |
307 | } |
308 | ||
309 | /** | |
310 | * aa_destroy_aafs - cleanup and free aafs | |
311 | * | |
312 | * releases dentries allocated by aa_create_aafs | |
313 | */ | |
314 | void __init aa_destroy_aafs(void) | |
315 | { | |
9acd494b | 316 | aafs_remove_dir(&aa_fs_entry); |
63e2b423 JJ |
317 | } |
318 | ||
319 | /** | |
320 | * aa_create_aafs - create the apparmor security filesystem | |
321 | * | |
322 | * dentries created here are released by aa_destroy_aafs | |
323 | * | |
324 | * Returns: error on failure | |
325 | */ | |
3417d8d5 | 326 | static int __init aa_create_aafs(void) |
63e2b423 JJ |
327 | { |
328 | int error; | |
329 | ||
330 | if (!apparmor_initialized) | |
331 | return 0; | |
332 | ||
9acd494b | 333 | if (aa_fs_entry.dentry) { |
63e2b423 JJ |
334 | AA_ERROR("%s: AppArmor securityfs already exists\n", __func__); |
335 | return -EEXIST; | |
336 | } | |
337 | ||
9acd494b KC |
338 | /* Populate fs tree. */ |
339 | error = aafs_create_dir(&aa_fs_entry, NULL); | |
63e2b423 JJ |
340 | if (error) |
341 | goto error; | |
342 | ||
343 | /* TODO: add support for apparmorfs_null and apparmorfs_mnt */ | |
344 | ||
345 | /* Report that AppArmor fs is enabled */ | |
346 | aa_info_message("AppArmor Filesystem Enabled"); | |
347 | return 0; | |
348 | ||
349 | error: | |
350 | aa_destroy_aafs(); | |
351 | AA_ERROR("Error creating AppArmor securityfs\n"); | |
352 | return error; | |
353 | } | |
354 | ||
355 | fs_initcall(aa_create_aafs); |