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15#include "include/apparmor.h"
16#include "include/audit.h"
17#include "include/file.h"
18#include "include/match.h"
19#include "include/path.h"
20#include "include/policy.h"
21
22struct file_perms nullperms;
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29
30static void audit_file_mask(struct audit_buffer *ab, u32 mask)
31{
32 char str[10];
33
34 char *m = str;
35
36 if (mask & AA_EXEC_MMAP)
37 *m++ = 'm';
38 if (mask & (MAY_READ | AA_MAY_META_READ))
39 *m++ = 'r';
40 if (mask & (MAY_WRITE | AA_MAY_META_WRITE | AA_MAY_CHMOD |
41 AA_MAY_CHOWN))
42 *m++ = 'w';
43 else if (mask & MAY_APPEND)
44 *m++ = 'a';
45 if (mask & AA_MAY_CREATE)
46 *m++ = 'c';
47 if (mask & AA_MAY_DELETE)
48 *m++ = 'd';
49 if (mask & AA_MAY_LINK)
50 *m++ = 'l';
51 if (mask & AA_MAY_LOCK)
52 *m++ = 'k';
53 if (mask & MAY_EXEC)
54 *m++ = 'x';
55 *m = '\0';
56
57 audit_log_string(ab, str);
58}
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64
65static void file_audit_cb(struct audit_buffer *ab, void *va)
66{
67 struct common_audit_data *sa = va;
68 kuid_t fsuid = current_fsuid();
69
70 if (sa->aad->fs.request & AA_AUDIT_FILE_MASK) {
71 audit_log_format(ab, " requested_mask=");
72 audit_file_mask(ab, sa->aad->fs.request);
73 }
74 if (sa->aad->fs.denied & AA_AUDIT_FILE_MASK) {
75 audit_log_format(ab, " denied_mask=");
76 audit_file_mask(ab, sa->aad->fs.denied);
77 }
78 if (sa->aad->fs.request & AA_AUDIT_FILE_MASK) {
79 audit_log_format(ab, " fsuid=%d",
80 from_kuid(&init_user_ns, fsuid));
81 audit_log_format(ab, " ouid=%d",
82 from_kuid(&init_user_ns, sa->aad->fs.ouid));
83 }
84
85 if (sa->aad->fs.target) {
86 audit_log_format(ab, " target=");
87 audit_log_untrustedstring(ab, sa->aad->fs.target);
88 }
89}
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106int aa_audit_file(struct aa_profile *profile, struct file_perms *perms,
107 gfp_t gfp, int op, u32 request, const char *name,
108 const char *target, kuid_t ouid, const char *info, int error)
109{
110 int type = AUDIT_APPARMOR_AUTO;
111 struct common_audit_data sa;
112 struct apparmor_audit_data aad = {0,};
113 sa.type = LSM_AUDIT_DATA_NONE;
114 sa.aad = &aad;
115 aad.op = op,
116 aad.fs.request = request;
117 aad.name = name;
118 aad.fs.target = target;
119 aad.fs.ouid = ouid;
120 aad.info = info;
121 aad.error = error;
122
123 if (likely(!sa.aad->error)) {
124 u32 mask = perms->audit;
125
126 if (unlikely(AUDIT_MODE(profile) == AUDIT_ALL))
127 mask = 0xffff;
128
129
130 sa.aad->fs.request &= mask;
131
132 if (likely(!sa.aad->fs.request))
133 return 0;
134 type = AUDIT_APPARMOR_AUDIT;
135 } else {
136
137 sa.aad->fs.request = sa.aad->fs.request & ~perms->allow;
138
139 if (sa.aad->fs.request & perms->kill)
140 type = AUDIT_APPARMOR_KILL;
141
142
143 if ((sa.aad->fs.request & perms->quiet) &&
144 AUDIT_MODE(profile) != AUDIT_NOQUIET &&
145 AUDIT_MODE(profile) != AUDIT_ALL)
146 sa.aad->fs.request &= ~perms->quiet;
147
148 if (!sa.aad->fs.request)
149 return COMPLAIN_MODE(profile) ? 0 : sa.aad->error;
150 }
151
152 sa.aad->fs.denied = sa.aad->fs.request & ~perms->allow;
153 return aa_audit(type, profile, gfp, &sa, file_audit_cb);
154}
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161
162static u32 map_old_perms(u32 old)
163{
164 u32 new = old & 0xf;
165 if (old & MAY_READ)
166 new |= AA_MAY_META_READ;
167 if (old & MAY_WRITE)
168 new |= AA_MAY_META_WRITE | AA_MAY_CREATE | AA_MAY_DELETE |
169 AA_MAY_CHMOD | AA_MAY_CHOWN;
170 if (old & 0x10)
171 new |= AA_MAY_LINK;
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175 if (old & 0x20)
176 new |= AA_MAY_LOCK | AA_LINK_SUBSET;
177 if (old & 0x40)
178 new |= AA_EXEC_MMAP;
179
180 return new;
181}
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194static struct file_perms compute_perms(struct aa_dfa *dfa, unsigned int state,
195 struct path_cond *cond)
196{
197 struct file_perms perms;
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204 perms.kill = 0;
205
206 if (uid_eq(current_fsuid(), cond->uid)) {
207 perms.allow = map_old_perms(dfa_user_allow(dfa, state));
208 perms.audit = map_old_perms(dfa_user_audit(dfa, state));
209 perms.quiet = map_old_perms(dfa_user_quiet(dfa, state));
210 perms.xindex = dfa_user_xindex(dfa, state);
211 } else {
212 perms.allow = map_old_perms(dfa_other_allow(dfa, state));
213 perms.audit = map_old_perms(dfa_other_audit(dfa, state));
214 perms.quiet = map_old_perms(dfa_other_quiet(dfa, state));
215 perms.xindex = dfa_other_xindex(dfa, state);
216 }
217 perms.allow |= AA_MAY_META_READ;
218
219
220 if (ACCEPT_TABLE(dfa)[state] & 0x80000000)
221 perms.allow |= AA_MAY_CHANGE_PROFILE;
222 if (ACCEPT_TABLE(dfa)[state] & 0x40000000)
223 perms.allow |= AA_MAY_ONEXEC;
224
225 return perms;
226}
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238unsigned int aa_str_perms(struct aa_dfa *dfa, unsigned int start,
239 const char *name, struct path_cond *cond,
240 struct file_perms *perms)
241{
242 unsigned int state;
243 if (!dfa) {
244 *perms = nullperms;
245 return DFA_NOMATCH;
246 }
247
248 state = aa_dfa_match(dfa, start, name);
249 *perms = compute_perms(dfa, state, cond);
250
251 return state;
252}
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260static inline bool is_deleted(struct dentry *dentry)
261{
262 if (d_unlinked(dentry) && dentry->d_inode->i_nlink == 0)
263 return 1;
264 return 0;
265}
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278int aa_path_perm(int op, struct aa_profile *profile, struct path *path,
279 int flags, u32 request, struct path_cond *cond)
280{
281 char *buffer = NULL;
282 struct file_perms perms = {};
283 const char *name, *info = NULL;
284 int error;
285
286 flags |= profile->path_flags | (S_ISDIR(cond->mode) ? PATH_IS_DIR : 0);
287 error = aa_path_name(path, flags, &buffer, &name, &info);
288 if (error) {
289 if (error == -ENOENT && is_deleted(path->dentry)) {
290
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293 error = 0;
294 info = NULL;
295 perms.allow = request;
296 }
297 } else {
298 aa_str_perms(profile->file.dfa, profile->file.start, name, cond,
299 &perms);
300 if (request & ~perms.allow)
301 error = -EACCES;
302 }
303 error = aa_audit_file(profile, &perms, GFP_KERNEL, op, request, name,
304 NULL, cond->uid, info, error);
305 kfree(buffer);
306
307 return error;
308}
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321static inline bool xindex_is_subset(u32 link, u32 target)
322{
323 if (((link & ~AA_X_UNSAFE) != (target & ~AA_X_UNSAFE)) ||
324 ((link & AA_X_UNSAFE) && !(target & AA_X_UNSAFE)))
325 return 0;
326
327 return 1;
328}
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348int aa_path_link(struct aa_profile *profile, struct dentry *old_dentry,
349 struct path *new_dir, struct dentry *new_dentry)
350{
351 struct path link = { new_dir->mnt, new_dentry };
352 struct path target = { new_dir->mnt, old_dentry };
353 struct path_cond cond = {
354 old_dentry->d_inode->i_uid,
355 old_dentry->d_inode->i_mode
356 };
357 char *buffer = NULL, *buffer2 = NULL;
358 const char *lname, *tname = NULL, *info = NULL;
359 struct file_perms lperms, perms;
360 u32 request = AA_MAY_LINK;
361 unsigned int state;
362 int error;
363
364 lperms = nullperms;
365
366
367 error = aa_path_name(&link, profile->path_flags, &buffer, &lname,
368 &info);
369 if (error)
370 goto audit;
371
372
373 error = aa_path_name(&target, profile->path_flags, &buffer2, &tname,
374 &info);
375 if (error)
376 goto audit;
377
378 error = -EACCES;
379
380 state = aa_str_perms(profile->file.dfa, profile->file.start, lname,
381 &cond, &lperms);
382
383 if (!(lperms.allow & AA_MAY_LINK))
384 goto audit;
385
386
387 state = aa_dfa_null_transition(profile->file.dfa, state);
388 aa_str_perms(profile->file.dfa, state, tname, &cond, &perms);
389
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392
393 lperms.audit = perms.audit;
394 lperms.quiet = perms.quiet;
395 lperms.kill = perms.kill;
396
397 if (!(perms.allow & AA_MAY_LINK)) {
398 info = "target restricted";
399 goto audit;
400 }
401
402
403 if (!(perms.allow & AA_LINK_SUBSET))
404 goto done_tests;
405
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409 aa_str_perms(profile->file.dfa, profile->file.start, tname, &cond,
410 &perms);
411
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413 request = lperms.allow & ~AA_MAY_LINK;
414 lperms.allow &= perms.allow | AA_MAY_LINK;
415
416 request |= AA_AUDIT_FILE_MASK & (lperms.allow & ~perms.allow);
417 if (request & ~lperms.allow) {
418 goto audit;
419 } else if ((lperms.allow & MAY_EXEC) &&
420 !xindex_is_subset(lperms.xindex, perms.xindex)) {
421 lperms.allow &= ~MAY_EXEC;
422 request |= MAY_EXEC;
423 info = "link not subset of target";
424 goto audit;
425 }
426
427done_tests:
428 error = 0;
429
430audit:
431 error = aa_audit_file(profile, &lperms, GFP_KERNEL, OP_LINK, request,
432 lname, tname, cond.uid, info, error);
433 kfree(buffer);
434 kfree(buffer2);
435
436 return error;
437}
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448int aa_file_perm(int op, struct aa_profile *profile, struct file *file,
449 u32 request)
450{
451 struct path_cond cond = {
452 .uid = file_inode(file)->i_uid,
453 .mode = file_inode(file)->i_mode
454 };
455
456 return aa_path_perm(op, profile, &file->f_path, PATH_DELEGATE_DELETED,
457 request, &cond);
458}
459