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TOMOYO Linux Cross Reference
Linux/kernel/auditfilter.c

Version: ~ [ linux-5.6 ] ~ [ linux-5.5.13 ] ~ [ linux-5.4.28 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.113 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.174 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.217 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.217 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.140 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.82 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-3.9.11 ] ~ [ linux-3.8.13 ] ~ [ linux-3.7.10 ] ~ [ linux-3.6.11 ] ~ [ linux-3.5.7 ] ~ [ linux-3.4.113 ] ~ [ linux-3.3.8 ] ~ [ linux-3.2.102 ] ~ [ linux-3.1.10 ] ~ [ linux-3.0.101 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  1 /* auditfilter.c -- filtering of audit events
  2  *
  3  * Copyright 2003-2004 Red Hat, Inc.
  4  * Copyright 2005 Hewlett-Packard Development Company, L.P.
  5  * Copyright 2005 IBM Corporation
  6  *
  7  * This program is free software; you can redistribute it and/or modify
  8  * it under the terms of the GNU General Public License as published by
  9  * the Free Software Foundation; either version 2 of the License, or
 10  * (at your option) any later version.
 11  *
 12  * This program is distributed in the hope that it will be useful,
 13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
 14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 15  * GNU General Public License for more details.
 16  *
 17  * You should have received a copy of the GNU General Public License
 18  * along with this program; if not, write to the Free Software
 19  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 20  */
 21 
 22 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 23 
 24 #include <linux/kernel.h>
 25 #include <linux/audit.h>
 26 #include <linux/kthread.h>
 27 #include <linux/mutex.h>
 28 #include <linux/fs.h>
 29 #include <linux/namei.h>
 30 #include <linux/netlink.h>
 31 #include <linux/sched.h>
 32 #include <linux/slab.h>
 33 #include <linux/security.h>
 34 #include <net/net_namespace.h>
 35 #include <net/sock.h>
 36 #include "audit.h"
 37 
 38 /*
 39  * Locking model:
 40  *
 41  * audit_filter_mutex:
 42  *              Synchronizes writes and blocking reads of audit's filterlist
 43  *              data.  Rcu is used to traverse the filterlist and access
 44  *              contents of structs audit_entry, audit_watch and opaque
 45  *              LSM rules during filtering.  If modified, these structures
 46  *              must be copied and replace their counterparts in the filterlist.
 47  *              An audit_parent struct is not accessed during filtering, so may
 48  *              be written directly provided audit_filter_mutex is held.
 49  */
 50 
 51 /* Audit filter lists, defined in <linux/audit.h> */
 52 struct list_head audit_filter_list[AUDIT_NR_FILTERS] = {
 53         LIST_HEAD_INIT(audit_filter_list[0]),
 54         LIST_HEAD_INIT(audit_filter_list[1]),
 55         LIST_HEAD_INIT(audit_filter_list[2]),
 56         LIST_HEAD_INIT(audit_filter_list[3]),
 57         LIST_HEAD_INIT(audit_filter_list[4]),
 58         LIST_HEAD_INIT(audit_filter_list[5]),
 59 #if AUDIT_NR_FILTERS != 6
 60 #error Fix audit_filter_list initialiser
 61 #endif
 62 };
 63 static struct list_head audit_rules_list[AUDIT_NR_FILTERS] = {
 64         LIST_HEAD_INIT(audit_rules_list[0]),
 65         LIST_HEAD_INIT(audit_rules_list[1]),
 66         LIST_HEAD_INIT(audit_rules_list[2]),
 67         LIST_HEAD_INIT(audit_rules_list[3]),
 68         LIST_HEAD_INIT(audit_rules_list[4]),
 69         LIST_HEAD_INIT(audit_rules_list[5]),
 70 };
 71 
 72 DEFINE_MUTEX(audit_filter_mutex);
 73 
 74 static void audit_free_lsm_field(struct audit_field *f)
 75 {
 76         switch (f->type) {
 77         case AUDIT_SUBJ_USER:
 78         case AUDIT_SUBJ_ROLE:
 79         case AUDIT_SUBJ_TYPE:
 80         case AUDIT_SUBJ_SEN:
 81         case AUDIT_SUBJ_CLR:
 82         case AUDIT_OBJ_USER:
 83         case AUDIT_OBJ_ROLE:
 84         case AUDIT_OBJ_TYPE:
 85         case AUDIT_OBJ_LEV_LOW:
 86         case AUDIT_OBJ_LEV_HIGH:
 87                 kfree(f->lsm_str);
 88                 security_audit_rule_free(f->lsm_rule);
 89         }
 90 }
 91 
 92 static inline void audit_free_rule(struct audit_entry *e)
 93 {
 94         int i;
 95         struct audit_krule *erule = &e->rule;
 96 
 97         /* some rules don't have associated watches */
 98         if (erule->watch)
 99                 audit_put_watch(erule->watch);
100         if (erule->fields)
101                 for (i = 0; i < erule->field_count; i++)
102                         audit_free_lsm_field(&erule->fields[i]);
103         kfree(erule->fields);
104         kfree(erule->filterkey);
105         kfree(e);
106 }
107 
108 void audit_free_rule_rcu(struct rcu_head *head)
109 {
110         struct audit_entry *e = container_of(head, struct audit_entry, rcu);
111         audit_free_rule(e);
112 }
113 
114 /* Initialize an audit filterlist entry. */
115 static inline struct audit_entry *audit_init_entry(u32 field_count)
116 {
117         struct audit_entry *entry;
118         struct audit_field *fields;
119 
120         entry = kzalloc(sizeof(*entry), GFP_KERNEL);
121         if (unlikely(!entry))
122                 return NULL;
123 
124         fields = kcalloc(field_count, sizeof(*fields), GFP_KERNEL);
125         if (unlikely(!fields)) {
126                 kfree(entry);
127                 return NULL;
128         }
129         entry->rule.fields = fields;
130 
131         return entry;
132 }
133 
134 /* Unpack a filter field's string representation from user-space
135  * buffer. */
136 char *audit_unpack_string(void **bufp, size_t *remain, size_t len)
137 {
138         char *str;
139 
140         if (!*bufp || (len == 0) || (len > *remain))
141                 return ERR_PTR(-EINVAL);
142 
143         /* Of the currently implemented string fields, PATH_MAX
144          * defines the longest valid length.
145          */
146         if (len > PATH_MAX)
147                 return ERR_PTR(-ENAMETOOLONG);
148 
149         str = kmalloc(len + 1, GFP_KERNEL);
150         if (unlikely(!str))
151                 return ERR_PTR(-ENOMEM);
152 
153         memcpy(str, *bufp, len);
154         str[len] = 0;
155         *bufp += len;
156         *remain -= len;
157 
158         return str;
159 }
160 
161 /* Translate an inode field to kernel representation. */
162 static inline int audit_to_inode(struct audit_krule *krule,
163                                  struct audit_field *f)
164 {
165         if (krule->listnr != AUDIT_FILTER_EXIT ||
166             krule->inode_f || krule->watch || krule->tree ||
167             (f->op != Audit_equal && f->op != Audit_not_equal))
168                 return -EINVAL;
169 
170         krule->inode_f = f;
171         return 0;
172 }
173 
174 static __u32 *classes[AUDIT_SYSCALL_CLASSES];
175 
176 int __init audit_register_class(int class, unsigned *list)
177 {
178         __u32 *p = kcalloc(AUDIT_BITMASK_SIZE, sizeof(__u32), GFP_KERNEL);
179         if (!p)
180                 return -ENOMEM;
181         while (*list != ~0U) {
182                 unsigned n = *list++;
183                 if (n >= AUDIT_BITMASK_SIZE * 32 - AUDIT_SYSCALL_CLASSES) {
184                         kfree(p);
185                         return -EINVAL;
186                 }
187                 p[AUDIT_WORD(n)] |= AUDIT_BIT(n);
188         }
189         if (class >= AUDIT_SYSCALL_CLASSES || classes[class]) {
190                 kfree(p);
191                 return -EINVAL;
192         }
193         classes[class] = p;
194         return 0;
195 }
196 
197 int audit_match_class(int class, unsigned syscall)
198 {
199         if (unlikely(syscall >= AUDIT_BITMASK_SIZE * 32))
200                 return 0;
201         if (unlikely(class >= AUDIT_SYSCALL_CLASSES || !classes[class]))
202                 return 0;
203         return classes[class][AUDIT_WORD(syscall)] & AUDIT_BIT(syscall);
204 }
205 
206 #ifdef CONFIG_AUDITSYSCALL
207 static inline int audit_match_class_bits(int class, u32 *mask)
208 {
209         int i;
210 
211         if (classes[class]) {
212                 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
213                         if (mask[i] & classes[class][i])
214                                 return 0;
215         }
216         return 1;
217 }
218 
219 static int audit_match_signal(struct audit_entry *entry)
220 {
221         struct audit_field *arch = entry->rule.arch_f;
222 
223         if (!arch) {
224                 /* When arch is unspecified, we must check both masks on biarch
225                  * as syscall number alone is ambiguous. */
226                 return (audit_match_class_bits(AUDIT_CLASS_SIGNAL,
227                                                entry->rule.mask) &&
228                         audit_match_class_bits(AUDIT_CLASS_SIGNAL_32,
229                                                entry->rule.mask));
230         }
231 
232         switch(audit_classify_arch(arch->val)) {
233         case 0: /* native */
234                 return (audit_match_class_bits(AUDIT_CLASS_SIGNAL,
235                                                entry->rule.mask));
236         case 1: /* 32bit on biarch */
237                 return (audit_match_class_bits(AUDIT_CLASS_SIGNAL_32,
238                                                entry->rule.mask));
239         default:
240                 return 1;
241         }
242 }
243 #endif
244 
245 /* Common user-space to kernel rule translation. */
246 static inline struct audit_entry *audit_to_entry_common(struct audit_rule_data *rule)
247 {
248         unsigned listnr;
249         struct audit_entry *entry;
250         int i, err;
251 
252         err = -EINVAL;
253         listnr = rule->flags & ~AUDIT_FILTER_PREPEND;
254         switch(listnr) {
255         default:
256                 goto exit_err;
257 #ifdef CONFIG_AUDITSYSCALL
258         case AUDIT_FILTER_ENTRY:
259                 if (rule->action == AUDIT_ALWAYS)
260                         goto exit_err;
261         case AUDIT_FILTER_EXIT:
262         case AUDIT_FILTER_TASK:
263 #endif
264         case AUDIT_FILTER_USER:
265         case AUDIT_FILTER_TYPE:
266                 ;
267         }
268         if (unlikely(rule->action == AUDIT_POSSIBLE)) {
269                 pr_err("AUDIT_POSSIBLE is deprecated\n");
270                 goto exit_err;
271         }
272         if (rule->action != AUDIT_NEVER && rule->action != AUDIT_ALWAYS)
273                 goto exit_err;
274         if (rule->field_count > AUDIT_MAX_FIELDS)
275                 goto exit_err;
276 
277         err = -ENOMEM;
278         entry = audit_init_entry(rule->field_count);
279         if (!entry)
280                 goto exit_err;
281 
282         entry->rule.flags = rule->flags & AUDIT_FILTER_PREPEND;
283         entry->rule.listnr = listnr;
284         entry->rule.action = rule->action;
285         entry->rule.field_count = rule->field_count;
286 
287         for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
288                 entry->rule.mask[i] = rule->mask[i];
289 
290         for (i = 0; i < AUDIT_SYSCALL_CLASSES; i++) {
291                 int bit = AUDIT_BITMASK_SIZE * 32 - i - 1;
292                 __u32 *p = &entry->rule.mask[AUDIT_WORD(bit)];
293                 __u32 *class;
294 
295                 if (!(*p & AUDIT_BIT(bit)))
296                         continue;
297                 *p &= ~AUDIT_BIT(bit);
298                 class = classes[i];
299                 if (class) {
300                         int j;
301                         for (j = 0; j < AUDIT_BITMASK_SIZE; j++)
302                                 entry->rule.mask[j] |= class[j];
303                 }
304         }
305 
306         return entry;
307 
308 exit_err:
309         return ERR_PTR(err);
310 }
311 
312 static u32 audit_ops[] =
313 {
314         [Audit_equal] = AUDIT_EQUAL,
315         [Audit_not_equal] = AUDIT_NOT_EQUAL,
316         [Audit_bitmask] = AUDIT_BIT_MASK,
317         [Audit_bittest] = AUDIT_BIT_TEST,
318         [Audit_lt] = AUDIT_LESS_THAN,
319         [Audit_gt] = AUDIT_GREATER_THAN,
320         [Audit_le] = AUDIT_LESS_THAN_OR_EQUAL,
321         [Audit_ge] = AUDIT_GREATER_THAN_OR_EQUAL,
322 };
323 
324 static u32 audit_to_op(u32 op)
325 {
326         u32 n;
327         for (n = Audit_equal; n < Audit_bad && audit_ops[n] != op; n++)
328                 ;
329         return n;
330 }
331 
332 /* check if an audit field is valid */
333 static int audit_field_valid(struct audit_entry *entry, struct audit_field *f)
334 {
335         switch(f->type) {
336         case AUDIT_MSGTYPE:
337                 if (entry->rule.listnr != AUDIT_FILTER_TYPE &&
338                     entry->rule.listnr != AUDIT_FILTER_USER)
339                         return -EINVAL;
340                 break;
341         };
342 
343         switch(f->type) {
344         default:
345                 return -EINVAL;
346         case AUDIT_UID:
347         case AUDIT_EUID:
348         case AUDIT_SUID:
349         case AUDIT_FSUID:
350         case AUDIT_LOGINUID:
351         case AUDIT_OBJ_UID:
352         case AUDIT_GID:
353         case AUDIT_EGID:
354         case AUDIT_SGID:
355         case AUDIT_FSGID:
356         case AUDIT_OBJ_GID:
357         case AUDIT_PID:
358         case AUDIT_PERS:
359         case AUDIT_MSGTYPE:
360         case AUDIT_PPID:
361         case AUDIT_DEVMAJOR:
362         case AUDIT_DEVMINOR:
363         case AUDIT_EXIT:
364         case AUDIT_SUCCESS:
365         case AUDIT_INODE:
366                 /* bit ops are only useful on syscall args */
367                 if (f->op == Audit_bitmask || f->op == Audit_bittest)
368                         return -EINVAL;
369                 break;
370         case AUDIT_ARG0:
371         case AUDIT_ARG1:
372         case AUDIT_ARG2:
373         case AUDIT_ARG3:
374         case AUDIT_SUBJ_USER:
375         case AUDIT_SUBJ_ROLE:
376         case AUDIT_SUBJ_TYPE:
377         case AUDIT_SUBJ_SEN:
378         case AUDIT_SUBJ_CLR:
379         case AUDIT_OBJ_USER:
380         case AUDIT_OBJ_ROLE:
381         case AUDIT_OBJ_TYPE:
382         case AUDIT_OBJ_LEV_LOW:
383         case AUDIT_OBJ_LEV_HIGH:
384         case AUDIT_WATCH:
385         case AUDIT_DIR:
386         case AUDIT_FILTERKEY:
387                 break;
388         case AUDIT_LOGINUID_SET:
389                 if ((f->val != 0) && (f->val != 1))
390                         return -EINVAL;
391         /* FALL THROUGH */
392         case AUDIT_ARCH:
393                 if (f->op != Audit_not_equal && f->op != Audit_equal)
394                         return -EINVAL;
395                 break;
396         case AUDIT_PERM:
397                 if (f->val & ~15)
398                         return -EINVAL;
399                 break;
400         case AUDIT_FILETYPE:
401                 if (f->val & ~S_IFMT)
402                         return -EINVAL;
403                 break;
404         case AUDIT_FIELD_COMPARE:
405                 if (f->val > AUDIT_MAX_FIELD_COMPARE)
406                         return -EINVAL;
407                 break;
408         case AUDIT_EXE:
409                 if (f->op != Audit_equal)
410                         return -EINVAL;
411                 if (entry->rule.listnr != AUDIT_FILTER_EXIT)
412                         return -EINVAL;
413                 break;
414         };
415         return 0;
416 }
417 
418 /* Translate struct audit_rule_data to kernel's rule representation. */
419 static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data,
420                                                size_t datasz)
421 {
422         int err = 0;
423         struct audit_entry *entry;
424         void *bufp;
425         size_t remain = datasz - sizeof(struct audit_rule_data);
426         int i;
427         char *str;
428         struct audit_fsnotify_mark *audit_mark;
429 
430         entry = audit_to_entry_common(data);
431         if (IS_ERR(entry))
432                 goto exit_nofree;
433 
434         bufp = data->buf;
435         for (i = 0; i < data->field_count; i++) {
436                 struct audit_field *f = &entry->rule.fields[i];
437 
438                 err = -EINVAL;
439 
440                 f->op = audit_to_op(data->fieldflags[i]);
441                 if (f->op == Audit_bad)
442                         goto exit_free;
443 
444                 f->type = data->fields[i];
445                 f->val = data->values[i];
446 
447                 /* Support legacy tests for a valid loginuid */
448                 if ((f->type == AUDIT_LOGINUID) && (f->val == AUDIT_UID_UNSET)) {
449                         f->type = AUDIT_LOGINUID_SET;
450                         f->val = 0;
451                         entry->rule.pflags |= AUDIT_LOGINUID_LEGACY;
452                 }
453 
454                 err = audit_field_valid(entry, f);
455                 if (err)
456                         goto exit_free;
457 
458                 err = -EINVAL;
459                 switch (f->type) {
460                 case AUDIT_LOGINUID:
461                 case AUDIT_UID:
462                 case AUDIT_EUID:
463                 case AUDIT_SUID:
464                 case AUDIT_FSUID:
465                 case AUDIT_OBJ_UID:
466                         f->uid = make_kuid(current_user_ns(), f->val);
467                         if (!uid_valid(f->uid))
468                                 goto exit_free;
469                         break;
470                 case AUDIT_GID:
471                 case AUDIT_EGID:
472                 case AUDIT_SGID:
473                 case AUDIT_FSGID:
474                 case AUDIT_OBJ_GID:
475                         f->gid = make_kgid(current_user_ns(), f->val);
476                         if (!gid_valid(f->gid))
477                                 goto exit_free;
478                         break;
479                 case AUDIT_ARCH:
480                         entry->rule.arch_f = f;
481                         break;
482                 case AUDIT_SUBJ_USER:
483                 case AUDIT_SUBJ_ROLE:
484                 case AUDIT_SUBJ_TYPE:
485                 case AUDIT_SUBJ_SEN:
486                 case AUDIT_SUBJ_CLR:
487                 case AUDIT_OBJ_USER:
488                 case AUDIT_OBJ_ROLE:
489                 case AUDIT_OBJ_TYPE:
490                 case AUDIT_OBJ_LEV_LOW:
491                 case AUDIT_OBJ_LEV_HIGH:
492                         str = audit_unpack_string(&bufp, &remain, f->val);
493                         if (IS_ERR(str))
494                                 goto exit_free;
495                         entry->rule.buflen += f->val;
496 
497                         err = security_audit_rule_init(f->type, f->op, str,
498                                                        (void **)&f->lsm_rule);
499                         /* Keep currently invalid fields around in case they
500                          * become valid after a policy reload. */
501                         if (err == -EINVAL) {
502                                 pr_warn("audit rule for LSM \'%s\' is invalid\n",
503                                         str);
504                                 err = 0;
505                         }
506                         if (err) {
507                                 kfree(str);
508                                 goto exit_free;
509                         } else
510                                 f->lsm_str = str;
511                         break;
512                 case AUDIT_WATCH:
513                         str = audit_unpack_string(&bufp, &remain, f->val);
514                         if (IS_ERR(str))
515                                 goto exit_free;
516                         entry->rule.buflen += f->val;
517 
518                         err = audit_to_watch(&entry->rule, str, f->val, f->op);
519                         if (err) {
520                                 kfree(str);
521                                 goto exit_free;
522                         }
523                         break;
524                 case AUDIT_DIR:
525                         str = audit_unpack_string(&bufp, &remain, f->val);
526                         if (IS_ERR(str))
527                                 goto exit_free;
528                         entry->rule.buflen += f->val;
529 
530                         err = audit_make_tree(&entry->rule, str, f->op);
531                         kfree(str);
532                         if (err)
533                                 goto exit_free;
534                         break;
535                 case AUDIT_INODE:
536                         err = audit_to_inode(&entry->rule, f);
537                         if (err)
538                                 goto exit_free;
539                         break;
540                 case AUDIT_FILTERKEY:
541                         if (entry->rule.filterkey || f->val > AUDIT_MAX_KEY_LEN)
542                                 goto exit_free;
543                         str = audit_unpack_string(&bufp, &remain, f->val);
544                         if (IS_ERR(str))
545                                 goto exit_free;
546                         entry->rule.buflen += f->val;
547                         entry->rule.filterkey = str;
548                         break;
549                 case AUDIT_EXE:
550                         if (entry->rule.exe || f->val > PATH_MAX)
551                                 goto exit_free;
552                         str = audit_unpack_string(&bufp, &remain, f->val);
553                         if (IS_ERR(str)) {
554                                 err = PTR_ERR(str);
555                                 goto exit_free;
556                         }
557                         entry->rule.buflen += f->val;
558 
559                         audit_mark = audit_alloc_mark(&entry->rule, str, f->val);
560                         if (IS_ERR(audit_mark)) {
561                                 kfree(str);
562                                 err = PTR_ERR(audit_mark);
563                                 goto exit_free;
564                         }
565                         entry->rule.exe = audit_mark;
566                         break;
567                 }
568         }
569 
570         if (entry->rule.inode_f && entry->rule.inode_f->op == Audit_not_equal)
571                 entry->rule.inode_f = NULL;
572 
573 exit_nofree:
574         return entry;
575 
576 exit_free:
577         if (entry->rule.tree)
578                 audit_put_tree(entry->rule.tree); /* that's the temporary one */
579         if (entry->rule.exe)
580                 audit_remove_mark(entry->rule.exe); /* that's the template one */
581         audit_free_rule(entry);
582         return ERR_PTR(err);
583 }
584 
585 /* Pack a filter field's string representation into data block. */
586 static inline size_t audit_pack_string(void **bufp, const char *str)
587 {
588         size_t len = strlen(str);
589 
590         memcpy(*bufp, str, len);
591         *bufp += len;
592 
593         return len;
594 }
595 
596 /* Translate kernel rule representation to struct audit_rule_data. */
597 static struct audit_rule_data *audit_krule_to_data(struct audit_krule *krule)
598 {
599         struct audit_rule_data *data;
600         void *bufp;
601         int i;
602 
603         data = kmalloc(sizeof(*data) + krule->buflen, GFP_KERNEL);
604         if (unlikely(!data))
605                 return NULL;
606         memset(data, 0, sizeof(*data));
607 
608         data->flags = krule->flags | krule->listnr;
609         data->action = krule->action;
610         data->field_count = krule->field_count;
611         bufp = data->buf;
612         for (i = 0; i < data->field_count; i++) {
613                 struct audit_field *f = &krule->fields[i];
614 
615                 data->fields[i] = f->type;
616                 data->fieldflags[i] = audit_ops[f->op];
617                 switch(f->type) {
618                 case AUDIT_SUBJ_USER:
619                 case AUDIT_SUBJ_ROLE:
620                 case AUDIT_SUBJ_TYPE:
621                 case AUDIT_SUBJ_SEN:
622                 case AUDIT_SUBJ_CLR:
623                 case AUDIT_OBJ_USER:
624                 case AUDIT_OBJ_ROLE:
625                 case AUDIT_OBJ_TYPE:
626                 case AUDIT_OBJ_LEV_LOW:
627                 case AUDIT_OBJ_LEV_HIGH:
628                         data->buflen += data->values[i] =
629                                 audit_pack_string(&bufp, f->lsm_str);
630                         break;
631                 case AUDIT_WATCH:
632                         data->buflen += data->values[i] =
633                                 audit_pack_string(&bufp,
634                                                   audit_watch_path(krule->watch));
635                         break;
636                 case AUDIT_DIR:
637                         data->buflen += data->values[i] =
638                                 audit_pack_string(&bufp,
639                                                   audit_tree_path(krule->tree));
640                         break;
641                 case AUDIT_FILTERKEY:
642                         data->buflen += data->values[i] =
643                                 audit_pack_string(&bufp, krule->filterkey);
644                         break;
645                 case AUDIT_EXE:
646                         data->buflen += data->values[i] =
647                                 audit_pack_string(&bufp, audit_mark_path(krule->exe));
648                         break;
649                 case AUDIT_LOGINUID_SET:
650                         if (krule->pflags & AUDIT_LOGINUID_LEGACY && !f->val) {
651                                 data->fields[i] = AUDIT_LOGINUID;
652                                 data->values[i] = AUDIT_UID_UNSET;
653                                 break;
654                         }
655                         /* fallthrough if set */
656                 default:
657                         data->values[i] = f->val;
658                 }
659         }
660         for (i = 0; i < AUDIT_BITMASK_SIZE; i++) data->mask[i] = krule->mask[i];
661 
662         return data;
663 }
664 
665 /* Compare two rules in kernel format.  Considered success if rules
666  * don't match. */
667 static int audit_compare_rule(struct audit_krule *a, struct audit_krule *b)
668 {
669         int i;
670 
671         if (a->flags != b->flags ||
672             a->pflags != b->pflags ||
673             a->listnr != b->listnr ||
674             a->action != b->action ||
675             a->field_count != b->field_count)
676                 return 1;
677 
678         for (i = 0; i < a->field_count; i++) {
679                 if (a->fields[i].type != b->fields[i].type ||
680                     a->fields[i].op != b->fields[i].op)
681                         return 1;
682 
683                 switch(a->fields[i].type) {
684                 case AUDIT_SUBJ_USER:
685                 case AUDIT_SUBJ_ROLE:
686                 case AUDIT_SUBJ_TYPE:
687                 case AUDIT_SUBJ_SEN:
688                 case AUDIT_SUBJ_CLR:
689                 case AUDIT_OBJ_USER:
690                 case AUDIT_OBJ_ROLE:
691                 case AUDIT_OBJ_TYPE:
692                 case AUDIT_OBJ_LEV_LOW:
693                 case AUDIT_OBJ_LEV_HIGH:
694                         if (strcmp(a->fields[i].lsm_str, b->fields[i].lsm_str))
695                                 return 1;
696                         break;
697                 case AUDIT_WATCH:
698                         if (strcmp(audit_watch_path(a->watch),
699                                    audit_watch_path(b->watch)))
700                                 return 1;
701                         break;
702                 case AUDIT_DIR:
703                         if (strcmp(audit_tree_path(a->tree),
704                                    audit_tree_path(b->tree)))
705                                 return 1;
706                         break;
707                 case AUDIT_FILTERKEY:
708                         /* both filterkeys exist based on above type compare */
709                         if (strcmp(a->filterkey, b->filterkey))
710                                 return 1;
711                         break;
712                 case AUDIT_EXE:
713                         /* both paths exist based on above type compare */
714                         if (strcmp(audit_mark_path(a->exe),
715                                    audit_mark_path(b->exe)))
716                                 return 1;
717                         break;
718                 case AUDIT_UID:
719                 case AUDIT_EUID:
720                 case AUDIT_SUID:
721                 case AUDIT_FSUID:
722                 case AUDIT_LOGINUID:
723                 case AUDIT_OBJ_UID:
724                         if (!uid_eq(a->fields[i].uid, b->fields[i].uid))
725                                 return 1;
726                         break;
727                 case AUDIT_GID:
728                 case AUDIT_EGID:
729                 case AUDIT_SGID:
730                 case AUDIT_FSGID:
731                 case AUDIT_OBJ_GID:
732                         if (!gid_eq(a->fields[i].gid, b->fields[i].gid))
733                                 return 1;
734                         break;
735                 default:
736                         if (a->fields[i].val != b->fields[i].val)
737                                 return 1;
738                 }
739         }
740 
741         for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
742                 if (a->mask[i] != b->mask[i])
743                         return 1;
744 
745         return 0;
746 }
747 
748 /* Duplicate LSM field information.  The lsm_rule is opaque, so must be
749  * re-initialized. */
750 static inline int audit_dupe_lsm_field(struct audit_field *df,
751                                            struct audit_field *sf)
752 {
753         int ret = 0;
754         char *lsm_str;
755 
756         /* our own copy of lsm_str */
757         lsm_str = kstrdup(sf->lsm_str, GFP_KERNEL);
758         if (unlikely(!lsm_str))
759                 return -ENOMEM;
760         df->lsm_str = lsm_str;
761 
762         /* our own (refreshed) copy of lsm_rule */
763         ret = security_audit_rule_init(df->type, df->op, df->lsm_str,
764                                        (void **)&df->lsm_rule);
765         /* Keep currently invalid fields around in case they
766          * become valid after a policy reload. */
767         if (ret == -EINVAL) {
768                 pr_warn("audit rule for LSM \'%s\' is invalid\n",
769                         df->lsm_str);
770                 ret = 0;
771         }
772 
773         return ret;
774 }
775 
776 /* Duplicate an audit rule.  This will be a deep copy with the exception
777  * of the watch - that pointer is carried over.  The LSM specific fields
778  * will be updated in the copy.  The point is to be able to replace the old
779  * rule with the new rule in the filterlist, then free the old rule.
780  * The rlist element is undefined; list manipulations are handled apart from
781  * the initial copy. */
782 struct audit_entry *audit_dupe_rule(struct audit_krule *old)
783 {
784         u32 fcount = old->field_count;
785         struct audit_entry *entry;
786         struct audit_krule *new;
787         char *fk;
788         int i, err = 0;
789 
790         entry = audit_init_entry(fcount);
791         if (unlikely(!entry))
792                 return ERR_PTR(-ENOMEM);
793 
794         new = &entry->rule;
795         new->flags = old->flags;
796         new->pflags = old->pflags;
797         new->listnr = old->listnr;
798         new->action = old->action;
799         for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
800                 new->mask[i] = old->mask[i];
801         new->prio = old->prio;
802         new->buflen = old->buflen;
803         new->inode_f = old->inode_f;
804         new->field_count = old->field_count;
805 
806         /*
807          * note that we are OK with not refcounting here; audit_match_tree()
808          * never dereferences tree and we can't get false positives there
809          * since we'd have to have rule gone from the list *and* removed
810          * before the chunks found by lookup had been allocated, i.e. before
811          * the beginning of list scan.
812          */
813         new->tree = old->tree;
814         memcpy(new->fields, old->fields, sizeof(struct audit_field) * fcount);
815 
816         /* deep copy this information, updating the lsm_rule fields, because
817          * the originals will all be freed when the old rule is freed. */
818         for (i = 0; i < fcount; i++) {
819                 switch (new->fields[i].type) {
820                 case AUDIT_SUBJ_USER:
821                 case AUDIT_SUBJ_ROLE:
822                 case AUDIT_SUBJ_TYPE:
823                 case AUDIT_SUBJ_SEN:
824                 case AUDIT_SUBJ_CLR:
825                 case AUDIT_OBJ_USER:
826                 case AUDIT_OBJ_ROLE:
827                 case AUDIT_OBJ_TYPE:
828                 case AUDIT_OBJ_LEV_LOW:
829                 case AUDIT_OBJ_LEV_HIGH:
830                         err = audit_dupe_lsm_field(&new->fields[i],
831                                                        &old->fields[i]);
832                         break;
833                 case AUDIT_FILTERKEY:
834                         fk = kstrdup(old->filterkey, GFP_KERNEL);
835                         if (unlikely(!fk))
836                                 err = -ENOMEM;
837                         else
838                                 new->filterkey = fk;
839                         break;
840                 case AUDIT_EXE:
841                         err = audit_dupe_exe(new, old);
842                         break;
843                 }
844                 if (err) {
845                         if (new->exe)
846                                 audit_remove_mark(new->exe);
847                         audit_free_rule(entry);
848                         return ERR_PTR(err);
849                 }
850         }
851 
852         if (old->watch) {
853                 audit_get_watch(old->watch);
854                 new->watch = old->watch;
855         }
856 
857         return entry;
858 }
859 
860 /* Find an existing audit rule.
861  * Caller must hold audit_filter_mutex to prevent stale rule data. */
862 static struct audit_entry *audit_find_rule(struct audit_entry *entry,
863                                            struct list_head **p)
864 {
865         struct audit_entry *e, *found = NULL;
866         struct list_head *list;
867         int h;
868 
869         if (entry->rule.inode_f) {
870                 h = audit_hash_ino(entry->rule.inode_f->val);
871                 *p = list = &audit_inode_hash[h];
872         } else if (entry->rule.watch) {
873                 /* we don't know the inode number, so must walk entire hash */
874                 for (h = 0; h < AUDIT_INODE_BUCKETS; h++) {
875                         list = &audit_inode_hash[h];
876                         list_for_each_entry(e, list, list)
877                                 if (!audit_compare_rule(&entry->rule, &e->rule)) {
878                                         found = e;
879                                         goto out;
880                                 }
881                 }
882                 goto out;
883         } else {
884                 *p = list = &audit_filter_list[entry->rule.listnr];
885         }
886 
887         list_for_each_entry(e, list, list)
888                 if (!audit_compare_rule(&entry->rule, &e->rule)) {
889                         found = e;
890                         goto out;
891                 }
892 
893 out:
894         return found;
895 }
896 
897 static u64 prio_low = ~0ULL/2;
898 static u64 prio_high = ~0ULL/2 - 1;
899 
900 /* Add rule to given filterlist if not a duplicate. */
901 static inline int audit_add_rule(struct audit_entry *entry)
902 {
903         struct audit_entry *e;
904         struct audit_watch *watch = entry->rule.watch;
905         struct audit_tree *tree = entry->rule.tree;
906         struct list_head *list;
907         int err = 0;
908 #ifdef CONFIG_AUDITSYSCALL
909         int dont_count = 0;
910 
911         /* If either of these, don't count towards total */
912         if (entry->rule.listnr == AUDIT_FILTER_USER ||
913                 entry->rule.listnr == AUDIT_FILTER_TYPE)
914                 dont_count = 1;
915 #endif
916 
917         mutex_lock(&audit_filter_mutex);
918         e = audit_find_rule(entry, &list);
919         if (e) {
920                 mutex_unlock(&audit_filter_mutex);
921                 err = -EEXIST;
922                 /* normally audit_add_tree_rule() will free it on failure */
923                 if (tree)
924                         audit_put_tree(tree);
925                 return err;
926         }
927 
928         if (watch) {
929                 /* audit_filter_mutex is dropped and re-taken during this call */
930                 err = audit_add_watch(&entry->rule, &list);
931                 if (err) {
932                         mutex_unlock(&audit_filter_mutex);
933                         /*
934                          * normally audit_add_tree_rule() will free it
935                          * on failure
936                          */
937                         if (tree)
938                                 audit_put_tree(tree);
939                         return err;
940                 }
941         }
942         if (tree) {
943                 err = audit_add_tree_rule(&entry->rule);
944                 if (err) {
945                         mutex_unlock(&audit_filter_mutex);
946                         return err;
947                 }
948         }
949 
950         entry->rule.prio = ~0ULL;
951         if (entry->rule.listnr == AUDIT_FILTER_EXIT) {
952                 if (entry->rule.flags & AUDIT_FILTER_PREPEND)
953                         entry->rule.prio = ++prio_high;
954                 else
955                         entry->rule.prio = --prio_low;
956         }
957 
958         if (entry->rule.flags & AUDIT_FILTER_PREPEND) {
959                 list_add(&entry->rule.list,
960                          &audit_rules_list[entry->rule.listnr]);
961                 list_add_rcu(&entry->list, list);
962                 entry->rule.flags &= ~AUDIT_FILTER_PREPEND;
963         } else {
964                 list_add_tail(&entry->rule.list,
965                               &audit_rules_list[entry->rule.listnr]);
966                 list_add_tail_rcu(&entry->list, list);
967         }
968 #ifdef CONFIG_AUDITSYSCALL
969         if (!dont_count)
970                 audit_n_rules++;
971 
972         if (!audit_match_signal(entry))
973                 audit_signals++;
974 #endif
975         mutex_unlock(&audit_filter_mutex);
976 
977         return err;
978 }
979 
980 /* Remove an existing rule from filterlist. */
981 int audit_del_rule(struct audit_entry *entry)
982 {
983         struct audit_entry  *e;
984         struct audit_tree *tree = entry->rule.tree;
985         struct list_head *list;
986         int ret = 0;
987 #ifdef CONFIG_AUDITSYSCALL
988         int dont_count = 0;
989 
990         /* If either of these, don't count towards total */
991         if (entry->rule.listnr == AUDIT_FILTER_USER ||
992                 entry->rule.listnr == AUDIT_FILTER_TYPE)
993                 dont_count = 1;
994 #endif
995 
996         mutex_lock(&audit_filter_mutex);
997         e = audit_find_rule(entry, &list);
998         if (!e) {
999                 ret = -ENOENT;
1000                 goto out;
1001         }
1002 
1003         if (e->rule.watch)
1004                 audit_remove_watch_rule(&e->rule);
1005 
1006         if (e->rule.tree)
1007                 audit_remove_tree_rule(&e->rule);
1008 
1009         if (e->rule.exe)
1010                 audit_remove_mark_rule(&e->rule);
1011 
1012 #ifdef CONFIG_AUDITSYSCALL
1013         if (!dont_count)
1014                 audit_n_rules--;
1015 
1016         if (!audit_match_signal(entry))
1017                 audit_signals--;
1018 #endif
1019 
1020         list_del_rcu(&e->list);
1021         list_del(&e->rule.list);
1022         call_rcu(&e->rcu, audit_free_rule_rcu);
1023 
1024 out:
1025         mutex_unlock(&audit_filter_mutex);
1026 
1027         if (tree)
1028                 audit_put_tree(tree);   /* that's the temporary one */
1029 
1030         return ret;
1031 }
1032 
1033 /* List rules using struct audit_rule_data. */
1034 static void audit_list_rules(__u32 portid, int seq, struct sk_buff_head *q)
1035 {
1036         struct sk_buff *skb;
1037         struct audit_krule *r;
1038         int i;
1039 
1040         /* This is a blocking read, so use audit_filter_mutex instead of rcu
1041          * iterator to sync with list writers. */
1042         for (i=0; i<AUDIT_NR_FILTERS; i++) {
1043                 list_for_each_entry(r, &audit_rules_list[i], list) {
1044                         struct audit_rule_data *data;
1045 
1046                         data = audit_krule_to_data(r);
1047                         if (unlikely(!data))
1048                                 break;
1049                         skb = audit_make_reply(portid, seq, AUDIT_LIST_RULES,
1050                                                0, 1, data,
1051                                                sizeof(*data) + data->buflen);
1052                         if (skb)
1053                                 skb_queue_tail(q, skb);
1054                         kfree(data);
1055                 }
1056         }
1057         skb = audit_make_reply(portid, seq, AUDIT_LIST_RULES, 1, 1, NULL, 0);
1058         if (skb)
1059                 skb_queue_tail(q, skb);
1060 }
1061 
1062 /* Log rule additions and removals */
1063 static void audit_log_rule_change(char *action, struct audit_krule *rule, int res)
1064 {
1065         struct audit_buffer *ab;
1066         uid_t loginuid = from_kuid(&init_user_ns, audit_get_loginuid(current));
1067         unsigned int sessionid = audit_get_sessionid(current);
1068 
1069         if (!audit_enabled)
1070                 return;
1071 
1072         ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
1073         if (!ab)
1074                 return;
1075         audit_log_format(ab, "auid=%u ses=%u" ,loginuid, sessionid);
1076         audit_log_task_context(ab);
1077         audit_log_format(ab, " op=");
1078         audit_log_string(ab, action);
1079         audit_log_key(ab, rule->filterkey);
1080         audit_log_format(ab, " list=%d res=%d", rule->listnr, res);
1081         audit_log_end(ab);
1082 }
1083 
1084 /**
1085  * audit_rule_change - apply all rules to the specified message type
1086  * @type: audit message type
1087  * @portid: target port id for netlink audit messages
1088  * @seq: netlink audit message sequence (serial) number
1089  * @data: payload data
1090  * @datasz: size of payload data
1091  */
1092 int audit_rule_change(int type, __u32 portid, int seq, void *data,
1093                         size_t datasz)
1094 {
1095         int err = 0;
1096         struct audit_entry *entry;
1097 
1098         entry = audit_data_to_entry(data, datasz);
1099         if (IS_ERR(entry))
1100                 return PTR_ERR(entry);
1101 
1102         switch (type) {
1103         case AUDIT_ADD_RULE:
1104                 err = audit_add_rule(entry);
1105                 audit_log_rule_change("add_rule", &entry->rule, !err);
1106                 break;
1107         case AUDIT_DEL_RULE:
1108                 err = audit_del_rule(entry);
1109                 audit_log_rule_change("remove_rule", &entry->rule, !err);
1110                 break;
1111         default:
1112                 err = -EINVAL;
1113                 WARN_ON(1);
1114         }
1115 
1116         if (err || type == AUDIT_DEL_RULE) {
1117                 if (entry->rule.exe)
1118                         audit_remove_mark(entry->rule.exe);
1119                 audit_free_rule(entry);
1120         }
1121 
1122         return err;
1123 }
1124 
1125 /**
1126  * audit_list_rules_send - list the audit rules
1127  * @request_skb: skb of request we are replying to (used to target the reply)
1128  * @seq: netlink audit message sequence (serial) number
1129  */
1130 int audit_list_rules_send(struct sk_buff *request_skb, int seq)
1131 {
1132         u32 portid = NETLINK_CB(request_skb).portid;
1133         struct net *net = sock_net(NETLINK_CB(request_skb).sk);
1134         struct task_struct *tsk;
1135         struct audit_netlink_list *dest;
1136         int err = 0;
1137 
1138         /* We can't just spew out the rules here because we might fill
1139          * the available socket buffer space and deadlock waiting for
1140          * auditctl to read from it... which isn't ever going to
1141          * happen if we're actually running in the context of auditctl
1142          * trying to _send_ the stuff */
1143 
1144         dest = kmalloc(sizeof(struct audit_netlink_list), GFP_KERNEL);
1145         if (!dest)
1146                 return -ENOMEM;
1147         dest->net = get_net(net);
1148         dest->portid = portid;
1149         skb_queue_head_init(&dest->q);
1150 
1151         mutex_lock(&audit_filter_mutex);
1152         audit_list_rules(portid, seq, &dest->q);
1153         mutex_unlock(&audit_filter_mutex);
1154 
1155         tsk = kthread_run(audit_send_list, dest, "audit_send_list");
1156         if (IS_ERR(tsk)) {
1157                 skb_queue_purge(&dest->q);
1158                 kfree(dest);
1159                 err = PTR_ERR(tsk);
1160         }
1161 
1162         return err;
1163 }
1164 
1165 int audit_comparator(u32 left, u32 op, u32 right)
1166 {
1167         switch (op) {
1168         case Audit_equal:
1169                 return (left == right);
1170         case Audit_not_equal:
1171                 return (left != right);
1172         case Audit_lt:
1173                 return (left < right);
1174         case Audit_le:
1175                 return (left <= right);
1176         case Audit_gt:
1177                 return (left > right);
1178         case Audit_ge:
1179                 return (left >= right);
1180         case Audit_bitmask:
1181                 return (left & right);
1182         case Audit_bittest:
1183                 return ((left & right) == right);
1184         default:
1185                 BUG();
1186                 return 0;
1187         }
1188 }
1189 
1190 int audit_uid_comparator(kuid_t left, u32 op, kuid_t right)
1191 {
1192         switch (op) {
1193         case Audit_equal:
1194                 return uid_eq(left, right);
1195         case Audit_not_equal:
1196                 return !uid_eq(left, right);
1197         case Audit_lt:
1198                 return uid_lt(left, right);
1199         case Audit_le:
1200                 return uid_lte(left, right);
1201         case Audit_gt:
1202                 return uid_gt(left, right);
1203         case Audit_ge:
1204                 return uid_gte(left, right);
1205         case Audit_bitmask:
1206         case Audit_bittest:
1207         default:
1208                 BUG();
1209                 return 0;
1210         }
1211 }
1212 
1213 int audit_gid_comparator(kgid_t left, u32 op, kgid_t right)
1214 {
1215         switch (op) {
1216         case Audit_equal:
1217                 return gid_eq(left, right);
1218         case Audit_not_equal:
1219                 return !gid_eq(left, right);
1220         case Audit_lt:
1221                 return gid_lt(left, right);
1222         case Audit_le:
1223                 return gid_lte(left, right);
1224         case Audit_gt:
1225                 return gid_gt(left, right);
1226         case Audit_ge:
1227                 return gid_gte(left, right);
1228         case Audit_bitmask:
1229         case Audit_bittest:
1230         default:
1231                 BUG();
1232                 return 0;
1233         }
1234 }
1235 
1236 /**
1237  * parent_len - find the length of the parent portion of a pathname
1238  * @path: pathname of which to determine length
1239  */
1240 int parent_len(const char *path)
1241 {
1242         int plen;
1243         const char *p;
1244 
1245         plen = strlen(path);
1246 
1247         if (plen == 0)
1248                 return plen;
1249 
1250         /* disregard trailing slashes */
1251         p = path + plen - 1;
1252         while ((*p == '/') && (p > path))
1253                 p--;
1254 
1255         /* walk backward until we find the next slash or hit beginning */
1256         while ((*p != '/') && (p > path))
1257                 p--;
1258 
1259         /* did we find a slash? Then increment to include it in path */
1260         if (*p == '/')
1261                 p++;
1262 
1263         return p - path;
1264 }
1265 
1266 /**
1267  * audit_compare_dname_path - compare given dentry name with last component in
1268  *                            given path. Return of 0 indicates a match.
1269  * @dname:      dentry name that we're comparing
1270  * @path:       full pathname that we're comparing
1271  * @parentlen:  length of the parent if known. Passing in AUDIT_NAME_FULL
1272  *              here indicates that we must compute this value.
1273  */
1274 int audit_compare_dname_path(const char *dname, const char *path, int parentlen)
1275 {
1276         int dlen, pathlen;
1277         const char *p;
1278 
1279         dlen = strlen(dname);
1280         pathlen = strlen(path);
1281         if (pathlen < dlen)
1282                 return 1;
1283 
1284         parentlen = parentlen == AUDIT_NAME_FULL ? parent_len(path) : parentlen;
1285         if (pathlen - parentlen != dlen)
1286                 return 1;
1287 
1288         p = path + parentlen;
1289 
1290         return strncmp(p, dname, dlen);
1291 }
1292 
1293 static int audit_filter_user_rules(struct audit_krule *rule, int type,
1294                                    enum audit_state *state)
1295 {
1296         int i;
1297 
1298         for (i = 0; i < rule->field_count; i++) {
1299                 struct audit_field *f = &rule->fields[i];
1300                 pid_t pid;
1301                 int result = 0;
1302                 u32 sid;
1303 
1304                 switch (f->type) {
1305                 case AUDIT_PID:
1306                         pid = task_pid_nr(current);
1307                         result = audit_comparator(pid, f->op, f->val);
1308                         break;
1309                 case AUDIT_UID:
1310                         result = audit_uid_comparator(current_uid(), f->op, f->uid);
1311                         break;
1312                 case AUDIT_GID:
1313                         result = audit_gid_comparator(current_gid(), f->op, f->gid);
1314                         break;
1315                 case AUDIT_LOGINUID:
1316                         result = audit_uid_comparator(audit_get_loginuid(current),
1317                                                   f->op, f->uid);
1318                         break;
1319                 case AUDIT_LOGINUID_SET:
1320                         result = audit_comparator(audit_loginuid_set(current),
1321                                                   f->op, f->val);
1322                         break;
1323                 case AUDIT_MSGTYPE:
1324                         result = audit_comparator(type, f->op, f->val);
1325                         break;
1326                 case AUDIT_SUBJ_USER:
1327                 case AUDIT_SUBJ_ROLE:
1328                 case AUDIT_SUBJ_TYPE:
1329                 case AUDIT_SUBJ_SEN:
1330                 case AUDIT_SUBJ_CLR:
1331                         if (f->lsm_rule) {
1332                                 security_task_getsecid(current, &sid);
1333                                 result = security_audit_rule_match(sid,
1334                                                                    f->type,
1335                                                                    f->op,
1336                                                                    f->lsm_rule,
1337                                                                    NULL);
1338                         }
1339                         break;
1340                 }
1341 
1342                 if (!result)
1343                         return 0;
1344         }
1345         switch (rule->action) {
1346         case AUDIT_NEVER:    *state = AUDIT_DISABLED;       break;
1347         case AUDIT_ALWAYS:   *state = AUDIT_RECORD_CONTEXT; break;
1348         }
1349         return 1;
1350 }
1351 
1352 int audit_filter_user(int type)
1353 {
1354         enum audit_state state = AUDIT_DISABLED;
1355         struct audit_entry *e;
1356         int rc, ret;
1357 
1358         ret = 1; /* Audit by default */
1359 
1360         rcu_read_lock();
1361         list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_USER], list) {
1362                 rc = audit_filter_user_rules(&e->rule, type, &state);
1363                 if (rc) {
1364                         if (rc > 0 && state == AUDIT_DISABLED)
1365                                 ret = 0;
1366                         break;
1367                 }
1368         }
1369         rcu_read_unlock();
1370 
1371         return ret;
1372 }
1373 
1374 int audit_filter_type(int type)
1375 {
1376         struct audit_entry *e;
1377         int result = 0;
1378 
1379         rcu_read_lock();
1380         if (list_empty(&audit_filter_list[AUDIT_FILTER_TYPE]))
1381                 goto unlock_and_return;
1382 
1383         list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_TYPE],
1384                                 list) {
1385                 int i;
1386                 for (i = 0; i < e->rule.field_count; i++) {
1387                         struct audit_field *f = &e->rule.fields[i];
1388                         if (f->type == AUDIT_MSGTYPE) {
1389                                 result = audit_comparator(type, f->op, f->val);
1390                                 if (!result)
1391                                         break;
1392                         }
1393                 }
1394                 if (result)
1395                         goto unlock_and_return;
1396         }
1397 unlock_and_return:
1398         rcu_read_unlock();
1399         return result;
1400 }
1401 
1402 static int update_lsm_rule(struct audit_krule *r)
1403 {
1404         struct audit_entry *entry = container_of(r, struct audit_entry, rule);
1405         struct audit_entry *nentry;
1406         int err = 0;
1407 
1408         if (!security_audit_rule_known(r))
1409                 return 0;
1410 
1411         nentry = audit_dupe_rule(r);
1412         if (entry->rule.exe)
1413                 audit_remove_mark(entry->rule.exe);
1414         if (IS_ERR(nentry)) {
1415                 /* save the first error encountered for the
1416                  * return value */
1417                 err = PTR_ERR(nentry);
1418                 audit_panic("error updating LSM filters");
1419                 if (r->watch)
1420                         list_del(&r->rlist);
1421                 list_del_rcu(&entry->list);
1422                 list_del(&r->list);
1423         } else {
1424                 if (r->watch || r->tree)
1425                         list_replace_init(&r->rlist, &nentry->rule.rlist);
1426                 list_replace_rcu(&entry->list, &nentry->list);
1427                 list_replace(&r->list, &nentry->rule.list);
1428         }
1429         call_rcu(&entry->rcu, audit_free_rule_rcu);
1430 
1431         return err;
1432 }
1433 
1434 /* This function will re-initialize the lsm_rule field of all applicable rules.
1435  * It will traverse the filter lists serarching for rules that contain LSM
1436  * specific filter fields.  When such a rule is found, it is copied, the
1437  * LSM field is re-initialized, and the old rule is replaced with the
1438  * updated rule. */
1439 int audit_update_lsm_rules(void)
1440 {
1441         struct audit_krule *r, *n;
1442         int i, err = 0;
1443 
1444         /* audit_filter_mutex synchronizes the writers */
1445         mutex_lock(&audit_filter_mutex);
1446 
1447         for (i = 0; i < AUDIT_NR_FILTERS; i++) {
1448                 list_for_each_entry_safe(r, n, &audit_rules_list[i], list) {
1449                         int res = update_lsm_rule(r);
1450                         if (!err)
1451                                 err = res;
1452                 }
1453         }
1454         mutex_unlock(&audit_filter_mutex);
1455 
1456         return err;
1457 }
1458 

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