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Linux/kernel/auditsc.c

  1 /* auditsc.c -- System-call auditing support
  2  * Handles all system-call specific auditing features.
  3  *
  4  * Copyright 2003-2004 Red Hat Inc., Durham, North Carolina.
  5  * Copyright 2005 Hewlett-Packard Development Company, L.P.
  6  * Copyright (C) 2005, 2006 IBM Corporation
  7  * All Rights Reserved.
  8  *
  9  * This program is free software; you can redistribute it and/or modify
 10  * it under the terms of the GNU General Public License as published by
 11  * the Free Software Foundation; either version 2 of the License, or
 12  * (at your option) any later version.
 13  *
 14  * This program is distributed in the hope that it will be useful,
 15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
 16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 17  * GNU General Public License for more details.
 18  *
 19  * You should have received a copy of the GNU General Public License
 20  * along with this program; if not, write to the Free Software
 21  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 22  *
 23  * Written by Rickard E. (Rik) Faith <faith@redhat.com>
 24  *
 25  * Many of the ideas implemented here are from Stephen C. Tweedie,
 26  * especially the idea of avoiding a copy by using getname.
 27  *
 28  * The method for actual interception of syscall entry and exit (not in
 29  * this file -- see entry.S) is based on a GPL'd patch written by
 30  * okir@suse.de and Copyright 2003 SuSE Linux AG.
 31  *
 32  * POSIX message queue support added by George Wilson <ltcgcw@us.ibm.com>,
 33  * 2006.
 34  *
 35  * The support of additional filter rules compares (>, <, >=, <=) was
 36  * added by Dustin Kirkland <dustin.kirkland@us.ibm.com>, 2005.
 37  *
 38  * Modified by Amy Griffis <amy.griffis@hp.com> to collect additional
 39  * filesystem information.
 40  *
 41  * Subject and object context labeling support added by <danjones@us.ibm.com>
 42  * and <dustin.kirkland@us.ibm.com> for LSPP certification compliance.
 43  */
 44 
 45 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 46 
 47 #include <linux/init.h>
 48 #include <asm/types.h>
 49 #include <linux/atomic.h>
 50 #include <linux/fs.h>
 51 #include <linux/namei.h>
 52 #include <linux/mm.h>
 53 #include <linux/export.h>
 54 #include <linux/slab.h>
 55 #include <linux/mount.h>
 56 #include <linux/socket.h>
 57 #include <linux/mqueue.h>
 58 #include <linux/audit.h>
 59 #include <linux/personality.h>
 60 #include <linux/time.h>
 61 #include <linux/netlink.h>
 62 #include <linux/compiler.h>
 63 #include <asm/unistd.h>
 64 #include <linux/security.h>
 65 #include <linux/list.h>
 66 #include <linux/binfmts.h>
 67 #include <linux/highmem.h>
 68 #include <linux/syscalls.h>
 69 #include <asm/syscall.h>
 70 #include <linux/capability.h>
 71 #include <linux/fs_struct.h>
 72 #include <linux/compat.h>
 73 #include <linux/ctype.h>
 74 #include <linux/string.h>
 75 #include <linux/uaccess.h>
 76 #include <uapi/linux/limits.h>
 77 
 78 #include "audit.h"
 79 
 80 /* flags stating the success for a syscall */
 81 #define AUDITSC_INVALID 0
 82 #define AUDITSC_SUCCESS 1
 83 #define AUDITSC_FAILURE 2
 84 
 85 /* no execve audit message should be longer than this (userspace limits),
 86  * see the note near the top of audit_log_execve_info() about this value */
 87 #define MAX_EXECVE_AUDIT_LEN 7500
 88 
 89 /* max length to print of cmdline/proctitle value during audit */
 90 #define MAX_PROCTITLE_AUDIT_LEN 128
 91 
 92 /* number of audit rules */
 93 int audit_n_rules;
 94 
 95 /* determines whether we collect data for signals sent */
 96 int audit_signals;
 97 
 98 struct audit_aux_data {
 99         struct audit_aux_data   *next;
100         int                     type;
101 };
102 
103 #define AUDIT_AUX_IPCPERM       0
104 
105 /* Number of target pids per aux struct. */
106 #define AUDIT_AUX_PIDS  16
107 
108 struct audit_aux_data_pids {
109         struct audit_aux_data   d;
110         pid_t                   target_pid[AUDIT_AUX_PIDS];
111         kuid_t                  target_auid[AUDIT_AUX_PIDS];
112         kuid_t                  target_uid[AUDIT_AUX_PIDS];
113         unsigned int            target_sessionid[AUDIT_AUX_PIDS];
114         u32                     target_sid[AUDIT_AUX_PIDS];
115         char                    target_comm[AUDIT_AUX_PIDS][TASK_COMM_LEN];
116         int                     pid_count;
117 };
118 
119 struct audit_aux_data_bprm_fcaps {
120         struct audit_aux_data   d;
121         struct audit_cap_data   fcap;
122         unsigned int            fcap_ver;
123         struct audit_cap_data   old_pcap;
124         struct audit_cap_data   new_pcap;
125 };
126 
127 struct audit_tree_refs {
128         struct audit_tree_refs *next;
129         struct audit_chunk *c[31];
130 };
131 
132 static int audit_match_perm(struct audit_context *ctx, int mask)
133 {
134         unsigned n;
135         if (unlikely(!ctx))
136                 return 0;
137         n = ctx->major;
138 
139         switch (audit_classify_syscall(ctx->arch, n)) {
140         case 0: /* native */
141                 if ((mask & AUDIT_PERM_WRITE) &&
142                      audit_match_class(AUDIT_CLASS_WRITE, n))
143                         return 1;
144                 if ((mask & AUDIT_PERM_READ) &&
145                      audit_match_class(AUDIT_CLASS_READ, n))
146                         return 1;
147                 if ((mask & AUDIT_PERM_ATTR) &&
148                      audit_match_class(AUDIT_CLASS_CHATTR, n))
149                         return 1;
150                 return 0;
151         case 1: /* 32bit on biarch */
152                 if ((mask & AUDIT_PERM_WRITE) &&
153                      audit_match_class(AUDIT_CLASS_WRITE_32, n))
154                         return 1;
155                 if ((mask & AUDIT_PERM_READ) &&
156                      audit_match_class(AUDIT_CLASS_READ_32, n))
157                         return 1;
158                 if ((mask & AUDIT_PERM_ATTR) &&
159                      audit_match_class(AUDIT_CLASS_CHATTR_32, n))
160                         return 1;
161                 return 0;
162         case 2: /* open */
163                 return mask & ACC_MODE(ctx->argv[1]);
164         case 3: /* openat */
165                 return mask & ACC_MODE(ctx->argv[2]);
166         case 4: /* socketcall */
167                 return ((mask & AUDIT_PERM_WRITE) && ctx->argv[0] == SYS_BIND);
168         case 5: /* execve */
169                 return mask & AUDIT_PERM_EXEC;
170         default:
171                 return 0;
172         }
173 }
174 
175 static int audit_match_filetype(struct audit_context *ctx, int val)
176 {
177         struct audit_names *n;
178         umode_t mode = (umode_t)val;
179 
180         if (unlikely(!ctx))
181                 return 0;
182 
183         list_for_each_entry(n, &ctx->names_list, list) {
184                 if ((n->ino != AUDIT_INO_UNSET) &&
185                     ((n->mode & S_IFMT) == mode))
186                         return 1;
187         }
188 
189         return 0;
190 }
191 
192 /*
193  * We keep a linked list of fixed-sized (31 pointer) arrays of audit_chunk *;
194  * ->first_trees points to its beginning, ->trees - to the current end of data.
195  * ->tree_count is the number of free entries in array pointed to by ->trees.
196  * Original condition is (NULL, NULL, 0); as soon as it grows we never revert to NULL,
197  * "empty" becomes (p, p, 31) afterwards.  We don't shrink the list (and seriously,
198  * it's going to remain 1-element for almost any setup) until we free context itself.
199  * References in it _are_ dropped - at the same time we free/drop aux stuff.
200  */
201 
202 #ifdef CONFIG_AUDIT_TREE
203 static void audit_set_auditable(struct audit_context *ctx)
204 {
205         if (!ctx->prio) {
206                 ctx->prio = 1;
207                 ctx->current_state = AUDIT_RECORD_CONTEXT;
208         }
209 }
210 
211 static int put_tree_ref(struct audit_context *ctx, struct audit_chunk *chunk)
212 {
213         struct audit_tree_refs *p = ctx->trees;
214         int left = ctx->tree_count;
215         if (likely(left)) {
216                 p->c[--left] = chunk;
217                 ctx->tree_count = left;
218                 return 1;
219         }
220         if (!p)
221                 return 0;
222         p = p->next;
223         if (p) {
224                 p->c[30] = chunk;
225                 ctx->trees = p;
226                 ctx->tree_count = 30;
227                 return 1;
228         }
229         return 0;
230 }
231 
232 static int grow_tree_refs(struct audit_context *ctx)
233 {
234         struct audit_tree_refs *p = ctx->trees;
235         ctx->trees = kzalloc(sizeof(struct audit_tree_refs), GFP_KERNEL);
236         if (!ctx->trees) {
237                 ctx->trees = p;
238                 return 0;
239         }
240         if (p)
241                 p->next = ctx->trees;
242         else
243                 ctx->first_trees = ctx->trees;
244         ctx->tree_count = 31;
245         return 1;
246 }
247 #endif
248 
249 static void unroll_tree_refs(struct audit_context *ctx,
250                       struct audit_tree_refs *p, int count)
251 {
252 #ifdef CONFIG_AUDIT_TREE
253         struct audit_tree_refs *q;
254         int n;
255         if (!p) {
256                 /* we started with empty chain */
257                 p = ctx->first_trees;
258                 count = 31;
259                 /* if the very first allocation has failed, nothing to do */
260                 if (!p)
261                         return;
262         }
263         n = count;
264         for (q = p; q != ctx->trees; q = q->next, n = 31) {
265                 while (n--) {
266                         audit_put_chunk(q->c[n]);
267                         q->c[n] = NULL;
268                 }
269         }
270         while (n-- > ctx->tree_count) {
271                 audit_put_chunk(q->c[n]);
272                 q->c[n] = NULL;
273         }
274         ctx->trees = p;
275         ctx->tree_count = count;
276 #endif
277 }
278 
279 static void free_tree_refs(struct audit_context *ctx)
280 {
281         struct audit_tree_refs *p, *q;
282         for (p = ctx->first_trees; p; p = q) {
283                 q = p->next;
284                 kfree(p);
285         }
286 }
287 
288 static int match_tree_refs(struct audit_context *ctx, struct audit_tree *tree)
289 {
290 #ifdef CONFIG_AUDIT_TREE
291         struct audit_tree_refs *p;
292         int n;
293         if (!tree)
294                 return 0;
295         /* full ones */
296         for (p = ctx->first_trees; p != ctx->trees; p = p->next) {
297                 for (n = 0; n < 31; n++)
298                         if (audit_tree_match(p->c[n], tree))
299                                 return 1;
300         }
301         /* partial */
302         if (p) {
303                 for (n = ctx->tree_count; n < 31; n++)
304                         if (audit_tree_match(p->c[n], tree))
305                                 return 1;
306         }
307 #endif
308         return 0;
309 }
310 
311 static int audit_compare_uid(kuid_t uid,
312                              struct audit_names *name,
313                              struct audit_field *f,
314                              struct audit_context *ctx)
315 {
316         struct audit_names *n;
317         int rc;
318  
319         if (name) {
320                 rc = audit_uid_comparator(uid, f->op, name->uid);
321                 if (rc)
322                         return rc;
323         }
324  
325         if (ctx) {
326                 list_for_each_entry(n, &ctx->names_list, list) {
327                         rc = audit_uid_comparator(uid, f->op, n->uid);
328                         if (rc)
329                                 return rc;
330                 }
331         }
332         return 0;
333 }
334 
335 static int audit_compare_gid(kgid_t gid,
336                              struct audit_names *name,
337                              struct audit_field *f,
338                              struct audit_context *ctx)
339 {
340         struct audit_names *n;
341         int rc;
342  
343         if (name) {
344                 rc = audit_gid_comparator(gid, f->op, name->gid);
345                 if (rc)
346                         return rc;
347         }
348  
349         if (ctx) {
350                 list_for_each_entry(n, &ctx->names_list, list) {
351                         rc = audit_gid_comparator(gid, f->op, n->gid);
352                         if (rc)
353                                 return rc;
354                 }
355         }
356         return 0;
357 }
358 
359 static int audit_field_compare(struct task_struct *tsk,
360                                const struct cred *cred,
361                                struct audit_field *f,
362                                struct audit_context *ctx,
363                                struct audit_names *name)
364 {
365         switch (f->val) {
366         /* process to file object comparisons */
367         case AUDIT_COMPARE_UID_TO_OBJ_UID:
368                 return audit_compare_uid(cred->uid, name, f, ctx);
369         case AUDIT_COMPARE_GID_TO_OBJ_GID:
370                 return audit_compare_gid(cred->gid, name, f, ctx);
371         case AUDIT_COMPARE_EUID_TO_OBJ_UID:
372                 return audit_compare_uid(cred->euid, name, f, ctx);
373         case AUDIT_COMPARE_EGID_TO_OBJ_GID:
374                 return audit_compare_gid(cred->egid, name, f, ctx);
375         case AUDIT_COMPARE_AUID_TO_OBJ_UID:
376                 return audit_compare_uid(tsk->loginuid, name, f, ctx);
377         case AUDIT_COMPARE_SUID_TO_OBJ_UID:
378                 return audit_compare_uid(cred->suid, name, f, ctx);
379         case AUDIT_COMPARE_SGID_TO_OBJ_GID:
380                 return audit_compare_gid(cred->sgid, name, f, ctx);
381         case AUDIT_COMPARE_FSUID_TO_OBJ_UID:
382                 return audit_compare_uid(cred->fsuid, name, f, ctx);
383         case AUDIT_COMPARE_FSGID_TO_OBJ_GID:
384                 return audit_compare_gid(cred->fsgid, name, f, ctx);
385         /* uid comparisons */
386         case AUDIT_COMPARE_UID_TO_AUID:
387                 return audit_uid_comparator(cred->uid, f->op, tsk->loginuid);
388         case AUDIT_COMPARE_UID_TO_EUID:
389                 return audit_uid_comparator(cred->uid, f->op, cred->euid);
390         case AUDIT_COMPARE_UID_TO_SUID:
391                 return audit_uid_comparator(cred->uid, f->op, cred->suid);
392         case AUDIT_COMPARE_UID_TO_FSUID:
393                 return audit_uid_comparator(cred->uid, f->op, cred->fsuid);
394         /* auid comparisons */
395         case AUDIT_COMPARE_AUID_TO_EUID:
396                 return audit_uid_comparator(tsk->loginuid, f->op, cred->euid);
397         case AUDIT_COMPARE_AUID_TO_SUID:
398                 return audit_uid_comparator(tsk->loginuid, f->op, cred->suid);
399         case AUDIT_COMPARE_AUID_TO_FSUID:
400                 return audit_uid_comparator(tsk->loginuid, f->op, cred->fsuid);
401         /* euid comparisons */
402         case AUDIT_COMPARE_EUID_TO_SUID:
403                 return audit_uid_comparator(cred->euid, f->op, cred->suid);
404         case AUDIT_COMPARE_EUID_TO_FSUID:
405                 return audit_uid_comparator(cred->euid, f->op, cred->fsuid);
406         /* suid comparisons */
407         case AUDIT_COMPARE_SUID_TO_FSUID:
408                 return audit_uid_comparator(cred->suid, f->op, cred->fsuid);
409         /* gid comparisons */
410         case AUDIT_COMPARE_GID_TO_EGID:
411                 return audit_gid_comparator(cred->gid, f->op, cred->egid);
412         case AUDIT_COMPARE_GID_TO_SGID:
413                 return audit_gid_comparator(cred->gid, f->op, cred->sgid);
414         case AUDIT_COMPARE_GID_TO_FSGID:
415                 return audit_gid_comparator(cred->gid, f->op, cred->fsgid);
416         /* egid comparisons */
417         case AUDIT_COMPARE_EGID_TO_SGID:
418                 return audit_gid_comparator(cred->egid, f->op, cred->sgid);
419         case AUDIT_COMPARE_EGID_TO_FSGID:
420                 return audit_gid_comparator(cred->egid, f->op, cred->fsgid);
421         /* sgid comparison */
422         case AUDIT_COMPARE_SGID_TO_FSGID:
423                 return audit_gid_comparator(cred->sgid, f->op, cred->fsgid);
424         default:
425                 WARN(1, "Missing AUDIT_COMPARE define.  Report as a bug\n");
426                 return 0;
427         }
428         return 0;
429 }
430 
431 /* Determine if any context name data matches a rule's watch data */
432 /* Compare a task_struct with an audit_rule.  Return 1 on match, 0
433  * otherwise.
434  *
435  * If task_creation is true, this is an explicit indication that we are
436  * filtering a task rule at task creation time.  This and tsk == current are
437  * the only situations where tsk->cred may be accessed without an rcu read lock.
438  */
439 static int audit_filter_rules(struct task_struct *tsk,
440                               struct audit_krule *rule,
441                               struct audit_context *ctx,
442                               struct audit_names *name,
443                               enum audit_state *state,
444                               bool task_creation)
445 {
446         const struct cred *cred;
447         int i, need_sid = 1;
448         u32 sid;
449         unsigned int sessionid;
450 
451         cred = rcu_dereference_check(tsk->cred, tsk == current || task_creation);
452 
453         for (i = 0; i < rule->field_count; i++) {
454                 struct audit_field *f = &rule->fields[i];
455                 struct audit_names *n;
456                 int result = 0;
457                 pid_t pid;
458 
459                 switch (f->type) {
460                 case AUDIT_PID:
461                         pid = task_tgid_nr(tsk);
462                         result = audit_comparator(pid, f->op, f->val);
463                         break;
464                 case AUDIT_PPID:
465                         if (ctx) {
466                                 if (!ctx->ppid)
467                                         ctx->ppid = task_ppid_nr(tsk);
468                                 result = audit_comparator(ctx->ppid, f->op, f->val);
469                         }
470                         break;
471                 case AUDIT_EXE:
472                         result = audit_exe_compare(tsk, rule->exe);
473                         break;
474                 case AUDIT_UID:
475                         result = audit_uid_comparator(cred->uid, f->op, f->uid);
476                         break;
477                 case AUDIT_EUID:
478                         result = audit_uid_comparator(cred->euid, f->op, f->uid);
479                         break;
480                 case AUDIT_SUID:
481                         result = audit_uid_comparator(cred->suid, f->op, f->uid);
482                         break;
483                 case AUDIT_FSUID:
484                         result = audit_uid_comparator(cred->fsuid, f->op, f->uid);
485                         break;
486                 case AUDIT_GID:
487                         result = audit_gid_comparator(cred->gid, f->op, f->gid);
488                         if (f->op == Audit_equal) {
489                                 if (!result)
490                                         result = in_group_p(f->gid);
491                         } else if (f->op == Audit_not_equal) {
492                                 if (result)
493                                         result = !in_group_p(f->gid);
494                         }
495                         break;
496                 case AUDIT_EGID:
497                         result = audit_gid_comparator(cred->egid, f->op, f->gid);
498                         if (f->op == Audit_equal) {
499                                 if (!result)
500                                         result = in_egroup_p(f->gid);
501                         } else if (f->op == Audit_not_equal) {
502                                 if (result)
503                                         result = !in_egroup_p(f->gid);
504                         }
505                         break;
506                 case AUDIT_SGID:
507                         result = audit_gid_comparator(cred->sgid, f->op, f->gid);
508                         break;
509                 case AUDIT_FSGID:
510                         result = audit_gid_comparator(cred->fsgid, f->op, f->gid);
511                         break;
512                 case AUDIT_SESSIONID:
513                         sessionid = audit_get_sessionid(current);
514                         result = audit_comparator(sessionid, f->op, f->val);
515                         break;
516                 case AUDIT_PERS:
517                         result = audit_comparator(tsk->personality, f->op, f->val);
518                         break;
519                 case AUDIT_ARCH:
520                         if (ctx)
521                                 result = audit_comparator(ctx->arch, f->op, f->val);
522                         break;
523 
524                 case AUDIT_EXIT:
525                         if (ctx && ctx->return_valid)
526                                 result = audit_comparator(ctx->return_code, f->op, f->val);
527                         break;
528                 case AUDIT_SUCCESS:
529                         if (ctx && ctx->return_valid) {
530                                 if (f->val)
531                                         result = audit_comparator(ctx->return_valid, f->op, AUDITSC_SUCCESS);
532                                 else
533                                         result = audit_comparator(ctx->return_valid, f->op, AUDITSC_FAILURE);
534                         }
535                         break;
536                 case AUDIT_DEVMAJOR:
537                         if (name) {
538                                 if (audit_comparator(MAJOR(name->dev), f->op, f->val) ||
539                                     audit_comparator(MAJOR(name->rdev), f->op, f->val))
540                                         ++result;
541                         } else if (ctx) {
542                                 list_for_each_entry(n, &ctx->names_list, list) {
543                                         if (audit_comparator(MAJOR(n->dev), f->op, f->val) ||
544                                             audit_comparator(MAJOR(n->rdev), f->op, f->val)) {
545                                                 ++result;
546                                                 break;
547                                         }
548                                 }
549                         }
550                         break;
551                 case AUDIT_DEVMINOR:
552                         if (name) {
553                                 if (audit_comparator(MINOR(name->dev), f->op, f->val) ||
554                                     audit_comparator(MINOR(name->rdev), f->op, f->val))
555                                         ++result;
556                         } else if (ctx) {
557                                 list_for_each_entry(n, &ctx->names_list, list) {
558                                         if (audit_comparator(MINOR(n->dev), f->op, f->val) ||
559                                             audit_comparator(MINOR(n->rdev), f->op, f->val)) {
560                                                 ++result;
561                                                 break;
562                                         }
563                                 }
564                         }
565                         break;
566                 case AUDIT_INODE:
567                         if (name)
568                                 result = audit_comparator(name->ino, f->op, f->val);
569                         else if (ctx) {
570                                 list_for_each_entry(n, &ctx->names_list, list) {
571                                         if (audit_comparator(n->ino, f->op, f->val)) {
572                                                 ++result;
573                                                 break;
574                                         }
575                                 }
576                         }
577                         break;
578                 case AUDIT_OBJ_UID:
579                         if (name) {
580                                 result = audit_uid_comparator(name->uid, f->op, f->uid);
581                         } else if (ctx) {
582                                 list_for_each_entry(n, &ctx->names_list, list) {
583                                         if (audit_uid_comparator(n->uid, f->op, f->uid)) {
584                                                 ++result;
585                                                 break;
586                                         }
587                                 }
588                         }
589                         break;
590                 case AUDIT_OBJ_GID:
591                         if (name) {
592                                 result = audit_gid_comparator(name->gid, f->op, f->gid);
593                         } else if (ctx) {
594                                 list_for_each_entry(n, &ctx->names_list, list) {
595                                         if (audit_gid_comparator(n->gid, f->op, f->gid)) {
596                                                 ++result;
597                                                 break;
598                                         }
599                                 }
600                         }
601                         break;
602                 case AUDIT_WATCH:
603                         if (name)
604                                 result = audit_watch_compare(rule->watch, name->ino, name->dev);
605                         break;
606                 case AUDIT_DIR:
607                         if (ctx)
608                                 result = match_tree_refs(ctx, rule->tree);
609                         break;
610                 case AUDIT_LOGINUID:
611                         result = audit_uid_comparator(tsk->loginuid, f->op, f->uid);
612                         break;
613                 case AUDIT_LOGINUID_SET:
614                         result = audit_comparator(audit_loginuid_set(tsk), f->op, f->val);
615                         break;
616                 case AUDIT_SUBJ_USER:
617                 case AUDIT_SUBJ_ROLE:
618                 case AUDIT_SUBJ_TYPE:
619                 case AUDIT_SUBJ_SEN:
620                 case AUDIT_SUBJ_CLR:
621                         /* NOTE: this may return negative values indicating
622                            a temporary error.  We simply treat this as a
623                            match for now to avoid losing information that
624                            may be wanted.   An error message will also be
625                            logged upon error */
626                         if (f->lsm_rule) {
627                                 if (need_sid) {
628                                         security_task_getsecid(tsk, &sid);
629                                         need_sid = 0;
630                                 }
631                                 result = security_audit_rule_match(sid, f->type,
632                                                                   f->op,
633                                                                   f->lsm_rule,
634                                                                   ctx);
635                         }
636                         break;
637                 case AUDIT_OBJ_USER:
638                 case AUDIT_OBJ_ROLE:
639                 case AUDIT_OBJ_TYPE:
640                 case AUDIT_OBJ_LEV_LOW:
641                 case AUDIT_OBJ_LEV_HIGH:
642                         /* The above note for AUDIT_SUBJ_USER...AUDIT_SUBJ_CLR
643                            also applies here */
644                         if (f->lsm_rule) {
645                                 /* Find files that match */
646                                 if (name) {
647                                         result = security_audit_rule_match(
648                                                    name->osid, f->type, f->op,
649                                                    f->lsm_rule, ctx);
650                                 } else if (ctx) {
651                                         list_for_each_entry(n, &ctx->names_list, list) {
652                                                 if (security_audit_rule_match(n->osid, f->type,
653                                                                               f->op, f->lsm_rule,
654                                                                               ctx)) {
655                                                         ++result;
656                                                         break;
657                                                 }
658                                         }
659                                 }
660                                 /* Find ipc objects that match */
661                                 if (!ctx || ctx->type != AUDIT_IPC)
662                                         break;
663                                 if (security_audit_rule_match(ctx->ipc.osid,
664                                                               f->type, f->op,
665                                                               f->lsm_rule, ctx))
666                                         ++result;
667                         }
668                         break;
669                 case AUDIT_ARG0:
670                 case AUDIT_ARG1:
671                 case AUDIT_ARG2:
672                 case AUDIT_ARG3:
673                         if (ctx)
674                                 result = audit_comparator(ctx->argv[f->type-AUDIT_ARG0], f->op, f->val);
675                         break;
676                 case AUDIT_FILTERKEY:
677                         /* ignore this field for filtering */
678                         result = 1;
679                         break;
680                 case AUDIT_PERM:
681                         result = audit_match_perm(ctx, f->val);
682                         break;
683                 case AUDIT_FILETYPE:
684                         result = audit_match_filetype(ctx, f->val);
685                         break;
686                 case AUDIT_FIELD_COMPARE:
687                         result = audit_field_compare(tsk, cred, f, ctx, name);
688                         break;
689                 }
690                 if (!result)
691                         return 0;
692         }
693 
694         if (ctx) {
695                 if (rule->prio <= ctx->prio)
696                         return 0;
697                 if (rule->filterkey) {
698                         kfree(ctx->filterkey);
699                         ctx->filterkey = kstrdup(rule->filterkey, GFP_ATOMIC);
700                 }
701                 ctx->prio = rule->prio;
702         }
703         switch (rule->action) {
704         case AUDIT_NEVER:
705                 *state = AUDIT_DISABLED;
706                 break;
707         case AUDIT_ALWAYS:
708                 *state = AUDIT_RECORD_CONTEXT;
709                 break;
710         }
711         return 1;
712 }
713 
714 /* At process creation time, we can determine if system-call auditing is
715  * completely disabled for this task.  Since we only have the task
716  * structure at this point, we can only check uid and gid.
717  */
718 static enum audit_state audit_filter_task(struct task_struct *tsk, char **key)
719 {
720         struct audit_entry *e;
721         enum audit_state   state;
722 
723         rcu_read_lock();
724         list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_TASK], list) {
725                 if (audit_filter_rules(tsk, &e->rule, NULL, NULL,
726                                        &state, true)) {
727                         if (state == AUDIT_RECORD_CONTEXT)
728                                 *key = kstrdup(e->rule.filterkey, GFP_ATOMIC);
729                         rcu_read_unlock();
730                         return state;
731                 }
732         }
733         rcu_read_unlock();
734         return AUDIT_BUILD_CONTEXT;
735 }
736 
737 static int audit_in_mask(const struct audit_krule *rule, unsigned long val)
738 {
739         int word, bit;
740 
741         if (val > 0xffffffff)
742                 return false;
743 
744         word = AUDIT_WORD(val);
745         if (word >= AUDIT_BITMASK_SIZE)
746                 return false;
747 
748         bit = AUDIT_BIT(val);
749 
750         return rule->mask[word] & bit;
751 }
752 
753 /* At syscall entry and exit time, this filter is called if the
754  * audit_state is not low enough that auditing cannot take place, but is
755  * also not high enough that we already know we have to write an audit
756  * record (i.e., the state is AUDIT_SETUP_CONTEXT or AUDIT_BUILD_CONTEXT).
757  */
758 static enum audit_state audit_filter_syscall(struct task_struct *tsk,
759                                              struct audit_context *ctx,
760                                              struct list_head *list)
761 {
762         struct audit_entry *e;
763         enum audit_state state;
764 
765         if (audit_pid && tsk->tgid == audit_pid)
766                 return AUDIT_DISABLED;
767 
768         rcu_read_lock();
769         if (!list_empty(list)) {
770                 list_for_each_entry_rcu(e, list, list) {
771                         if (audit_in_mask(&e->rule, ctx->major) &&
772                             audit_filter_rules(tsk, &e->rule, ctx, NULL,
773                                                &state, false)) {
774                                 rcu_read_unlock();
775                                 ctx->current_state = state;
776                                 return state;
777                         }
778                 }
779         }
780         rcu_read_unlock();
781         return AUDIT_BUILD_CONTEXT;
782 }
783 
784 /*
785  * Given an audit_name check the inode hash table to see if they match.
786  * Called holding the rcu read lock to protect the use of audit_inode_hash
787  */
788 static int audit_filter_inode_name(struct task_struct *tsk,
789                                    struct audit_names *n,
790                                    struct audit_context *ctx) {
791         int h = audit_hash_ino((u32)n->ino);
792         struct list_head *list = &audit_inode_hash[h];
793         struct audit_entry *e;
794         enum audit_state state;
795 
796         if (list_empty(list))
797                 return 0;
798 
799         list_for_each_entry_rcu(e, list, list) {
800                 if (audit_in_mask(&e->rule, ctx->major) &&
801                     audit_filter_rules(tsk, &e->rule, ctx, n, &state, false)) {
802                         ctx->current_state = state;
803                         return 1;
804                 }
805         }
806 
807         return 0;
808 }
809 
810 /* At syscall exit time, this filter is called if any audit_names have been
811  * collected during syscall processing.  We only check rules in sublists at hash
812  * buckets applicable to the inode numbers in audit_names.
813  * Regarding audit_state, same rules apply as for audit_filter_syscall().
814  */
815 void audit_filter_inodes(struct task_struct *tsk, struct audit_context *ctx)
816 {
817         struct audit_names *n;
818 
819         if (audit_pid && tsk->tgid == audit_pid)
820                 return;
821 
822         rcu_read_lock();
823 
824         list_for_each_entry(n, &ctx->names_list, list) {
825                 if (audit_filter_inode_name(tsk, n, ctx))
826                         break;
827         }
828         rcu_read_unlock();
829 }
830 
831 /* Transfer the audit context pointer to the caller, clearing it in the tsk's struct */
832 static inline struct audit_context *audit_take_context(struct task_struct *tsk,
833                                                       int return_valid,
834                                                       long return_code)
835 {
836         struct audit_context *context = tsk->audit_context;
837 
838         if (!context)
839                 return NULL;
840         context->return_valid = return_valid;
841 
842         /*
843          * we need to fix up the return code in the audit logs if the actual
844          * return codes are later going to be fixed up by the arch specific
845          * signal handlers
846          *
847          * This is actually a test for:
848          * (rc == ERESTARTSYS ) || (rc == ERESTARTNOINTR) ||
849          * (rc == ERESTARTNOHAND) || (rc == ERESTART_RESTARTBLOCK)
850          *
851          * but is faster than a bunch of ||
852          */
853         if (unlikely(return_code <= -ERESTARTSYS) &&
854             (return_code >= -ERESTART_RESTARTBLOCK) &&
855             (return_code != -ENOIOCTLCMD))
856                 context->return_code = -EINTR;
857         else
858                 context->return_code  = return_code;
859 
860         if (context->in_syscall && !context->dummy) {
861                 audit_filter_syscall(tsk, context, &audit_filter_list[AUDIT_FILTER_EXIT]);
862                 audit_filter_inodes(tsk, context);
863         }
864 
865         tsk->audit_context = NULL;
866         return context;
867 }
868 
869 static inline void audit_proctitle_free(struct audit_context *context)
870 {
871         kfree(context->proctitle.value);
872         context->proctitle.value = NULL;
873         context->proctitle.len = 0;
874 }
875 
876 static inline void audit_free_names(struct audit_context *context)
877 {
878         struct audit_names *n, *next;
879 
880         list_for_each_entry_safe(n, next, &context->names_list, list) {
881                 list_del(&n->list);
882                 if (n->name)
883                         putname(n->name);
884                 if (n->should_free)
885                         kfree(n);
886         }
887         context->name_count = 0;
888         path_put(&context->pwd);
889         context->pwd.dentry = NULL;
890         context->pwd.mnt = NULL;
891 }
892 
893 static inline void audit_free_aux(struct audit_context *context)
894 {
895         struct audit_aux_data *aux;
896 
897         while ((aux = context->aux)) {
898                 context->aux = aux->next;
899                 kfree(aux);
900         }
901         while ((aux = context->aux_pids)) {
902                 context->aux_pids = aux->next;
903                 kfree(aux);
904         }
905 }
906 
907 static inline struct audit_context *audit_alloc_context(enum audit_state state)
908 {
909         struct audit_context *context;
910 
911         context = kzalloc(sizeof(*context), GFP_KERNEL);
912         if (!context)
913                 return NULL;
914         context->state = state;
915         context->prio = state == AUDIT_RECORD_CONTEXT ? ~0ULL : 0;
916         INIT_LIST_HEAD(&context->killed_trees);
917         INIT_LIST_HEAD(&context->names_list);
918         return context;
919 }
920 
921 /**
922  * audit_alloc - allocate an audit context block for a task
923  * @tsk: task
924  *
925  * Filter on the task information and allocate a per-task audit context
926  * if necessary.  Doing so turns on system call auditing for the
927  * specified task.  This is called from copy_process, so no lock is
928  * needed.
929  */
930 int audit_alloc(struct task_struct *tsk)
931 {
932         struct audit_context *context;
933         enum audit_state     state;
934         char *key = NULL;
935 
936         if (likely(!audit_ever_enabled))
937                 return 0; /* Return if not auditing. */
938 
939         state = audit_filter_task(tsk, &key);
940         if (state == AUDIT_DISABLED) {
941                 clear_tsk_thread_flag(tsk, TIF_SYSCALL_AUDIT);
942                 return 0;
943         }
944 
945         if (!(context = audit_alloc_context(state))) {
946                 kfree(key);
947                 audit_log_lost("out of memory in audit_alloc");
948                 return -ENOMEM;
949         }
950         context->filterkey = key;
951 
952         tsk->audit_context  = context;
953         set_tsk_thread_flag(tsk, TIF_SYSCALL_AUDIT);
954         return 0;
955 }
956 
957 static inline void audit_free_context(struct audit_context *context)
958 {
959         audit_free_names(context);
960         unroll_tree_refs(context, NULL, 0);
961         free_tree_refs(context);
962         audit_free_aux(context);
963         kfree(context->filterkey);
964         kfree(context->sockaddr);
965         audit_proctitle_free(context);
966         kfree(context);
967 }
968 
969 static int audit_log_pid_context(struct audit_context *context, pid_t pid,
970                                  kuid_t auid, kuid_t uid, unsigned int sessionid,
971                                  u32 sid, char *comm)
972 {
973         struct audit_buffer *ab;
974         char *ctx = NULL;
975         u32 len;
976         int rc = 0;
977 
978         ab = audit_log_start(context, GFP_KERNEL, AUDIT_OBJ_PID);
979         if (!ab)
980                 return rc;
981 
982         audit_log_format(ab, "opid=%d oauid=%d ouid=%d oses=%d", pid,
983                          from_kuid(&init_user_ns, auid),
984                          from_kuid(&init_user_ns, uid), sessionid);
985         if (sid) {
986                 if (security_secid_to_secctx(sid, &ctx, &len)) {
987                         audit_log_format(ab, " obj=(none)");
988                         rc = 1;
989                 } else {
990                         audit_log_format(ab, " obj=%s", ctx);
991                         security_release_secctx(ctx, len);
992                 }
993         }
994         audit_log_format(ab, " ocomm=");
995         audit_log_untrustedstring(ab, comm);
996         audit_log_end(ab);
997 
998         return rc;
999 }
1000 
1001 static void audit_log_execve_info(struct audit_context *context,
1002                                   struct audit_buffer **ab)
1003 {
1004         long len_max;
1005         long len_rem;
1006         long len_full;
1007         long len_buf;
1008         long len_abuf = 0;
1009         long len_tmp;
1010         bool require_data;
1011         bool encode;
1012         unsigned int iter;
1013         unsigned int arg;
1014         char *buf_head;
1015         char *buf;
1016         const char __user *p = (const char __user *)current->mm->arg_start;
1017 
1018         /* NOTE: this buffer needs to be large enough to hold all the non-arg
1019          *       data we put in the audit record for this argument (see the
1020          *       code below) ... at this point in time 96 is plenty */
1021         char abuf[96];
1022 
1023         /* NOTE: we set MAX_EXECVE_AUDIT_LEN to a rather arbitrary limit, the
1024          *       current value of 7500 is not as important as the fact that it
1025          *       is less than 8k, a setting of 7500 gives us plenty of wiggle
1026          *       room if we go over a little bit in the logging below */
1027         WARN_ON_ONCE(MAX_EXECVE_AUDIT_LEN > 7500);
1028         len_max = MAX_EXECVE_AUDIT_LEN;
1029 
1030         /* scratch buffer to hold the userspace args */
1031         buf_head = kmalloc(MAX_EXECVE_AUDIT_LEN + 1, GFP_KERNEL);
1032         if (!buf_head) {
1033                 audit_panic("out of memory for argv string");
1034                 return;
1035         }
1036         buf = buf_head;
1037 
1038         audit_log_format(*ab, "argc=%d", context->execve.argc);
1039 
1040         len_rem = len_max;
1041         len_buf = 0;
1042         len_full = 0;
1043         require_data = true;
1044         encode = false;
1045         iter = 0;
1046         arg = 0;
1047         do {
1048                 /* NOTE: we don't ever want to trust this value for anything
1049                  *       serious, but the audit record format insists we
1050                  *       provide an argument length for really long arguments,
1051                  *       e.g. > MAX_EXECVE_AUDIT_LEN, so we have no choice but
1052                  *       to use strncpy_from_user() to obtain this value for
1053                  *       recording in the log, although we don't use it
1054                  *       anywhere here to avoid a double-fetch problem */
1055                 if (len_full == 0)
1056                         len_full = strnlen_user(p, MAX_ARG_STRLEN) - 1;
1057 
1058                 /* read more data from userspace */
1059                 if (require_data) {
1060                         /* can we make more room in the buffer? */
1061                         if (buf != buf_head) {
1062                                 memmove(buf_head, buf, len_buf);
1063                                 buf = buf_head;
1064                         }
1065 
1066                         /* fetch as much as we can of the argument */
1067                         len_tmp = strncpy_from_user(&buf_head[len_buf], p,
1068                                                     len_max - len_buf);
1069                         if (len_tmp == -EFAULT) {
1070                                 /* unable to copy from userspace */
1071                                 send_sig(SIGKILL, current, 0);
1072                                 goto out;
1073                         } else if (len_tmp == (len_max - len_buf)) {
1074                                 /* buffer is not large enough */
1075                                 require_data = true;
1076                                 /* NOTE: if we are going to span multiple
1077                                  *       buffers force the encoding so we stand
1078                                  *       a chance at a sane len_full value and
1079                                  *       consistent record encoding */
1080                                 encode = true;
1081                                 len_full = len_full * 2;
1082                                 p += len_tmp;
1083                         } else {
1084                                 require_data = false;
1085                                 if (!encode)
1086                                         encode = audit_string_contains_control(
1087                                                                 buf, len_tmp);
1088                                 /* try to use a trusted value for len_full */
1089                                 if (len_full < len_max)
1090                                         len_full = (encode ?
1091                                                     len_tmp * 2 : len_tmp);
1092                                 p += len_tmp + 1;
1093                         }
1094                         len_buf += len_tmp;
1095                         buf_head[len_buf] = '\0';
1096 
1097                         /* length of the buffer in the audit record? */
1098                         len_abuf = (encode ? len_buf * 2 : len_buf + 2);
1099                 }
1100 
1101                 /* write as much as we can to the audit log */
1102                 if (len_buf > 0) {
1103                         /* NOTE: some magic numbers here - basically if we
1104                          *       can't fit a reasonable amount of data into the
1105                          *       existing audit buffer, flush it and start with
1106                          *       a new buffer */
1107                         if ((sizeof(abuf) + 8) > len_rem) {
1108                                 len_rem = len_max;
1109                                 audit_log_end(*ab);
1110                                 *ab = audit_log_start(context,
1111                                                       GFP_KERNEL, AUDIT_EXECVE);
1112                                 if (!*ab)
1113                                         goto out;
1114                         }
1115 
1116                         /* create the non-arg portion of the arg record */
1117                         len_tmp = 0;
1118                         if (require_data || (iter > 0) ||
1119                             ((len_abuf + sizeof(abuf)) > len_rem)) {
1120                                 if (iter == 0) {
1121                                         len_tmp += snprintf(&abuf[len_tmp],
1122                                                         sizeof(abuf) - len_tmp,
1123                                                         " a%d_len=%lu",
1124                                                         arg, len_full);
1125                                 }
1126                                 len_tmp += snprintf(&abuf[len_tmp],
1127                                                     sizeof(abuf) - len_tmp,
1128                                                     " a%d[%d]=", arg, iter++);
1129                         } else
1130                                 len_tmp += snprintf(&abuf[len_tmp],
1131                                                     sizeof(abuf) - len_tmp,
1132                                                     " a%d=", arg);
1133                         WARN_ON(len_tmp >= sizeof(abuf));
1134                         abuf[sizeof(abuf) - 1] = '\0';
1135 
1136                         /* log the arg in the audit record */
1137                         audit_log_format(*ab, "%s", abuf);
1138                         len_rem -= len_tmp;
1139                         len_tmp = len_buf;
1140                         if (encode) {
1141                                 if (len_abuf > len_rem)
1142                                         len_tmp = len_rem / 2; /* encoding */
1143                                 audit_log_n_hex(*ab, buf, len_tmp);
1144                                 len_rem -= len_tmp * 2;
1145                                 len_abuf -= len_tmp * 2;
1146                         } else {
1147                                 if (len_abuf > len_rem)
1148                                         len_tmp = len_rem - 2; /* quotes */
1149                                 audit_log_n_string(*ab, buf, len_tmp);
1150                                 len_rem -= len_tmp + 2;
1151                                 /* don't subtract the "2" because we still need
1152                                  * to add quotes to the remaining string */
1153                                 len_abuf -= len_tmp;
1154                         }
1155                         len_buf -= len_tmp;
1156                         buf += len_tmp;
1157                 }
1158 
1159                 /* ready to move to the next argument? */
1160                 if ((len_buf == 0) && !require_data) {
1161                         arg++;
1162                         iter = 0;
1163                         len_full = 0;
1164                         require_data = true;
1165                         encode = false;
1166                 }
1167         } while (arg < context->execve.argc);
1168 
1169         /* NOTE: the caller handles the final audit_log_end() call */
1170 
1171 out:
1172         kfree(buf_head);
1173 }
1174 
1175 static void show_special(struct audit_context *context, int *call_panic)
1176 {
1177         struct audit_buffer *ab;
1178         int i;
1179 
1180         ab = audit_log_start(context, GFP_KERNEL, context->type);
1181         if (!ab)
1182                 return;
1183 
1184         switch (context->type) {
1185         case AUDIT_SOCKETCALL: {
1186                 int nargs = context->socketcall.nargs;
1187                 audit_log_format(ab, "nargs=%d", nargs);
1188                 for (i = 0; i < nargs; i++)
1189                         audit_log_format(ab, " a%d=%lx", i,
1190                                 context->socketcall.args[i]);
1191                 break; }
1192         case AUDIT_IPC: {
1193                 u32 osid = context->ipc.osid;
1194 
1195                 audit_log_format(ab, "ouid=%u ogid=%u mode=%#ho",
1196                                  from_kuid(&init_user_ns, context->ipc.uid),
1197                                  from_kgid(&init_user_ns, context->ipc.gid),
1198                                  context->ipc.mode);
1199                 if (osid) {
1200                         char *ctx = NULL;
1201                         u32 len;
1202                         if (security_secid_to_secctx(osid, &ctx, &len)) {
1203                                 audit_log_format(ab, " osid=%u", osid);
1204                                 *call_panic = 1;
1205                         } else {
1206                                 audit_log_format(ab, " obj=%s", ctx);
1207                                 security_release_secctx(ctx, len);
1208                         }
1209                 }
1210                 if (context->ipc.has_perm) {
1211                         audit_log_end(ab);
1212                         ab = audit_log_start(context, GFP_KERNEL,
1213                                              AUDIT_IPC_SET_PERM);
1214                         if (unlikely(!ab))
1215                                 return;
1216                         audit_log_format(ab,
1217                                 "qbytes=%lx ouid=%u ogid=%u mode=%#ho",
1218                                 context->ipc.qbytes,
1219                                 context->ipc.perm_uid,
1220                                 context->ipc.perm_gid,
1221                                 context->ipc.perm_mode);
1222                 }
1223                 break; }
1224         case AUDIT_MQ_OPEN: {
1225                 audit_log_format(ab,
1226                         "oflag=0x%x mode=%#ho mq_flags=0x%lx mq_maxmsg=%ld "
1227                         "mq_msgsize=%ld mq_curmsgs=%ld",
1228                         context->mq_open.oflag, context->mq_open.mode,
1229                         context->mq_open.attr.mq_flags,
1230                         context->mq_open.attr.mq_maxmsg,
1231                         context->mq_open.attr.mq_msgsize,
1232                         context->mq_open.attr.mq_curmsgs);
1233                 break; }
1234         case AUDIT_MQ_SENDRECV: {
1235                 audit_log_format(ab,
1236                         "mqdes=%d msg_len=%zd msg_prio=%u "
1237                         "abs_timeout_sec=%ld abs_timeout_nsec=%ld",
1238                         context->mq_sendrecv.mqdes,
1239                         context->mq_sendrecv.msg_len,
1240                         context->mq_sendrecv.msg_prio,
1241                         context->mq_sendrecv.abs_timeout.tv_sec,
1242                         context->mq_sendrecv.abs_timeout.tv_nsec);
1243                 break; }
1244         case AUDIT_MQ_NOTIFY: {
1245                 audit_log_format(ab, "mqdes=%d sigev_signo=%d",
1246                                 context->mq_notify.mqdes,
1247                                 context->mq_notify.sigev_signo);
1248                 break; }
1249         case AUDIT_MQ_GETSETATTR: {
1250                 struct mq_attr *attr = &context->mq_getsetattr.mqstat;
1251                 audit_log_format(ab,
1252                         "mqdes=%d mq_flags=0x%lx mq_maxmsg=%ld mq_msgsize=%ld "
1253                         "mq_curmsgs=%ld ",
1254                         context->mq_getsetattr.mqdes,
1255                         attr->mq_flags, attr->mq_maxmsg,
1256                         attr->mq_msgsize, attr->mq_curmsgs);
1257                 break; }
1258         case AUDIT_CAPSET: {
1259                 audit_log_format(ab, "pid=%d", context->capset.pid);
1260                 audit_log_cap(ab, "cap_pi", &context->capset.cap.inheritable);
1261                 audit_log_cap(ab, "cap_pp", &context->capset.cap.permitted);
1262                 audit_log_cap(ab, "cap_pe", &context->capset.cap.effective);
1263                 break; }
1264         case AUDIT_MMAP: {
1265                 audit_log_format(ab, "fd=%d flags=0x%x", context->mmap.fd,
1266                                  context->mmap.flags);
1267                 break; }
1268         case AUDIT_EXECVE: {
1269                 audit_log_execve_info(context, &ab);
1270                 break; }
1271         }
1272         audit_log_end(ab);
1273 }
1274 
1275 static inline int audit_proctitle_rtrim(char *proctitle, int len)
1276 {
1277         char *end = proctitle + len - 1;
1278         while (end > proctitle && !isprint(*end))
1279                 end--;
1280 
1281         /* catch the case where proctitle is only 1 non-print character */
1282         len = end - proctitle + 1;
1283         len -= isprint(proctitle[len-1]) == 0;
1284         return len;
1285 }
1286 
1287 static void audit_log_proctitle(struct task_struct *tsk,
1288                          struct audit_context *context)
1289 {
1290         int res;
1291         char *buf;
1292         char *msg = "(null)";
1293         int len = strlen(msg);
1294         struct audit_buffer *ab;
1295 
1296         ab = audit_log_start(context, GFP_KERNEL, AUDIT_PROCTITLE);
1297         if (!ab)
1298                 return; /* audit_panic or being filtered */
1299 
1300         audit_log_format(ab, "proctitle=");
1301 
1302         /* Not  cached */
1303         if (!context->proctitle.value) {
1304                 buf = kmalloc(MAX_PROCTITLE_AUDIT_LEN, GFP_KERNEL);
1305                 if (!buf)
1306                         goto out;
1307                 /* Historically called this from procfs naming */
1308                 res = get_cmdline(tsk, buf, MAX_PROCTITLE_AUDIT_LEN);
1309                 if (res == 0) {
1310                         kfree(buf);
1311                         goto out;
1312                 }
1313                 res = audit_proctitle_rtrim(buf, res);
1314                 if (res == 0) {
1315                         kfree(buf);
1316                         goto out;
1317                 }
1318                 context->proctitle.value = buf;
1319                 context->proctitle.len = res;
1320         }
1321         msg = context->proctitle.value;
1322         len = context->proctitle.len;
1323 out:
1324         audit_log_n_untrustedstring(ab, msg, len);
1325         audit_log_end(ab);
1326 }
1327 
1328 static void audit_log_exit(struct audit_context *context, struct task_struct *tsk)
1329 {
1330         int i, call_panic = 0;
1331         struct audit_buffer *ab;
1332         struct audit_aux_data *aux;
1333         struct audit_names *n;
1334 
1335         /* tsk == current */
1336         context->personality = tsk->personality;
1337 
1338         ab = audit_log_start(context, GFP_KERNEL, AUDIT_SYSCALL);
1339         if (!ab)
1340                 return;         /* audit_panic has been called */
1341         audit_log_format(ab, "arch=%x syscall=%d",
1342                          context->arch, context->major);
1343         if (context->personality != PER_LINUX)
1344                 audit_log_format(ab, " per=%lx", context->personality);
1345         if (context->return_valid)
1346                 audit_log_format(ab, " success=%s exit=%ld",
1347                                  (context->return_valid==AUDITSC_SUCCESS)?"yes":"no",
1348                                  context->return_code);
1349 
1350         audit_log_format(ab,
1351                          " a0=%lx a1=%lx a2=%lx a3=%lx items=%d",
1352                          context->argv[0],
1353                          context->argv[1],
1354                          context->argv[2],
1355                          context->argv[3],
1356                          context->name_count);
1357 
1358         audit_log_task_info(ab, tsk);
1359         audit_log_key(ab, context->filterkey);
1360         audit_log_end(ab);
1361 
1362         for (aux = context->aux; aux; aux = aux->next) {
1363 
1364                 ab = audit_log_start(context, GFP_KERNEL, aux->type);
1365                 if (!ab)
1366                         continue; /* audit_panic has been called */
1367 
1368                 switch (aux->type) {
1369 
1370                 case AUDIT_BPRM_FCAPS: {
1371                         struct audit_aux_data_bprm_fcaps *axs = (void *)aux;
1372                         audit_log_format(ab, "fver=%x", axs->fcap_ver);
1373                         audit_log_cap(ab, "fp", &axs->fcap.permitted);
1374                         audit_log_cap(ab, "fi", &axs->fcap.inheritable);
1375                         audit_log_format(ab, " fe=%d", axs->fcap.fE);
1376                         audit_log_cap(ab, "old_pp", &axs->old_pcap.permitted);
1377                         audit_log_cap(ab, "old_pi", &axs->old_pcap.inheritable);
1378                         audit_log_cap(ab, "old_pe", &axs->old_pcap.effective);
1379                         audit_log_cap(ab, "new_pp", &axs->new_pcap.permitted);
1380                         audit_log_cap(ab, "new_pi", &axs->new_pcap.inheritable);
1381                         audit_log_cap(ab, "new_pe", &axs->new_pcap.effective);
1382                         break; }
1383 
1384                 }
1385                 audit_log_end(ab);
1386         }
1387 
1388         if (context->type)
1389                 show_special(context, &call_panic);
1390 
1391         if (context->fds[0] >= 0) {
1392                 ab = audit_log_start(context, GFP_KERNEL, AUDIT_FD_PAIR);
1393                 if (ab) {
1394                         audit_log_format(ab, "fd0=%d fd1=%d",
1395                                         context->fds[0], context->fds[1]);
1396                         audit_log_end(ab);
1397                 }
1398         }
1399 
1400         if (context->sockaddr_len) {
1401                 ab = audit_log_start(context, GFP_KERNEL, AUDIT_SOCKADDR);
1402                 if (ab) {
1403                         audit_log_format(ab, "saddr=");
1404                         audit_log_n_hex(ab, (void *)context->sockaddr,
1405                                         context->sockaddr_len);
1406                         audit_log_end(ab);
1407                 }
1408         }
1409 
1410         for (aux = context->aux_pids; aux; aux = aux->next) {
1411                 struct audit_aux_data_pids *axs = (void *)aux;
1412 
1413                 for (i = 0; i < axs->pid_count; i++)
1414                         if (audit_log_pid_context(context, axs->target_pid[i],
1415                                                   axs->target_auid[i],
1416                                                   axs->target_uid[i],
1417                                                   axs->target_sessionid[i],
1418                                                   axs->target_sid[i],
1419                                                   axs->target_comm[i]))
1420                                 call_panic = 1;
1421         }
1422 
1423         if (context->target_pid &&
1424             audit_log_pid_context(context, context->target_pid,
1425                                   context->target_auid, context->target_uid,
1426                                   context->target_sessionid,
1427                                   context->target_sid, context->target_comm))
1428                         call_panic = 1;
1429 
1430         if (context->pwd.dentry && context->pwd.mnt) {
1431                 ab = audit_log_start(context, GFP_KERNEL, AUDIT_CWD);
1432                 if (ab) {
1433                         audit_log_d_path(ab, "cwd=", &context->pwd);
1434                         audit_log_end(ab);
1435                 }
1436         }
1437 
1438         i = 0;
1439         list_for_each_entry(n, &context->names_list, list) {
1440                 if (n->hidden)
1441                         continue;
1442                 audit_log_name(context, n, NULL, i++, &call_panic);
1443         }
1444 
1445         audit_log_proctitle(tsk, context);
1446 
1447         /* Send end of event record to help user space know we are finished */
1448         ab = audit_log_start(context, GFP_KERNEL, AUDIT_EOE);
1449         if (ab)
1450                 audit_log_end(ab);
1451         if (call_panic)
1452                 audit_panic("error converting sid to string");
1453 }
1454 
1455 /**
1456  * audit_free - free a per-task audit context
1457  * @tsk: task whose audit context block to free
1458  *
1459  * Called from copy_process and do_exit
1460  */
1461 void __audit_free(struct task_struct *tsk)
1462 {
1463         struct audit_context *context;
1464 
1465         context = audit_take_context(tsk, 0, 0);
1466         if (!context)
1467                 return;
1468 
1469         /* Check for system calls that do not go through the exit
1470          * function (e.g., exit_group), then free context block.
1471          * We use GFP_ATOMIC here because we might be doing this
1472          * in the context of the idle thread */
1473         /* that can happen only if we are called from do_exit() */
1474         if (context->in_syscall && context->current_state == AUDIT_RECORD_CONTEXT)
1475                 audit_log_exit(context, tsk);
1476         if (!list_empty(&context->killed_trees))
1477                 audit_kill_trees(&context->killed_trees);
1478 
1479         audit_free_context(context);
1480 }
1481 
1482 /**
1483  * audit_syscall_entry - fill in an audit record at syscall entry
1484  * @major: major syscall type (function)
1485  * @a1: additional syscall register 1
1486  * @a2: additional syscall register 2
1487  * @a3: additional syscall register 3
1488  * @a4: additional syscall register 4
1489  *
1490  * Fill in audit context at syscall entry.  This only happens if the
1491  * audit context was created when the task was created and the state or
1492  * filters demand the audit context be built.  If the state from the
1493  * per-task filter or from the per-syscall filter is AUDIT_RECORD_CONTEXT,
1494  * then the record will be written at syscall exit time (otherwise, it
1495  * will only be written if another part of the kernel requests that it
1496  * be written).
1497  */
1498 void __audit_syscall_entry(int major, unsigned long a1, unsigned long a2,
1499                            unsigned long a3, unsigned long a4)
1500 {
1501         struct task_struct *tsk = current;
1502         struct audit_context *context = tsk->audit_context;
1503         enum audit_state     state;
1504 
1505         if (!context)
1506                 return;
1507 
1508         BUG_ON(context->in_syscall || context->name_count);
1509 
1510         if (!audit_enabled)
1511                 return;
1512 
1513         context->arch       = syscall_get_arch();
1514         context->major      = major;
1515         context->argv[0]    = a1;
1516         context->argv[1]    = a2;
1517         context->argv[2]    = a3;
1518         context->argv[3]    = a4;
1519 
1520         state = context->state;
1521         context->dummy = !audit_n_rules;
1522         if (!context->dummy && state == AUDIT_BUILD_CONTEXT) {
1523                 context->prio = 0;
1524                 state = audit_filter_syscall(tsk, context, &audit_filter_list[AUDIT_FILTER_ENTRY]);
1525         }
1526         if (state == AUDIT_DISABLED)
1527                 return;
1528 
1529         context->serial     = 0;
1530         context->ctime      = CURRENT_TIME;
1531         context->in_syscall = 1;
1532         context->current_state  = state;
1533         context->ppid       = 0;
1534 }
1535 
1536 /**
1537  * audit_syscall_exit - deallocate audit context after a system call
1538  * @success: success value of the syscall
1539  * @return_code: return value of the syscall
1540  *
1541  * Tear down after system call.  If the audit context has been marked as
1542  * auditable (either because of the AUDIT_RECORD_CONTEXT state from
1543  * filtering, or because some other part of the kernel wrote an audit
1544  * message), then write out the syscall information.  In call cases,
1545  * free the names stored from getname().
1546  */
1547 void __audit_syscall_exit(int success, long return_code)
1548 {
1549         struct task_struct *tsk = current;
1550         struct audit_context *context;
1551 
1552         if (success)
1553                 success = AUDITSC_SUCCESS;
1554         else
1555                 success = AUDITSC_FAILURE;
1556 
1557         context = audit_take_context(tsk, success, return_code);
1558         if (!context)
1559                 return;
1560 
1561         if (context->in_syscall && context->current_state == AUDIT_RECORD_CONTEXT)
1562                 audit_log_exit(context, tsk);
1563 
1564         context->in_syscall = 0;
1565         context->prio = context->state == AUDIT_RECORD_CONTEXT ? ~0ULL : 0;
1566 
1567         if (!list_empty(&context->killed_trees))
1568                 audit_kill_trees(&context->killed_trees);
1569 
1570         audit_free_names(context);
1571         unroll_tree_refs(context, NULL, 0);
1572         audit_free_aux(context);
1573         context->aux = NULL;
1574         context->aux_pids = NULL;
1575         context->target_pid = 0;
1576         context->target_sid = 0;
1577         context->sockaddr_len = 0;
1578         context->type = 0;
1579         context->fds[0] = -1;
1580         if (context->state != AUDIT_RECORD_CONTEXT) {
1581                 kfree(context->filterkey);
1582                 context->filterkey = NULL;
1583         }
1584         tsk->audit_context = context;
1585 }
1586 
1587 static inline void handle_one(const struct inode *inode)
1588 {
1589 #ifdef CONFIG_AUDIT_TREE
1590         struct audit_context *context;
1591         struct audit_tree_refs *p;
1592         struct audit_chunk *chunk;
1593         int count;
1594         if (likely(hlist_empty(&inode->i_fsnotify_marks)))
1595                 return;
1596         context = current->audit_context;
1597         p = context->trees;
1598         count = context->tree_count;
1599         rcu_read_lock();
1600         chunk = audit_tree_lookup(inode);
1601         rcu_read_unlock();
1602         if (!chunk)
1603                 return;
1604         if (likely(put_tree_ref(context, chunk)))
1605                 return;
1606         if (unlikely(!grow_tree_refs(context))) {
1607                 pr_warn("out of memory, audit has lost a tree reference\n");
1608                 audit_set_auditable(context);
1609                 audit_put_chunk(chunk);
1610                 unroll_tree_refs(context, p, count);
1611                 return;
1612         }
1613         put_tree_ref(context, chunk);
1614 #endif
1615 }
1616 
1617 static void handle_path(const struct dentry *dentry)
1618 {
1619 #ifdef CONFIG_AUDIT_TREE
1620         struct audit_context *context;
1621         struct audit_tree_refs *p;
1622         const struct dentry *d, *parent;
1623         struct audit_chunk *drop;
1624         unsigned long seq;
1625         int count;
1626 
1627         context = current->audit_context;
1628         p = context->trees;
1629         count = context->tree_count;
1630 retry:
1631         drop = NULL;
1632         d = dentry;
1633         rcu_read_lock();
1634         seq = read_seqbegin(&rename_lock);
1635         for(;;) {
1636                 struct inode *inode = d_backing_inode(d);
1637                 if (inode && unlikely(!hlist_empty(&inode->i_fsnotify_marks))) {
1638                         struct audit_chunk *chunk;
1639                         chunk = audit_tree_lookup(inode);
1640                         if (chunk) {
1641                                 if (unlikely(!put_tree_ref(context, chunk))) {
1642                                         drop = chunk;
1643                                         break;
1644                                 }
1645                         }
1646                 }
1647                 parent = d->d_parent;
1648                 if (parent == d)
1649                         break;
1650                 d = parent;
1651         }
1652         if (unlikely(read_seqretry(&rename_lock, seq) || drop)) {  /* in this order */
1653                 rcu_read_unlock();
1654                 if (!drop) {
1655                         /* just a race with rename */
1656                         unroll_tree_refs(context, p, count);
1657                         goto retry;
1658                 }
1659                 audit_put_chunk(drop);
1660                 if (grow_tree_refs(context)) {
1661                         /* OK, got more space */
1662                         unroll_tree_refs(context, p, count);
1663                         goto retry;
1664                 }
1665                 /* too bad */
1666                 pr_warn("out of memory, audit has lost a tree reference\n");
1667                 unroll_tree_refs(context, p, count);
1668                 audit_set_auditable(context);
1669                 return;
1670         }
1671         rcu_read_unlock();
1672 #endif
1673 }
1674 
1675 static struct audit_names *audit_alloc_name(struct audit_context *context,
1676                                                 unsigned char type)
1677 {
1678         struct audit_names *aname;
1679 
1680         if (context->name_count < AUDIT_NAMES) {
1681                 aname = &context->preallocated_names[context->name_count];
1682                 memset(aname, 0, sizeof(*aname));
1683         } else {
1684                 aname = kzalloc(sizeof(*aname), GFP_NOFS);
1685                 if (!aname)
1686                         return NULL;
1687                 aname->should_free = true;
1688         }
1689 
1690         aname->ino = AUDIT_INO_UNSET;
1691         aname->type = type;
1692         list_add_tail(&aname->list, &context->names_list);
1693 
1694         context->name_count++;
1695         return aname;
1696 }
1697 
1698 /**
1699  * audit_reusename - fill out filename with info from existing entry
1700  * @uptr: userland ptr to pathname
1701  *
1702  * Search the audit_names list for the current audit context. If there is an
1703  * existing entry with a matching "uptr" then return the filename
1704  * associated with that audit_name. If not, return NULL.
1705  */
1706 struct filename *
1707 __audit_reusename(const __user char *uptr)
1708 {
1709         struct audit_context *context = current->audit_context;
1710         struct audit_names *n;
1711 
1712         list_for_each_entry(n, &context->names_list, list) {
1713                 if (!n->name)
1714                         continue;
1715                 if (n->name->uptr == uptr) {
1716                         n->name->refcnt++;
1717                         return n->name;
1718                 }
1719         }
1720         return NULL;
1721 }
1722 
1723 /**
1724  * audit_getname - add a name to the list
1725  * @name: name to add
1726  *
1727  * Add a name to the list of audit names for this context.
1728  * Called from fs/namei.c:getname().
1729  */
1730 void __audit_getname(struct filename *name)
1731 {
1732         struct audit_context *context = current->audit_context;
1733         struct audit_names *n;
1734 
1735         if (!context->in_syscall)
1736                 return;
1737 
1738         n = audit_alloc_name(context, AUDIT_TYPE_UNKNOWN);
1739         if (!n)
1740                 return;
1741 
1742         n->name = name;
1743         n->name_len = AUDIT_NAME_FULL;
1744         name->aname = n;
1745         name->refcnt++;
1746 
1747         if (!context->pwd.dentry)
1748                 get_fs_pwd(current->fs, &context->pwd);
1749 }
1750 
1751 /**
1752  * __audit_inode - store the inode and device from a lookup
1753  * @name: name being audited
1754  * @dentry: dentry being audited
1755  * @flags: attributes for this particular entry
1756  */
1757 void __audit_inode(struct filename *name, const struct dentry *dentry,
1758                    unsigned int flags)
1759 {
1760         struct audit_context *context = current->audit_context;
1761         struct inode *inode = d_backing_inode(dentry);
1762         struct audit_names *n;
1763         bool parent = flags & AUDIT_INODE_PARENT;
1764 
1765         if (!context->in_syscall)
1766                 return;
1767 
1768         if (!name)
1769                 goto out_alloc;
1770 
1771         /*
1772          * If we have a pointer to an audit_names entry already, then we can
1773          * just use it directly if the type is correct.
1774          */
1775         n = name->aname;
1776         if (n) {
1777                 if (parent) {
1778                         if (n->type == AUDIT_TYPE_PARENT ||
1779                             n->type == AUDIT_TYPE_UNKNOWN)
1780                                 goto out;
1781                 } else {
1782                         if (n->type != AUDIT_TYPE_PARENT)
1783                                 goto out;
1784                 }
1785         }
1786 
1787         list_for_each_entry_reverse(n, &context->names_list, list) {
1788                 if (n->ino) {
1789                         /* valid inode number, use that for the comparison */
1790                         if (n->ino != inode->i_ino ||
1791                             n->dev != inode->i_sb->s_dev)
1792                                 continue;
1793                 } else if (n->name) {
1794                         /* inode number has not been set, check the name */
1795                         if (strcmp(n->name->name, name->name))
1796                                 continue;
1797                 } else
1798                         /* no inode and no name (?!) ... this is odd ... */
1799                         continue;
1800 
1801                 /* match the correct record type */
1802                 if (parent) {
1803                         if (n->type == AUDIT_TYPE_PARENT ||
1804                             n->type == AUDIT_TYPE_UNKNOWN)
1805                                 goto out;
1806                 } else {
1807                         if (n->type != AUDIT_TYPE_PARENT)
1808                                 goto out;
1809                 }
1810         }
1811 
1812 out_alloc:
1813         /* unable to find an entry with both a matching name and type */
1814         n = audit_alloc_name(context, AUDIT_TYPE_UNKNOWN);
1815         if (!n)
1816                 return;
1817         if (name) {
1818                 n->name = name;
1819                 name->refcnt++;
1820         }
1821 
1822 out:
1823         if (parent) {
1824                 n->name_len = n->name ? parent_len(n->name->name) : AUDIT_NAME_FULL;
1825                 n->type = AUDIT_TYPE_PARENT;
1826                 if (flags & AUDIT_INODE_HIDDEN)
1827                         n->hidden = true;
1828         } else {
1829                 n->name_len = AUDIT_NAME_FULL;
1830                 n->type = AUDIT_TYPE_NORMAL;
1831         }
1832         handle_path(dentry);
1833         audit_copy_inode(n, dentry, inode);
1834 }
1835 
1836 void __audit_file(const struct file *file)
1837 {
1838         __audit_inode(NULL, file->f_path.dentry, 0);
1839 }
1840 
1841 /**
1842  * __audit_inode_child - collect inode info for created/removed objects
1843  * @parent: inode of dentry parent
1844  * @dentry: dentry being audited
1845  * @type:   AUDIT_TYPE_* value that we're looking for
1846  *
1847  * For syscalls that create or remove filesystem objects, audit_inode
1848  * can only collect information for the filesystem object's parent.
1849  * This call updates the audit context with the child's information.
1850  * Syscalls that create a new filesystem object must be hooked after
1851  * the object is created.  Syscalls that remove a filesystem object
1852  * must be hooked prior, in order to capture the target inode during
1853  * unsuccessful attempts.
1854  */
1855 void __audit_inode_child(struct inode *parent,
1856                          const struct dentry *dentry,
1857                          const unsigned char type)
1858 {
1859         struct audit_context *context = current->audit_context;
1860         struct inode *inode = d_backing_inode(dentry);
1861         const char *dname = dentry->d_name.name;
1862         struct audit_names *n, *found_parent = NULL, *found_child = NULL;
1863 
1864         if (!context->in_syscall)
1865                 return;
1866 
1867         if (inode)
1868                 handle_one(inode);
1869 
1870         /* look for a parent entry first */
1871         list_for_each_entry(n, &context->names_list, list) {
1872                 if (!n->name ||
1873                     (n->type != AUDIT_TYPE_PARENT &&
1874                      n->type != AUDIT_TYPE_UNKNOWN))
1875                         continue;
1876 
1877                 if (n->ino == parent->i_ino && n->dev == parent->i_sb->s_dev &&
1878                     !audit_compare_dname_path(dname,
1879                                               n->name->name, n->name_len)) {
1880                         if (n->type == AUDIT_TYPE_UNKNOWN)
1881                                 n->type = AUDIT_TYPE_PARENT;
1882                         found_parent = n;
1883                         break;
1884                 }
1885         }
1886 
1887         /* is there a matching child entry? */
1888         list_for_each_entry(n, &context->names_list, list) {
1889                 /* can only match entries that have a name */
1890                 if (!n->name ||
1891                     (n->type != type && n->type != AUDIT_TYPE_UNKNOWN))
1892                         continue;
1893 
1894                 if (!strcmp(dname, n->name->name) ||
1895                     !audit_compare_dname_path(dname, n->name->name,
1896                                                 found_parent ?
1897                                                 found_parent->name_len :
1898                                                 AUDIT_NAME_FULL)) {
1899                         if (n->type == AUDIT_TYPE_UNKNOWN)
1900                                 n->type = type;
1901                         found_child = n;
1902                         break;
1903                 }
1904         }
1905 
1906         if (!found_parent) {
1907                 /* create a new, "anonymous" parent record */
1908                 n = audit_alloc_name(context, AUDIT_TYPE_PARENT);
1909                 if (!n)
1910                         return;
1911                 audit_copy_inode(n, NULL, parent);
1912         }
1913 
1914         if (!found_child) {
1915                 found_child = audit_alloc_name(context, type);
1916                 if (!found_child)
1917                         return;
1918 
1919                 /* Re-use the name belonging to the slot for a matching parent
1920                  * directory. All names for this context are relinquished in
1921                  * audit_free_names() */
1922                 if (found_parent) {
1923                         found_child->name = found_parent->name;
1924                         found_child->name_len = AUDIT_NAME_FULL;
1925                         found_child->name->refcnt++;
1926                 }
1927         }
1928 
1929         if (inode)
1930                 audit_copy_inode(found_child, dentry, inode);
1931         else
1932                 found_child->ino = AUDIT_INO_UNSET;
1933 }
1934 EXPORT_SYMBOL_GPL(__audit_inode_child);
1935 
1936 /**
1937  * auditsc_get_stamp - get local copies of audit_context values
1938  * @ctx: audit_context for the task
1939  * @t: timespec to store time recorded in the audit_context
1940  * @serial: serial value that is recorded in the audit_context
1941  *
1942  * Also sets the context as auditable.
1943  */
1944 int auditsc_get_stamp(struct audit_context *ctx,
1945                        struct timespec *t, unsigned int *serial)
1946 {
1947         if (!ctx->in_syscall)
1948                 return 0;
1949         if (!ctx->serial)
1950                 ctx->serial = audit_serial();
1951         t->tv_sec  = ctx->ctime.tv_sec;
1952         t->tv_nsec = ctx->ctime.tv_nsec;
1953         *serial    = ctx->serial;
1954         if (!ctx->prio) {
1955                 ctx->prio = 1;
1956                 ctx->current_state = AUDIT_RECORD_CONTEXT;
1957         }
1958         return 1;
1959 }
1960 
1961 /* global counter which is incremented every time something logs in */
1962 static atomic_t session_id = ATOMIC_INIT(0);
1963 
1964 static int audit_set_loginuid_perm(kuid_t loginuid)
1965 {
1966         /* if we are unset, we don't need privs */
1967         if (!audit_loginuid_set(current))
1968                 return 0;
1969         /* if AUDIT_FEATURE_LOGINUID_IMMUTABLE means never ever allow a change*/
1970         if (is_audit_feature_set(AUDIT_FEATURE_LOGINUID_IMMUTABLE))
1971                 return -EPERM;
1972         /* it is set, you need permission */
1973         if (!capable(CAP_AUDIT_CONTROL))
1974                 return -EPERM;
1975         /* reject if this is not an unset and we don't allow that */
1976         if (is_audit_feature_set(AUDIT_FEATURE_ONLY_UNSET_LOGINUID) && uid_valid(loginuid))
1977                 return -EPERM;
1978         return 0;
1979 }
1980 
1981 static void audit_log_set_loginuid(kuid_t koldloginuid, kuid_t kloginuid,
1982                                    unsigned int oldsessionid, unsigned int sessionid,
1983                                    int rc)
1984 {
1985         struct audit_buffer *ab;
1986         uid_t uid, oldloginuid, loginuid;
1987         struct tty_struct *tty;
1988 
1989         if (!audit_enabled)
1990                 return;
1991 
1992         ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_LOGIN);
1993         if (!ab)
1994                 return;
1995 
1996         uid = from_kuid(&init_user_ns, task_uid(current));
1997         oldloginuid = from_kuid(&init_user_ns, koldloginuid);
1998         loginuid = from_kuid(&init_user_ns, kloginuid),
1999         tty = audit_get_tty(current);
2000 
2001         audit_log_format(ab, "pid=%d uid=%u", task_tgid_nr(current), uid);
2002         audit_log_task_context(ab);
2003         audit_log_format(ab, " old-auid=%u auid=%u tty=%s old-ses=%u ses=%u res=%d",
2004                          oldloginuid, loginuid, tty ? tty_name(tty) : "(none)",
2005                          oldsessionid, sessionid, !rc);
2006         audit_put_tty(tty);
2007         audit_log_end(ab);
2008 }
2009 
2010 /**
2011  * audit_set_loginuid - set current task's audit_context loginuid
2012  * @loginuid: loginuid value
2013  *
2014  * Returns 0.
2015  *
2016  * Called (set) from fs/proc/base.c::proc_loginuid_write().
2017  */
2018 int audit_set_loginuid(kuid_t loginuid)
2019 {
2020         struct task_struct *task = current;
2021         unsigned int oldsessionid, sessionid = (unsigned int)-1;
2022         kuid_t oldloginuid;
2023         int rc;
2024 
2025         oldloginuid = audit_get_loginuid(current);
2026         oldsessionid = audit_get_sessionid(current);
2027 
2028         rc = audit_set_loginuid_perm(loginuid);
2029         if (rc)
2030                 goto out;
2031 
2032         /* are we setting or clearing? */
2033         if (uid_valid(loginuid)) {
2034                 sessionid = (unsigned int)atomic_inc_return(&session_id);
2035                 if (unlikely(sessionid == (unsigned int)-1))
2036                         sessionid = (unsigned int)atomic_inc_return(&session_id);
2037         }
2038 
2039         task->sessionid = sessionid;
2040         task->loginuid = loginuid;
2041 out:
2042         audit_log_set_loginuid(oldloginuid, loginuid, oldsessionid, sessionid, rc);
2043         return rc;
2044 }
2045 
2046 /**
2047  * __audit_mq_open - record audit data for a POSIX MQ open
2048  * @oflag: open flag
2049  * @mode: mode bits
2050  * @attr: queue attributes
2051  *
2052  */
2053 void __audit_mq_open(int oflag, umode_t mode, struct mq_attr *attr)
2054 {
2055         struct audit_context *context = current->audit_context;
2056 
2057         if (attr)
2058                 memcpy(&context->mq_open.attr, attr, sizeof(struct mq_attr));
2059         else
2060                 memset(&context->mq_open.attr, 0, sizeof(struct mq_attr));
2061 
2062         context->mq_open.oflag = oflag;
2063         context->mq_open.mode = mode;
2064 
2065         context->type = AUDIT_MQ_OPEN;
2066 }
2067 
2068 /**
2069  * __audit_mq_sendrecv - record audit data for a POSIX MQ timed send/receive
2070  * @mqdes: MQ descriptor
2071  * @msg_len: Message length
2072  * @msg_prio: Message priority
2073  * @abs_timeout: Message timeout in absolute time
2074  *
2075  */
2076 void __audit_mq_sendrecv(mqd_t mqdes, size_t msg_len, unsigned int msg_prio,
2077                         const struct timespec *abs_timeout)
2078 {
2079         struct audit_context *context = current->audit_context;
2080         struct timespec *p = &context->mq_sendrecv.abs_timeout;
2081 
2082         if (abs_timeout)
2083                 memcpy(p, abs_timeout, sizeof(struct timespec));
2084         else
2085                 memset(p, 0, sizeof(struct timespec));
2086 
2087         context->mq_sendrecv.mqdes = mqdes;
2088         context->mq_sendrecv.msg_len = msg_len;
2089         context->mq_sendrecv.msg_prio = msg_prio;
2090 
2091         context->type = AUDIT_MQ_SENDRECV;
2092 }
2093 
2094 /**
2095  * __audit_mq_notify - record audit data for a POSIX MQ notify
2096  * @mqdes: MQ descriptor
2097  * @notification: Notification event
2098  *
2099  */
2100 
2101 void __audit_mq_notify(mqd_t mqdes, const struct sigevent *notification)
2102 {
2103         struct audit_context *context = current->audit_context;
2104 
2105         if (notification)
2106                 context->mq_notify.sigev_signo = notification->sigev_signo;
2107         else
2108                 context->mq_notify.sigev_signo = 0;
2109 
2110         context->mq_notify.mqdes = mqdes;
2111         context->type = AUDIT_MQ_NOTIFY;
2112 }
2113 
2114 /**
2115  * __audit_mq_getsetattr - record audit data for a POSIX MQ get/set attribute
2116  * @mqdes: MQ descriptor
2117  * @mqstat: MQ flags
2118  *
2119  */
2120 void __audit_mq_getsetattr(mqd_t mqdes, struct mq_attr *mqstat)
2121 {
2122         struct audit_context *context = current->audit_context;
2123         context->mq_getsetattr.mqdes = mqdes;
2124         context->mq_getsetattr.mqstat = *mqstat;
2125         context->type = AUDIT_MQ_GETSETATTR;
2126 }
2127 
2128 /**
2129  * audit_ipc_obj - record audit data for ipc object
2130  * @ipcp: ipc permissions
2131  *
2132  */
2133 void __audit_ipc_obj(struct kern_ipc_perm *ipcp)
2134 {
2135         struct audit_context *context = current->audit_context;
2136         context->ipc.uid = ipcp->uid;
2137         context->ipc.gid = ipcp->gid;
2138         context->ipc.mode = ipcp->mode;
2139         context->ipc.has_perm = 0;
2140         security_ipc_getsecid(ipcp, &context->ipc.osid);
2141         context->type = AUDIT_IPC;
2142 }
2143 
2144 /**
2145  * audit_ipc_set_perm - record audit data for new ipc permissions
2146  * @qbytes: msgq bytes
2147  * @uid: msgq user id
2148  * @gid: msgq group id
2149  * @mode: msgq mode (permissions)
2150  *
2151  * Called only after audit_ipc_obj().
2152  */
2153 void __audit_ipc_set_perm(unsigned long qbytes, uid_t uid, gid_t gid, umode_t mode)
2154 {
2155         struct audit_context *context = current->audit_context;
2156 
2157         context->ipc.qbytes = qbytes;
2158         context->ipc.perm_uid = uid;
2159         context->ipc.perm_gid = gid;
2160         context->ipc.perm_mode = mode;
2161         context->ipc.has_perm = 1;
2162 }
2163 
2164 void __audit_bprm(struct linux_binprm *bprm)
2165 {
2166         struct audit_context *context = current->audit_context;
2167 
2168         context->type = AUDIT_EXECVE;
2169         context->execve.argc = bprm->argc;
2170 }
2171 
2172 
2173 /**
2174  * audit_socketcall - record audit data for sys_socketcall
2175  * @nargs: number of args, which should not be more than AUDITSC_ARGS.
2176  * @args: args array
2177  *
2178  */
2179 int __audit_socketcall(int nargs, unsigned long *args)
2180 {
2181         struct audit_context *context = current->audit_context;
2182 
2183         if (nargs <= 0 || nargs > AUDITSC_ARGS || !args)
2184                 return -EINVAL;
2185         context->type = AUDIT_SOCKETCALL;
2186         context->socketcall.nargs = nargs;
2187         memcpy(context->socketcall.args, args, nargs * sizeof(unsigned long));
2188         return 0;
2189 }
2190 
2191 /**
2192  * __audit_fd_pair - record audit data for pipe and socketpair
2193  * @fd1: the first file descriptor
2194  * @fd2: the second file descriptor
2195  *
2196  */
2197 void __audit_fd_pair(int fd1, int fd2)
2198 {
2199         struct audit_context *context = current->audit_context;
2200         context->fds[0] = fd1;
2201         context->fds[1] = fd2;
2202 }
2203 
2204 /**
2205  * audit_sockaddr - record audit data for sys_bind, sys_connect, sys_sendto
2206  * @len: data length in user space
2207  * @a: data address in kernel space
2208  *
2209  * Returns 0 for success or NULL context or < 0 on error.
2210  */
2211 int __audit_sockaddr(int len, void *a)
2212 {
2213         struct audit_context *context = current->audit_context;
2214 
2215         if (!context->sockaddr) {
2216                 void *p = kmalloc(sizeof(struct sockaddr_storage), GFP_KERNEL);
2217                 if (!p)
2218                         return -ENOMEM;
2219                 context->sockaddr = p;
2220         }
2221 
2222         context->sockaddr_len = len;
2223         memcpy(context->sockaddr, a, len);
2224         return 0;
2225 }
2226 
2227 void __audit_ptrace(struct task_struct *t)
2228 {
2229         struct audit_context *context = current->audit_context;
2230 
2231         context->target_pid = task_tgid_nr(t);
2232         context->target_auid = audit_get_loginuid(t);
2233         context->target_uid = task_uid(t);
2234         context->target_sessionid = audit_get_sessionid(t);
2235         security_task_getsecid(t, &context->target_sid);
2236         memcpy(context->target_comm, t->comm, TASK_COMM_LEN);
2237 }
2238 
2239 /**
2240  * audit_signal_info - record signal info for shutting down audit subsystem
2241  * @sig: signal value
2242  * @t: task being signaled
2243  *
2244  * If the audit subsystem is being terminated, record the task (pid)
2245  * and uid that is doing that.
2246  */
2247 int __audit_signal_info(int sig, struct task_struct *t)
2248 {
2249         struct audit_aux_data_pids *axp;
2250         struct task_struct *tsk = current;
2251         struct audit_context *ctx = tsk->audit_context;
2252         kuid_t uid = current_uid(), t_uid = task_uid(t);
2253 
2254         if (audit_pid && t->tgid == audit_pid) {
2255                 if (sig == SIGTERM || sig == SIGHUP || sig == SIGUSR1 || sig == SIGUSR2) {
2256                         audit_sig_pid = task_tgid_nr(tsk);
2257                         if (uid_valid(tsk->loginuid))
2258                                 audit_sig_uid = tsk->loginuid;
2259                         else
2260                                 audit_sig_uid = uid;
2261                         security_task_getsecid(tsk, &audit_sig_sid);
2262                 }
2263                 if (!audit_signals || audit_dummy_context())
2264                         return 0;
2265         }
2266 
2267         /* optimize the common case by putting first signal recipient directly
2268          * in audit_context */
2269         if (!ctx->target_pid) {
2270                 ctx->target_pid = task_tgid_nr(t);
2271                 ctx->target_auid = audit_get_loginuid(t);
2272                 ctx->target_uid = t_uid;
2273                 ctx->target_sessionid = audit_get_sessionid(t);
2274                 security_task_getsecid(t, &ctx->target_sid);
2275                 memcpy(ctx->target_comm, t->comm, TASK_COMM_LEN);
2276                 return 0;
2277         }
2278 
2279         axp = (void *)ctx->aux_pids;
2280         if (!axp || axp->pid_count == AUDIT_AUX_PIDS) {
2281                 axp = kzalloc(sizeof(*axp), GFP_ATOMIC);
2282                 if (!axp)
2283                         return -ENOMEM;
2284 
2285                 axp->d.type = AUDIT_OBJ_PID;
2286                 axp->d.next = ctx->aux_pids;
2287                 ctx->aux_pids = (void *)axp;
2288         }
2289         BUG_ON(axp->pid_count >= AUDIT_AUX_PIDS);
2290 
2291         axp->target_pid[axp->pid_count] = task_tgid_nr(t);
2292         axp->target_auid[axp->pid_count] = audit_get_loginuid(t);
2293         axp->target_uid[axp->pid_count] = t_uid;
2294         axp->target_sessionid[axp->pid_count] = audit_get_sessionid(t);
2295         security_task_getsecid(t, &axp->target_sid[axp->pid_count]);
2296         memcpy(axp->target_comm[axp->pid_count], t->comm, TASK_COMM_LEN);
2297         axp->pid_count++;
2298 
2299         return 0;
2300 }
2301 
2302 /**
2303  * __audit_log_bprm_fcaps - store information about a loading bprm and relevant fcaps
2304  * @bprm: pointer to the bprm being processed
2305  * @new: the proposed new credentials
2306  * @old: the old credentials
2307  *
2308  * Simply check if the proc already has the caps given by the file and if not
2309  * store the priv escalation info for later auditing at the end of the syscall
2310  *
2311  * -Eric
2312  */
2313 int __audit_log_bprm_fcaps(struct linux_binprm *bprm,
2314                            const struct cred *new, const struct cred *old)
2315 {
2316         struct audit_aux_data_bprm_fcaps *ax;
2317         struct audit_context *context = current->audit_context;
2318         struct cpu_vfs_cap_data vcaps;
2319 
2320         ax = kmalloc(sizeof(*ax), GFP_KERNEL);
2321         if (!ax)
2322                 return -ENOMEM;
2323 
2324         ax->d.type = AUDIT_BPRM_FCAPS;
2325         ax->d.next = context->aux;
2326         context->aux = (void *)ax;
2327 
2328         get_vfs_caps_from_disk(bprm->file->f_path.dentry, &vcaps);
2329 
2330         ax->fcap.permitted = vcaps.permitted;
2331         ax->fcap.inheritable = vcaps.inheritable;
2332         ax->fcap.fE = !!(vcaps.magic_etc & VFS_CAP_FLAGS_EFFECTIVE);
2333         ax->fcap_ver = (vcaps.magic_etc & VFS_CAP_REVISION_MASK) >> VFS_CAP_REVISION_SHIFT;
2334 
2335         ax->old_pcap.permitted   = old->cap_permitted;
2336         ax->old_pcap.inheritable = old->cap_inheritable;
2337         ax->old_pcap.effective   = old->cap_effective;
2338 
2339         ax->new_pcap.permitted   = new->cap_permitted;
2340         ax->new_pcap.inheritable = new->cap_inheritable;
2341         ax->new_pcap.effective   = new->cap_effective;
2342         return 0;
2343 }
2344 
2345 /**
2346  * __audit_log_capset - store information about the arguments to the capset syscall
2347  * @new: the new credentials
2348  * @old: the old (current) credentials
2349  *
2350  * Record the arguments userspace sent to sys_capset for later printing by the
2351  * audit system if applicable
2352  */
2353 void __audit_log_capset(const struct cred *new, const struct cred *old)
2354 {
2355         struct audit_context *context = current->audit_context;
2356         context->capset.pid = task_tgid_nr(current);
2357         context->capset.cap.effective   = new->cap_effective;
2358         context->capset.cap.inheritable = new->cap_effective;
2359         context->capset.cap.permitted   = new->cap_permitted;
2360         context->type = AUDIT_CAPSET;
2361 }
2362 
2363 void __audit_mmap_fd(int fd, int flags)
2364 {
2365         struct audit_context *context = current->audit_context;
2366         context->mmap.fd = fd;
2367         context->mmap.flags = flags;
2368         context->type = AUDIT_MMAP;
2369 }
2370 
2371 static void audit_log_task(struct audit_buffer *ab)
2372 {
2373         kuid_t auid, uid;
2374         kgid_t gid;
2375         unsigned int sessionid;
2376         char comm[sizeof(current->comm)];
2377 
2378         auid = audit_get_loginuid(current);
2379         sessionid = audit_get_sessionid(current);
2380         current_uid_gid(&uid, &gid);
2381 
2382         audit_log_format(ab, "auid=%u uid=%u gid=%u ses=%u",
2383                          from_kuid(&init_user_ns, auid),
2384                          from_kuid(&init_user_ns, uid),
2385                          from_kgid(&init_user_ns, gid),
2386                          sessionid);
2387         audit_log_task_context(ab);
2388         audit_log_format(ab, " pid=%d comm=", task_tgid_nr(current));
2389         audit_log_untrustedstring(ab, get_task_comm(comm, current));
2390         audit_log_d_path_exe(ab, current->mm);
2391 }
2392 
2393 /**
2394  * audit_core_dumps - record information about processes that end abnormally
2395  * @signr: signal value
2396  *
2397  * If a process ends with a core dump, something fishy is going on and we
2398  * should record the event for investigation.
2399  */
2400 void audit_core_dumps(long signr)
2401 {
2402         struct audit_buffer *ab;
2403 
2404         if (!audit_enabled)
2405                 return;
2406 
2407         if (signr == SIGQUIT)   /* don't care for those */
2408                 return;
2409 
2410         ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_ANOM_ABEND);
2411         if (unlikely(!ab))
2412                 return;
2413         audit_log_task(ab);
2414         audit_log_format(ab, " sig=%ld", signr);
2415         audit_log_end(ab);
2416 }
2417 
2418 void __audit_seccomp(unsigned long syscall, long signr, int code)
2419 {
2420         struct audit_buffer *ab;
2421 
2422         ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_SECCOMP);
2423         if (unlikely(!ab))
2424                 return;
2425         audit_log_task(ab);
2426         audit_log_format(ab, " sig=%ld arch=%x syscall=%ld compat=%d ip=0x%lx code=0x%x",
2427                          signr, syscall_get_arch(), syscall,
2428                          in_compat_syscall(), KSTK_EIP(current), code);
2429         audit_log_end(ab);
2430 }
2431 
2432 struct list_head *audit_killed_trees(void)
2433 {
2434         struct audit_context *ctx = current->audit_context;
2435         if (likely(!ctx || !ctx->in_syscall))
2436                 return NULL;
2437         return &ctx->killed_trees;
2438 }
2439 

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