SAFE public projects git trees. - safe/jmp/linux-2.6/blob - kernel/auditfilter.c

   1 /* auditfilter.c -- filtering of audit events
   2  *
   3  * Copyright 2003-2004 Red Hat, Inc.
   4  * Copyright 2005 Hewlett-Packard Development Company, L.P.
   5  * Copyright 2005 IBM Corporation
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  20  */
  21
  22 #include <linux/kernel.h>
  23 #include <linux/audit.h>
  24 #include <linux/kthread.h>
  25 #include <linux/mutex.h>
  26 #include <linux/fs.h>
  27 #include <linux/namei.h>
  28 #include <linux/netlink.h>
  29 #include <linux/sched.h>
  30 #include <linux/inotify.h>
  31 #include <linux/security.h>
  32 #include <linux/selinux.h>
  33 #include "audit.h"
  34
  35 /*
  36  * Locking model:
  37  *
  38  * audit_filter_mutex:
  39  *              Synchronizes writes and blocking reads of audit's filterlist
  40  *              data.  Rcu is used to traverse the filterlist and access
  41  *              contents of structs audit_entry, audit_watch and opaque
  42  *              selinux rules during filtering.  If modified, these structures
  43  *              must be copied and replace their counterparts in the filterlist.
  44  *              An audit_parent struct is not accessed during filtering, so may
  45  *              be written directly provided audit_filter_mutex is held.
  46  */
  47
  48 /*
  49  * Reference counting:
  50  *
  51  * audit_parent: lifetime is from audit_init_parent() to receipt of an IN_IGNORED
  52  *      event.  Each audit_watch holds a reference to its associated parent.
  53  *
  54  * audit_watch: if added to lists, lifetime is from audit_init_watch() to
  55  *      audit_remove_watch().  Additionally, an audit_watch may exist
  56  *      temporarily to assist in searching existing filter data.  Each
  57  *      audit_krule holds a reference to its associated watch.
  58  */
  59
  60 struct audit_parent {
  61         struct list_head        ilist;  /* entry in inotify registration list */
  62         struct list_head        watches; /* associated watches */
  63         struct inotify_watch    wdata;  /* inotify watch data */
  64         unsigned                flags;  /* status flags */
  65 };
  66
  67 /*
  68  * audit_parent status flags:
  69  *
  70  * AUDIT_PARENT_INVALID - set anytime rules/watches are auto-removed due to
  71  * a filesystem event to ensure we're adding audit watches to a valid parent.
  72  * Technically not needed for IN_DELETE_SELF or IN_UNMOUNT events, as we cannot
  73  * receive them while we have nameidata, but must be used for IN_MOVE_SELF which
  74  * we can receive while holding nameidata.
  75  */
  76 #define AUDIT_PARENT_INVALID    0x001
  77
  78 /* Audit filter lists, defined in <linux/audit.h> */
  79 struct list_head audit_filter_list[AUDIT_NR_FILTERS] = {
  80         LIST_HEAD_INIT(audit_filter_list[0]),
  81         LIST_HEAD_INIT(audit_filter_list[1]),
  82         LIST_HEAD_INIT(audit_filter_list[2]),
  83         LIST_HEAD_INIT(audit_filter_list[3]),
  84         LIST_HEAD_INIT(audit_filter_list[4]),
  85         LIST_HEAD_INIT(audit_filter_list[5]),
  86 #if AUDIT_NR_FILTERS != 6
  87 #error Fix audit_filter_list initialiser
  88 #endif
  89 };
  90
  91 DEFINE_MUTEX(audit_filter_mutex);
  92
  93 /* Inotify handle */
  94 extern struct inotify_handle *audit_ih;
  95
  96 /* Inotify events we care about. */
  97 #define AUDIT_IN_WATCH IN_MOVE|IN_CREATE|IN_DELETE|IN_DELETE_SELF|IN_MOVE_SELF
  98
  99 extern int audit_enabled;
 100
 101 void audit_free_parent(struct inotify_watch *i_watch)
 102 {
 103         struct audit_parent *parent;
 104
 105         parent = container_of(i_watch, struct audit_parent, wdata);
 106         WARN_ON(!list_empty(&parent->watches));
 107         kfree(parent);
 108 }
 109
 110 static inline void audit_get_watch(struct audit_watch *watch)
 111 {
 112         atomic_inc(&watch->count);
 113 }
 114
 115 static void audit_put_watch(struct audit_watch *watch)
 116 {
 117         if (atomic_dec_and_test(&watch->count)) {
 118                 WARN_ON(watch->parent);
 119                 WARN_ON(!list_empty(&watch->rules));
 120                 kfree(watch->path);
 121                 kfree(watch);
 122         }
 123 }
 124
 125 static void audit_remove_watch(struct audit_watch *watch)
 126 {
 127         list_del(&watch->wlist);
 128         put_inotify_watch(&watch->parent->wdata);
 129         watch->parent = NULL;
 130         audit_put_watch(watch); /* match initial get */
 131 }
 132
 133 static inline void audit_free_rule(struct audit_entry *e)
 134 {
 135         int i;
 136
 137         /* some rules don't have associated watches */
 138         if (e->rule.watch)
 139                 audit_put_watch(e->rule.watch);
 140         if (e->rule.fields)
 141                 for (i = 0; i < e->rule.field_count; i++) {
 142                         struct audit_field *f = &e->rule.fields[i];
 143                         kfree(f->se_str);
 144                         selinux_audit_rule_free(f->se_rule);
 145                 }
 146         kfree(e->rule.fields);
 147         kfree(e->rule.filterkey);
 148         kfree(e);
 149 }
 150
 151 void audit_free_rule_rcu(struct rcu_head *head)
 152 {
 153         struct audit_entry *e = container_of(head, struct audit_entry, rcu);
 154         audit_free_rule(e);
 155 }
 156
 157 /* Initialize a parent watch entry. */
 158 static struct audit_parent *audit_init_parent(struct nameidata *ndp)
 159 {
 160         struct audit_parent *parent;
 161         s32 wd;
 162
 163         parent = kzalloc(sizeof(*parent), GFP_KERNEL);
 164         if (unlikely(!parent))
 165                 return ERR_PTR(-ENOMEM);
 166
 167         INIT_LIST_HEAD(&parent->watches);
 168         parent->flags = 0;
 169
 170         inotify_init_watch(&parent->wdata);
 171         /* grab a ref so inotify watch hangs around until we take audit_filter_mutex */
 172         get_inotify_watch(&parent->wdata);
 173         wd = inotify_add_watch(audit_ih, &parent->wdata,
 174                                ndp->path.dentry->d_inode, AUDIT_IN_WATCH);
 175         if (wd < 0) {
 176                 audit_free_parent(&parent->wdata);
 177                 return ERR_PTR(wd);
 178         }
 179
 180         return parent;
 181 }
 182
 183 /* Initialize a watch entry. */
 184 static struct audit_watch *audit_init_watch(char *path)
 185 {
 186         struct audit_watch *watch;
 187
 188         watch = kzalloc(sizeof(*watch), GFP_KERNEL);
 189         if (unlikely(!watch))
 190                 return ERR_PTR(-ENOMEM);
 191
 192         INIT_LIST_HEAD(&watch->rules);
 193         atomic_set(&watch->count, 1);
 194         watch->path = path;
 195         watch->dev = (dev_t)-1;
 196         watch->ino = (unsigned long)-1;
 197
 198         return watch;
 199 }
 200
 201 /* Initialize an audit filterlist entry. */
 202 static inline struct audit_entry *audit_init_entry(u32 field_count)
 203 {
 204         struct audit_entry *entry;
 205         struct audit_field *fields;
 206
 207         entry = kzalloc(sizeof(*entry), GFP_KERNEL);
 208         if (unlikely(!entry))
 209                 return NULL;
 210
 211         fields = kzalloc(sizeof(*fields) * field_count, GFP_KERNEL);
 212         if (unlikely(!fields)) {
 213                 kfree(entry);
 214                 return NULL;
 215         }
 216         entry->rule.fields = fields;
 217
 218         return entry;
 219 }
 220
 221 /* Unpack a filter field's string representation from user-space
 222  * buffer. */
 223 char *audit_unpack_string(void **bufp, size_t *remain, size_t len)
 224 {
 225         char *str;
 226
 227         if (!*bufp || (len == 0) || (len > *remain))
 228                 return ERR_PTR(-EINVAL);
 229
 230         /* Of the currently implemented string fields, PATH_MAX
 231          * defines the longest valid length.
 232          */
 233         if (len > PATH_MAX)
 234                 return ERR_PTR(-ENAMETOOLONG);
 235
 236         str = kmalloc(len + 1, GFP_KERNEL);
 237         if (unlikely(!str))
 238                 return ERR_PTR(-ENOMEM);
 239
 240         memcpy(str, *bufp, len);
 241         str[len] = 0;
 242         *bufp += len;
 243         *remain -= len;
 244
 245         return str;
 246 }
 247
 248 /* Translate an inode field to kernel respresentation. */
 249 static inline int audit_to_inode(struct audit_krule *krule,
 250                                  struct audit_field *f)
 251 {
 252         if (krule->listnr != AUDIT_FILTER_EXIT ||
 253             krule->watch || krule->inode_f || krule->tree)
 254                 return -EINVAL;
 255
 256         krule->inode_f = f;
 257         return 0;
 258 }
 259
 260 /* Translate a watch string to kernel respresentation. */
 261 static int audit_to_watch(struct audit_krule *krule, char *path, int len,
 262                           u32 op)
 263 {
 264         struct audit_watch *watch;
 265
 266         if (!audit_ih)
 267                 return -EOPNOTSUPP;
 268
 269         if (path[0] != '/' || path[len-1] == '/' ||
 270             krule->listnr != AUDIT_FILTER_EXIT ||
 271             op & ~AUDIT_EQUAL ||
 272             krule->inode_f || krule->watch || krule->tree)
 273                 return -EINVAL;
 274
 275         watch = audit_init_watch(path);
 276         if (unlikely(IS_ERR(watch)))
 277                 return PTR_ERR(watch);
 278
 279         audit_get_watch(watch);
 280         krule->watch = watch;
 281
 282         return 0;
 283 }
 284
 285 static __u32 *classes[AUDIT_SYSCALL_CLASSES];
 286
 287 int __init audit_register_class(int class, unsigned *list)
 288 {
 289         __u32 *p = kzalloc(AUDIT_BITMASK_SIZE * sizeof(__u32), GFP_KERNEL);
 290         if (!p)
 291                 return -ENOMEM;
 292         while (*list != ~0U) {
 293                 unsigned n = *list++;
 294                 if (n >= AUDIT_BITMASK_SIZE * 32 - AUDIT_SYSCALL_CLASSES) {
 295                         kfree(p);
 296                         return -EINVAL;
 297                 }
 298                 p[AUDIT_WORD(n)] |= AUDIT_BIT(n);
 299         }
 300         if (class >= AUDIT_SYSCALL_CLASSES || classes[class]) {
 301                 kfree(p);
 302                 return -EINVAL;
 303         }
 304         classes[class] = p;
 305         return 0;
 306 }
 307
 308 int audit_match_class(int class, unsigned syscall)
 309 {
 310         if (unlikely(syscall >= AUDIT_BITMASK_SIZE * 32))
 311                 return 0;
 312         if (unlikely(class >= AUDIT_SYSCALL_CLASSES || !classes[class]))
 313                 return 0;
 314         return classes[class][AUDIT_WORD(syscall)] & AUDIT_BIT(syscall);
 315 }
 316
 317 #ifdef CONFIG_AUDITSYSCALL
 318 static inline int audit_match_class_bits(int class, u32 *mask)
 319 {
 320         int i;
 321
 322         if (classes[class]) {
 323                 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
 324                         if (mask[i] & classes[class][i])
 325                                 return 0;
 326         }
 327         return 1;
 328 }
 329
 330 static int audit_match_signal(struct audit_entry *entry)
 331 {
 332         struct audit_field *arch = entry->rule.arch_f;
 333
 334         if (!arch) {
 335                 /* When arch is unspecified, we must check both masks on biarch
 336                  * as syscall number alone is ambiguous. */
 337                 return (audit_match_class_bits(AUDIT_CLASS_SIGNAL,
 338                                                entry->rule.mask) &&
 339                         audit_match_class_bits(AUDIT_CLASS_SIGNAL_32,
 340                                                entry->rule.mask));
 341         }
 342
 343         switch(audit_classify_arch(arch->val)) {
 344         case 0: /* native */
 345                 return (audit_match_class_bits(AUDIT_CLASS_SIGNAL,
 346                                                entry->rule.mask));
 347         case 1: /* 32bit on biarch */
 348                 return (audit_match_class_bits(AUDIT_CLASS_SIGNAL_32,
 349                                                entry->rule.mask));
 350         default:
 351                 return 1;
 352         }
 353 }
 354 #endif
 355
 356 /* Common user-space to kernel rule translation. */
 357 static inline struct audit_entry *audit_to_entry_common(struct audit_rule *rule)
 358 {
 359         unsigned listnr;
 360         struct audit_entry *entry;
 361         int i, err;
 362
 363         err = -EINVAL;
 364         listnr = rule->flags & ~AUDIT_FILTER_PREPEND;
 365         switch(listnr) {
 366         default:
 367                 goto exit_err;
 368         case AUDIT_FILTER_USER:
 369         case AUDIT_FILTER_TYPE:
 370 #ifdef CONFIG_AUDITSYSCALL
 371         case AUDIT_FILTER_ENTRY:
 372         case AUDIT_FILTER_EXIT:
 373         case AUDIT_FILTER_TASK:
 374 #endif
 375                 ;
 376         }
 377         if (unlikely(rule->action == AUDIT_POSSIBLE)) {
 378                 printk(KERN_ERR "AUDIT_POSSIBLE is deprecated\n");
 379                 goto exit_err;
 380         }
 381         if (rule->action != AUDIT_NEVER && rule->action != AUDIT_ALWAYS)
 382                 goto exit_err;
 383         if (rule->field_count > AUDIT_MAX_FIELDS)
 384                 goto exit_err;
 385
 386         err = -ENOMEM;
 387         entry = audit_init_entry(rule->field_count);
 388         if (!entry)
 389                 goto exit_err;
 390
 391         entry->rule.flags = rule->flags & AUDIT_FILTER_PREPEND;
 392         entry->rule.listnr = listnr;
 393         entry->rule.action = rule->action;
 394         entry->rule.field_count = rule->field_count;
 395
 396         for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
 397                 entry->rule.mask[i] = rule->mask[i];
 398
 399         for (i = 0; i < AUDIT_SYSCALL_CLASSES; i++) {
 400                 int bit = AUDIT_BITMASK_SIZE * 32 - i - 1;
 401                 __u32 *p = &entry->rule.mask[AUDIT_WORD(bit)];
 402                 __u32 *class;
 403
 404                 if (!(*p & AUDIT_BIT(bit)))
 405                         continue;
 406                 *p &= ~AUDIT_BIT(bit);
 407                 class = classes[i];
 408                 if (class) {
 409                         int j;
 410                         for (j = 0; j < AUDIT_BITMASK_SIZE; j++)
 411                                 entry->rule.mask[j] |= class[j];
 412                 }
 413         }
 414
 415         return entry;
 416
 417 exit_err:
 418         return ERR_PTR(err);
 419 }
 420
 421 /* Translate struct audit_rule to kernel's rule respresentation.
 422  * Exists for backward compatibility with userspace. */
 423 static struct audit_entry *audit_rule_to_entry(struct audit_rule *rule)
 424 {
 425         struct audit_entry *entry;
 426         struct audit_field *f;
 427         int err = 0;
 428         int i;
 429
 430         entry = audit_to_entry_common(rule);
 431         if (IS_ERR(entry))
 432                 goto exit_nofree;
 433
 434         for (i = 0; i < rule->field_count; i++) {
 435                 struct audit_field *f = &entry->rule.fields[i];
 436
 437                 f->op = rule->fields[i] & (AUDIT_NEGATE|AUDIT_OPERATORS);
 438                 f->type = rule->fields[i] & ~(AUDIT_NEGATE|AUDIT_OPERATORS);
 439                 f->val = rule->values[i];
 440
 441                 err = -EINVAL;
 442                 switch(f->type) {
 443                 default:
 444                         goto exit_free;
 445                 case AUDIT_PID:
 446                 case AUDIT_UID:
 447                 case AUDIT_EUID:
 448                 case AUDIT_SUID:
 449                 case AUDIT_FSUID:
 450                 case AUDIT_GID:
 451                 case AUDIT_EGID:
 452                 case AUDIT_SGID:
 453                 case AUDIT_FSGID:
 454                 case AUDIT_LOGINUID:
 455                 case AUDIT_PERS:
 456                 case AUDIT_MSGTYPE:
 457                 case AUDIT_PPID:
 458                 case AUDIT_DEVMAJOR:
 459                 case AUDIT_DEVMINOR:
 460                 case AUDIT_EXIT:
 461                 case AUDIT_SUCCESS:
 462                         /* bit ops are only useful on syscall args */
 463                         if (f->op == AUDIT_BIT_MASK ||
 464                                                 f->op == AUDIT_BIT_TEST) {
 465                                 err = -EINVAL;
 466                                 goto exit_free;
 467                         }
 468                         break;
 469                 case AUDIT_ARG0:
 470                 case AUDIT_ARG1:
 471                 case AUDIT_ARG2:
 472                 case AUDIT_ARG3:
 473                         break;
 474                 /* arch is only allowed to be = or != */
 475                 case AUDIT_ARCH:
 476                         if ((f->op != AUDIT_NOT_EQUAL) && (f->op != AUDIT_EQUAL)
 477                                         && (f->op != AUDIT_NEGATE) && (f->op)) {
 478                                 err = -EINVAL;
 479                                 goto exit_free;
 480                         }
 481                         entry->rule.arch_f = f;
 482                         break;
 483                 case AUDIT_PERM:
 484                         if (f->val & ~15)
 485                                 goto exit_free;
 486                         break;
 487                 case AUDIT_INODE:
 488                         err = audit_to_inode(&entry->rule, f);
 489                         if (err)
 490                                 goto exit_free;
 491                         break;
 492                 }
 493
 494                 entry->rule.vers_ops = (f->op & AUDIT_OPERATORS) ? 2 : 1;
 495
 496                 /* Support for legacy operators where
 497                  * AUDIT_NEGATE bit signifies != and otherwise assumes == */
 498                 if (f->op & AUDIT_NEGATE)
 499                         f->op = AUDIT_NOT_EQUAL;
 500                 else if (!f->op)
 501                         f->op = AUDIT_EQUAL;
 502                 else if (f->op == AUDIT_OPERATORS) {
 503                         err = -EINVAL;
 504                         goto exit_free;
 505                 }
 506         }
 507
 508         f = entry->rule.inode_f;
 509         if (f) {
 510                 switch(f->op) {
 511                 case AUDIT_NOT_EQUAL:
 512                         entry->rule.inode_f = NULL;
 513                 case AUDIT_EQUAL:
 514                         break;
 515                 default:
 516                         err = -EINVAL;
 517                         goto exit_free;
 518                 }
 519         }
 520
 521 exit_nofree:
 522         return entry;
 523
 524 exit_free:
 525         audit_free_rule(entry);
 526         return ERR_PTR(err);
 527 }
 528
 529 /* Translate struct audit_rule_data to kernel's rule respresentation. */
 530 static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data,
 531                                                size_t datasz)
 532 {
 533         int err = 0;
 534         struct audit_entry *entry;
 535         struct audit_field *f;
 536         void *bufp;
 537         size_t remain = datasz - sizeof(struct audit_rule_data);
 538         int i;
 539         char *str;
 540
 541         entry = audit_to_entry_common((struct audit_rule *)data);
 542         if (IS_ERR(entry))
 543                 goto exit_nofree;
 544
 545         bufp = data->buf;
 546         entry->rule.vers_ops = 2;
 547         for (i = 0; i < data->field_count; i++) {
 548                 struct audit_field *f = &entry->rule.fields[i];
 549
 550                 err = -EINVAL;
 551                 if (!(data->fieldflags[i] & AUDIT_OPERATORS) ||
 552                     data->fieldflags[i] & ~AUDIT_OPERATORS)
 553                         goto exit_free;
 554
 555                 f->op = data->fieldflags[i] & AUDIT_OPERATORS;
 556                 f->type = data->fields[i];
 557                 f->val = data->values[i];
 558                 f->se_str = NULL;
 559                 f->se_rule = NULL;
 560                 switch(f->type) {
 561                 case AUDIT_PID:
 562                 case AUDIT_UID:
 563                 case AUDIT_EUID:
 564                 case AUDIT_SUID:
 565                 case AUDIT_FSUID:
 566                 case AUDIT_GID:
 567                 case AUDIT_EGID:
 568                 case AUDIT_SGID:
 569                 case AUDIT_FSGID:
 570                 case AUDIT_LOGINUID:
 571                 case AUDIT_PERS:
 572                 case AUDIT_MSGTYPE:
 573                 case AUDIT_PPID:
 574                 case AUDIT_DEVMAJOR:
 575                 case AUDIT_DEVMINOR:
 576                 case AUDIT_EXIT:
 577                 case AUDIT_SUCCESS:
 578                 case AUDIT_ARG0:
 579                 case AUDIT_ARG1:
 580                 case AUDIT_ARG2:
 581                 case AUDIT_ARG3:
 582                         break;
 583                 case AUDIT_ARCH:
 584                         entry->rule.arch_f = f;
 585                         break;
 586                 case AUDIT_SUBJ_USER:
 587                 case AUDIT_SUBJ_ROLE:
 588                 case AUDIT_SUBJ_TYPE:
 589                 case AUDIT_SUBJ_SEN:
 590                 case AUDIT_SUBJ_CLR:
 591                 case AUDIT_OBJ_USER:
 592                 case AUDIT_OBJ_ROLE:
 593                 case AUDIT_OBJ_TYPE:
 594                 case AUDIT_OBJ_LEV_LOW:
 595                 case AUDIT_OBJ_LEV_HIGH:
 596                         str = audit_unpack_string(&bufp, &remain, f->val);
 597                         if (IS_ERR(str))
 598                                 goto exit_free;
 599                         entry->rule.buflen += f->val;
 600
 601                         err = selinux_audit_rule_init(f->type, f->op, str,
 602                                                       &f->se_rule);
 603                         /* Keep currently invalid fields around in case they
 604                          * become valid after a policy reload. */
 605                         if (err == -EINVAL) {
 606                                 printk(KERN_WARNING "audit rule for selinux "
 607                                        "\'%s\' is invalid\n",  str);
 608                                 err = 0;
 609                         }
 610                         if (err) {
 611                                 kfree(str);
 612                                 goto exit_free;
 613                         } else
 614                                 f->se_str = str;
 615                         break;
 616                 case AUDIT_WATCH:
 617                         str = audit_unpack_string(&bufp, &remain, f->val);
 618                         if (IS_ERR(str))
 619                                 goto exit_free;
 620                         entry->rule.buflen += f->val;
 621
 622                         err = audit_to_watch(&entry->rule, str, f->val, f->op);
 623                         if (err) {
 624                                 kfree(str);
 625                                 goto exit_free;
 626                         }
 627                         break;
 628                 case AUDIT_DIR:
 629                         str = audit_unpack_string(&bufp, &remain, f->val);
 630                         if (IS_ERR(str))
 631                                 goto exit_free;
 632                         entry->rule.buflen += f->val;
 633
 634                         err = audit_make_tree(&entry->rule, str, f->op);
 635                         kfree(str);
 636                         if (err)
 637                                 goto exit_free;
 638                         break;
 639                 case AUDIT_INODE:
 640                         err = audit_to_inode(&entry->rule, f);
 641                         if (err)
 642                                 goto exit_free;
 643                         break;
 644                 case AUDIT_FILTERKEY:
 645                         err = -EINVAL;
 646                         if (entry->rule.filterkey || f->val > AUDIT_MAX_KEY_LEN)
 647                                 goto exit_free;
 648                         str = audit_unpack_string(&bufp, &remain, f->val);
 649                         if (IS_ERR(str))
 650                                 goto exit_free;
 651                         entry->rule.buflen += f->val;
 652                         entry->rule.filterkey = str;
 653                         break;
 654                 case AUDIT_PERM:
 655                         if (f->val & ~15)
 656                                 goto exit_free;
 657                         break;
 658                 default:
 659                         goto exit_free;
 660                 }
 661         }
 662
 663         f = entry->rule.inode_f;
 664         if (f) {
 665                 switch(f->op) {
 666                 case AUDIT_NOT_EQUAL:
 667                         entry->rule.inode_f = NULL;
 668                 case AUDIT_EQUAL:
 669                         break;
 670                 default:
 671                         err = -EINVAL;
 672                         goto exit_free;
 673                 }
 674         }
 675
 676 exit_nofree:
 677         return entry;
 678
 679 exit_free:
 680         audit_free_rule(entry);
 681         return ERR_PTR(err);
 682 }
 683
 684 /* Pack a filter field's string representation into data block. */
 685 static inline size_t audit_pack_string(void **bufp, const char *str)
 686 {
 687         size_t len = strlen(str);
 688
 689         memcpy(*bufp, str, len);
 690         *bufp += len;
 691
 692         return len;
 693 }
 694
 695 /* Translate kernel rule respresentation to struct audit_rule.
 696  * Exists for backward compatibility with userspace. */
 697 static struct audit_rule *audit_krule_to_rule(struct audit_krule *krule)
 698 {
 699         struct audit_rule *rule;
 700         int i;
 701
 702         rule = kzalloc(sizeof(*rule), GFP_KERNEL);
 703         if (unlikely(!rule))
 704                 return NULL;
 705
 706         rule->flags = krule->flags | krule->listnr;
 707         rule->action = krule->action;
 708         rule->field_count = krule->field_count;
 709         for (i = 0; i < rule->field_count; i++) {
 710                 rule->values[i] = krule->fields[i].val;
 711                 rule->fields[i] = krule->fields[i].type;
 712
 713                 if (krule->vers_ops == 1) {
 714                         if (krule->fields[i].op & AUDIT_NOT_EQUAL)
 715                                 rule->fields[i] |= AUDIT_NEGATE;
 716                 } else {
 717                         rule->fields[i] |= krule->fields[i].op;
 718                 }
 719         }
 720         for (i = 0; i < AUDIT_BITMASK_SIZE; i++) rule->mask[i] = krule->mask[i];
 721
 722         return rule;
 723 }
 724
 725 /* Translate kernel rule respresentation to struct audit_rule_data. */
 726 static struct audit_rule_data *audit_krule_to_data(struct audit_krule *krule)
 727 {
 728         struct audit_rule_data *data;
 729         void *bufp;
 730         int i;
 731
 732         data = kmalloc(sizeof(*data) + krule->buflen, GFP_KERNEL);
 733         if (unlikely(!data))
 734                 return NULL;
 735         memset(data, 0, sizeof(*data));
 736
 737         data->flags = krule->flags | krule->listnr;
 738         data->action = krule->action;
 739         data->field_count = krule->field_count;
 740         bufp = data->buf;
 741         for (i = 0; i < data->field_count; i++) {
 742                 struct audit_field *f = &krule->fields[i];
 743
 744                 data->fields[i] = f->type;
 745                 data->fieldflags[i] = f->op;
 746                 switch(f->type) {
 747                 case AUDIT_SUBJ_USER:
 748                 case AUDIT_SUBJ_ROLE:
 749                 case AUDIT_SUBJ_TYPE:
 750                 case AUDIT_SUBJ_SEN:
 751                 case AUDIT_SUBJ_CLR:
 752                 case AUDIT_OBJ_USER:
 753                 case AUDIT_OBJ_ROLE:
 754                 case AUDIT_OBJ_TYPE:
 755                 case AUDIT_OBJ_LEV_LOW:
 756                 case AUDIT_OBJ_LEV_HIGH:
 757                         data->buflen += data->values[i] =
 758                                 audit_pack_string(&bufp, f->se_str);
 759                         break;
 760                 case AUDIT_WATCH:
 761                         data->buflen += data->values[i] =
 762                                 audit_pack_string(&bufp, krule->watch->path);
 763                         break;
 764                 case AUDIT_DIR:
 765                         data->buflen += data->values[i] =
 766                                 audit_pack_string(&bufp,
 767                                                   audit_tree_path(krule->tree));
 768                         break;
 769                 case AUDIT_FILTERKEY:
 770                         data->buflen += data->values[i] =
 771                                 audit_pack_string(&bufp, krule->filterkey);
 772                         break;
 773                 default:
 774                         data->values[i] = f->val;
 775                 }
 776         }
 777         for (i = 0; i < AUDIT_BITMASK_SIZE; i++) data->mask[i] = krule->mask[i];
 778
 779         return data;
 780 }
 781
 782 /* Compare two rules in kernel format.  Considered success if rules
 783  * don't match. */
 784 static int audit_compare_rule(struct audit_krule *a, struct audit_krule *b)
 785 {
 786         int i;
 787
 788         if (a->flags != b->flags ||
 789             a->listnr != b->listnr ||
 790             a->action != b->action ||
 791             a->field_count != b->field_count)
 792                 return 1;
 793
 794         for (i = 0; i < a->field_count; i++) {
 795                 if (a->fields[i].type != b->fields[i].type ||
 796                     a->fields[i].op != b->fields[i].op)
 797                         return 1;
 798
 799                 switch(a->fields[i].type) {
 800                 case AUDIT_SUBJ_USER:
 801                 case AUDIT_SUBJ_ROLE:
 802                 case AUDIT_SUBJ_TYPE:
 803                 case AUDIT_SUBJ_SEN:
 804                 case AUDIT_SUBJ_CLR:
 805                 case AUDIT_OBJ_USER:
 806                 case AUDIT_OBJ_ROLE:
 807                 case AUDIT_OBJ_TYPE:
 808                 case AUDIT_OBJ_LEV_LOW:
 809                 case AUDIT_OBJ_LEV_HIGH:
 810                         if (strcmp(a->fields[i].se_str, b->fields[i].se_str))
 811                                 return 1;
 812                         break;
 813                 case AUDIT_WATCH:
 814                         if (strcmp(a->watch->path, b->watch->path))
 815                                 return 1;
 816                         break;
 817                 case AUDIT_DIR:
 818                         if (strcmp(audit_tree_path(a->tree),
 819                                    audit_tree_path(b->tree)))
 820                                 return 1;
 821                         break;
 822                 case AUDIT_FILTERKEY:
 823                         /* both filterkeys exist based on above type compare */
 824                         if (strcmp(a->filterkey, b->filterkey))
 825                                 return 1;
 826                         break;
 827                 default:
 828                         if (a->fields[i].val != b->fields[i].val)
 829                                 return 1;
 830                 }
 831         }
 832
 833         for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
 834                 if (a->mask[i] != b->mask[i])
 835                         return 1;
 836
 837         return 0;
 838 }
 839
 840 /* Duplicate the given audit watch.  The new watch's rules list is initialized
 841  * to an empty list and wlist is undefined. */
 842 static struct audit_watch *audit_dupe_watch(struct audit_watch *old)
 843 {
 844         char *path;
 845         struct audit_watch *new;
 846
 847         path = kstrdup(old->path, GFP_KERNEL);
 848         if (unlikely(!path))
 849                 return ERR_PTR(-ENOMEM);
 850
 851         new = audit_init_watch(path);
 852         if (unlikely(IS_ERR(new))) {
 853                 kfree(path);
 854                 goto out;
 855         }
 856
 857         new->dev = old->dev;
 858         new->ino = old->ino;
 859         get_inotify_watch(&old->parent->wdata);
 860         new->parent = old->parent;
 861
 862 out:
 863         return new;
 864 }
 865
 866 /* Duplicate selinux field information.  The se_rule is opaque, so must be
 867  * re-initialized. */
 868 static inline int audit_dupe_selinux_field(struct audit_field *df,
 869                                            struct audit_field *sf)
 870 {
 871         int ret = 0;
 872         char *se_str;
 873
 874         /* our own copy of se_str */
 875         se_str = kstrdup(sf->se_str, GFP_KERNEL);
 876         if (unlikely(!se_str))
 877                 return -ENOMEM;
 878         df->se_str = se_str;
 879
 880         /* our own (refreshed) copy of se_rule */
 881         ret = selinux_audit_rule_init(df->type, df->op, df->se_str,
 882                                       &df->se_rule);
 883         /* Keep currently invalid fields around in case they
 884          * become valid after a policy reload. */
 885         if (ret == -EINVAL) {
 886                 printk(KERN_WARNING "audit rule for selinux \'%s\' is "
 887                        "invalid\n", df->se_str);
 888                 ret = 0;
 889         }
 890
 891         return ret;
 892 }
 893
 894 /* Duplicate an audit rule.  This will be a deep copy with the exception
 895  * of the watch - that pointer is carried over.  The selinux specific fields
 896  * will be updated in the copy.  The point is to be able to replace the old
 897  * rule with the new rule in the filterlist, then free the old rule.
 898  * The rlist element is undefined; list manipulations are handled apart from
 899  * the initial copy. */
 900 static struct audit_entry *audit_dupe_rule(struct audit_krule *old,
 901                                            struct audit_watch *watch)
 902 {
 903         u32 fcount = old->field_count;
 904         struct audit_entry *entry;
 905         struct audit_krule *new;
 906         char *fk;
 907         int i, err = 0;
 908
 909         entry = audit_init_entry(fcount);
 910         if (unlikely(!entry))
 911                 return ERR_PTR(-ENOMEM);
 912
 913         new = &entry->rule;
 914         new->vers_ops = old->vers_ops;
 915         new->flags = old->flags;
 916         new->listnr = old->listnr;
 917         new->action = old->action;
 918         for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
 919                 new->mask[i] = old->mask[i];
 920         new->buflen = old->buflen;
 921         new->inode_f = old->inode_f;
 922         new->watch = NULL;
 923         new->field_count = old->field_count;
 924         /*
 925          * note that we are OK with not refcounting here; audit_match_tree()
 926          * never dereferences tree and we can't get false positives there
 927          * since we'd have to have rule gone from the list *and* removed
 928          * before the chunks found by lookup had been allocated, i.e. before
 929          * the beginning of list scan.
 930          */
 931         new->tree = old->tree;
 932         memcpy(new->fields, old->fields, sizeof(struct audit_field) * fcount);
 933
 934         /* deep copy this information, updating the se_rule fields, because
 935          * the originals will all be freed when the old rule is freed. */
 936         for (i = 0; i < fcount; i++) {
 937                 switch (new->fields[i].type) {
 938                 case AUDIT_SUBJ_USER:
 939                 case AUDIT_SUBJ_ROLE:
 940                 case AUDIT_SUBJ_TYPE:
 941                 case AUDIT_SUBJ_SEN:
 942                 case AUDIT_SUBJ_CLR:
 943                 case AUDIT_OBJ_USER:
 944                 case AUDIT_OBJ_ROLE:
 945                 case AUDIT_OBJ_TYPE:
 946                 case AUDIT_OBJ_LEV_LOW:
 947                 case AUDIT_OBJ_LEV_HIGH:
 948                         err = audit_dupe_selinux_field(&new->fields[i],
 949                                                        &old->fields[i]);
 950                         break;
 951                 case AUDIT_FILTERKEY:
 952                         fk = kstrdup(old->filterkey, GFP_KERNEL);
 953                         if (unlikely(!fk))
 954                                 err = -ENOMEM;
 955                         else
 956                                 new->filterkey = fk;
 957                 }
 958                 if (err) {
 959                         audit_free_rule(entry);
 960                         return ERR_PTR(err);
 961                 }
 962         }
 963
 964         if (watch) {
 965                 audit_get_watch(watch);
 966                 new->watch = watch;
 967         }
 968
 969         return entry;
 970 }
 971
 972 /* Update inode info in audit rules based on filesystem event. */
 973 static void audit_update_watch(struct audit_parent *parent,
 974                                const char *dname, dev_t dev,
 975                                unsigned long ino, unsigned invalidating)
 976 {
 977         struct audit_watch *owatch, *nwatch, *nextw;
 978         struct audit_krule *r, *nextr;
 979         struct audit_entry *oentry, *nentry;
 980
 981         mutex_lock(&audit_filter_mutex);
 982         list_for_each_entry_safe(owatch, nextw, &parent->watches, wlist) {
 983                 if (audit_compare_dname_path(dname, owatch->path, NULL))
 984                         continue;
 985
 986                 /* If the update involves invalidating rules, do the inode-based
 987                  * filtering now, so we don't omit records. */
 988                 if (invalidating && current->audit_context &&
 989                     audit_filter_inodes(current, current->audit_context) == AUDIT_RECORD_CONTEXT)
 990                         audit_set_auditable(current->audit_context);
 991
 992                 nwatch = audit_dupe_watch(owatch);
 993                 if (unlikely(IS_ERR(nwatch))) {
 994                         mutex_unlock(&audit_filter_mutex);
 995                         audit_panic("error updating watch, skipping");
 996                         return;
 997                 }
 998                 nwatch->dev = dev;
 999                 nwatch->ino = ino;
1000
1001                 list_for_each_entry_safe(r, nextr, &owatch->rules, rlist) {
1002
1003                         oentry = container_of(r, struct audit_entry, rule);
1004                         list_del(&oentry->rule.rlist);
1005                         list_del_rcu(&oentry->list);
1006
1007                         nentry = audit_dupe_rule(&oentry->rule, nwatch);
1008                         if (unlikely(IS_ERR(nentry)))
1009                                 audit_panic("error updating watch, removing");
1010                         else {
1011                                 int h = audit_hash_ino((u32)ino);
1012                                 list_add(&nentry->rule.rlist, &nwatch->rules);
1013                                 list_add_rcu(&nentry->list, &audit_inode_hash[h]);
1014                         }
1015
1016                         call_rcu(&oentry->rcu, audit_free_rule_rcu);
1017                 }
1018
1019                 if (audit_enabled) {
1020                         struct audit_buffer *ab;
1021                         ab = audit_log_start(NULL, GFP_KERNEL,
1022                                 AUDIT_CONFIG_CHANGE);
1023                         audit_log_format(ab,
1024                                 "op=updated rules specifying path=");
1025                         audit_log_untrustedstring(ab, owatch->path);
1026                         audit_log_format(ab, " with dev=%u ino=%lu\n",
1027                                  dev, ino);
1028                         audit_log_format(ab, " list=%d res=1", r->listnr);
1029                         audit_log_end(ab);
1030                 }
1031                 audit_remove_watch(owatch);
1032                 goto add_watch_to_parent; /* event applies to a single watch */
1033         }
1034         mutex_unlock(&audit_filter_mutex);
1035         return;
1036
1037 add_watch_to_parent:
1038         list_add(&nwatch->wlist, &parent->watches);
1039         mutex_unlock(&audit_filter_mutex);
1040         return;
1041 }
1042
1043 /* Remove all watches & rules associated with a parent that is going away. */
1044 static void audit_remove_parent_watches(struct audit_parent *parent)
1045 {
1046         struct audit_watch *w, *nextw;
1047         struct audit_krule *r, *nextr;
1048         struct audit_entry *e;
1049
1050         mutex_lock(&audit_filter_mutex);
1051         parent->flags |= AUDIT_PARENT_INVALID;
1052         list_for_each_entry_safe(w, nextw, &parent->watches, wlist) {
1053                 list_for_each_entry_safe(r, nextr, &w->rules, rlist) {
1054                         e = container_of(r, struct audit_entry, rule);
1055                         if (audit_enabled) {
1056                                 struct audit_buffer *ab;
1057                                 ab = audit_log_start(NULL, GFP_KERNEL,
1058                                         AUDIT_CONFIG_CHANGE);
1059                                 audit_log_format(ab, "op=remove rule path=");
1060                                 audit_log_untrustedstring(ab, w->path);
1061                                 if (r->filterkey) {
1062                                         audit_log_format(ab, " key=");
1063                                         audit_log_untrustedstring(ab,
1064                                                         r->filterkey);
1065                                 } else
1066                                         audit_log_format(ab, " key=(null)");
1067                                 audit_log_format(ab, " list=%d res=1",
1068                                         r->listnr);
1069                                 audit_log_end(ab);
1070                         }
1071                         list_del(&r->rlist);
1072                         list_del_rcu(&e->list);
1073                         call_rcu(&e->rcu, audit_free_rule_rcu);
1074                 }
1075                 audit_remove_watch(w);
1076         }
1077         mutex_unlock(&audit_filter_mutex);
1078 }
1079
1080 /* Unregister inotify watches for parents on in_list.
1081  * Generates an IN_IGNORED event. */
1082 static void audit_inotify_unregister(struct list_head *in_list)
1083 {
1084         struct audit_parent *p, *n;
1085
1086         list_for_each_entry_safe(p, n, in_list, ilist) {
1087                 list_del(&p->ilist);
1088                 inotify_rm_watch(audit_ih, &p->wdata);
1089                 /* the put matching the get in audit_do_del_rule() */
1090                 put_inotify_watch(&p->wdata);
1091         }
1092 }
1093
1094 /* Find an existing audit rule.
1095  * Caller must hold audit_filter_mutex to prevent stale rule data. */
1096 static struct audit_entry *audit_find_rule(struct audit_entry *entry,
1097                                            struct list_head *list)
1098 {
1099         struct audit_entry *e, *found = NULL;
1100         int h;
1101
1102         if (entry->rule.watch) {
1103                 /* we don't know the inode number, so must walk entire hash */
1104                 for (h = 0; h < AUDIT_INODE_BUCKETS; h++) {
1105                         list = &audit_inode_hash[h];
1106                         list_for_each_entry(e, list, list)
1107                                 if (!audit_compare_rule(&entry->rule, &e->rule)) {
1108                                         found = e;
1109                                         goto out;
1110                                 }
1111                 }
1112                 goto out;
1113         }
1114
1115         list_for_each_entry(e, list, list)
1116                 if (!audit_compare_rule(&entry->rule, &e->rule)) {
1117                         found = e;
1118                         goto out;
1119                 }
1120
1121 out:
1122         return found;
1123 }
1124
1125 /* Get path information necessary for adding watches. */
1126 static int audit_get_nd(char *path, struct nameidata **ndp,
1127                         struct nameidata **ndw)
1128 {
1129         struct nameidata *ndparent, *ndwatch;
1130         int err;
1131
1132         ndparent = kmalloc(sizeof(*ndparent), GFP_KERNEL);
1133         if (unlikely(!ndparent))
1134                 return -ENOMEM;
1135
1136         ndwatch = kmalloc(sizeof(*ndwatch), GFP_KERNEL);
1137         if (unlikely(!ndwatch)) {
1138                 kfree(ndparent);
1139                 return -ENOMEM;
1140         }
1141
1142         err = path_lookup(path, LOOKUP_PARENT, ndparent);
1143         if (err) {
1144                 kfree(ndparent);
1145                 kfree(ndwatch);
1146                 return err;
1147         }
1148
1149         err = path_lookup(path, 0, ndwatch);
1150         if (err) {
1151                 kfree(ndwatch);
1152                 ndwatch = NULL;
1153         }
1154
1155         *ndp = ndparent;
1156         *ndw = ndwatch;
1157
1158         return 0;
1159 }
1160
1161 /* Release resources used for watch path information. */
1162 static void audit_put_nd(struct nameidata *ndp, struct nameidata *ndw)
1163 {
1164         if (ndp) {
1165                 path_put(&ndp->path);
1166                 kfree(ndp);
1167         }
1168         if (ndw) {
1169                 path_put(&ndw->path);
1170                 kfree(ndw);
1171         }
1172 }
1173
1174 /* Associate the given rule with an existing parent inotify_watch.
1175  * Caller must hold audit_filter_mutex. */
1176 static void audit_add_to_parent(struct audit_krule *krule,
1177                                 struct audit_parent *parent)
1178 {
1179         struct audit_watch *w, *watch = krule->watch;
1180         int watch_found = 0;
1181
1182         list_for_each_entry(w, &parent->watches, wlist) {
1183                 if (strcmp(watch->path, w->path))
1184                         continue;
1185
1186                 watch_found = 1;
1187
1188                 /* put krule's and initial refs to temporary watch */
1189                 audit_put_watch(watch);
1190                 audit_put_watch(watch);
1191
1192                 audit_get_watch(w);
1193                 krule->watch = watch = w;
1194                 break;
1195         }
1196
1197         if (!watch_found) {
1198                 get_inotify_watch(&parent->wdata);
1199                 watch->parent = parent;
1200
1201                 list_add(&watch->wlist, &parent->watches);
1202         }
1203         list_add(&krule->rlist, &watch->rules);
1204 }
1205
1206 /* Find a matching watch entry, or add this one.
1207  * Caller must hold audit_filter_mutex. */
1208 static int audit_add_watch(struct audit_krule *krule, struct nameidata *ndp,
1209                            struct nameidata *ndw)
1210 {
1211         struct audit_watch *watch = krule->watch;
1212         struct inotify_watch *i_watch;
1213         struct audit_parent *parent;
1214         int ret = 0;
1215
1216         /* update watch filter fields */
1217         if (ndw) {
1218                 watch->dev = ndw->path.dentry->d_inode->i_sb->s_dev;
1219                 watch->ino = ndw->path.dentry->d_inode->i_ino;
1220         }
1221
1222         /* The audit_filter_mutex must not be held during inotify calls because
1223          * we hold it during inotify event callback processing.  If an existing
1224          * inotify watch is found, inotify_find_watch() grabs a reference before
1225          * returning.
1226          */
1227         mutex_unlock(&audit_filter_mutex);
1228
1229         if (inotify_find_watch(audit_ih, ndp->path.dentry->d_inode,
1230                                &i_watch) < 0) {
1231                 parent = audit_init_parent(ndp);
1232                 if (IS_ERR(parent)) {
1233                         /* caller expects mutex locked */
1234                         mutex_lock(&audit_filter_mutex);
1235                         return PTR_ERR(parent);
1236                 }
1237         } else
1238                 parent = container_of(i_watch, struct audit_parent, wdata);
1239
1240         mutex_lock(&audit_filter_mutex);
1241
1242         /* parent was moved before we took audit_filter_mutex */
1243         if (parent->flags & AUDIT_PARENT_INVALID)
1244                 ret = -ENOENT;
1245         else
1246                 audit_add_to_parent(krule, parent);
1247
1248         /* match get in audit_init_parent or inotify_find_watch */
1249         put_inotify_watch(&parent->wdata);
1250         return ret;
1251 }
1252
1253 /* Add rule to given filterlist if not a duplicate. */
1254 static inline int audit_add_rule(struct audit_entry *entry,
1255                                  struct list_head *list)
1256 {
1257         struct audit_entry *e;
1258         struct audit_field *inode_f = entry->rule.inode_f;
1259         struct audit_watch *watch = entry->rule.watch;
1260         struct audit_tree *tree = entry->rule.tree;
1261         struct nameidata *ndp = NULL, *ndw = NULL;
1262         int h, err;
1263 #ifdef CONFIG_AUDITSYSCALL
1264         int dont_count = 0;
1265
1266         /* If either of these, don't count towards total */
1267         if (entry->rule.listnr == AUDIT_FILTER_USER ||
1268                 entry->rule.listnr == AUDIT_FILTER_TYPE)
1269                 dont_count = 1;
1270 #endif
1271
1272         if (inode_f) {
1273                 h = audit_hash_ino(inode_f->val);
1274                 list = &audit_inode_hash[h];
1275         }
1276
1277         mutex_lock(&audit_filter_mutex);
1278         e = audit_find_rule(entry, list);
1279         mutex_unlock(&audit_filter_mutex);
1280         if (e) {
1281                 err = -EEXIST;
1282                 /* normally audit_add_tree_rule() will free it on failure */
1283                 if (tree)
1284                         audit_put_tree(tree);
1285                 goto error;
1286         }
1287
1288         /* Avoid calling path_lookup under audit_filter_mutex. */
1289         if (watch) {
1290                 err = audit_get_nd(watch->path, &ndp, &ndw);
1291                 if (err)
1292                         goto error;
1293         }
1294
1295         mutex_lock(&audit_filter_mutex);
1296         if (watch) {
1297                 /* audit_filter_mutex is dropped and re-taken during this call */
1298                 err = audit_add_watch(&entry->rule, ndp, ndw);
1299                 if (err) {
1300                         mutex_unlock(&audit_filter_mutex);
1301                         goto error;
1302                 }
1303                 h = audit_hash_ino((u32)watch->ino);
1304                 list = &audit_inode_hash[h];
1305         }
1306         if (tree) {
1307                 err = audit_add_tree_rule(&entry->rule);
1308                 if (err) {
1309                         mutex_unlock(&audit_filter_mutex);
1310                         goto error;
1311                 }
1312         }
1313
1314         if (entry->rule.flags & AUDIT_FILTER_PREPEND) {
1315                 list_add_rcu(&entry->list, list);
1316                 entry->rule.flags &= ~AUDIT_FILTER_PREPEND;
1317         } else {
1318                 list_add_tail_rcu(&entry->list, list);
1319         }
1320 #ifdef CONFIG_AUDITSYSCALL
1321         if (!dont_count)
1322                 audit_n_rules++;
1323
1324         if (!audit_match_signal(entry))
1325                 audit_signals++;
1326 #endif
1327         mutex_unlock(&audit_filter_mutex);
1328
1329         audit_put_nd(ndp, ndw);         /* NULL args OK */
1330         return 0;
1331
1332 error:
1333         audit_put_nd(ndp, ndw);         /* NULL args OK */
1334         if (watch)
1335                 audit_put_watch(watch); /* tmp watch, matches initial get */
1336         return err;
1337 }
1338
1339 /* Remove an existing rule from filterlist. */
1340 static inline int audit_del_rule(struct audit_entry *entry,
1341                                  struct list_head *list)
1342 {
1343         struct audit_entry  *e;
1344         struct audit_field *inode_f = entry->rule.inode_f;
1345         struct audit_watch *watch, *tmp_watch = entry->rule.watch;
1346         struct audit_tree *tree = entry->rule.tree;
1347         LIST_HEAD(inotify_list);
1348         int h, ret = 0;
1349 #ifdef CONFIG_AUDITSYSCALL
1350         int dont_count = 0;
1351
1352         /* If either of these, don't count towards total */
1353         if (entry->rule.listnr == AUDIT_FILTER_USER ||
1354                 entry->rule.listnr == AUDIT_FILTER_TYPE)
1355                 dont_count = 1;
1356 #endif
1357
1358         if (inode_f) {
1359                 h = audit_hash_ino(inode_f->val);
1360                 list = &audit_inode_hash[h];
1361         }
1362
1363         mutex_lock(&audit_filter_mutex);
1364         e = audit_find_rule(entry, list);
1365         if (!e) {
1366                 mutex_unlock(&audit_filter_mutex);
1367                 ret = -ENOENT;
1368                 goto out;
1369         }
1370
1371         watch = e->rule.watch;
1372         if (watch) {
1373                 struct audit_parent *parent = watch->parent;
1374
1375                 list_del(&e->rule.rlist);
1376
1377                 if (list_empty(&watch->rules)) {
1378                         audit_remove_watch(watch);
1379
1380                         if (list_empty(&parent->watches)) {
1381                                 /* Put parent on the inotify un-registration
1382                                  * list.  Grab a reference before releasing
1383                                  * audit_filter_mutex, to be released in
1384                                  * audit_inotify_unregister(). */
1385                                 list_add(&parent->ilist, &inotify_list);
1386                                 get_inotify_watch(&parent->wdata);
1387                         }
1388                 }
1389         }
1390
1391         if (e->rule.tree)
1392                 audit_remove_tree_rule(&e->rule);
1393
1394         list_del_rcu(&e->list);
1395         call_rcu(&e->rcu, audit_free_rule_rcu);
1396
1397 #ifdef CONFIG_AUDITSYSCALL
1398         if (!dont_count)
1399                 audit_n_rules--;
1400
1401         if (!audit_match_signal(entry))
1402                 audit_signals--;
1403 #endif
1404         mutex_unlock(&audit_filter_mutex);
1405
1406         if (!list_empty(&inotify_list))
1407                 audit_inotify_unregister(&inotify_list);
1408
1409 out:
1410         if (tmp_watch)
1411                 audit_put_watch(tmp_watch); /* match initial get */
1412         if (tree)
1413                 audit_put_tree(tree);   /* that's the temporary one */
1414
1415         return ret;
1416 }
1417
1418 /* List rules using struct audit_rule.  Exists for backward
1419  * compatibility with userspace. */
1420 static void audit_list(int pid, int seq, struct sk_buff_head *q)
1421 {
1422         struct sk_buff *skb;
1423         struct audit_entry *entry;
1424         int i;
1425
1426         /* This is a blocking read, so use audit_filter_mutex instead of rcu
1427          * iterator to sync with list writers. */
1428         for (i=0; i<AUDIT_NR_FILTERS; i++) {
1429                 list_for_each_entry(entry, &audit_filter_list[i], list) {
1430                         struct audit_rule *rule;
1431
1432                         rule = audit_krule_to_rule(&entry->rule);
1433                         if (unlikely(!rule))
1434                                 break;
1435                         skb = audit_make_reply(pid, seq, AUDIT_LIST, 0, 1,
1436                                          rule, sizeof(*rule));
1437                         if (skb)
1438                                 skb_queue_tail(q, skb);
1439                         kfree(rule);
1440                 }
1441         }
1442         for (i = 0; i < AUDIT_INODE_BUCKETS; i++) {
1443                 list_for_each_entry(entry, &audit_inode_hash[i], list) {
1444                         struct audit_rule *rule;
1445
1446                         rule = audit_krule_to_rule(&entry->rule);
1447                         if (unlikely(!rule))
1448                                 break;
1449                         skb = audit_make_reply(pid, seq, AUDIT_LIST, 0, 1,
1450                                          rule, sizeof(*rule));
1451                         if (skb)
1452                                 skb_queue_tail(q, skb);
1453                         kfree(rule);
1454                 }
1455         }
1456         skb = audit_make_reply(pid, seq, AUDIT_LIST, 1, 1, NULL, 0);
1457         if (skb)
1458                 skb_queue_tail(q, skb);
1459 }
1460
1461 /* List rules using struct audit_rule_data. */
1462 static void audit_list_rules(int pid, int seq, struct sk_buff_head *q)
1463 {
1464         struct sk_buff *skb;
1465         struct audit_entry *e;
1466         int i;
1467
1468         /* This is a blocking read, so use audit_filter_mutex instead of rcu
1469          * iterator to sync with list writers. */
1470         for (i=0; i<AUDIT_NR_FILTERS; i++) {
1471                 list_for_each_entry(e, &audit_filter_list[i], list) {
1472                         struct audit_rule_data *data;
1473
1474                         data = audit_krule_to_data(&e->rule);
1475                         if (unlikely(!data))
1476                                 break;
1477                         skb = audit_make_reply(pid, seq, AUDIT_LIST_RULES, 0, 1,
1478                                          data, sizeof(*data) + data->buflen);
1479                         if (skb)
1480                                 skb_queue_tail(q, skb);
1481                         kfree(data);
1482                 }
1483         }
1484         for (i=0; i< AUDIT_INODE_BUCKETS; i++) {
1485                 list_for_each_entry(e, &audit_inode_hash[i], list) {
1486                         struct audit_rule_data *data;
1487
1488                         data = audit_krule_to_data(&e->rule);
1489                         if (unlikely(!data))
1490                                 break;
1491                         skb = audit_make_reply(pid, seq, AUDIT_LIST_RULES, 0, 1,
1492                                          data, sizeof(*data) + data->buflen);
1493                         if (skb)
1494                                 skb_queue_tail(q, skb);
1495                         kfree(data);
1496                 }
1497         }
1498         skb = audit_make_reply(pid, seq, AUDIT_LIST_RULES, 1, 1, NULL, 0);
1499         if (skb)
1500                 skb_queue_tail(q, skb);
1501 }
1502
1503 /* Log rule additions and removals */
1504 static void audit_log_rule_change(uid_t loginuid, u32 sid, char *action,
1505                                   struct audit_krule *rule, int res)
1506 {
1507         struct audit_buffer *ab;
1508
1509         if (!audit_enabled)
1510                 return;
1511
1512         ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
1513         if (!ab)
1514                 return;
1515         audit_log_format(ab, "auid=%u", loginuid);
1516         if (sid) {
1517                 char *ctx = NULL;
1518                 u32 len;
1519                 if (security_secid_to_secctx(sid, &ctx, &len))
1520                         audit_log_format(ab, " ssid=%u", sid);
1521                 else {
1522                         audit_log_format(ab, " subj=%s", ctx);
1523                         security_release_secctx(ctx, len);
1524                 }
1525         }
1526         audit_log_format(ab, " op=%s rule key=", action);
1527         if (rule->filterkey)
1528                 audit_log_untrustedstring(ab, rule->filterkey);
1529         else
1530                 audit_log_format(ab, "(null)");
1531         audit_log_format(ab, " list=%d res=%d", rule->listnr, res);
1532         audit_log_end(ab);
1533 }
1534
1535 /**
1536  * audit_receive_filter - apply all rules to the specified message type
1537  * @type: audit message type
1538  * @pid: target pid for netlink audit messages
1539  * @uid: target uid for netlink audit messages
1540  * @seq: netlink audit message sequence (serial) number
1541  * @data: payload data
1542  * @datasz: size of payload data
1543  * @loginuid: loginuid of sender
1544  * @sid: SE Linux Security ID of sender
1545  */
1546 int audit_receive_filter(int type, int pid, int uid, int seq, void *data,
1547                          size_t datasz, uid_t loginuid, u32 sid)
1548 {
1549         struct task_struct *tsk;
1550         struct audit_netlink_list *dest;
1551         int err = 0;
1552         struct audit_entry *entry;
1553
1554         switch (type) {
1555         case AUDIT_LIST:
1556         case AUDIT_LIST_RULES:
1557                 /* We can't just spew out the rules here because we might fill
1558                  * the available socket buffer space and deadlock waiting for
1559                  * auditctl to read from it... which isn't ever going to
1560                  * happen if we're actually running in the context of auditctl
1561                  * trying to _send_ the stuff */
1562
1563                 dest = kmalloc(sizeof(struct audit_netlink_list), GFP_KERNEL);
1564                 if (!dest)
1565                         return -ENOMEM;
1566                 dest->pid = pid;
1567                 skb_queue_head_init(&dest->q);
1568
1569                 mutex_lock(&audit_filter_mutex);
1570                 if (type == AUDIT_LIST)
1571                         audit_list(pid, seq, &dest->q);
1572                 else
1573                         audit_list_rules(pid, seq, &dest->q);
1574                 mutex_unlock(&audit_filter_mutex);
1575
1576                 tsk = kthread_run(audit_send_list, dest, "audit_send_list");
1577                 if (IS_ERR(tsk)) {
1578                         skb_queue_purge(&dest->q);
1579                         kfree(dest);
1580                         err = PTR_ERR(tsk);
1581                 }
1582                 break;
1583         case AUDIT_ADD:
1584         case AUDIT_ADD_RULE:
1585                 if (type == AUDIT_ADD)
1586                         entry = audit_rule_to_entry(data);
1587                 else
1588                         entry = audit_data_to_entry(data, datasz);
1589                 if (IS_ERR(entry))
1590                         return PTR_ERR(entry);
1591
1592                 err = audit_add_rule(entry,
1593                                      &audit_filter_list[entry->rule.listnr]);
1594                 audit_log_rule_change(loginuid, sid, "add", &entry->rule, !err);
1595
1596                 if (err)
1597                         audit_free_rule(entry);
1598                 break;
1599         case AUDIT_DEL:
1600         case AUDIT_DEL_RULE:
1601                 if (type == AUDIT_DEL)
1602                         entry = audit_rule_to_entry(data);
1603                 else
1604                         entry = audit_data_to_entry(data, datasz);
1605                 if (IS_ERR(entry))
1606                         return PTR_ERR(entry);
1607
1608                 err = audit_del_rule(entry,
1609                                      &audit_filter_list[entry->rule.listnr]);
1610                 audit_log_rule_change(loginuid, sid, "remove", &entry->rule,
1611                                       !err);
1612
1613                 audit_free_rule(entry);
1614                 break;
1615         default:
1616                 return -EINVAL;
1617         }
1618
1619         return err;
1620 }
1621
1622 int audit_comparator(const u32 left, const u32 op, const u32 right)
1623 {
1624         switch (op) {
1625         case AUDIT_EQUAL:
1626                 return (left == right);
1627         case AUDIT_NOT_EQUAL:
1628                 return (left != right);
1629         case AUDIT_LESS_THAN:
1630                 return (left < right);
1631         case AUDIT_LESS_THAN_OR_EQUAL:
1632                 return (left <= right);
1633         case AUDIT_GREATER_THAN:
1634                 return (left > right);
1635         case AUDIT_GREATER_THAN_OR_EQUAL:
1636                 return (left >= right);
1637         case AUDIT_BIT_MASK:
1638                 return (left & right);
1639         case AUDIT_BIT_TEST:
1640                 return ((left & right) == right);
1641         }
1642         BUG();
1643         return 0;
1644 }
1645
1646 /* Compare given dentry name with last component in given path,
1647  * return of 0 indicates a match. */
1648 int audit_compare_dname_path(const char *dname, const char *path,
1649                              int *dirlen)
1650 {
1651         int dlen, plen;
1652         const char *p;
1653
1654         if (!dname || !path)
1655                 return 1;
1656
1657         dlen = strlen(dname);
1658         plen = strlen(path);
1659         if (plen < dlen)
1660                 return 1;
1661
1662         /* disregard trailing slashes */
1663         p = path + plen - 1;
1664         while ((*p == '/') && (p > path))
1665                 p--;
1666
1667         /* find last path component */
1668         p = p - dlen + 1;
1669         if (p < path)
1670                 return 1;
1671         else if (p > path) {
1672                 if (*--p != '/')
1673                         return 1;
1674                 else
1675                         p++;
1676         }
1677
1678         /* return length of path's directory component */
1679         if (dirlen)
1680                 *dirlen = p - path;
1681         return strncmp(p, dname, dlen);
1682 }
1683
1684 static int audit_filter_user_rules(struct netlink_skb_parms *cb,
1685                                    struct audit_krule *rule,
1686                                    enum audit_state *state)
1687 {
1688         int i;
1689
1690         for (i = 0; i < rule->field_count; i++) {
1691                 struct audit_field *f = &rule->fields[i];
1692                 int result = 0;
1693
1694                 switch (f->type) {
1695                 case AUDIT_PID:
1696                         result = audit_comparator(cb->creds.pid, f->op, f->val);
1697                         break;
1698                 case AUDIT_UID:
1699                         result = audit_comparator(cb->creds.uid, f->op, f->val);
1700                         break;
1701                 case AUDIT_GID:
1702                         result = audit_comparator(cb->creds.gid, f->op, f->val);
1703                         break;
1704                 case AUDIT_LOGINUID:
1705                         result = audit_comparator(cb->loginuid, f->op, f->val);
1706                         break;
1707                 }
1708
1709                 if (!result)
1710                         return 0;
1711         }
1712         switch (rule->action) {
1713         case AUDIT_NEVER:    *state = AUDIT_DISABLED;       break;
1714         case AUDIT_ALWAYS:   *state = AUDIT_RECORD_CONTEXT; break;
1715         }
1716         return 1;
1717 }
1718
1719 int audit_filter_user(struct netlink_skb_parms *cb, int type)
1720 {
1721         enum audit_state state = AUDIT_DISABLED;
1722         struct audit_entry *e;
1723         int ret = 1;
1724
1725         rcu_read_lock();
1726         list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_USER], list) {
1727                 if (audit_filter_user_rules(cb, &e->rule, &state)) {
1728                         if (state == AUDIT_DISABLED)
1729                                 ret = 0;
1730                         break;
1731                 }
1732         }
1733         rcu_read_unlock();
1734
1735         return ret; /* Audit by default */
1736 }
1737
1738 int audit_filter_type(int type)
1739 {
1740         struct audit_entry *e;
1741         int result = 0;
1742
1743         rcu_read_lock();
1744         if (list_empty(&audit_filter_list[AUDIT_FILTER_TYPE]))
1745                 goto unlock_and_return;
1746
1747         list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_TYPE],
1748                                 list) {
1749                 int i;
1750                 for (i = 0; i < e->rule.field_count; i++) {
1751                         struct audit_field *f = &e->rule.fields[i];
1752                         if (f->type == AUDIT_MSGTYPE) {
1753                                 result = audit_comparator(type, f->op, f->val);
1754                                 if (!result)
1755                                         break;
1756                         }
1757                 }
1758                 if (result)
1759                         goto unlock_and_return;
1760         }
1761 unlock_and_return:
1762         rcu_read_unlock();
1763         return result;
1764 }
1765
1766 /* Check to see if the rule contains any selinux fields.  Returns 1 if there
1767    are selinux fields specified in the rule, 0 otherwise. */
1768 static inline int audit_rule_has_selinux(struct audit_krule *rule)
1769 {
1770         int i;
1771
1772         for (i = 0; i < rule->field_count; i++) {
1773                 struct audit_field *f = &rule->fields[i];
1774                 switch (f->type) {
1775                 case AUDIT_SUBJ_USER:
1776                 case AUDIT_SUBJ_ROLE:
1777                 case AUDIT_SUBJ_TYPE:
1778                 case AUDIT_SUBJ_SEN:
1779                 case AUDIT_SUBJ_CLR:
1780                 case AUDIT_OBJ_USER:
1781                 case AUDIT_OBJ_ROLE:
1782                 case AUDIT_OBJ_TYPE:
1783                 case AUDIT_OBJ_LEV_LOW:
1784                 case AUDIT_OBJ_LEV_HIGH:
1785                         return 1;
1786                 }
1787         }
1788
1789         return 0;
1790 }
1791
1792 /* This function will re-initialize the se_rule field of all applicable rules.
1793  * It will traverse the filter lists serarching for rules that contain selinux
1794  * specific filter fields.  When such a rule is found, it is copied, the
1795  * selinux field is re-initialized, and the old rule is replaced with the
1796  * updated rule. */
1797 int selinux_audit_rule_update(void)
1798 {
1799         struct audit_entry *entry, *n, *nentry;
1800         struct audit_watch *watch;
1801         struct audit_tree *tree;
1802         int i, err = 0;
1803
1804         /* audit_filter_mutex synchronizes the writers */
1805         mutex_lock(&audit_filter_mutex);
1806
1807         for (i = 0; i < AUDIT_NR_FILTERS; i++) {
1808                 list_for_each_entry_safe(entry, n, &audit_filter_list[i], list) {
1809                         if (!audit_rule_has_selinux(&entry->rule))
1810                                 continue;
1811
1812                         watch = entry->rule.watch;
1813                         tree = entry->rule.tree;
1814                         nentry = audit_dupe_rule(&entry->rule, watch);
1815                         if (unlikely(IS_ERR(nentry))) {
1816                                 /* save the first error encountered for the
1817                                  * return value */
1818                                 if (!err)
1819                                         err = PTR_ERR(nentry);
1820                                 audit_panic("error updating selinux filters");
1821                                 if (watch)
1822                                         list_del(&entry->rule.rlist);
1823                                 list_del_rcu(&entry->list);
1824                         } else {
1825                                 if (watch) {
1826                                         list_add(&nentry->rule.rlist,
1827                                                  &watch->rules);
1828                                         list_del(&entry->rule.rlist);
1829                                 } else if (tree)
1830                                         list_replace_init(&entry->rule.rlist,
1831                                                      &nentry->rule.rlist);
1832                                 list_replace_rcu(&entry->list, &nentry->list);
1833                         }
1834                         call_rcu(&entry->rcu, audit_free_rule_rcu);
1835                 }
1836         }
1837
1838         mutex_unlock(&audit_filter_mutex);
1839
1840         return err;
1841 }
1842
1843 /* Update watch data in audit rules based on inotify events. */
1844 void audit_handle_ievent(struct inotify_watch *i_watch, u32 wd, u32 mask,
1845                          u32 cookie, const char *dname, struct inode *inode)
1846 {
1847         struct audit_parent *parent;
1848
1849         parent = container_of(i_watch, struct audit_parent, wdata);
1850
1851         if (mask & (IN_CREATE|IN_MOVED_TO) && inode)
1852                 audit_update_watch(parent, dname, inode->i_sb->s_dev,
1853                                    inode->i_ino, 0);
1854         else if (mask & (IN_DELETE|IN_MOVED_FROM))
1855                 audit_update_watch(parent, dname, (dev_t)-1, (unsigned long)-1, 1);
1856         /* inotify automatically removes the watch and sends IN_IGNORED */
1857         else if (mask & (IN_DELETE_SELF|IN_UNMOUNT))
1858                 audit_remove_parent_watches(parent);
1859         /* inotify does not remove the watch, so remove it manually */
1860         else if(mask & IN_MOVE_SELF) {
1861                 audit_remove_parent_watches(parent);
1862                 inotify_remove_watch_locked(audit_ih, i_watch);
1863         } else if (mask & IN_IGNORED)
1864                 put_inotify_watch(i_watch);
1865 }