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 #include <linux/init.h>
  46 #include <asm/types.h>
  47 #include <asm/atomic.h>
  48 #include <asm/types.h>
  49 #include <linux/fs.h>
  50 #include <linux/namei.h>
  51 #include <linux/mm.h>
  52 #include <linux/module.h>
  53 #include <linux/mount.h>
  54 #include <linux/socket.h>
  55 #include <linux/mqueue.h>
  56 #include <linux/audit.h>
  57 #include <linux/personality.h>
  58 #include <linux/time.h>
  59 #include <linux/netlink.h>
  60 #include <linux/compiler.h>
  61 #include <asm/unistd.h>
  62 #include <linux/security.h>
  63 #include <linux/list.h>
  64 #include <linux/tty.h>
  65 #include <linux/selinux.h>
  66 #include <linux/binfmts.h>
  67 #include <linux/syscalls.h>
  68
  69 #include "audit.h"
  70
  71 extern struct list_head audit_filter_list[];
  72
  73 /* No syscall auditing will take place unless audit_enabled != 0. */
  74 extern int audit_enabled;
  75
  76 /* AUDIT_NAMES is the number of slots we reserve in the audit_context
  77  * for saving names from getname(). */
  78 #define AUDIT_NAMES    20
  79
  80 /* AUDIT_NAMES_RESERVED is the number of slots we reserve in the
  81  * audit_context from being used for nameless inodes from
  82  * path_lookup. */
  83 #define AUDIT_NAMES_RESERVED 7
  84
  85 /* Indicates that audit should log the full pathname. */
  86 #define AUDIT_NAME_FULL -1
  87
  88 /* number of audit rules */
  89 int audit_n_rules;
  90
  91 /* When fs/namei.c:getname() is called, we store the pointer in name and
  92  * we don't let putname() free it (instead we free all of the saved
  93  * pointers at syscall exit time).
  94  *
  95  * Further, in fs/namei.c:path_lookup() we store the inode and device. */
  96 struct audit_names {
  97         const char      *name;
  98         int             name_len;       /* number of name's characters to log */
  99         unsigned        name_put;       /* call __putname() for this name */
 100         unsigned long   ino;
 101         dev_t           dev;
 102         umode_t         mode;
 103         uid_t           uid;
 104         gid_t           gid;
 105         dev_t           rdev;
 106         u32             osid;
 107 };
 108
 109 struct audit_aux_data {
 110         struct audit_aux_data   *next;
 111         int                     type;
 112 };
 113
 114 #define AUDIT_AUX_IPCPERM       0
 115
 116 struct audit_aux_data_mq_open {
 117         struct audit_aux_data   d;
 118         int                     oflag;
 119         mode_t                  mode;
 120         struct mq_attr          attr;
 121 };
 122
 123 struct audit_aux_data_mq_sendrecv {
 124         struct audit_aux_data   d;
 125         mqd_t                   mqdes;
 126         size_t                  msg_len;
 127         unsigned int            msg_prio;
 128         struct timespec         abs_timeout;
 129 };
 130
 131 struct audit_aux_data_mq_notify {
 132         struct audit_aux_data   d;
 133         mqd_t                   mqdes;
 134         struct sigevent         notification;
 135 };
 136
 137 struct audit_aux_data_mq_getsetattr {
 138         struct audit_aux_data   d;
 139         mqd_t                   mqdes;
 140         struct mq_attr          mqstat;
 141 };
 142
 143 struct audit_aux_data_ipcctl {
 144         struct audit_aux_data   d;
 145         struct ipc_perm         p;
 146         unsigned long           qbytes;
 147         uid_t                   uid;
 148         gid_t                   gid;
 149         mode_t                  mode;
 150         u32                     osid;
 151 };
 152
 153 struct audit_aux_data_execve {
 154         struct audit_aux_data   d;
 155         int argc;
 156         int envc;
 157         char mem[0];
 158 };
 159
 160 struct audit_aux_data_socketcall {
 161         struct audit_aux_data   d;
 162         int                     nargs;
 163         unsigned long           args[0];
 164 };
 165
 166 struct audit_aux_data_sockaddr {
 167         struct audit_aux_data   d;
 168         int                     len;
 169         char                    a[0];
 170 };
 171
 172 struct audit_aux_data_path {
 173         struct audit_aux_data   d;
 174         struct dentry           *dentry;
 175         struct vfsmount         *mnt;
 176 };
 177
 178 /* The per-task audit context. */
 179 struct audit_context {
 180         int                 dummy;      /* must be the first element */
 181         int                 in_syscall; /* 1 if task is in a syscall */
 182         enum audit_state    state;
 183         unsigned int        serial;     /* serial number for record */
 184         struct timespec     ctime;      /* time of syscall entry */
 185         uid_t               loginuid;   /* login uid (identity) */
 186         int                 major;      /* syscall number */
 187         unsigned long       argv[4];    /* syscall arguments */
 188         int                 return_valid; /* return code is valid */
 189         long                return_code;/* syscall return code */
 190         int                 auditable;  /* 1 if record should be written */
 191         int                 name_count;
 192         struct audit_names  names[AUDIT_NAMES];
 193         char *              filterkey;  /* key for rule that triggered record */
 194         struct dentry *     pwd;
 195         struct vfsmount *   pwdmnt;
 196         struct audit_context *previous; /* For nested syscalls */
 197         struct audit_aux_data *aux;
 198
 199                                 /* Save things to print about task_struct */
 200         pid_t               pid, ppid;
 201         uid_t               uid, euid, suid, fsuid;
 202         gid_t               gid, egid, sgid, fsgid;
 203         unsigned long       personality;
 204         int                 arch;
 205
 206 #if AUDIT_DEBUG
 207         int                 put_count;
 208         int                 ino_count;
 209 #endif
 210 };
 211
 212 #define ACC_MODE(x) ("\004\002\006\006"[(x)&O_ACCMODE])
 213 static inline int open_arg(int flags, int mask)
 214 {
 215         int n = ACC_MODE(flags);
 216         if (flags & (O_TRUNC | O_CREAT))
 217                 n |= AUDIT_PERM_WRITE;
 218         return n & mask;
 219 }
 220
 221 static int audit_match_perm(struct audit_context *ctx, int mask)
 222 {
 223         unsigned n = ctx->major;
 224         switch (audit_classify_syscall(ctx->arch, n)) {
 225         case 0: /* native */
 226                 if ((mask & AUDIT_PERM_WRITE) &&
 227                      audit_match_class(AUDIT_CLASS_WRITE, n))
 228                         return 1;
 229                 if ((mask & AUDIT_PERM_READ) &&
 230                      audit_match_class(AUDIT_CLASS_READ, n))
 231                         return 1;
 232                 if ((mask & AUDIT_PERM_ATTR) &&
 233                      audit_match_class(AUDIT_CLASS_CHATTR, n))
 234                         return 1;
 235                 return 0;
 236         case 1: /* 32bit on biarch */
 237                 if ((mask & AUDIT_PERM_WRITE) &&
 238                      audit_match_class(AUDIT_CLASS_WRITE_32, n))
 239                         return 1;
 240                 if ((mask & AUDIT_PERM_READ) &&
 241                      audit_match_class(AUDIT_CLASS_READ_32, n))
 242                         return 1;
 243                 if ((mask & AUDIT_PERM_ATTR) &&
 244                      audit_match_class(AUDIT_CLASS_CHATTR_32, n))
 245                         return 1;
 246                 return 0;
 247         case 2: /* open */
 248                 return mask & ACC_MODE(ctx->argv[1]);
 249         case 3: /* openat */
 250                 return mask & ACC_MODE(ctx->argv[2]);
 251         case 4: /* socketcall */
 252                 return ((mask & AUDIT_PERM_WRITE) && ctx->argv[0] == SYS_BIND);
 253         case 5: /* execve */
 254                 return mask & AUDIT_PERM_EXEC;
 255         default:
 256                 return 0;
 257         }
 258 }
 259
 260 /* Determine if any context name data matches a rule's watch data */
 261 /* Compare a task_struct with an audit_rule.  Return 1 on match, 0
 262  * otherwise. */
 263 static int audit_filter_rules(struct task_struct *tsk,
 264                               struct audit_krule *rule,
 265                               struct audit_context *ctx,
 266                               struct audit_names *name,
 267                               enum audit_state *state)
 268 {
 269         int i, j, need_sid = 1;
 270         u32 sid;
 271
 272         for (i = 0; i < rule->field_count; i++) {
 273                 struct audit_field *f = &rule->fields[i];
 274                 int result = 0;
 275
 276                 switch (f->type) {
 277                 case AUDIT_PID:
 278                         result = audit_comparator(tsk->pid, f->op, f->val);
 279                         break;
 280                 case AUDIT_PPID:
 281                         if (ctx)
 282                                 result = audit_comparator(ctx->ppid, f->op, f->val);
 283                         break;
 284                 case AUDIT_UID:
 285                         result = audit_comparator(tsk->uid, f->op, f->val);
 286                         break;
 287                 case AUDIT_EUID:
 288                         result = audit_comparator(tsk->euid, f->op, f->val);
 289                         break;
 290                 case AUDIT_SUID:
 291                         result = audit_comparator(tsk->suid, f->op, f->val);
 292                         break;
 293                 case AUDIT_FSUID:
 294                         result = audit_comparator(tsk->fsuid, f->op, f->val);
 295                         break;
 296                 case AUDIT_GID:
 297                         result = audit_comparator(tsk->gid, f->op, f->val);
 298                         break;
 299                 case AUDIT_EGID:
 300                         result = audit_comparator(tsk->egid, f->op, f->val);
 301                         break;
 302                 case AUDIT_SGID:
 303                         result = audit_comparator(tsk->sgid, f->op, f->val);
 304                         break;
 305                 case AUDIT_FSGID:
 306                         result = audit_comparator(tsk->fsgid, f->op, f->val);
 307                         break;
 308                 case AUDIT_PERS:
 309                         result = audit_comparator(tsk->personality, f->op, f->val);
 310                         break;
 311                 case AUDIT_ARCH:
 312                         if (ctx)
 313                                 result = audit_comparator(ctx->arch, f->op, f->val);
 314                         break;
 315
 316                 case AUDIT_EXIT:
 317                         if (ctx && ctx->return_valid)
 318                                 result = audit_comparator(ctx->return_code, f->op, f->val);
 319                         break;
 320                 case AUDIT_SUCCESS:
 321                         if (ctx && ctx->return_valid) {
 322                                 if (f->val)
 323                                         result = audit_comparator(ctx->return_valid, f->op, AUDITSC_SUCCESS);
 324                                 else
 325                                         result = audit_comparator(ctx->return_valid, f->op, AUDITSC_FAILURE);
 326                         }
 327                         break;
 328                 case AUDIT_DEVMAJOR:
 329                         if (name)
 330                                 result = audit_comparator(MAJOR(name->dev),
 331                                                           f->op, f->val);
 332                         else if (ctx) {
 333                                 for (j = 0; j < ctx->name_count; j++) {
 334                                         if (audit_comparator(MAJOR(ctx->names[j].dev),  f->op, f->val)) {
 335                                                 ++result;
 336                                                 break;
 337                                         }
 338                                 }
 339                         }
 340                         break;
 341                 case AUDIT_DEVMINOR:
 342                         if (name)
 343                                 result = audit_comparator(MINOR(name->dev),
 344                                                           f->op, f->val);
 345                         else if (ctx) {
 346                                 for (j = 0; j < ctx->name_count; j++) {
 347                                         if (audit_comparator(MINOR(ctx->names[j].dev), f->op, f->val)) {
 348                                                 ++result;
 349                                                 break;
 350                                         }
 351                                 }
 352                         }
 353                         break;
 354                 case AUDIT_INODE:
 355                         if (name)
 356                                 result = (name->ino == f->val);
 357                         else if (ctx) {
 358                                 for (j = 0; j < ctx->name_count; j++) {
 359                                         if (audit_comparator(ctx->names[j].ino, f->op, f->val)) {
 360                                                 ++result;
 361                                                 break;
 362                                         }
 363                                 }
 364                         }
 365                         break;
 366                 case AUDIT_WATCH:
 367                         if (name && rule->watch->ino != (unsigned long)-1)
 368                                 result = (name->dev == rule->watch->dev &&
 369                                           name->ino == rule->watch->ino);
 370                         break;
 371                 case AUDIT_LOGINUID:
 372                         result = 0;
 373                         if (ctx)
 374                                 result = audit_comparator(ctx->loginuid, f->op, f->val);
 375                         break;
 376                 case AUDIT_SUBJ_USER:
 377                 case AUDIT_SUBJ_ROLE:
 378                 case AUDIT_SUBJ_TYPE:
 379                 case AUDIT_SUBJ_SEN:
 380                 case AUDIT_SUBJ_CLR:
 381                         /* NOTE: this may return negative values indicating
 382                            a temporary error.  We simply treat this as a
 383                            match for now to avoid losing information that
 384                            may be wanted.   An error message will also be
 385                            logged upon error */
 386                         if (f->se_rule) {
 387                                 if (need_sid) {
 388                                         selinux_task_ctxid(tsk, &sid);
 389                                         need_sid = 0;
 390                                 }
 391                                 result = selinux_audit_rule_match(sid, f->type,
 392                                                                   f->op,
 393                                                                   f->se_rule,
 394                                                                   ctx);
 395                         }
 396                         break;
 397                 case AUDIT_OBJ_USER:
 398                 case AUDIT_OBJ_ROLE:
 399                 case AUDIT_OBJ_TYPE:
 400                 case AUDIT_OBJ_LEV_LOW:
 401                 case AUDIT_OBJ_LEV_HIGH:
 402                         /* The above note for AUDIT_SUBJ_USER...AUDIT_SUBJ_CLR
 403                            also applies here */
 404                         if (f->se_rule) {
 405                                 /* Find files that match */
 406                                 if (name) {
 407                                         result = selinux_audit_rule_match(
 408                                                    name->osid, f->type, f->op,
 409                                                    f->se_rule, ctx);
 410                                 } else if (ctx) {
 411                                         for (j = 0; j < ctx->name_count; j++) {
 412                                                 if (selinux_audit_rule_match(
 413                                                       ctx->names[j].osid,
 414                                                       f->type, f->op,
 415                                                       f->se_rule, ctx)) {
 416                                                         ++result;
 417                                                         break;
 418                                                 }
 419                                         }
 420                                 }
 421                                 /* Find ipc objects that match */
 422                                 if (ctx) {
 423                                         struct audit_aux_data *aux;
 424                                         for (aux = ctx->aux; aux;
 425                                              aux = aux->next) {
 426                                                 if (aux->type == AUDIT_IPC) {
 427                                                         struct audit_aux_data_ipcctl *axi = (void *)aux;
 428                                                         if (selinux_audit_rule_match(axi->osid, f->type, f->op, f->se_rule, ctx)) {
 429                                                                 ++result;
 430                                                                 break;
 431                                                         }
 432                                                 }
 433                                         }
 434                                 }
 435                         }
 436                         break;
 437                 case AUDIT_ARG0:
 438                 case AUDIT_ARG1:
 439                 case AUDIT_ARG2:
 440                 case AUDIT_ARG3:
 441                         if (ctx)
 442                                 result = audit_comparator(ctx->argv[f->type-AUDIT_ARG0], f->op, f->val);
 443                         break;
 444                 case AUDIT_FILTERKEY:
 445                         /* ignore this field for filtering */
 446                         result = 1;
 447                         break;
 448                 case AUDIT_PERM:
 449                         result = audit_match_perm(ctx, f->val);
 450                         break;
 451                 }
 452
 453                 if (!result)
 454                         return 0;
 455         }
 456         if (rule->filterkey)
 457                 ctx->filterkey = kstrdup(rule->filterkey, GFP_ATOMIC);
 458         switch (rule->action) {
 459         case AUDIT_NEVER:    *state = AUDIT_DISABLED;       break;
 460         case AUDIT_ALWAYS:   *state = AUDIT_RECORD_CONTEXT; break;
 461         }
 462         return 1;
 463 }
 464
 465 /* At process creation time, we can determine if system-call auditing is
 466  * completely disabled for this task.  Since we only have the task
 467  * structure at this point, we can only check uid and gid.
 468  */
 469 static enum audit_state audit_filter_task(struct task_struct *tsk)
 470 {
 471         struct audit_entry *e;
 472         enum audit_state   state;
 473
 474         rcu_read_lock();
 475         list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_TASK], list) {
 476                 if (audit_filter_rules(tsk, &e->rule, NULL, NULL, &state)) {
 477                         rcu_read_unlock();
 478                         return state;
 479                 }
 480         }
 481         rcu_read_unlock();
 482         return AUDIT_BUILD_CONTEXT;
 483 }
 484
 485 /* At syscall entry and exit time, this filter is called if the
 486  * audit_state is not low enough that auditing cannot take place, but is
 487  * also not high enough that we already know we have to write an audit
 488  * record (i.e., the state is AUDIT_SETUP_CONTEXT or AUDIT_BUILD_CONTEXT).
 489  */
 490 static enum audit_state audit_filter_syscall(struct task_struct *tsk,
 491                                              struct audit_context *ctx,
 492                                              struct list_head *list)
 493 {
 494         struct audit_entry *e;
 495         enum audit_state state;
 496
 497         if (audit_pid && tsk->tgid == audit_pid)
 498                 return AUDIT_DISABLED;
 499
 500         rcu_read_lock();
 501         if (!list_empty(list)) {
 502                 int word = AUDIT_WORD(ctx->major);
 503                 int bit  = AUDIT_BIT(ctx->major);
 504
 505                 list_for_each_entry_rcu(e, list, list) {
 506                         if ((e->rule.mask[word] & bit) == bit &&
 507                             audit_filter_rules(tsk, &e->rule, ctx, NULL,
 508                                                &state)) {
 509                                 rcu_read_unlock();
 510                                 return state;
 511                         }
 512                 }
 513         }
 514         rcu_read_unlock();
 515         return AUDIT_BUILD_CONTEXT;
 516 }
 517
 518 /* At syscall exit time, this filter is called if any audit_names[] have been
 519  * collected during syscall processing.  We only check rules in sublists at hash
 520  * buckets applicable to the inode numbers in audit_names[].
 521  * Regarding audit_state, same rules apply as for audit_filter_syscall().
 522  */
 523 enum audit_state audit_filter_inodes(struct task_struct *tsk,
 524                                      struct audit_context *ctx)
 525 {
 526         int i;
 527         struct audit_entry *e;
 528         enum audit_state state;
 529
 530         if (audit_pid && tsk->tgid == audit_pid)
 531                 return AUDIT_DISABLED;
 532
 533         rcu_read_lock();
 534         for (i = 0; i < ctx->name_count; i++) {
 535                 int word = AUDIT_WORD(ctx->major);
 536                 int bit  = AUDIT_BIT(ctx->major);
 537                 struct audit_names *n = &ctx->names[i];
 538                 int h = audit_hash_ino((u32)n->ino);
 539                 struct list_head *list = &audit_inode_hash[h];
 540
 541                 if (list_empty(list))
 542                         continue;
 543
 544                 list_for_each_entry_rcu(e, list, list) {
 545                         if ((e->rule.mask[word] & bit) == bit &&
 546                             audit_filter_rules(tsk, &e->rule, ctx, n, &state)) {
 547                                 rcu_read_unlock();
 548                                 return state;
 549                         }
 550                 }
 551         }
 552         rcu_read_unlock();
 553         return AUDIT_BUILD_CONTEXT;
 554 }
 555
 556 void audit_set_auditable(struct audit_context *ctx)
 557 {
 558         ctx->auditable = 1;
 559 }
 560
 561 static inline struct audit_context *audit_get_context(struct task_struct *tsk,
 562                                                       int return_valid,
 563                                                       int return_code)
 564 {
 565         struct audit_context *context = tsk->audit_context;
 566
 567         if (likely(!context))
 568                 return NULL;
 569         context->return_valid = return_valid;
 570         context->return_code  = return_code;
 571
 572         if (context->in_syscall && !context->dummy && !context->auditable) {
 573                 enum audit_state state;
 574
 575                 state = audit_filter_syscall(tsk, context, &audit_filter_list[AUDIT_FILTER_EXIT]);
 576                 if (state == AUDIT_RECORD_CONTEXT) {
 577                         context->auditable = 1;
 578                         goto get_context;
 579                 }
 580
 581                 state = audit_filter_inodes(tsk, context);
 582                 if (state == AUDIT_RECORD_CONTEXT)
 583                         context->auditable = 1;
 584
 585         }
 586
 587 get_context:
 588
 589         tsk->audit_context = NULL;
 590         return context;
 591 }
 592
 593 static inline void audit_free_names(struct audit_context *context)
 594 {
 595         int i;
 596
 597 #if AUDIT_DEBUG == 2
 598         if (context->auditable
 599             ||context->put_count + context->ino_count != context->name_count) {
 600                 printk(KERN_ERR "%s:%d(:%d): major=%d in_syscall=%d"
 601                        " name_count=%d put_count=%d"
 602                        " ino_count=%d [NOT freeing]\n",
 603                        __FILE__, __LINE__,
 604                        context->serial, context->major, context->in_syscall,
 605                        context->name_count, context->put_count,
 606                        context->ino_count);
 607                 for (i = 0; i < context->name_count; i++) {
 608                         printk(KERN_ERR "names[%d] = %p = %s\n", i,
 609                                context->names[i].name,
 610                                context->names[i].name ?: "(null)");
 611                 }
 612                 dump_stack();
 613                 return;
 614         }
 615 #endif
 616 #if AUDIT_DEBUG
 617         context->put_count  = 0;
 618         context->ino_count  = 0;
 619 #endif
 620
 621         for (i = 0; i < context->name_count; i++) {
 622                 if (context->names[i].name && context->names[i].name_put)
 623                         __putname(context->names[i].name);
 624         }
 625         context->name_count = 0;
 626         if (context->pwd)
 627                 dput(context->pwd);
 628         if (context->pwdmnt)
 629                 mntput(context->pwdmnt);
 630         context->pwd = NULL;
 631         context->pwdmnt = NULL;
 632 }
 633
 634 static inline void audit_free_aux(struct audit_context *context)
 635 {
 636         struct audit_aux_data *aux;
 637
 638         while ((aux = context->aux)) {
 639                 if (aux->type == AUDIT_AVC_PATH) {
 640                         struct audit_aux_data_path *axi = (void *)aux;
 641                         dput(axi->dentry);
 642                         mntput(axi->mnt);
 643                 }
 644
 645                 context->aux = aux->next;
 646                 kfree(aux);
 647         }
 648 }
 649
 650 static inline void audit_zero_context(struct audit_context *context,
 651                                       enum audit_state state)
 652 {
 653         uid_t loginuid = context->loginuid;
 654
 655         memset(context, 0, sizeof(*context));
 656         context->state      = state;
 657         context->loginuid   = loginuid;
 658 }
 659
 660 static inline struct audit_context *audit_alloc_context(enum audit_state state)
 661 {
 662         struct audit_context *context;
 663
 664         if (!(context = kmalloc(sizeof(*context), GFP_KERNEL)))
 665                 return NULL;
 666         audit_zero_context(context, state);
 667         return context;
 668 }
 669
 670 /**
 671  * audit_alloc - allocate an audit context block for a task
 672  * @tsk: task
 673  *
 674  * Filter on the task information and allocate a per-task audit context
 675  * if necessary.  Doing so turns on system call auditing for the
 676  * specified task.  This is called from copy_process, so no lock is
 677  * needed.
 678  */
 679 int audit_alloc(struct task_struct *tsk)
 680 {
 681         struct audit_context *context;
 682         enum audit_state     state;
 683
 684         if (likely(!audit_enabled))
 685                 return 0; /* Return if not auditing. */
 686
 687         state = audit_filter_task(tsk);
 688         if (likely(state == AUDIT_DISABLED))
 689                 return 0;
 690
 691         if (!(context = audit_alloc_context(state))) {
 692                 audit_log_lost("out of memory in audit_alloc");
 693                 return -ENOMEM;
 694         }
 695
 696                                 /* Preserve login uid */
 697         context->loginuid = -1;
 698         if (current->audit_context)
 699                 context->loginuid = current->audit_context->loginuid;
 700
 701         tsk->audit_context  = context;
 702         set_tsk_thread_flag(tsk, TIF_SYSCALL_AUDIT);
 703         return 0;
 704 }
 705
 706 static inline void audit_free_context(struct audit_context *context)
 707 {
 708         struct audit_context *previous;
 709         int                  count = 0;
 710
 711         do {
 712                 previous = context->previous;
 713                 if (previous || (count &&  count < 10)) {
 714                         ++count;
 715                         printk(KERN_ERR "audit(:%d): major=%d name_count=%d:"
 716                                " freeing multiple contexts (%d)\n",
 717                                context->serial, context->major,
 718                                context->name_count, count);
 719                 }
 720                 audit_free_names(context);
 721                 audit_free_aux(context);
 722                 kfree(context->filterkey);
 723                 kfree(context);
 724                 context  = previous;
 725         } while (context);
 726         if (count >= 10)
 727                 printk(KERN_ERR "audit: freed %d contexts\n", count);
 728 }
 729
 730 static void audit_log_task_context(struct audit_buffer *ab)
 731 {
 732         char *ctx = NULL;
 733         ssize_t len = 0;
 734
 735         len = security_getprocattr(current, "current", NULL, 0);
 736         if (len < 0) {
 737                 if (len != -EINVAL)
 738                         goto error_path;
 739                 return;
 740         }
 741
 742         ctx = kmalloc(len, GFP_KERNEL);
 743         if (!ctx)
 744                 goto error_path;
 745
 746         len = security_getprocattr(current, "current", ctx, len);
 747         if (len < 0 )
 748                 goto error_path;
 749
 750         audit_log_format(ab, " subj=%s", ctx);
 751         return;
 752
 753 error_path:
 754         kfree(ctx);
 755         audit_panic("error in audit_log_task_context");
 756         return;
 757 }
 758
 759 static void audit_log_task_info(struct audit_buffer *ab, struct task_struct *tsk)
 760 {
 761         char name[sizeof(tsk->comm)];
 762         struct mm_struct *mm = tsk->mm;
 763         struct vm_area_struct *vma;
 764
 765         /* tsk == current */
 766
 767         get_task_comm(name, tsk);
 768         audit_log_format(ab, " comm=");
 769         audit_log_untrustedstring(ab, name);
 770
 771         if (mm) {
 772                 down_read(&mm->mmap_sem);
 773                 vma = mm->mmap;
 774                 while (vma) {
 775                         if ((vma->vm_flags & VM_EXECUTABLE) &&
 776                             vma->vm_file) {
 777                                 audit_log_d_path(ab, "exe=",
 778                                                  vma->vm_file->f_dentry,
 779                                                  vma->vm_file->f_vfsmnt);
 780                                 break;
 781                         }
 782                         vma = vma->vm_next;
 783                 }
 784                 up_read(&mm->mmap_sem);
 785         }
 786         audit_log_task_context(ab);
 787 }
 788
 789 static void audit_log_exit(struct audit_context *context, struct task_struct *tsk)
 790 {
 791         int i, call_panic = 0;
 792         struct audit_buffer *ab;
 793         struct audit_aux_data *aux;
 794         const char *tty;
 795
 796         /* tsk == current */
 797         context->pid = tsk->pid;
 798         context->ppid = sys_getppid();  /* sic.  tsk == current in all cases */
 799         context->uid = tsk->uid;
 800         context->gid = tsk->gid;
 801         context->euid = tsk->euid;
 802         context->suid = tsk->suid;
 803         context->fsuid = tsk->fsuid;
 804         context->egid = tsk->egid;
 805         context->sgid = tsk->sgid;
 806         context->fsgid = tsk->fsgid;
 807         context->personality = tsk->personality;
 808
 809         ab = audit_log_start(context, GFP_KERNEL, AUDIT_SYSCALL);
 810         if (!ab)
 811                 return;         /* audit_panic has been called */
 812         audit_log_format(ab, "arch=%x syscall=%d",
 813                          context->arch, context->major);
 814         if (context->personality != PER_LINUX)
 815                 audit_log_format(ab, " per=%lx", context->personality);
 816         if (context->return_valid)
 817                 audit_log_format(ab, " success=%s exit=%ld",
 818                                  (context->return_valid==AUDITSC_SUCCESS)?"yes":"no",
 819                                  context->return_code);
 820         if (tsk->signal && tsk->signal->tty && tsk->signal->tty->name)
 821                 tty = tsk->signal->tty->name;
 822         else
 823                 tty = "(none)";
 824         audit_log_format(ab,
 825                   " a0=%lx a1=%lx a2=%lx a3=%lx items=%d"
 826                   " ppid=%d pid=%d auid=%u uid=%u gid=%u"
 827                   " euid=%u suid=%u fsuid=%u"
 828                   " egid=%u sgid=%u fsgid=%u tty=%s",
 829                   context->argv[0],
 830                   context->argv[1],
 831                   context->argv[2],
 832                   context->argv[3],
 833                   context->name_count,
 834                   context->ppid,
 835                   context->pid,
 836                   context->loginuid,
 837                   context->uid,
 838                   context->gid,
 839                   context->euid, context->suid, context->fsuid,
 840                   context->egid, context->sgid, context->fsgid, tty);
 841         audit_log_task_info(ab, tsk);
 842         if (context->filterkey) {
 843                 audit_log_format(ab, " key=");
 844                 audit_log_untrustedstring(ab, context->filterkey);
 845         } else
 846                 audit_log_format(ab, " key=(null)");
 847         audit_log_end(ab);
 848
 849         for (aux = context->aux; aux; aux = aux->next) {
 850
 851                 ab = audit_log_start(context, GFP_KERNEL, aux->type);
 852                 if (!ab)
 853                         continue; /* audit_panic has been called */
 854
 855                 switch (aux->type) {
 856                 case AUDIT_MQ_OPEN: {
 857                         struct audit_aux_data_mq_open *axi = (void *)aux;
 858                         audit_log_format(ab,
 859                                 "oflag=0x%x mode=%#o mq_flags=0x%lx mq_maxmsg=%ld "
 860                                 "mq_msgsize=%ld mq_curmsgs=%ld",
 861                                 axi->oflag, axi->mode, axi->attr.mq_flags,
 862                                 axi->attr.mq_maxmsg, axi->attr.mq_msgsize,
 863                                 axi->attr.mq_curmsgs);
 864                         break; }
 865
 866                 case AUDIT_MQ_SENDRECV: {
 867                         struct audit_aux_data_mq_sendrecv *axi = (void *)aux;
 868                         audit_log_format(ab,
 869                                 "mqdes=%d msg_len=%zd msg_prio=%u "
 870                                 "abs_timeout_sec=%ld abs_timeout_nsec=%ld",
 871                                 axi->mqdes, axi->msg_len, axi->msg_prio,
 872                                 axi->abs_timeout.tv_sec, axi->abs_timeout.tv_nsec);
 873                         break; }
 874
 875                 case AUDIT_MQ_NOTIFY: {
 876                         struct audit_aux_data_mq_notify *axi = (void *)aux;
 877                         audit_log_format(ab,
 878                                 "mqdes=%d sigev_signo=%d",
 879                                 axi->mqdes,
 880                                 axi->notification.sigev_signo);
 881                         break; }
 882
 883                 case AUDIT_MQ_GETSETATTR: {
 884                         struct audit_aux_data_mq_getsetattr *axi = (void *)aux;
 885                         audit_log_format(ab,
 886                                 "mqdes=%d mq_flags=0x%lx mq_maxmsg=%ld mq_msgsize=%ld "
 887                                 "mq_curmsgs=%ld ",
 888                                 axi->mqdes,
 889                                 axi->mqstat.mq_flags, axi->mqstat.mq_maxmsg,
 890                                 axi->mqstat.mq_msgsize, axi->mqstat.mq_curmsgs);
 891                         break; }
 892
 893                 case AUDIT_IPC: {
 894                         struct audit_aux_data_ipcctl *axi = (void *)aux;
 895                         audit_log_format(ab,
 896                                  "ouid=%u ogid=%u mode=%x",
 897                                  axi->uid, axi->gid, axi->mode);
 898                         if (axi->osid != 0) {
 899                                 char *ctx = NULL;
 900                                 u32 len;
 901                                 if (selinux_ctxid_to_string(
 902                                                 axi->osid, &ctx, &len)) {
 903                                         audit_log_format(ab, " osid=%u",
 904                                                         axi->osid);
 905                                         call_panic = 1;
 906                                 } else
 907                                         audit_log_format(ab, " obj=%s", ctx);
 908                                 kfree(ctx);
 909                         }
 910                         break; }
 911
 912                 case AUDIT_IPC_SET_PERM: {
 913                         struct audit_aux_data_ipcctl *axi = (void *)aux;
 914                         audit_log_format(ab,
 915                                 "qbytes=%lx ouid=%u ogid=%u mode=%x",
 916                                 axi->qbytes, axi->uid, axi->gid, axi->mode);
 917                         break; }
 918
 919                 case AUDIT_EXECVE: {
 920                         struct audit_aux_data_execve *axi = (void *)aux;
 921                         int i;
 922                         const char *p;
 923                         for (i = 0, p = axi->mem; i < axi->argc; i++) {
 924                                 audit_log_format(ab, "a%d=", i);
 925                                 p = audit_log_untrustedstring(ab, p);
 926                                 audit_log_format(ab, "\n");
 927                         }
 928                         break; }
 929
 930                 case AUDIT_SOCKETCALL: {
 931                         int i;
 932                         struct audit_aux_data_socketcall *axs = (void *)aux;
 933                         audit_log_format(ab, "nargs=%d", axs->nargs);
 934                         for (i=0; i<axs->nargs; i++)
 935                                 audit_log_format(ab, " a%d=%lx", i, axs->args[i]);
 936                         break; }
 937
 938                 case AUDIT_SOCKADDR: {
 939                         struct audit_aux_data_sockaddr *axs = (void *)aux;
 940
 941                         audit_log_format(ab, "saddr=");
 942                         audit_log_hex(ab, axs->a, axs->len);
 943                         break; }
 944
 945                 case AUDIT_AVC_PATH: {
 946                         struct audit_aux_data_path *axi = (void *)aux;
 947                         audit_log_d_path(ab, "path=", axi->dentry, axi->mnt);
 948                         break; }
 949
 950                 }
 951                 audit_log_end(ab);
 952         }
 953
 954         if (context->pwd && context->pwdmnt) {
 955                 ab = audit_log_start(context, GFP_KERNEL, AUDIT_CWD);
 956                 if (ab) {
 957                         audit_log_d_path(ab, "cwd=", context->pwd, context->pwdmnt);
 958                         audit_log_end(ab);
 959                 }
 960         }
 961         for (i = 0; i < context->name_count; i++) {
 962                 struct audit_names *n = &context->names[i];
 963
 964                 ab = audit_log_start(context, GFP_KERNEL, AUDIT_PATH);
 965                 if (!ab)
 966                         continue; /* audit_panic has been called */
 967
 968                 audit_log_format(ab, "item=%d", i);
 969
 970                 if (n->name) {
 971                         switch(n->name_len) {
 972                         case AUDIT_NAME_FULL:
 973                                 /* log the full path */
 974                                 audit_log_format(ab, " name=");
 975                                 audit_log_untrustedstring(ab, n->name);
 976                                 break;
 977                         case 0:
 978                                 /* name was specified as a relative path and the
 979                                  * directory component is the cwd */
 980                                 audit_log_d_path(ab, " name=", context->pwd,
 981                                                  context->pwdmnt);
 982                                 break;
 983                         default:
 984                                 /* log the name's directory component */
 985                                 audit_log_format(ab, " name=");
 986                                 audit_log_n_untrustedstring(ab, n->name_len,
 987                                                             n->name);
 988                         }
 989                 } else
 990                         audit_log_format(ab, " name=(null)");
 991
 992                 if (n->ino != (unsigned long)-1) {
 993                         audit_log_format(ab, " inode=%lu"
 994                                          " dev=%02x:%02x mode=%#o"
 995                                          " ouid=%u ogid=%u rdev=%02x:%02x",
 996                                          n->ino,
 997                                          MAJOR(n->dev),
 998                                          MINOR(n->dev),
 999                                          n->mode,
1000                                          n->uid,
1001                                          n->gid,
1002                                          MAJOR(n->rdev),
1003                                          MINOR(n->rdev));
1004                 }
1005                 if (n->osid != 0) {
1006                         char *ctx = NULL;
1007                         u32 len;
1008                         if (selinux_ctxid_to_string(
1009                                 n->osid, &ctx, &len)) {
1010                                 audit_log_format(ab, " osid=%u", n->osid);
1011                                 call_panic = 2;
1012                         } else
1013                                 audit_log_format(ab, " obj=%s", ctx);
1014                         kfree(ctx);
1015                 }
1016
1017                 audit_log_end(ab);
1018         }
1019         if (call_panic)
1020                 audit_panic("error converting sid to string");
1021 }
1022
1023 /**
1024  * audit_free - free a per-task audit context
1025  * @tsk: task whose audit context block to free
1026  *
1027  * Called from copy_process and do_exit
1028  */
1029 void audit_free(struct task_struct *tsk)
1030 {
1031         struct audit_context *context;
1032
1033         context = audit_get_context(tsk, 0, 0);
1034         if (likely(!context))
1035                 return;
1036
1037         /* Check for system calls that do not go through the exit
1038          * function (e.g., exit_group), then free context block.
1039          * We use GFP_ATOMIC here because we might be doing this
1040          * in the context of the idle thread */
1041         /* that can happen only if we are called from do_exit() */
1042         if (context->in_syscall && context->auditable)
1043                 audit_log_exit(context, tsk);
1044
1045         audit_free_context(context);
1046 }
1047
1048 /**
1049  * audit_syscall_entry - fill in an audit record at syscall entry
1050  * @tsk: task being audited
1051  * @arch: architecture type
1052  * @major: major syscall type (function)
1053  * @a1: additional syscall register 1
1054  * @a2: additional syscall register 2
1055  * @a3: additional syscall register 3
1056  * @a4: additional syscall register 4
1057  *
1058  * Fill in audit context at syscall entry.  This only happens if the
1059  * audit context was created when the task was created and the state or
1060  * filters demand the audit context be built.  If the state from the
1061  * per-task filter or from the per-syscall filter is AUDIT_RECORD_CONTEXT,
1062  * then the record will be written at syscall exit time (otherwise, it
1063  * will only be written if another part of the kernel requests that it
1064  * be written).
1065  */
1066 void audit_syscall_entry(int arch, int major,
1067                          unsigned long a1, unsigned long a2,
1068                          unsigned long a3, unsigned long a4)
1069 {
1070         struct task_struct *tsk = current;
1071         struct audit_context *context = tsk->audit_context;
1072         enum audit_state     state;
1073
1074         BUG_ON(!context);
1075
1076         /*
1077          * This happens only on certain architectures that make system
1078          * calls in kernel_thread via the entry.S interface, instead of
1079          * with direct calls.  (If you are porting to a new
1080          * architecture, hitting this condition can indicate that you
1081          * got the _exit/_leave calls backward in entry.S.)
1082          *
1083          * i386     no
1084          * x86_64   no
1085          * ppc64    yes (see arch/powerpc/platforms/iseries/misc.S)
1086          *
1087          * This also happens with vm86 emulation in a non-nested manner
1088          * (entries without exits), so this case must be caught.
1089          */
1090         if (context->in_syscall) {
1091                 struct audit_context *newctx;
1092
1093 #if AUDIT_DEBUG
1094                 printk(KERN_ERR
1095                        "audit(:%d) pid=%d in syscall=%d;"
1096                        " entering syscall=%d\n",
1097                        context->serial, tsk->pid, context->major, major);
1098 #endif
1099                 newctx = audit_alloc_context(context->state);
1100                 if (newctx) {
1101                         newctx->previous   = context;
1102                         context            = newctx;
1103                         tsk->audit_context = newctx;
1104                 } else  {
1105                         /* If we can't alloc a new context, the best we
1106                          * can do is to leak memory (any pending putname
1107                          * will be lost).  The only other alternative is
1108                          * to abandon auditing. */
1109                         audit_zero_context(context, context->state);
1110                 }
1111         }
1112         BUG_ON(context->in_syscall || context->name_count);
1113
1114         if (!audit_enabled)
1115                 return;
1116
1117         context->arch       = arch;
1118         context->major      = major;
1119         context->argv[0]    = a1;
1120         context->argv[1]    = a2;
1121         context->argv[2]    = a3;
1122         context->argv[3]    = a4;
1123
1124         state = context->state;
1125         context->dummy = !audit_n_rules;
1126         if (!context->dummy && (state == AUDIT_SETUP_CONTEXT || state == AUDIT_BUILD_CONTEXT))
1127                 state = audit_filter_syscall(tsk, context, &audit_filter_list[AUDIT_FILTER_ENTRY]);
1128         if (likely(state == AUDIT_DISABLED))
1129                 return;
1130
1131         context->serial     = 0;
1132         context->ctime      = CURRENT_TIME;
1133         context->in_syscall = 1;
1134         context->auditable  = !!(state == AUDIT_RECORD_CONTEXT);
1135 }
1136
1137 /**
1138  * audit_syscall_exit - deallocate audit context after a system call
1139  * @tsk: task being audited
1140  * @valid: success/failure flag
1141  * @return_code: syscall return value
1142  *
1143  * Tear down after system call.  If the audit context has been marked as
1144  * auditable (either because of the AUDIT_RECORD_CONTEXT state from
1145  * filtering, or because some other part of the kernel write an audit
1146  * message), then write out the syscall information.  In call cases,
1147  * free the names stored from getname().
1148  */
1149 void audit_syscall_exit(int valid, long return_code)
1150 {
1151         struct task_struct *tsk = current;
1152         struct audit_context *context;
1153
1154         context = audit_get_context(tsk, valid, return_code);
1155
1156         if (likely(!context))
1157                 return;
1158
1159         if (context->in_syscall && context->auditable)
1160                 audit_log_exit(context, tsk);
1161
1162         context->in_syscall = 0;
1163         context->auditable  = 0;
1164
1165         if (context->previous) {
1166                 struct audit_context *new_context = context->previous;
1167                 context->previous  = NULL;
1168                 audit_free_context(context);
1169                 tsk->audit_context = new_context;
1170         } else {
1171                 audit_free_names(context);
1172                 audit_free_aux(context);
1173                 kfree(context->filterkey);
1174                 context->filterkey = NULL;
1175                 tsk->audit_context = context;
1176         }
1177 }
1178
1179 /**
1180  * audit_getname - add a name to the list
1181  * @name: name to add
1182  *
1183  * Add a name to the list of audit names for this context.
1184  * Called from fs/namei.c:getname().
1185  */
1186 void __audit_getname(const char *name)
1187 {
1188         struct audit_context *context = current->audit_context;
1189
1190         if (IS_ERR(name) || !name)
1191                 return;
1192
1193         if (!context->in_syscall) {
1194 #if AUDIT_DEBUG == 2
1195                 printk(KERN_ERR "%s:%d(:%d): ignoring getname(%p)\n",
1196                        __FILE__, __LINE__, context->serial, name);
1197                 dump_stack();
1198 #endif
1199                 return;
1200         }
1201         BUG_ON(context->name_count >= AUDIT_NAMES);
1202         context->names[context->name_count].name = name;
1203         context->names[context->name_count].name_len = AUDIT_NAME_FULL;
1204         context->names[context->name_count].name_put = 1;
1205         context->names[context->name_count].ino  = (unsigned long)-1;
1206         ++context->name_count;
1207         if (!context->pwd) {
1208                 read_lock(&current->fs->lock);
1209                 context->pwd = dget(current->fs->pwd);
1210                 context->pwdmnt = mntget(current->fs->pwdmnt);
1211                 read_unlock(&current->fs->lock);
1212         }
1213
1214 }
1215
1216 /* audit_putname - intercept a putname request
1217  * @name: name to intercept and delay for putname
1218  *
1219  * If we have stored the name from getname in the audit context,
1220  * then we delay the putname until syscall exit.
1221  * Called from include/linux/fs.h:putname().
1222  */
1223 void audit_putname(const char *name)
1224 {
1225         struct audit_context *context = current->audit_context;
1226
1227         BUG_ON(!context);
1228         if (!context->in_syscall) {
1229 #if AUDIT_DEBUG == 2
1230                 printk(KERN_ERR "%s:%d(:%d): __putname(%p)\n",
1231                        __FILE__, __LINE__, context->serial, name);
1232                 if (context->name_count) {
1233                         int i;
1234                         for (i = 0; i < context->name_count; i++)
1235                                 printk(KERN_ERR "name[%d] = %p = %s\n", i,
1236                                        context->names[i].name,
1237                                        context->names[i].name ?: "(null)");
1238                 }
1239 #endif
1240                 __putname(name);
1241         }
1242 #if AUDIT_DEBUG
1243         else {
1244                 ++context->put_count;
1245                 if (context->put_count > context->name_count) {
1246                         printk(KERN_ERR "%s:%d(:%d): major=%d"
1247                                " in_syscall=%d putname(%p) name_count=%d"
1248                                " put_count=%d\n",
1249                                __FILE__, __LINE__,
1250                                context->serial, context->major,
1251                                context->in_syscall, name, context->name_count,
1252                                context->put_count);
1253                         dump_stack();
1254                 }
1255         }
1256 #endif
1257 }
1258
1259 /* Copy inode data into an audit_names. */
1260 static void audit_copy_inode(struct audit_names *name, const struct inode *inode)
1261 {
1262         name->ino   = inode->i_ino;
1263         name->dev   = inode->i_sb->s_dev;
1264         name->mode  = inode->i_mode;
1265         name->uid   = inode->i_uid;
1266         name->gid   = inode->i_gid;
1267         name->rdev  = inode->i_rdev;
1268         selinux_get_inode_sid(inode, &name->osid);
1269 }
1270
1271 /**
1272  * audit_inode - store the inode and device from a lookup
1273  * @name: name being audited
1274  * @inode: inode being audited
1275  *
1276  * Called from fs/namei.c:path_lookup().
1277  */
1278 void __audit_inode(const char *name, const struct inode *inode)
1279 {
1280         int idx;
1281         struct audit_context *context = current->audit_context;
1282
1283         if (!context->in_syscall)
1284                 return;
1285         if (context->name_count
1286             && context->names[context->name_count-1].name
1287             && context->names[context->name_count-1].name == name)
1288                 idx = context->name_count - 1;
1289         else if (context->name_count > 1
1290                  && context->names[context->name_count-2].name
1291                  && context->names[context->name_count-2].name == name)
1292                 idx = context->name_count - 2;
1293         else {
1294                 /* FIXME: how much do we care about inodes that have no
1295                  * associated name? */
1296                 if (context->name_count >= AUDIT_NAMES - AUDIT_NAMES_RESERVED)
1297                         return;
1298                 idx = context->name_count++;
1299                 context->names[idx].name = NULL;
1300 #if AUDIT_DEBUG
1301                 ++context->ino_count;
1302 #endif
1303         }
1304         audit_copy_inode(&context->names[idx], inode);
1305 }
1306
1307 /**
1308  * audit_inode_child - collect inode info for created/removed objects
1309  * @dname: inode's dentry name
1310  * @inode: inode being audited
1311  * @parent: inode of dentry parent
1312  *
1313  * For syscalls that create or remove filesystem objects, audit_inode
1314  * can only collect information for the filesystem object's parent.
1315  * This call updates the audit context with the child's information.
1316  * Syscalls that create a new filesystem object must be hooked after
1317  * the object is created.  Syscalls that remove a filesystem object
1318  * must be hooked prior, in order to capture the target inode during
1319  * unsuccessful attempts.
1320  */
1321 void __audit_inode_child(const char *dname, const struct inode *inode,
1322                          const struct inode *parent)
1323 {
1324         int idx;
1325         struct audit_context *context = current->audit_context;
1326         const char *found_name = NULL;
1327         int dirlen = 0;
1328
1329         if (!context->in_syscall)
1330                 return;
1331
1332         /* determine matching parent */
1333         if (!dname)
1334                 goto update_context;
1335         for (idx = 0; idx < context->name_count; idx++)
1336                 if (context->names[idx].ino == parent->i_ino) {
1337                         const char *name = context->names[idx].name;
1338
1339                         if (!name)
1340                                 continue;
1341
1342                         if (audit_compare_dname_path(dname, name, &dirlen) == 0) {
1343                                 context->names[idx].name_len = dirlen;
1344                                 found_name = name;
1345                                 break;
1346                         }
1347                 }
1348
1349 update_context:
1350         idx = context->name_count++;
1351 #if AUDIT_DEBUG
1352         context->ino_count++;
1353 #endif
1354         /* Re-use the name belonging to the slot for a matching parent directory.
1355          * All names for this context are relinquished in audit_free_names() */
1356         context->names[idx].name = found_name;
1357         context->names[idx].name_len = AUDIT_NAME_FULL;
1358         context->names[idx].name_put = 0;       /* don't call __putname() */
1359
1360         if (!inode)
1361                 context->names[idx].ino = (unsigned long)-1;
1362         else
1363                 audit_copy_inode(&context->names[idx], inode);
1364
1365         /* A parent was not found in audit_names, so copy the inode data for the
1366          * provided parent. */
1367         if (!found_name) {
1368                 idx = context->name_count++;
1369 #if AUDIT_DEBUG
1370                 context->ino_count++;
1371 #endif
1372                 audit_copy_inode(&context->names[idx], parent);
1373         }
1374 }
1375
1376 /**
1377  * audit_inode_update - update inode info for last collected name
1378  * @inode: inode being audited
1379  *
1380  * When open() is called on an existing object with the O_CREAT flag, the inode
1381  * data audit initially collects is incorrect.  This additional hook ensures
1382  * audit has the inode data for the actual object to be opened.
1383  */
1384 void __audit_inode_update(const struct inode *inode)
1385 {
1386         struct audit_context *context = current->audit_context;
1387         int idx;
1388
1389         if (!context->in_syscall || !inode)
1390                 return;
1391
1392         if (context->name_count == 0) {
1393                 context->name_count++;
1394 #if AUDIT_DEBUG
1395                 context->ino_count++;
1396 #endif
1397         }
1398         idx = context->name_count - 1;
1399
1400         audit_copy_inode(&context->names[idx], inode);
1401 }
1402
1403 /**
1404  * auditsc_get_stamp - get local copies of audit_context values
1405  * @ctx: audit_context for the task
1406  * @t: timespec to store time recorded in the audit_context
1407  * @serial: serial value that is recorded in the audit_context
1408  *
1409  * Also sets the context as auditable.
1410  */
1411 void auditsc_get_stamp(struct audit_context *ctx,
1412                        struct timespec *t, unsigned int *serial)
1413 {
1414         if (!ctx->serial)
1415                 ctx->serial = audit_serial();
1416         t->tv_sec  = ctx->ctime.tv_sec;
1417         t->tv_nsec = ctx->ctime.tv_nsec;
1418         *serial    = ctx->serial;
1419         ctx->auditable = 1;
1420 }
1421
1422 /**
1423  * audit_set_loginuid - set a task's audit_context loginuid
1424  * @task: task whose audit context is being modified
1425  * @loginuid: loginuid value
1426  *
1427  * Returns 0.
1428  *
1429  * Called (set) from fs/proc/base.c::proc_loginuid_write().
1430  */
1431 int audit_set_loginuid(struct task_struct *task, uid_t loginuid)
1432 {
1433         struct audit_context *context = task->audit_context;
1434
1435         if (context) {
1436                 /* Only log if audit is enabled */
1437                 if (context->in_syscall) {
1438                         struct audit_buffer *ab;
1439
1440                         ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_LOGIN);
1441                         if (ab) {
1442                                 audit_log_format(ab, "login pid=%d uid=%u "
1443                                         "old auid=%u new auid=%u",
1444                                         task->pid, task->uid,
1445                                         context->loginuid, loginuid);
1446                                 audit_log_end(ab);
1447                         }
1448                 }
1449                 context->loginuid = loginuid;
1450         }
1451         return 0;
1452 }
1453
1454 /**
1455  * audit_get_loginuid - get the loginuid for an audit_context
1456  * @ctx: the audit_context
1457  *
1458  * Returns the context's loginuid or -1 if @ctx is NULL.
1459  */
1460 uid_t audit_get_loginuid(struct audit_context *ctx)
1461 {
1462         return ctx ? ctx->loginuid : -1;
1463 }
1464
1465 /**
1466  * __audit_mq_open - record audit data for a POSIX MQ open
1467  * @oflag: open flag
1468  * @mode: mode bits
1469  * @u_attr: queue attributes
1470  *
1471  * Returns 0 for success or NULL context or < 0 on error.
1472  */
1473 int __audit_mq_open(int oflag, mode_t mode, struct mq_attr __user *u_attr)
1474 {
1475         struct audit_aux_data_mq_open *ax;
1476         struct audit_context *context = current->audit_context;
1477
1478         if (!audit_enabled)
1479                 return 0;
1480
1481         if (likely(!context))
1482                 return 0;
1483
1484         ax = kmalloc(sizeof(*ax), GFP_ATOMIC);
1485         if (!ax)
1486                 return -ENOMEM;
1487
1488         if (u_attr != NULL) {
1489                 if (copy_from_user(&ax->attr, u_attr, sizeof(ax->attr))) {
1490                         kfree(ax);
1491                         return -EFAULT;
1492                 }
1493         } else
1494                 memset(&ax->attr, 0, sizeof(ax->attr));
1495
1496         ax->oflag = oflag;
1497         ax->mode = mode;
1498
1499         ax->d.type = AUDIT_MQ_OPEN;
1500         ax->d.next = context->aux;
1501         context->aux = (void *)ax;
1502         return 0;
1503 }
1504
1505 /**
1506  * __audit_mq_timedsend - record audit data for a POSIX MQ timed send
1507  * @mqdes: MQ descriptor
1508  * @msg_len: Message length
1509  * @msg_prio: Message priority
1510  * @u_abs_timeout: Message timeout in absolute time
1511  *
1512  * Returns 0 for success or NULL context or < 0 on error.
1513  */
1514 int __audit_mq_timedsend(mqd_t mqdes, size_t msg_len, unsigned int msg_prio,
1515                         const struct timespec __user *u_abs_timeout)
1516 {
1517         struct audit_aux_data_mq_sendrecv *ax;
1518         struct audit_context *context = current->audit_context;
1519
1520         if (!audit_enabled)
1521                 return 0;
1522
1523         if (likely(!context))
1524                 return 0;
1525
1526         ax = kmalloc(sizeof(*ax), GFP_ATOMIC);
1527         if (!ax)
1528                 return -ENOMEM;
1529
1530         if (u_abs_timeout != NULL) {
1531                 if (copy_from_user(&ax->abs_timeout, u_abs_timeout, sizeof(ax->abs_timeout))) {
1532                         kfree(ax);
1533                         return -EFAULT;
1534                 }
1535         } else
1536                 memset(&ax->abs_timeout, 0, sizeof(ax->abs_timeout));
1537
1538         ax->mqdes = mqdes;
1539         ax->msg_len = msg_len;
1540         ax->msg_prio = msg_prio;
1541
1542         ax->d.type = AUDIT_MQ_SENDRECV;
1543         ax->d.next = context->aux;
1544         context->aux = (void *)ax;
1545         return 0;
1546 }
1547
1548 /**
1549  * __audit_mq_timedreceive - record audit data for a POSIX MQ timed receive
1550  * @mqdes: MQ descriptor
1551  * @msg_len: Message length
1552  * @u_msg_prio: Message priority
1553  * @u_abs_timeout: Message timeout in absolute time
1554  *
1555  * Returns 0 for success or NULL context or < 0 on error.
1556  */
1557 int __audit_mq_timedreceive(mqd_t mqdes, size_t msg_len,
1558                                 unsigned int __user *u_msg_prio,
1559                                 const struct timespec __user *u_abs_timeout)
1560 {
1561         struct audit_aux_data_mq_sendrecv *ax;
1562         struct audit_context *context = current->audit_context;
1563
1564         if (!audit_enabled)
1565                 return 0;
1566
1567         if (likely(!context))
1568                 return 0;
1569
1570         ax = kmalloc(sizeof(*ax), GFP_ATOMIC);
1571         if (!ax)
1572                 return -ENOMEM;
1573
1574         if (u_msg_prio != NULL) {
1575                 if (get_user(ax->msg_prio, u_msg_prio)) {
1576                         kfree(ax);
1577                         return -EFAULT;
1578                 }
1579         } else
1580                 ax->msg_prio = 0;
1581
1582         if (u_abs_timeout != NULL) {
1583                 if (copy_from_user(&ax->abs_timeout, u_abs_timeout, sizeof(ax->abs_timeout))) {
1584                         kfree(ax);
1585                         return -EFAULT;
1586                 }
1587         } else
1588                 memset(&ax->abs_timeout, 0, sizeof(ax->abs_timeout));
1589
1590         ax->mqdes = mqdes;
1591         ax->msg_len = msg_len;
1592
1593         ax->d.type = AUDIT_MQ_SENDRECV;
1594         ax->d.next = context->aux;
1595         context->aux = (void *)ax;
1596         return 0;
1597 }
1598
1599 /**
1600  * __audit_mq_notify - record audit data for a POSIX MQ notify
1601  * @mqdes: MQ descriptor
1602  * @u_notification: Notification event
1603  *
1604  * Returns 0 for success or NULL context or < 0 on error.
1605  */
1606
1607 int __audit_mq_notify(mqd_t mqdes, const struct sigevent __user *u_notification)
1608 {
1609         struct audit_aux_data_mq_notify *ax;
1610         struct audit_context *context = current->audit_context;
1611
1612         if (!audit_enabled)
1613                 return 0;
1614
1615         if (likely(!context))
1616                 return 0;
1617
1618         ax = kmalloc(sizeof(*ax), GFP_ATOMIC);
1619         if (!ax)
1620                 return -ENOMEM;
1621
1622         if (u_notification != NULL) {
1623                 if (copy_from_user(&ax->notification, u_notification, sizeof(ax->notification))) {
1624                         kfree(ax);
1625                         return -EFAULT;
1626                 }
1627         } else
1628                 memset(&ax->notification, 0, sizeof(ax->notification));
1629
1630         ax->mqdes = mqdes;
1631
1632         ax->d.type = AUDIT_MQ_NOTIFY;
1633         ax->d.next = context->aux;
1634         context->aux = (void *)ax;
1635         return 0;
1636 }
1637
1638 /**
1639  * __audit_mq_getsetattr - record audit data for a POSIX MQ get/set attribute
1640  * @mqdes: MQ descriptor
1641  * @mqstat: MQ flags
1642  *
1643  * Returns 0 for success or NULL context or < 0 on error.
1644  */
1645 int __audit_mq_getsetattr(mqd_t mqdes, struct mq_attr *mqstat)
1646 {
1647         struct audit_aux_data_mq_getsetattr *ax;
1648         struct audit_context *context = current->audit_context;
1649
1650         if (!audit_enabled)
1651                 return 0;
1652
1653         if (likely(!context))
1654                 return 0;
1655
1656         ax = kmalloc(sizeof(*ax), GFP_ATOMIC);
1657         if (!ax)
1658                 return -ENOMEM;
1659
1660         ax->mqdes = mqdes;
1661         ax->mqstat = *mqstat;
1662
1663         ax->d.type = AUDIT_MQ_GETSETATTR;
1664         ax->d.next = context->aux;
1665         context->aux = (void *)ax;
1666         return 0;
1667 }
1668
1669 /**
1670  * audit_ipc_obj - record audit data for ipc object
1671  * @ipcp: ipc permissions
1672  *
1673  * Returns 0 for success or NULL context or < 0 on error.
1674  */
1675 int __audit_ipc_obj(struct kern_ipc_perm *ipcp)
1676 {
1677         struct audit_aux_data_ipcctl *ax;
1678         struct audit_context *context = current->audit_context;
1679
1680         ax = kmalloc(sizeof(*ax), GFP_ATOMIC);
1681         if (!ax)
1682                 return -ENOMEM;
1683
1684         ax->uid = ipcp->uid;
1685         ax->gid = ipcp->gid;
1686         ax->mode = ipcp->mode;
1687         selinux_get_ipc_sid(ipcp, &ax->osid);
1688
1689         ax->d.type = AUDIT_IPC;
1690         ax->d.next = context->aux;
1691         context->aux = (void *)ax;
1692         return 0;
1693 }
1694
1695 /**
1696  * audit_ipc_set_perm - record audit data for new ipc permissions
1697  * @qbytes: msgq bytes
1698  * @uid: msgq user id
1699  * @gid: msgq group id
1700  * @mode: msgq mode (permissions)
1701  *
1702  * Returns 0 for success or NULL context or < 0 on error.
1703  */
1704 int __audit_ipc_set_perm(unsigned long qbytes, uid_t uid, gid_t gid, mode_t mode)
1705 {
1706         struct audit_aux_data_ipcctl *ax;
1707         struct audit_context *context = current->audit_context;
1708
1709         ax = kmalloc(sizeof(*ax), GFP_ATOMIC);
1710         if (!ax)
1711                 return -ENOMEM;
1712
1713         ax->qbytes = qbytes;
1714         ax->uid = uid;
1715         ax->gid = gid;
1716         ax->mode = mode;
1717
1718         ax->d.type = AUDIT_IPC_SET_PERM;
1719         ax->d.next = context->aux;
1720         context->aux = (void *)ax;
1721         return 0;
1722 }
1723
1724 int audit_bprm(struct linux_binprm *bprm)
1725 {
1726         struct audit_aux_data_execve *ax;
1727         struct audit_context *context = current->audit_context;
1728         unsigned long p, next;
1729         void *to;
1730
1731         if (likely(!audit_enabled || !context || context->dummy))
1732                 return 0;
1733
1734         ax = kmalloc(sizeof(*ax) + PAGE_SIZE * MAX_ARG_PAGES - bprm->p,
1735                                 GFP_KERNEL);
1736         if (!ax)
1737                 return -ENOMEM;
1738
1739         ax->argc = bprm->argc;
1740         ax->envc = bprm->envc;
1741         for (p = bprm->p, to = ax->mem; p < MAX_ARG_PAGES*PAGE_SIZE; p = next) {
1742                 struct page *page = bprm->page[p / PAGE_SIZE];
1743                 void *kaddr = kmap(page);
1744                 next = (p + PAGE_SIZE) & ~(PAGE_SIZE - 1);
1745                 memcpy(to, kaddr + (p & (PAGE_SIZE - 1)), next - p);
1746                 to += next - p;
1747                 kunmap(page);
1748         }
1749
1750         ax->d.type = AUDIT_EXECVE;
1751         ax->d.next = context->aux;
1752         context->aux = (void *)ax;
1753         return 0;
1754 }
1755
1756
1757 /**
1758  * audit_socketcall - record audit data for sys_socketcall
1759  * @nargs: number of args
1760  * @args: args array
1761  *
1762  * Returns 0 for success or NULL context or < 0 on error.
1763  */
1764 int audit_socketcall(int nargs, unsigned long *args)
1765 {
1766         struct audit_aux_data_socketcall *ax;
1767         struct audit_context *context = current->audit_context;
1768
1769         if (likely(!context || context->dummy))
1770                 return 0;
1771
1772         ax = kmalloc(sizeof(*ax) + nargs * sizeof(unsigned long), GFP_KERNEL);
1773         if (!ax)
1774                 return -ENOMEM;
1775
1776         ax->nargs = nargs;
1777         memcpy(ax->args, args, nargs * sizeof(unsigned long));
1778
1779         ax->d.type = AUDIT_SOCKETCALL;
1780         ax->d.next = context->aux;
1781         context->aux = (void *)ax;
1782         return 0;
1783 }
1784
1785 /**
1786  * audit_sockaddr - record audit data for sys_bind, sys_connect, sys_sendto
1787  * @len: data length in user space
1788  * @a: data address in kernel space
1789  *
1790  * Returns 0 for success or NULL context or < 0 on error.
1791  */
1792 int audit_sockaddr(int len, void *a)
1793 {
1794         struct audit_aux_data_sockaddr *ax;
1795         struct audit_context *context = current->audit_context;
1796
1797         if (likely(!context || context->dummy))
1798                 return 0;
1799
1800         ax = kmalloc(sizeof(*ax) + len, GFP_KERNEL);
1801         if (!ax)
1802                 return -ENOMEM;
1803
1804         ax->len = len;
1805         memcpy(ax->a, a, len);
1806
1807         ax->d.type = AUDIT_SOCKADDR;
1808         ax->d.next = context->aux;
1809         context->aux = (void *)ax;
1810         return 0;
1811 }
1812
1813 /**
1814  * audit_avc_path - record the granting or denial of permissions
1815  * @dentry: dentry to record
1816  * @mnt: mnt to record
1817  *
1818  * Returns 0 for success or NULL context or < 0 on error.
1819  *
1820  * Called from security/selinux/avc.c::avc_audit()
1821  */
1822 int audit_avc_path(struct dentry *dentry, struct vfsmount *mnt)
1823 {
1824         struct audit_aux_data_path *ax;
1825         struct audit_context *context = current->audit_context;
1826
1827         if (likely(!context))
1828                 return 0;
1829
1830         ax = kmalloc(sizeof(*ax), GFP_ATOMIC);
1831         if (!ax)
1832                 return -ENOMEM;
1833
1834         ax->dentry = dget(dentry);
1835         ax->mnt = mntget(mnt);
1836
1837         ax->d.type = AUDIT_AVC_PATH;
1838         ax->d.next = context->aux;
1839         context->aux = (void *)ax;
1840         return 0;
1841 }
1842
1843 /**
1844  * audit_signal_info - record signal info for shutting down audit subsystem
1845  * @sig: signal value
1846  * @t: task being signaled
1847  *
1848  * If the audit subsystem is being terminated, record the task (pid)
1849  * and uid that is doing that.
1850  */
1851 void __audit_signal_info(int sig, struct task_struct *t)
1852 {
1853         extern pid_t audit_sig_pid;
1854         extern uid_t audit_sig_uid;
1855         extern u32 audit_sig_sid;
1856
1857         if (sig == SIGTERM || sig == SIGHUP || sig == SIGUSR1) {
1858                 struct task_struct *tsk = current;
1859                 struct audit_context *ctx = tsk->audit_context;
1860                 audit_sig_pid = tsk->pid;
1861                 if (ctx)
1862                         audit_sig_uid = ctx->loginuid;
1863                 else
1864                         audit_sig_uid = tsk->uid;
1865                 selinux_get_task_sid(tsk, &audit_sig_sid);
1866         }
1867 }