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                                 if (!ctx->ppid)
 283                                         ctx->ppid = sys_getppid();
 284                                 result = audit_comparator(ctx->ppid, f->op, f->val);
 285                         }
 286                         break;
 287                 case AUDIT_UID:
 288                         result = audit_comparator(tsk->uid, f->op, f->val);
 289                         break;
 290                 case AUDIT_EUID:
 291                         result = audit_comparator(tsk->euid, f->op, f->val);
 292                         break;
 293                 case AUDIT_SUID:
 294                         result = audit_comparator(tsk->suid, f->op, f->val);
 295                         break;
 296                 case AUDIT_FSUID:
 297                         result = audit_comparator(tsk->fsuid, f->op, f->val);
 298                         break;
 299                 case AUDIT_GID:
 300                         result = audit_comparator(tsk->gid, f->op, f->val);
 301                         break;
 302                 case AUDIT_EGID:
 303                         result = audit_comparator(tsk->egid, f->op, f->val);
 304                         break;
 305                 case AUDIT_SGID:
 306                         result = audit_comparator(tsk->sgid, f->op, f->val);
 307                         break;
 308                 case AUDIT_FSGID:
 309                         result = audit_comparator(tsk->fsgid, f->op, f->val);
 310                         break;
 311                 case AUDIT_PERS:
 312                         result = audit_comparator(tsk->personality, f->op, f->val);
 313                         break;
 314                 case AUDIT_ARCH:
 315                         if (ctx)
 316                                 result = audit_comparator(ctx->arch, f->op, f->val);
 317                         break;
 318
 319                 case AUDIT_EXIT:
 320                         if (ctx && ctx->return_valid)
 321                                 result = audit_comparator(ctx->return_code, f->op, f->val);
 322                         break;
 323                 case AUDIT_SUCCESS:
 324                         if (ctx && ctx->return_valid) {
 325                                 if (f->val)
 326                                         result = audit_comparator(ctx->return_valid, f->op, AUDITSC_SUCCESS);
 327                                 else
 328                                         result = audit_comparator(ctx->return_valid, f->op, AUDITSC_FAILURE);
 329                         }
 330                         break;
 331                 case AUDIT_DEVMAJOR:
 332                         if (name)
 333                                 result = audit_comparator(MAJOR(name->dev),
 334                                                           f->op, f->val);
 335                         else if (ctx) {
 336                                 for (j = 0; j < ctx->name_count; j++) {
 337                                         if (audit_comparator(MAJOR(ctx->names[j].dev),  f->op, f->val)) {
 338                                                 ++result;
 339                                                 break;
 340                                         }
 341                                 }
 342                         }
 343                         break;
 344                 case AUDIT_DEVMINOR:
 345                         if (name)
 346                                 result = audit_comparator(MINOR(name->dev),
 347                                                           f->op, f->val);
 348                         else if (ctx) {
 349                                 for (j = 0; j < ctx->name_count; j++) {
 350                                         if (audit_comparator(MINOR(ctx->names[j].dev), f->op, f->val)) {
 351                                                 ++result;
 352                                                 break;
 353                                         }
 354                                 }
 355                         }
 356                         break;
 357                 case AUDIT_INODE:
 358                         if (name)
 359                                 result = (name->ino == f->val);
 360                         else if (ctx) {
 361                                 for (j = 0; j < ctx->name_count; j++) {
 362                                         if (audit_comparator(ctx->names[j].ino, f->op, f->val)) {
 363                                                 ++result;
 364                                                 break;
 365                                         }
 366                                 }
 367                         }
 368                         break;
 369                 case AUDIT_WATCH:
 370                         if (name && rule->watch->ino != (unsigned long)-1)
 371                                 result = (name->dev == rule->watch->dev &&
 372                                           name->ino == rule->watch->ino);
 373                         break;
 374                 case AUDIT_LOGINUID:
 375                         result = 0;
 376                         if (ctx)
 377                                 result = audit_comparator(ctx->loginuid, f->op, f->val);
 378                         break;
 379                 case AUDIT_SUBJ_USER:
 380                 case AUDIT_SUBJ_ROLE:
 381                 case AUDIT_SUBJ_TYPE:
 382                 case AUDIT_SUBJ_SEN:
 383                 case AUDIT_SUBJ_CLR:
 384                         /* NOTE: this may return negative values indicating
 385                            a temporary error.  We simply treat this as a
 386                            match for now to avoid losing information that
 387                            may be wanted.   An error message will also be
 388                            logged upon error */
 389                         if (f->se_rule) {
 390                                 if (need_sid) {
 391                                         selinux_get_task_sid(tsk, &sid);
 392                                         need_sid = 0;
 393                                 }
 394                                 result = selinux_audit_rule_match(sid, f->type,
 395                                                                   f->op,
 396                                                                   f->se_rule,
 397                                                                   ctx);
 398                         }
 399                         break;
 400                 case AUDIT_OBJ_USER:
 401                 case AUDIT_OBJ_ROLE:
 402                 case AUDIT_OBJ_TYPE:
 403                 case AUDIT_OBJ_LEV_LOW:
 404                 case AUDIT_OBJ_LEV_HIGH:
 405                         /* The above note for AUDIT_SUBJ_USER...AUDIT_SUBJ_CLR
 406                            also applies here */
 407                         if (f->se_rule) {
 408                                 /* Find files that match */
 409                                 if (name) {
 410                                         result = selinux_audit_rule_match(
 411                                                    name->osid, f->type, f->op,
 412                                                    f->se_rule, ctx);
 413                                 } else if (ctx) {
 414                                         for (j = 0; j < ctx->name_count; j++) {
 415                                                 if (selinux_audit_rule_match(
 416                                                       ctx->names[j].osid,
 417                                                       f->type, f->op,
 418                                                       f->se_rule, ctx)) {
 419                                                         ++result;
 420                                                         break;
 421                                                 }
 422                                         }
 423                                 }
 424                                 /* Find ipc objects that match */
 425                                 if (ctx) {
 426                                         struct audit_aux_data *aux;
 427                                         for (aux = ctx->aux; aux;
 428                                              aux = aux->next) {
 429                                                 if (aux->type == AUDIT_IPC) {
 430                                                         struct audit_aux_data_ipcctl *axi = (void *)aux;
 431                                                         if (selinux_audit_rule_match(axi->osid, f->type, f->op, f->se_rule, ctx)) {
 432                                                                 ++result;
 433                                                                 break;
 434                                                         }
 435                                                 }
 436                                         }
 437                                 }
 438                         }
 439                         break;
 440                 case AUDIT_ARG0:
 441                 case AUDIT_ARG1:
 442                 case AUDIT_ARG2:
 443                 case AUDIT_ARG3:
 444                         if (ctx)
 445                                 result = audit_comparator(ctx->argv[f->type-AUDIT_ARG0], f->op, f->val);
 446                         break;
 447                 case AUDIT_FILTERKEY:
 448                         /* ignore this field for filtering */
 449                         result = 1;
 450                         break;
 451                 case AUDIT_PERM:
 452                         result = audit_match_perm(ctx, f->val);
 453                         break;
 454                 }
 455
 456                 if (!result)
 457                         return 0;
 458         }
 459         if (rule->filterkey)
 460                 ctx->filterkey = kstrdup(rule->filterkey, GFP_ATOMIC);
 461         switch (rule->action) {
 462         case AUDIT_NEVER:    *state = AUDIT_DISABLED;       break;
 463         case AUDIT_ALWAYS:   *state = AUDIT_RECORD_CONTEXT; break;
 464         }
 465         return 1;
 466 }
 467
 468 /* At process creation time, we can determine if system-call auditing is
 469  * completely disabled for this task.  Since we only have the task
 470  * structure at this point, we can only check uid and gid.
 471  */
 472 static enum audit_state audit_filter_task(struct task_struct *tsk)
 473 {
 474         struct audit_entry *e;
 475         enum audit_state   state;
 476
 477         rcu_read_lock();
 478         list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_TASK], list) {
 479                 if (audit_filter_rules(tsk, &e->rule, NULL, NULL, &state)) {
 480                         rcu_read_unlock();
 481                         return state;
 482                 }
 483         }
 484         rcu_read_unlock();
 485         return AUDIT_BUILD_CONTEXT;
 486 }
 487
 488 /* At syscall entry and exit time, this filter is called if the
 489  * audit_state is not low enough that auditing cannot take place, but is
 490  * also not high enough that we already know we have to write an audit
 491  * record (i.e., the state is AUDIT_SETUP_CONTEXT or AUDIT_BUILD_CONTEXT).
 492  */
 493 static enum audit_state audit_filter_syscall(struct task_struct *tsk,
 494                                              struct audit_context *ctx,
 495                                              struct list_head *list)
 496 {
 497         struct audit_entry *e;
 498         enum audit_state state;
 499
 500         if (audit_pid && tsk->tgid == audit_pid)
 501                 return AUDIT_DISABLED;
 502
 503         rcu_read_lock();
 504         if (!list_empty(list)) {
 505                 int word = AUDIT_WORD(ctx->major);
 506                 int bit  = AUDIT_BIT(ctx->major);
 507
 508                 list_for_each_entry_rcu(e, list, list) {
 509                         if ((e->rule.mask[word] & bit) == bit &&
 510                             audit_filter_rules(tsk, &e->rule, ctx, NULL,
 511                                                &state)) {
 512                                 rcu_read_unlock();
 513                                 return state;
 514                         }
 515                 }
 516         }
 517         rcu_read_unlock();
 518         return AUDIT_BUILD_CONTEXT;
 519 }
 520
 521 /* At syscall exit time, this filter is called if any audit_names[] have been
 522  * collected during syscall processing.  We only check rules in sublists at hash
 523  * buckets applicable to the inode numbers in audit_names[].
 524  * Regarding audit_state, same rules apply as for audit_filter_syscall().
 525  */
 526 enum audit_state audit_filter_inodes(struct task_struct *tsk,
 527                                      struct audit_context *ctx)
 528 {
 529         int i;
 530         struct audit_entry *e;
 531         enum audit_state state;
 532
 533         if (audit_pid && tsk->tgid == audit_pid)
 534                 return AUDIT_DISABLED;
 535
 536         rcu_read_lock();
 537         for (i = 0; i < ctx->name_count; i++) {
 538                 int word = AUDIT_WORD(ctx->major);
 539                 int bit  = AUDIT_BIT(ctx->major);
 540                 struct audit_names *n = &ctx->names[i];
 541                 int h = audit_hash_ino((u32)n->ino);
 542                 struct list_head *list = &audit_inode_hash[h];
 543
 544                 if (list_empty(list))
 545                         continue;
 546
 547                 list_for_each_entry_rcu(e, list, list) {
 548                         if ((e->rule.mask[word] & bit) == bit &&
 549                             audit_filter_rules(tsk, &e->rule, ctx, n, &state)) {
 550                                 rcu_read_unlock();
 551                                 return state;
 552                         }
 553                 }
 554         }
 555         rcu_read_unlock();
 556         return AUDIT_BUILD_CONTEXT;
 557 }
 558
 559 void audit_set_auditable(struct audit_context *ctx)
 560 {
 561         ctx->auditable = 1;
 562 }
 563
 564 static inline struct audit_context *audit_get_context(struct task_struct *tsk,
 565                                                       int return_valid,
 566                                                       int return_code)
 567 {
 568         struct audit_context *context = tsk->audit_context;
 569
 570         if (likely(!context))
 571                 return NULL;
 572         context->return_valid = return_valid;
 573         context->return_code  = return_code;
 574
 575         if (context->in_syscall && !context->dummy && !context->auditable) {
 576                 enum audit_state state;
 577
 578                 state = audit_filter_syscall(tsk, context, &audit_filter_list[AUDIT_FILTER_EXIT]);
 579                 if (state == AUDIT_RECORD_CONTEXT) {
 580                         context->auditable = 1;
 581                         goto get_context;
 582                 }
 583
 584                 state = audit_filter_inodes(tsk, context);
 585                 if (state == AUDIT_RECORD_CONTEXT)
 586                         context->auditable = 1;
 587
 588         }
 589
 590 get_context:
 591
 592         tsk->audit_context = NULL;
 593         return context;
 594 }
 595
 596 static inline void audit_free_names(struct audit_context *context)
 597 {
 598         int i;
 599
 600 #if AUDIT_DEBUG == 2
 601         if (context->auditable
 602             ||context->put_count + context->ino_count != context->name_count) {
 603                 printk(KERN_ERR "%s:%d(:%d): major=%d in_syscall=%d"
 604                        " name_count=%d put_count=%d"
 605                        " ino_count=%d [NOT freeing]\n",
 606                        __FILE__, __LINE__,
 607                        context->serial, context->major, context->in_syscall,
 608                        context->name_count, context->put_count,
 609                        context->ino_count);
 610                 for (i = 0; i < context->name_count; i++) {
 611                         printk(KERN_ERR "names[%d] = %p = %s\n", i,
 612                                context->names[i].name,
 613                                context->names[i].name ?: "(null)");
 614                 }
 615                 dump_stack();
 616                 return;
 617         }
 618 #endif
 619 #if AUDIT_DEBUG
 620         context->put_count  = 0;
 621         context->ino_count  = 0;
 622 #endif
 623
 624         for (i = 0; i < context->name_count; i++) {
 625                 if (context->names[i].name && context->names[i].name_put)
 626                         __putname(context->names[i].name);
 627         }
 628         context->name_count = 0;
 629         if (context->pwd)
 630                 dput(context->pwd);
 631         if (context->pwdmnt)
 632                 mntput(context->pwdmnt);
 633         context->pwd = NULL;
 634         context->pwdmnt = NULL;
 635 }
 636
 637 static inline void audit_free_aux(struct audit_context *context)
 638 {
 639         struct audit_aux_data *aux;
 640
 641         while ((aux = context->aux)) {
 642                 if (aux->type == AUDIT_AVC_PATH) {
 643                         struct audit_aux_data_path *axi = (void *)aux;
 644                         dput(axi->dentry);
 645                         mntput(axi->mnt);
 646                 }
 647
 648                 context->aux = aux->next;
 649                 kfree(aux);
 650         }
 651 }
 652
 653 static inline void audit_zero_context(struct audit_context *context,
 654                                       enum audit_state state)
 655 {
 656         uid_t loginuid = context->loginuid;
 657
 658         memset(context, 0, sizeof(*context));
 659         context->state      = state;
 660         context->loginuid   = loginuid;
 661 }
 662
 663 static inline struct audit_context *audit_alloc_context(enum audit_state state)
 664 {
 665         struct audit_context *context;
 666
 667         if (!(context = kmalloc(sizeof(*context), GFP_KERNEL)))
 668                 return NULL;
 669         audit_zero_context(context, state);
 670         return context;
 671 }
 672
 673 /**
 674  * audit_alloc - allocate an audit context block for a task
 675  * @tsk: task
 676  *
 677  * Filter on the task information and allocate a per-task audit context
 678  * if necessary.  Doing so turns on system call auditing for the
 679  * specified task.  This is called from copy_process, so no lock is
 680  * needed.
 681  */
 682 int audit_alloc(struct task_struct *tsk)
 683 {
 684         struct audit_context *context;
 685         enum audit_state     state;
 686
 687         if (likely(!audit_enabled))
 688                 return 0; /* Return if not auditing. */
 689
 690         state = audit_filter_task(tsk);
 691         if (likely(state == AUDIT_DISABLED))
 692                 return 0;
 693
 694         if (!(context = audit_alloc_context(state))) {
 695                 audit_log_lost("out of memory in audit_alloc");
 696                 return -ENOMEM;
 697         }
 698
 699                                 /* Preserve login uid */
 700         context->loginuid = -1;
 701         if (current->audit_context)
 702                 context->loginuid = current->audit_context->loginuid;
 703
 704         tsk->audit_context  = context;
 705         set_tsk_thread_flag(tsk, TIF_SYSCALL_AUDIT);
 706         return 0;
 707 }
 708
 709 static inline void audit_free_context(struct audit_context *context)
 710 {
 711         struct audit_context *previous;
 712         int                  count = 0;
 713
 714         do {
 715                 previous = context->previous;
 716                 if (previous || (count &&  count < 10)) {
 717                         ++count;
 718                         printk(KERN_ERR "audit(:%d): major=%d name_count=%d:"
 719                                " freeing multiple contexts (%d)\n",
 720                                context->serial, context->major,
 721                                context->name_count, count);
 722                 }
 723                 audit_free_names(context);
 724                 audit_free_aux(context);
 725                 kfree(context->filterkey);
 726                 kfree(context);
 727                 context  = previous;
 728         } while (context);
 729         if (count >= 10)
 730                 printk(KERN_ERR "audit: freed %d contexts\n", count);
 731 }
 732
 733 static void audit_log_task_context(struct audit_buffer *ab)
 734 {
 735         char *ctx = NULL;
 736         ssize_t len = 0;
 737
 738         len = security_getprocattr(current, "current", NULL, 0);
 739         if (len < 0) {
 740                 if (len != -EINVAL)
 741                         goto error_path;
 742                 return;
 743         }
 744
 745         ctx = kmalloc(len, GFP_KERNEL);
 746         if (!ctx)
 747                 goto error_path;
 748
 749         len = security_getprocattr(current, "current", ctx, len);
 750         if (len < 0 )
 751                 goto error_path;
 752
 753         audit_log_format(ab, " subj=%s", ctx);
 754         return;
 755
 756 error_path:
 757         kfree(ctx);
 758         audit_panic("error in audit_log_task_context");
 759         return;
 760 }
 761
 762 static void audit_log_task_info(struct audit_buffer *ab, struct task_struct *tsk)
 763 {
 764         char name[sizeof(tsk->comm)];
 765         struct mm_struct *mm = tsk->mm;
 766         struct vm_area_struct *vma;
 767
 768         /* tsk == current */
 769
 770         get_task_comm(name, tsk);
 771         audit_log_format(ab, " comm=");
 772         audit_log_untrustedstring(ab, name);
 773
 774         if (mm) {
 775                 down_read(&mm->mmap_sem);
 776                 vma = mm->mmap;
 777                 while (vma) {
 778                         if ((vma->vm_flags & VM_EXECUTABLE) &&
 779                             vma->vm_file) {
 780                                 audit_log_d_path(ab, "exe=",
 781                                                  vma->vm_file->f_dentry,
 782                                                  vma->vm_file->f_vfsmnt);
 783                                 break;
 784                         }
 785                         vma = vma->vm_next;
 786                 }
 787                 up_read(&mm->mmap_sem);
 788         }
 789         audit_log_task_context(ab);
 790 }
 791
 792 static void audit_log_exit(struct audit_context *context, struct task_struct *tsk)
 793 {
 794         int i, call_panic = 0;
 795         struct audit_buffer *ab;
 796         struct audit_aux_data *aux;
 797         const char *tty;
 798
 799         /* tsk == current */
 800         context->pid = tsk->pid;
 801         if (!context->ppid)
 802                 context->ppid = sys_getppid();
 803         context->uid = tsk->uid;
 804         context->gid = tsk->gid;
 805         context->euid = tsk->euid;
 806         context->suid = tsk->suid;
 807         context->fsuid = tsk->fsuid;
 808         context->egid = tsk->egid;
 809         context->sgid = tsk->sgid;
 810         context->fsgid = tsk->fsgid;
 811         context->personality = tsk->personality;
 812
 813         ab = audit_log_start(context, GFP_KERNEL, AUDIT_SYSCALL);
 814         if (!ab)
 815                 return;         /* audit_panic has been called */
 816         audit_log_format(ab, "arch=%x syscall=%d",
 817                          context->arch, context->major);
 818         if (context->personality != PER_LINUX)
 819                 audit_log_format(ab, " per=%lx", context->personality);
 820         if (context->return_valid)
 821                 audit_log_format(ab, " success=%s exit=%ld",
 822                                  (context->return_valid==AUDITSC_SUCCESS)?"yes":"no",
 823                                  context->return_code);
 824
 825         mutex_lock(&tty_mutex);
 826         if (tsk->signal && tsk->signal->tty && tsk->signal->tty->name)
 827                 tty = tsk->signal->tty->name;
 828         else
 829                 tty = "(none)";
 830         audit_log_format(ab,
 831                   " a0=%lx a1=%lx a2=%lx a3=%lx items=%d"
 832                   " ppid=%d pid=%d auid=%u uid=%u gid=%u"
 833                   " euid=%u suid=%u fsuid=%u"
 834                   " egid=%u sgid=%u fsgid=%u tty=%s",
 835                   context->argv[0],
 836                   context->argv[1],
 837                   context->argv[2],
 838                   context->argv[3],
 839                   context->name_count,
 840                   context->ppid,
 841                   context->pid,
 842                   context->loginuid,
 843                   context->uid,
 844                   context->gid,
 845                   context->euid, context->suid, context->fsuid,
 846                   context->egid, context->sgid, context->fsgid, tty);
 847
 848         mutex_unlock(&tty_mutex);
 849
 850         audit_log_task_info(ab, tsk);
 851         if (context->filterkey) {
 852                 audit_log_format(ab, " key=");
 853                 audit_log_untrustedstring(ab, context->filterkey);
 854         } else
 855                 audit_log_format(ab, " key=(null)");
 856         audit_log_end(ab);
 857
 858         for (aux = context->aux; aux; aux = aux->next) {
 859
 860                 ab = audit_log_start(context, GFP_KERNEL, aux->type);
 861                 if (!ab)
 862                         continue; /* audit_panic has been called */
 863
 864                 switch (aux->type) {
 865                 case AUDIT_MQ_OPEN: {
 866                         struct audit_aux_data_mq_open *axi = (void *)aux;
 867                         audit_log_format(ab,
 868                                 "oflag=0x%x mode=%#o mq_flags=0x%lx mq_maxmsg=%ld "
 869                                 "mq_msgsize=%ld mq_curmsgs=%ld",
 870                                 axi->oflag, axi->mode, axi->attr.mq_flags,
 871                                 axi->attr.mq_maxmsg, axi->attr.mq_msgsize,
 872                                 axi->attr.mq_curmsgs);
 873                         break; }
 874
 875                 case AUDIT_MQ_SENDRECV: {
 876                         struct audit_aux_data_mq_sendrecv *axi = (void *)aux;
 877                         audit_log_format(ab,
 878                                 "mqdes=%d msg_len=%zd msg_prio=%u "
 879                                 "abs_timeout_sec=%ld abs_timeout_nsec=%ld",
 880                                 axi->mqdes, axi->msg_len, axi->msg_prio,
 881                                 axi->abs_timeout.tv_sec, axi->abs_timeout.tv_nsec);
 882                         break; }
 883
 884                 case AUDIT_MQ_NOTIFY: {
 885                         struct audit_aux_data_mq_notify *axi = (void *)aux;
 886                         audit_log_format(ab,
 887                                 "mqdes=%d sigev_signo=%d",
 888                                 axi->mqdes,
 889                                 axi->notification.sigev_signo);
 890                         break; }
 891
 892                 case AUDIT_MQ_GETSETATTR: {
 893                         struct audit_aux_data_mq_getsetattr *axi = (void *)aux;
 894                         audit_log_format(ab,
 895                                 "mqdes=%d mq_flags=0x%lx mq_maxmsg=%ld mq_msgsize=%ld "
 896                                 "mq_curmsgs=%ld ",
 897                                 axi->mqdes,
 898                                 axi->mqstat.mq_flags, axi->mqstat.mq_maxmsg,
 899                                 axi->mqstat.mq_msgsize, axi->mqstat.mq_curmsgs);
 900                         break; }
 901
 902                 case AUDIT_IPC: {
 903                         struct audit_aux_data_ipcctl *axi = (void *)aux;
 904                         audit_log_format(ab,
 905                                  "ouid=%u ogid=%u mode=%x",
 906                                  axi->uid, axi->gid, axi->mode);
 907                         if (axi->osid != 0) {
 908                                 char *ctx = NULL;
 909                                 u32 len;
 910                                 if (selinux_sid_to_string(
 911                                                 axi->osid, &ctx, &len)) {
 912                                         audit_log_format(ab, " osid=%u",
 913                                                         axi->osid);
 914                                         call_panic = 1;
 915                                 } else
 916                                         audit_log_format(ab, " obj=%s", ctx);
 917                                 kfree(ctx);
 918                         }
 919                         break; }
 920
 921                 case AUDIT_IPC_SET_PERM: {
 922                         struct audit_aux_data_ipcctl *axi = (void *)aux;
 923                         audit_log_format(ab,
 924                                 "qbytes=%lx ouid=%u ogid=%u mode=%x",
 925                                 axi->qbytes, axi->uid, axi->gid, axi->mode);
 926                         break; }
 927
 928                 case AUDIT_EXECVE: {
 929                         struct audit_aux_data_execve *axi = (void *)aux;
 930                         int i;
 931                         const char *p;
 932                         for (i = 0, p = axi->mem; i < axi->argc; i++) {
 933                                 audit_log_format(ab, "a%d=", i);
 934                                 p = audit_log_untrustedstring(ab, p);
 935                                 audit_log_format(ab, "\n");
 936                         }
 937                         break; }
 938
 939                 case AUDIT_SOCKETCALL: {
 940                         int i;
 941                         struct audit_aux_data_socketcall *axs = (void *)aux;
 942                         audit_log_format(ab, "nargs=%d", axs->nargs);
 943                         for (i=0; i<axs->nargs; i++)
 944                                 audit_log_format(ab, " a%d=%lx", i, axs->args[i]);
 945                         break; }
 946
 947                 case AUDIT_SOCKADDR: {
 948                         struct audit_aux_data_sockaddr *axs = (void *)aux;
 949
 950                         audit_log_format(ab, "saddr=");
 951                         audit_log_hex(ab, axs->a, axs->len);
 952                         break; }
 953
 954                 case AUDIT_AVC_PATH: {
 955                         struct audit_aux_data_path *axi = (void *)aux;
 956                         audit_log_d_path(ab, "path=", axi->dentry, axi->mnt);
 957                         break; }
 958
 959                 }
 960                 audit_log_end(ab);
 961         }
 962
 963         if (context->pwd && context->pwdmnt) {
 964                 ab = audit_log_start(context, GFP_KERNEL, AUDIT_CWD);
 965                 if (ab) {
 966                         audit_log_d_path(ab, "cwd=", context->pwd, context->pwdmnt);
 967                         audit_log_end(ab);
 968                 }
 969         }
 970         for (i = 0; i < context->name_count; i++) {
 971                 struct audit_names *n = &context->names[i];
 972
 973                 ab = audit_log_start(context, GFP_KERNEL, AUDIT_PATH);
 974                 if (!ab)
 975                         continue; /* audit_panic has been called */
 976
 977                 audit_log_format(ab, "item=%d", i);
 978
 979                 if (n->name) {
 980                         switch(n->name_len) {
 981                         case AUDIT_NAME_FULL:
 982                                 /* log the full path */
 983                                 audit_log_format(ab, " name=");
 984                                 audit_log_untrustedstring(ab, n->name);
 985                                 break;
 986                         case 0:
 987                                 /* name was specified as a relative path and the
 988                                  * directory component is the cwd */
 989                                 audit_log_d_path(ab, " name=", context->pwd,
 990                                                  context->pwdmnt);
 991                                 break;
 992                         default:
 993                                 /* log the name's directory component */
 994                                 audit_log_format(ab, " name=");
 995                                 audit_log_n_untrustedstring(ab, n->name_len,
 996                                                             n->name);
 997                         }
 998                 } else
 999                         audit_log_format(ab, " name=(null)");
1000
1001                 if (n->ino != (unsigned long)-1) {
1002                         audit_log_format(ab, " inode=%lu"
1003                                          " dev=%02x:%02x mode=%#o"
1004                                          " ouid=%u ogid=%u rdev=%02x:%02x",
1005                                          n->ino,
1006                                          MAJOR(n->dev),
1007                                          MINOR(n->dev),
1008                                          n->mode,
1009                                          n->uid,
1010                                          n->gid,
1011                                          MAJOR(n->rdev),
1012                                          MINOR(n->rdev));
1013                 }
1014                 if (n->osid != 0) {
1015                         char *ctx = NULL;
1016                         u32 len;
1017                         if (selinux_sid_to_string(
1018                                 n->osid, &ctx, &len)) {
1019                                 audit_log_format(ab, " osid=%u", n->osid);
1020                                 call_panic = 2;
1021                         } else
1022                                 audit_log_format(ab, " obj=%s", ctx);
1023                         kfree(ctx);
1024                 }
1025
1026                 audit_log_end(ab);
1027         }
1028         if (call_panic)
1029                 audit_panic("error converting sid to string");
1030 }
1031
1032 /**
1033  * audit_free - free a per-task audit context
1034  * @tsk: task whose audit context block to free
1035  *
1036  * Called from copy_process and do_exit
1037  */
1038 void audit_free(struct task_struct *tsk)
1039 {
1040         struct audit_context *context;
1041
1042         context = audit_get_context(tsk, 0, 0);
1043         if (likely(!context))
1044                 return;
1045
1046         /* Check for system calls that do not go through the exit
1047          * function (e.g., exit_group), then free context block.
1048          * We use GFP_ATOMIC here because we might be doing this
1049          * in the context of the idle thread */
1050         /* that can happen only if we are called from do_exit() */
1051         if (context->in_syscall && context->auditable)
1052                 audit_log_exit(context, tsk);
1053
1054         audit_free_context(context);
1055 }
1056
1057 /**
1058  * audit_syscall_entry - fill in an audit record at syscall entry
1059  * @tsk: task being audited
1060  * @arch: architecture type
1061  * @major: major syscall type (function)
1062  * @a1: additional syscall register 1
1063  * @a2: additional syscall register 2
1064  * @a3: additional syscall register 3
1065  * @a4: additional syscall register 4
1066  *
1067  * Fill in audit context at syscall entry.  This only happens if the
1068  * audit context was created when the task was created and the state or
1069  * filters demand the audit context be built.  If the state from the
1070  * per-task filter or from the per-syscall filter is AUDIT_RECORD_CONTEXT,
1071  * then the record will be written at syscall exit time (otherwise, it
1072  * will only be written if another part of the kernel requests that it
1073  * be written).
1074  */
1075 void audit_syscall_entry(int arch, int major,
1076                          unsigned long a1, unsigned long a2,
1077                          unsigned long a3, unsigned long a4)
1078 {
1079         struct task_struct *tsk = current;
1080         struct audit_context *context = tsk->audit_context;
1081         enum audit_state     state;
1082
1083         BUG_ON(!context);
1084
1085         /*
1086          * This happens only on certain architectures that make system
1087          * calls in kernel_thread via the entry.S interface, instead of
1088          * with direct calls.  (If you are porting to a new
1089          * architecture, hitting this condition can indicate that you
1090          * got the _exit/_leave calls backward in entry.S.)
1091          *
1092          * i386     no
1093          * x86_64   no
1094          * ppc64    yes (see arch/powerpc/platforms/iseries/misc.S)
1095          *
1096          * This also happens with vm86 emulation in a non-nested manner
1097          * (entries without exits), so this case must be caught.
1098          */
1099         if (context->in_syscall) {
1100                 struct audit_context *newctx;
1101
1102 #if AUDIT_DEBUG
1103                 printk(KERN_ERR
1104                        "audit(:%d) pid=%d in syscall=%d;"
1105                        " entering syscall=%d\n",
1106                        context->serial, tsk->pid, context->major, major);
1107 #endif
1108                 newctx = audit_alloc_context(context->state);
1109                 if (newctx) {
1110                         newctx->previous   = context;
1111                         context            = newctx;
1112                         tsk->audit_context = newctx;
1113                 } else  {
1114                         /* If we can't alloc a new context, the best we
1115                          * can do is to leak memory (any pending putname
1116                          * will be lost).  The only other alternative is
1117                          * to abandon auditing. */
1118                         audit_zero_context(context, context->state);
1119                 }
1120         }
1121         BUG_ON(context->in_syscall || context->name_count);
1122
1123         if (!audit_enabled)
1124                 return;
1125
1126         context->arch       = arch;
1127         context->major      = major;
1128         context->argv[0]    = a1;
1129         context->argv[1]    = a2;
1130         context->argv[2]    = a3;
1131         context->argv[3]    = a4;
1132
1133         state = context->state;
1134         context->dummy = !audit_n_rules;
1135         if (!context->dummy && (state == AUDIT_SETUP_CONTEXT || state == AUDIT_BUILD_CONTEXT))
1136                 state = audit_filter_syscall(tsk, context, &audit_filter_list[AUDIT_FILTER_ENTRY]);
1137         if (likely(state == AUDIT_DISABLED))
1138                 return;
1139
1140         context->serial     = 0;
1141         context->ctime      = CURRENT_TIME;
1142         context->in_syscall = 1;
1143         context->auditable  = !!(state == AUDIT_RECORD_CONTEXT);
1144         context->ppid       = 0;
1145 }
1146
1147 /**
1148  * audit_syscall_exit - deallocate audit context after a system call
1149  * @tsk: task being audited
1150  * @valid: success/failure flag
1151  * @return_code: syscall return value
1152  *
1153  * Tear down after system call.  If the audit context has been marked as
1154  * auditable (either because of the AUDIT_RECORD_CONTEXT state from
1155  * filtering, or because some other part of the kernel write an audit
1156  * message), then write out the syscall information.  In call cases,
1157  * free the names stored from getname().
1158  */
1159 void audit_syscall_exit(int valid, long return_code)
1160 {
1161         struct task_struct *tsk = current;
1162         struct audit_context *context;
1163
1164         context = audit_get_context(tsk, valid, return_code);
1165
1166         if (likely(!context))
1167                 return;
1168
1169         if (context->in_syscall && context->auditable)
1170                 audit_log_exit(context, tsk);
1171
1172         context->in_syscall = 0;
1173         context->auditable  = 0;
1174
1175         if (context->previous) {
1176                 struct audit_context *new_context = context->previous;
1177                 context->previous  = NULL;
1178                 audit_free_context(context);
1179                 tsk->audit_context = new_context;
1180         } else {
1181                 audit_free_names(context);
1182                 audit_free_aux(context);
1183                 kfree(context->filterkey);
1184                 context->filterkey = NULL;
1185                 tsk->audit_context = context;
1186         }
1187 }
1188
1189 /**
1190  * audit_getname - add a name to the list
1191  * @name: name to add
1192  *
1193  * Add a name to the list of audit names for this context.
1194  * Called from fs/namei.c:getname().
1195  */
1196 void __audit_getname(const char *name)
1197 {
1198         struct audit_context *context = current->audit_context;
1199
1200         if (IS_ERR(name) || !name)
1201                 return;
1202
1203         if (!context->in_syscall) {
1204 #if AUDIT_DEBUG == 2
1205                 printk(KERN_ERR "%s:%d(:%d): ignoring getname(%p)\n",
1206                        __FILE__, __LINE__, context->serial, name);
1207                 dump_stack();
1208 #endif
1209                 return;
1210         }
1211         BUG_ON(context->name_count >= AUDIT_NAMES);
1212         context->names[context->name_count].name = name;
1213         context->names[context->name_count].name_len = AUDIT_NAME_FULL;
1214         context->names[context->name_count].name_put = 1;
1215         context->names[context->name_count].ino  = (unsigned long)-1;
1216         ++context->name_count;
1217         if (!context->pwd) {
1218                 read_lock(&current->fs->lock);
1219                 context->pwd = dget(current->fs->pwd);
1220                 context->pwdmnt = mntget(current->fs->pwdmnt);
1221                 read_unlock(&current->fs->lock);
1222         }
1223
1224 }
1225
1226 /* audit_putname - intercept a putname request
1227  * @name: name to intercept and delay for putname
1228  *
1229  * If we have stored the name from getname in the audit context,
1230  * then we delay the putname until syscall exit.
1231  * Called from include/linux/fs.h:putname().
1232  */
1233 void audit_putname(const char *name)
1234 {
1235         struct audit_context *context = current->audit_context;
1236
1237         BUG_ON(!context);
1238         if (!context->in_syscall) {
1239 #if AUDIT_DEBUG == 2
1240                 printk(KERN_ERR "%s:%d(:%d): __putname(%p)\n",
1241                        __FILE__, __LINE__, context->serial, name);
1242                 if (context->name_count) {
1243                         int i;
1244                         for (i = 0; i < context->name_count; i++)
1245                                 printk(KERN_ERR "name[%d] = %p = %s\n", i,
1246                                        context->names[i].name,
1247                                        context->names[i].name ?: "(null)");
1248                 }
1249 #endif
1250                 __putname(name);
1251         }
1252 #if AUDIT_DEBUG
1253         else {
1254                 ++context->put_count;
1255                 if (context->put_count > context->name_count) {
1256                         printk(KERN_ERR "%s:%d(:%d): major=%d"
1257                                " in_syscall=%d putname(%p) name_count=%d"
1258                                " put_count=%d\n",
1259                                __FILE__, __LINE__,
1260                                context->serial, context->major,
1261                                context->in_syscall, name, context->name_count,
1262                                context->put_count);
1263                         dump_stack();
1264                 }
1265         }
1266 #endif
1267 }
1268
1269 /* Copy inode data into an audit_names. */
1270 static void audit_copy_inode(struct audit_names *name, const struct inode *inode)
1271 {
1272         name->ino   = inode->i_ino;
1273         name->dev   = inode->i_sb->s_dev;
1274         name->mode  = inode->i_mode;
1275         name->uid   = inode->i_uid;
1276         name->gid   = inode->i_gid;
1277         name->rdev  = inode->i_rdev;
1278         selinux_get_inode_sid(inode, &name->osid);
1279 }
1280
1281 /**
1282  * audit_inode - store the inode and device from a lookup
1283  * @name: name being audited
1284  * @inode: inode being audited
1285  *
1286  * Called from fs/namei.c:path_lookup().
1287  */
1288 void __audit_inode(const char *name, const struct inode *inode)
1289 {
1290         int idx;
1291         struct audit_context *context = current->audit_context;
1292
1293         if (!context->in_syscall)
1294                 return;
1295         if (context->name_count
1296             && context->names[context->name_count-1].name
1297             && context->names[context->name_count-1].name == name)
1298                 idx = context->name_count - 1;
1299         else if (context->name_count > 1
1300                  && context->names[context->name_count-2].name
1301                  && context->names[context->name_count-2].name == name)
1302                 idx = context->name_count - 2;
1303         else {
1304                 /* FIXME: how much do we care about inodes that have no
1305                  * associated name? */
1306                 if (context->name_count >= AUDIT_NAMES - AUDIT_NAMES_RESERVED)
1307                         return;
1308                 idx = context->name_count++;
1309                 context->names[idx].name = NULL;
1310 #if AUDIT_DEBUG
1311                 ++context->ino_count;
1312 #endif
1313         }
1314         audit_copy_inode(&context->names[idx], inode);
1315 }
1316
1317 /**
1318  * audit_inode_child - collect inode info for created/removed objects
1319  * @dname: inode's dentry name
1320  * @inode: inode being audited
1321  * @parent: inode of dentry parent
1322  *
1323  * For syscalls that create or remove filesystem objects, audit_inode
1324  * can only collect information for the filesystem object's parent.
1325  * This call updates the audit context with the child's information.
1326  * Syscalls that create a new filesystem object must be hooked after
1327  * the object is created.  Syscalls that remove a filesystem object
1328  * must be hooked prior, in order to capture the target inode during
1329  * unsuccessful attempts.
1330  */
1331 void __audit_inode_child(const char *dname, const struct inode *inode,
1332                          const struct inode *parent)
1333 {
1334         int idx;
1335         struct audit_context *context = current->audit_context;
1336         const char *found_name = NULL;
1337         int dirlen = 0;
1338
1339         if (!context->in_syscall)
1340                 return;
1341
1342         /* determine matching parent */
1343         if (!dname)
1344                 goto update_context;
1345         for (idx = 0; idx < context->name_count; idx++)
1346                 if (context->names[idx].ino == parent->i_ino) {
1347                         const char *name = context->names[idx].name;
1348
1349                         if (!name)
1350                                 continue;
1351
1352                         if (audit_compare_dname_path(dname, name, &dirlen) == 0) {
1353                                 context->names[idx].name_len = dirlen;
1354                                 found_name = name;
1355                                 break;
1356                         }
1357                 }
1358
1359 update_context:
1360         idx = context->name_count;
1361         if (context->name_count == AUDIT_NAMES) {
1362                 printk(KERN_DEBUG "name_count maxed and losing %s\n",
1363                         found_name ?: "(null)");
1364                 return;
1365         }
1366         context->name_count++;
1367 #if AUDIT_DEBUG
1368         context->ino_count++;
1369 #endif
1370         /* Re-use the name belonging to the slot for a matching parent directory.
1371          * All names for this context are relinquished in audit_free_names() */
1372         context->names[idx].name = found_name;
1373         context->names[idx].name_len = AUDIT_NAME_FULL;
1374         context->names[idx].name_put = 0;       /* don't call __putname() */
1375
1376         if (!inode)
1377                 context->names[idx].ino = (unsigned long)-1;
1378         else
1379                 audit_copy_inode(&context->names[idx], inode);
1380
1381         /* A parent was not found in audit_names, so copy the inode data for the
1382          * provided parent. */
1383         if (!found_name) {
1384                 idx = context->name_count;
1385                 if (context->name_count == AUDIT_NAMES) {
1386                         printk(KERN_DEBUG
1387                                 "name_count maxed and losing parent inode data: dev=%02x:%02x, inode=%lu",
1388                                 MAJOR(parent->i_sb->s_dev),
1389                                 MINOR(parent->i_sb->s_dev),
1390                                 parent->i_ino);
1391                         return;
1392                 }
1393                 context->name_count++;
1394 #if AUDIT_DEBUG
1395                 context->ino_count++;
1396 #endif
1397                 audit_copy_inode(&context->names[idx], parent);
1398         }
1399 }
1400
1401 /**
1402  * audit_inode_update - update inode info for last collected name
1403  * @inode: inode being audited
1404  *
1405  * When open() is called on an existing object with the O_CREAT flag, the inode
1406  * data audit initially collects is incorrect.  This additional hook ensures
1407  * audit has the inode data for the actual object to be opened.
1408  */
1409 void __audit_inode_update(const struct inode *inode)
1410 {
1411         struct audit_context *context = current->audit_context;
1412         int idx;
1413
1414         if (!context->in_syscall || !inode)
1415                 return;
1416
1417         if (context->name_count == 0) {
1418                 context->name_count++;
1419 #if AUDIT_DEBUG
1420                 context->ino_count++;
1421 #endif
1422         }
1423         idx = context->name_count - 1;
1424
1425         audit_copy_inode(&context->names[idx], inode);
1426 }
1427
1428 /**
1429  * auditsc_get_stamp - get local copies of audit_context values
1430  * @ctx: audit_context for the task
1431  * @t: timespec to store time recorded in the audit_context
1432  * @serial: serial value that is recorded in the audit_context
1433  *
1434  * Also sets the context as auditable.
1435  */
1436 void auditsc_get_stamp(struct audit_context *ctx,
1437                        struct timespec *t, unsigned int *serial)
1438 {
1439         if (!ctx->serial)
1440                 ctx->serial = audit_serial();
1441         t->tv_sec  = ctx->ctime.tv_sec;
1442         t->tv_nsec = ctx->ctime.tv_nsec;
1443         *serial    = ctx->serial;
1444         ctx->auditable = 1;
1445 }
1446
1447 /**
1448  * audit_set_loginuid - set a task's audit_context loginuid
1449  * @task: task whose audit context is being modified
1450  * @loginuid: loginuid value
1451  *
1452  * Returns 0.
1453  *
1454  * Called (set) from fs/proc/base.c::proc_loginuid_write().
1455  */
1456 int audit_set_loginuid(struct task_struct *task, uid_t loginuid)
1457 {
1458         struct audit_context *context = task->audit_context;
1459
1460         if (context) {
1461                 /* Only log if audit is enabled */
1462                 if (context->in_syscall) {
1463                         struct audit_buffer *ab;
1464
1465                         ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_LOGIN);
1466                         if (ab) {
1467                                 audit_log_format(ab, "login pid=%d uid=%u "
1468                                         "old auid=%u new auid=%u",
1469                                         task->pid, task->uid,
1470                                         context->loginuid, loginuid);
1471                                 audit_log_end(ab);
1472                         }
1473                 }
1474                 context->loginuid = loginuid;
1475         }
1476         return 0;
1477 }
1478
1479 /**
1480  * audit_get_loginuid - get the loginuid for an audit_context
1481  * @ctx: the audit_context
1482  *
1483  * Returns the context's loginuid or -1 if @ctx is NULL.
1484  */
1485 uid_t audit_get_loginuid(struct audit_context *ctx)
1486 {
1487         return ctx ? ctx->loginuid : -1;
1488 }
1489
1490 /**
1491  * __audit_mq_open - record audit data for a POSIX MQ open
1492  * @oflag: open flag
1493  * @mode: mode bits
1494  * @u_attr: queue attributes
1495  *
1496  * Returns 0 for success or NULL context or < 0 on error.
1497  */
1498 int __audit_mq_open(int oflag, mode_t mode, struct mq_attr __user *u_attr)
1499 {
1500         struct audit_aux_data_mq_open *ax;
1501         struct audit_context *context = current->audit_context;
1502
1503         if (!audit_enabled)
1504                 return 0;
1505
1506         if (likely(!context))
1507                 return 0;
1508
1509         ax = kmalloc(sizeof(*ax), GFP_ATOMIC);
1510         if (!ax)
1511                 return -ENOMEM;
1512
1513         if (u_attr != NULL) {
1514                 if (copy_from_user(&ax->attr, u_attr, sizeof(ax->attr))) {
1515                         kfree(ax);
1516                         return -EFAULT;
1517                 }
1518         } else
1519                 memset(&ax->attr, 0, sizeof(ax->attr));
1520
1521         ax->oflag = oflag;
1522         ax->mode = mode;
1523
1524         ax->d.type = AUDIT_MQ_OPEN;
1525         ax->d.next = context->aux;
1526         context->aux = (void *)ax;
1527         return 0;
1528 }
1529
1530 /**
1531  * __audit_mq_timedsend - record audit data for a POSIX MQ timed send
1532  * @mqdes: MQ descriptor
1533  * @msg_len: Message length
1534  * @msg_prio: Message priority
1535  * @u_abs_timeout: Message timeout in absolute time
1536  *
1537  * Returns 0 for success or NULL context or < 0 on error.
1538  */
1539 int __audit_mq_timedsend(mqd_t mqdes, size_t msg_len, unsigned int msg_prio,
1540                         const struct timespec __user *u_abs_timeout)
1541 {
1542         struct audit_aux_data_mq_sendrecv *ax;
1543         struct audit_context *context = current->audit_context;
1544
1545         if (!audit_enabled)
1546                 return 0;
1547
1548         if (likely(!context))
1549                 return 0;
1550
1551         ax = kmalloc(sizeof(*ax), GFP_ATOMIC);
1552         if (!ax)
1553                 return -ENOMEM;
1554
1555         if (u_abs_timeout != NULL) {
1556                 if (copy_from_user(&ax->abs_timeout, u_abs_timeout, sizeof(ax->abs_timeout))) {
1557                         kfree(ax);
1558                         return -EFAULT;
1559                 }
1560         } else
1561                 memset(&ax->abs_timeout, 0, sizeof(ax->abs_timeout));
1562
1563         ax->mqdes = mqdes;
1564         ax->msg_len = msg_len;
1565         ax->msg_prio = msg_prio;
1566
1567         ax->d.type = AUDIT_MQ_SENDRECV;
1568         ax->d.next = context->aux;
1569         context->aux = (void *)ax;
1570         return 0;
1571 }
1572
1573 /**
1574  * __audit_mq_timedreceive - record audit data for a POSIX MQ timed receive
1575  * @mqdes: MQ descriptor
1576  * @msg_len: Message length
1577  * @u_msg_prio: Message priority
1578  * @u_abs_timeout: Message timeout in absolute time
1579  *
1580  * Returns 0 for success or NULL context or < 0 on error.
1581  */
1582 int __audit_mq_timedreceive(mqd_t mqdes, size_t msg_len,
1583                                 unsigned int __user *u_msg_prio,
1584                                 const struct timespec __user *u_abs_timeout)
1585 {
1586         struct audit_aux_data_mq_sendrecv *ax;
1587         struct audit_context *context = current->audit_context;
1588
1589         if (!audit_enabled)
1590                 return 0;
1591
1592         if (likely(!context))
1593                 return 0;
1594
1595         ax = kmalloc(sizeof(*ax), GFP_ATOMIC);
1596         if (!ax)
1597                 return -ENOMEM;
1598
1599         if (u_msg_prio != NULL) {
1600                 if (get_user(ax->msg_prio, u_msg_prio)) {
1601                         kfree(ax);
1602                         return -EFAULT;
1603                 }
1604         } else
1605                 ax->msg_prio = 0;
1606
1607         if (u_abs_timeout != NULL) {
1608                 if (copy_from_user(&ax->abs_timeout, u_abs_timeout, sizeof(ax->abs_timeout))) {
1609                         kfree(ax);
1610                         return -EFAULT;
1611                 }
1612         } else
1613                 memset(&ax->abs_timeout, 0, sizeof(ax->abs_timeout));
1614
1615         ax->mqdes = mqdes;
1616         ax->msg_len = msg_len;
1617
1618         ax->d.type = AUDIT_MQ_SENDRECV;
1619         ax->d.next = context->aux;
1620         context->aux = (void *)ax;
1621         return 0;
1622 }
1623
1624 /**
1625  * __audit_mq_notify - record audit data for a POSIX MQ notify
1626  * @mqdes: MQ descriptor
1627  * @u_notification: Notification event
1628  *
1629  * Returns 0 for success or NULL context or < 0 on error.
1630  */
1631
1632 int __audit_mq_notify(mqd_t mqdes, const struct sigevent __user *u_notification)
1633 {
1634         struct audit_aux_data_mq_notify *ax;
1635         struct audit_context *context = current->audit_context;
1636
1637         if (!audit_enabled)
1638                 return 0;
1639
1640         if (likely(!context))
1641                 return 0;
1642
1643         ax = kmalloc(sizeof(*ax), GFP_ATOMIC);
1644         if (!ax)
1645                 return -ENOMEM;
1646
1647         if (u_notification != NULL) {
1648                 if (copy_from_user(&ax->notification, u_notification, sizeof(ax->notification))) {
1649                         kfree(ax);
1650                         return -EFAULT;
1651                 }
1652         } else
1653                 memset(&ax->notification, 0, sizeof(ax->notification));
1654
1655         ax->mqdes = mqdes;
1656
1657         ax->d.type = AUDIT_MQ_NOTIFY;
1658         ax->d.next = context->aux;
1659         context->aux = (void *)ax;
1660         return 0;
1661 }
1662
1663 /**
1664  * __audit_mq_getsetattr - record audit data for a POSIX MQ get/set attribute
1665  * @mqdes: MQ descriptor
1666  * @mqstat: MQ flags
1667  *
1668  * Returns 0 for success or NULL context or < 0 on error.
1669  */
1670 int __audit_mq_getsetattr(mqd_t mqdes, struct mq_attr *mqstat)
1671 {
1672         struct audit_aux_data_mq_getsetattr *ax;
1673         struct audit_context *context = current->audit_context;
1674
1675         if (!audit_enabled)
1676                 return 0;
1677
1678         if (likely(!context))
1679                 return 0;
1680
1681         ax = kmalloc(sizeof(*ax), GFP_ATOMIC);
1682         if (!ax)
1683                 return -ENOMEM;
1684
1685         ax->mqdes = mqdes;
1686         ax->mqstat = *mqstat;
1687
1688         ax->d.type = AUDIT_MQ_GETSETATTR;
1689         ax->d.next = context->aux;
1690         context->aux = (void *)ax;
1691         return 0;
1692 }
1693
1694 /**
1695  * audit_ipc_obj - record audit data for ipc object
1696  * @ipcp: ipc permissions
1697  *
1698  * Returns 0 for success or NULL context or < 0 on error.
1699  */
1700 int __audit_ipc_obj(struct kern_ipc_perm *ipcp)
1701 {
1702         struct audit_aux_data_ipcctl *ax;
1703         struct audit_context *context = current->audit_context;
1704
1705         ax = kmalloc(sizeof(*ax), GFP_ATOMIC);
1706         if (!ax)
1707                 return -ENOMEM;
1708
1709         ax->uid = ipcp->uid;
1710         ax->gid = ipcp->gid;
1711         ax->mode = ipcp->mode;
1712         selinux_get_ipc_sid(ipcp, &ax->osid);
1713
1714         ax->d.type = AUDIT_IPC;
1715         ax->d.next = context->aux;
1716         context->aux = (void *)ax;
1717         return 0;
1718 }
1719
1720 /**
1721  * audit_ipc_set_perm - record audit data for new ipc permissions
1722  * @qbytes: msgq bytes
1723  * @uid: msgq user id
1724  * @gid: msgq group id
1725  * @mode: msgq mode (permissions)
1726  *
1727  * Returns 0 for success or NULL context or < 0 on error.
1728  */
1729 int __audit_ipc_set_perm(unsigned long qbytes, uid_t uid, gid_t gid, mode_t mode)
1730 {
1731         struct audit_aux_data_ipcctl *ax;
1732         struct audit_context *context = current->audit_context;
1733
1734         ax = kmalloc(sizeof(*ax), GFP_ATOMIC);
1735         if (!ax)
1736                 return -ENOMEM;
1737
1738         ax->qbytes = qbytes;
1739         ax->uid = uid;
1740         ax->gid = gid;
1741         ax->mode = mode;
1742
1743         ax->d.type = AUDIT_IPC_SET_PERM;
1744         ax->d.next = context->aux;
1745         context->aux = (void *)ax;
1746         return 0;
1747 }
1748
1749 int audit_bprm(struct linux_binprm *bprm)
1750 {
1751         struct audit_aux_data_execve *ax;
1752         struct audit_context *context = current->audit_context;
1753         unsigned long p, next;
1754         void *to;
1755
1756         if (likely(!audit_enabled || !context || context->dummy))
1757                 return 0;
1758
1759         ax = kmalloc(sizeof(*ax) + PAGE_SIZE * MAX_ARG_PAGES - bprm->p,
1760                                 GFP_KERNEL);
1761         if (!ax)
1762                 return -ENOMEM;
1763
1764         ax->argc = bprm->argc;
1765         ax->envc = bprm->envc;
1766         for (p = bprm->p, to = ax->mem; p < MAX_ARG_PAGES*PAGE_SIZE; p = next) {
1767                 struct page *page = bprm->page[p / PAGE_SIZE];
1768                 void *kaddr = kmap(page);
1769                 next = (p + PAGE_SIZE) & ~(PAGE_SIZE - 1);
1770                 memcpy(to, kaddr + (p & (PAGE_SIZE - 1)), next - p);
1771                 to += next - p;
1772                 kunmap(page);
1773         }
1774
1775         ax->d.type = AUDIT_EXECVE;
1776         ax->d.next = context->aux;
1777         context->aux = (void *)ax;
1778         return 0;
1779 }
1780
1781
1782 /**
1783  * audit_socketcall - record audit data for sys_socketcall
1784  * @nargs: number of args
1785  * @args: args array
1786  *
1787  * Returns 0 for success or NULL context or < 0 on error.
1788  */
1789 int audit_socketcall(int nargs, unsigned long *args)
1790 {
1791         struct audit_aux_data_socketcall *ax;
1792         struct audit_context *context = current->audit_context;
1793
1794         if (likely(!context || context->dummy))
1795                 return 0;
1796
1797         ax = kmalloc(sizeof(*ax) + nargs * sizeof(unsigned long), GFP_KERNEL);
1798         if (!ax)
1799                 return -ENOMEM;
1800
1801         ax->nargs = nargs;
1802         memcpy(ax->args, args, nargs * sizeof(unsigned long));
1803
1804         ax->d.type = AUDIT_SOCKETCALL;
1805         ax->d.next = context->aux;
1806         context->aux = (void *)ax;
1807         return 0;
1808 }
1809
1810 /**
1811  * audit_sockaddr - record audit data for sys_bind, sys_connect, sys_sendto
1812  * @len: data length in user space
1813  * @a: data address in kernel space
1814  *
1815  * Returns 0 for success or NULL context or < 0 on error.
1816  */
1817 int audit_sockaddr(int len, void *a)
1818 {
1819         struct audit_aux_data_sockaddr *ax;
1820         struct audit_context *context = current->audit_context;
1821
1822         if (likely(!context || context->dummy))
1823                 return 0;
1824
1825         ax = kmalloc(sizeof(*ax) + len, GFP_KERNEL);
1826         if (!ax)
1827                 return -ENOMEM;
1828
1829         ax->len = len;
1830         memcpy(ax->a, a, len);
1831
1832         ax->d.type = AUDIT_SOCKADDR;
1833         ax->d.next = context->aux;
1834         context->aux = (void *)ax;
1835         return 0;
1836 }
1837
1838 /**
1839  * audit_avc_path - record the granting or denial of permissions
1840  * @dentry: dentry to record
1841  * @mnt: mnt to record
1842  *
1843  * Returns 0 for success or NULL context or < 0 on error.
1844  *
1845  * Called from security/selinux/avc.c::avc_audit()
1846  */
1847 int audit_avc_path(struct dentry *dentry, struct vfsmount *mnt)
1848 {
1849         struct audit_aux_data_path *ax;
1850         struct audit_context *context = current->audit_context;
1851
1852         if (likely(!context))
1853                 return 0;
1854
1855         ax = kmalloc(sizeof(*ax), GFP_ATOMIC);
1856         if (!ax)
1857                 return -ENOMEM;
1858
1859         ax->dentry = dget(dentry);
1860         ax->mnt = mntget(mnt);
1861
1862         ax->d.type = AUDIT_AVC_PATH;
1863         ax->d.next = context->aux;
1864         context->aux = (void *)ax;
1865         return 0;
1866 }
1867
1868 /**
1869  * audit_signal_info - record signal info for shutting down audit subsystem
1870  * @sig: signal value
1871  * @t: task being signaled
1872  *
1873  * If the audit subsystem is being terminated, record the task (pid)
1874  * and uid that is doing that.
1875  */
1876 void __audit_signal_info(int sig, struct task_struct *t)
1877 {
1878         extern pid_t audit_sig_pid;
1879         extern uid_t audit_sig_uid;
1880         extern u32 audit_sig_sid;
1881
1882         if (sig == SIGTERM || sig == SIGHUP || sig == SIGUSR1) {
1883                 struct task_struct *tsk = current;
1884                 struct audit_context *ctx = tsk->audit_context;
1885                 audit_sig_pid = tsk->pid;
1886                 if (ctx)
1887                         audit_sig_uid = ctx->loginuid;
1888                 else
1889                         audit_sig_uid = tsk->uid;
1890                 selinux_get_task_sid(tsk, &audit_sig_sid);
1891         }
1892 }