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