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 <linux/fsnotify_backend.h>
  77#include <uapi/linux/limits.h>
  78
  79#include "audit.h"
  80
  81/* flags stating the success for a syscall */
  82#define AUDITSC_INVALID 0
  83#define AUDITSC_SUCCESS 1
  84#define AUDITSC_FAILURE 2
  85
  86/* no execve audit message should be longer than this (userspace limits),
  87 * see the note near the top of audit_log_execve_info() about this value */
  88#define MAX_EXECVE_AUDIT_LEN 7500
  89
  90/* max length to print of cmdline/proctitle value during audit */
  91#define MAX_PROCTITLE_AUDIT_LEN 128
  92
  93/* number of audit rules */
  94int audit_n_rules;
  95
  96/* determines whether we collect data for signals sent */
  97int audit_signals;
  98
  99struct audit_aux_data {
 100	struct audit_aux_data	*next;
 101	int			type;
 102};
 103
 104#define AUDIT_AUX_IPCPERM	0
 105
 106/* Number of target pids per aux struct. */
 107#define AUDIT_AUX_PIDS	16
 108
 109struct audit_aux_data_pids {
 110	struct audit_aux_data	d;
 111	pid_t			target_pid[AUDIT_AUX_PIDS];
 112	kuid_t			target_auid[AUDIT_AUX_PIDS];
 113	kuid_t			target_uid[AUDIT_AUX_PIDS];
 114	unsigned int		target_sessionid[AUDIT_AUX_PIDS];
 115	u32			target_sid[AUDIT_AUX_PIDS];
 116	char 			target_comm[AUDIT_AUX_PIDS][TASK_COMM_LEN];
 117	int			pid_count;
 118};
 119
 120struct audit_aux_data_bprm_fcaps {
 121	struct audit_aux_data	d;
 122	struct audit_cap_data	fcap;
 123	unsigned int		fcap_ver;
 124	struct audit_cap_data	old_pcap;
 125	struct audit_cap_data	new_pcap;
 126};
 127
 128struct audit_tree_refs {
 129	struct audit_tree_refs *next;
 130	struct audit_chunk *c[31];
 131};
 132
 133static int audit_match_perm(struct audit_context *ctx, int mask)
 134{
 135	unsigned n;
 136	if (unlikely(!ctx))
 137		return 0;
 138	n = ctx->major;
 139
 140	switch (audit_classify_syscall(ctx->arch, n)) {
 141	case 0:	/* native */
 142		if ((mask & AUDIT_PERM_WRITE) &&
 143		     audit_match_class(AUDIT_CLASS_WRITE, n))
 144			return 1;
 145		if ((mask & AUDIT_PERM_READ) &&
 146		     audit_match_class(AUDIT_CLASS_READ, n))
 147			return 1;
 148		if ((mask & AUDIT_PERM_ATTR) &&
 149		     audit_match_class(AUDIT_CLASS_CHATTR, n))
 150			return 1;
 151		return 0;
 152	case 1: /* 32bit on biarch */
 153		if ((mask & AUDIT_PERM_WRITE) &&
 154		     audit_match_class(AUDIT_CLASS_WRITE_32, n))
 155			return 1;
 156		if ((mask & AUDIT_PERM_READ) &&
 157		     audit_match_class(AUDIT_CLASS_READ_32, n))
 158			return 1;
 159		if ((mask & AUDIT_PERM_ATTR) &&
 160		     audit_match_class(AUDIT_CLASS_CHATTR_32, n))
 161			return 1;
 162		return 0;
 163	case 2: /* open */
 164		return mask & ACC_MODE(ctx->argv[1]);
 165	case 3: /* openat */
 166		return mask & ACC_MODE(ctx->argv[2]);
 167	case 4: /* socketcall */
 168		return ((mask & AUDIT_PERM_WRITE) && ctx->argv[0] == SYS_BIND);
 169	case 5: /* execve */
 170		return mask & AUDIT_PERM_EXEC;
 171	default:
 172		return 0;
 173	}
 174}
 175
 176static int audit_match_filetype(struct audit_context *ctx, int val)
 177{
 178	struct audit_names *n;
 179	umode_t mode = (umode_t)val;
 180
 181	if (unlikely(!ctx))
 182		return 0;
 183
 184	list_for_each_entry(n, &ctx->names_list, list) {
 185		if ((n->ino != AUDIT_INO_UNSET) &&
 186		    ((n->mode & S_IFMT) == mode))
 187			return 1;
 188	}
 189
 190	return 0;
 191}
 192
 193/*
 194 * We keep a linked list of fixed-sized (31 pointer) arrays of audit_chunk *;
 195 * ->first_trees points to its beginning, ->trees - to the current end of data.
 196 * ->tree_count is the number of free entries in array pointed to by ->trees.
 197 * Original condition is (NULL, NULL, 0); as soon as it grows we never revert to NULL,
 198 * "empty" becomes (p, p, 31) afterwards.  We don't shrink the list (and seriously,
 199 * it's going to remain 1-element for almost any setup) until we free context itself.
 200 * References in it _are_ dropped - at the same time we free/drop aux stuff.
 201 */
 202
 203#ifdef CONFIG_AUDIT_TREE
 204static void audit_set_auditable(struct audit_context *ctx)
 205{
 206	if (!ctx->prio) {
 207		ctx->prio = 1;
 208		ctx->current_state = AUDIT_RECORD_CONTEXT;
 209	}
 210}
 211
 212static int put_tree_ref(struct audit_context *ctx, struct audit_chunk *chunk)
 213{
 214	struct audit_tree_refs *p = ctx->trees;
 215	int left = ctx->tree_count;
 216	if (likely(left)) {
 217		p->c[--left] = chunk;
 218		ctx->tree_count = left;
 219		return 1;
 220	}
 221	if (!p)
 222		return 0;
 223	p = p->next;
 224	if (p) {
 225		p->c[30] = chunk;
 226		ctx->trees = p;
 227		ctx->tree_count = 30;
 228		return 1;
 229	}
 230	return 0;
 231}
 232
 233static int grow_tree_refs(struct audit_context *ctx)
 234{
 235	struct audit_tree_refs *p = ctx->trees;
 236	ctx->trees = kzalloc(sizeof(struct audit_tree_refs), GFP_KERNEL);
 237	if (!ctx->trees) {
 238		ctx->trees = p;
 239		return 0;
 240	}
 241	if (p)
 242		p->next = ctx->trees;
 243	else
 244		ctx->first_trees = ctx->trees;
 245	ctx->tree_count = 31;
 246	return 1;
 247}
 248#endif
 249
 250static void unroll_tree_refs(struct audit_context *ctx,
 251		      struct audit_tree_refs *p, int count)
 252{
 253#ifdef CONFIG_AUDIT_TREE
 254	struct audit_tree_refs *q;
 255	int n;
 256	if (!p) {
 257		/* we started with empty chain */
 258		p = ctx->first_trees;
 259		count = 31;
 260		/* if the very first allocation has failed, nothing to do */
 261		if (!p)
 262			return;
 263	}
 264	n = count;
 265	for (q = p; q != ctx->trees; q = q->next, n = 31) {
 266		while (n--) {
 267			audit_put_chunk(q->c[n]);
 268			q->c[n] = NULL;
 269		}
 270	}
 271	while (n-- > ctx->tree_count) {
 272		audit_put_chunk(q->c[n]);
 273		q->c[n] = NULL;
 274	}
 275	ctx->trees = p;
 276	ctx->tree_count = count;
 277#endif
 278}
 279
 280static void free_tree_refs(struct audit_context *ctx)
 281{
 282	struct audit_tree_refs *p, *q;
 283	for (p = ctx->first_trees; p; p = q) {
 284		q = p->next;
 285		kfree(p);
 286	}
 287}
 288
 289static int match_tree_refs(struct audit_context *ctx, struct audit_tree *tree)
 290{
 291#ifdef CONFIG_AUDIT_TREE
 292	struct audit_tree_refs *p;
 293	int n;
 294	if (!tree)
 295		return 0;
 296	/* full ones */
 297	for (p = ctx->first_trees; p != ctx->trees; p = p->next) {
 298		for (n = 0; n < 31; n++)
 299			if (audit_tree_match(p->c[n], tree))
 300				return 1;
 301	}
 302	/* partial */
 303	if (p) {
 304		for (n = ctx->tree_count; n < 31; n++)
 305			if (audit_tree_match(p->c[n], tree))
 306				return 1;
 307	}
 308#endif
 309	return 0;
 310}
 311
 312static int audit_compare_uid(kuid_t uid,
 313			     struct audit_names *name,
 314			     struct audit_field *f,
 315			     struct audit_context *ctx)
 316{
 317	struct audit_names *n;
 318	int rc;
 319 
 320	if (name) {
 321		rc = audit_uid_comparator(uid, f->op, name->uid);
 322		if (rc)
 323			return rc;
 324	}
 325 
 326	if (ctx) {
 327		list_for_each_entry(n, &ctx->names_list, list) {
 328			rc = audit_uid_comparator(uid, f->op, n->uid);
 329			if (rc)
 330				return rc;
 331		}
 332	}
 333	return 0;
 334}
 335
 336static int audit_compare_gid(kgid_t gid,
 337			     struct audit_names *name,
 338			     struct audit_field *f,
 339			     struct audit_context *ctx)
 340{
 341	struct audit_names *n;
 342	int rc;
 343 
 344	if (name) {
 345		rc = audit_gid_comparator(gid, f->op, name->gid);
 346		if (rc)
 347			return rc;
 348	}
 349 
 350	if (ctx) {
 351		list_for_each_entry(n, &ctx->names_list, list) {
 352			rc = audit_gid_comparator(gid, f->op, n->gid);
 353			if (rc)
 354				return rc;
 355		}
 356	}
 357	return 0;
 358}
 359
 360static int audit_field_compare(struct task_struct *tsk,
 361			       const struct cred *cred,
 362			       struct audit_field *f,
 363			       struct audit_context *ctx,
 364			       struct audit_names *name)
 365{
 366	switch (f->val) {
 367	/* process to file object comparisons */
 368	case AUDIT_COMPARE_UID_TO_OBJ_UID:
 369		return audit_compare_uid(cred->uid, name, f, ctx);
 370	case AUDIT_COMPARE_GID_TO_OBJ_GID:
 371		return audit_compare_gid(cred->gid, name, f, ctx);
 372	case AUDIT_COMPARE_EUID_TO_OBJ_UID:
 373		return audit_compare_uid(cred->euid, name, f, ctx);
 374	case AUDIT_COMPARE_EGID_TO_OBJ_GID:
 375		return audit_compare_gid(cred->egid, name, f, ctx);
 376	case AUDIT_COMPARE_AUID_TO_OBJ_UID:
 377		return audit_compare_uid(tsk->loginuid, name, f, ctx);
 378	case AUDIT_COMPARE_SUID_TO_OBJ_UID:
 379		return audit_compare_uid(cred->suid, name, f, ctx);
 380	case AUDIT_COMPARE_SGID_TO_OBJ_GID:
 381		return audit_compare_gid(cred->sgid, name, f, ctx);
 382	case AUDIT_COMPARE_FSUID_TO_OBJ_UID:
 383		return audit_compare_uid(cred->fsuid, name, f, ctx);
 384	case AUDIT_COMPARE_FSGID_TO_OBJ_GID:
 385		return audit_compare_gid(cred->fsgid, name, f, ctx);
 386	/* uid comparisons */
 387	case AUDIT_COMPARE_UID_TO_AUID:
 388		return audit_uid_comparator(cred->uid, f->op, tsk->loginuid);
 389	case AUDIT_COMPARE_UID_TO_EUID:
 390		return audit_uid_comparator(cred->uid, f->op, cred->euid);
 391	case AUDIT_COMPARE_UID_TO_SUID:
 392		return audit_uid_comparator(cred->uid, f->op, cred->suid);
 393	case AUDIT_COMPARE_UID_TO_FSUID:
 394		return audit_uid_comparator(cred->uid, f->op, cred->fsuid);
 395	/* auid comparisons */
 396	case AUDIT_COMPARE_AUID_TO_EUID:
 397		return audit_uid_comparator(tsk->loginuid, f->op, cred->euid);
 398	case AUDIT_COMPARE_AUID_TO_SUID:
 399		return audit_uid_comparator(tsk->loginuid, f->op, cred->suid);
 400	case AUDIT_COMPARE_AUID_TO_FSUID:
 401		return audit_uid_comparator(tsk->loginuid, f->op, cred->fsuid);
 402	/* euid comparisons */
 403	case AUDIT_COMPARE_EUID_TO_SUID:
 404		return audit_uid_comparator(cred->euid, f->op, cred->suid);
 405	case AUDIT_COMPARE_EUID_TO_FSUID:
 406		return audit_uid_comparator(cred->euid, f->op, cred->fsuid);
 407	/* suid comparisons */
 408	case AUDIT_COMPARE_SUID_TO_FSUID:
 409		return audit_uid_comparator(cred->suid, f->op, cred->fsuid);
 410	/* gid comparisons */
 411	case AUDIT_COMPARE_GID_TO_EGID:
 412		return audit_gid_comparator(cred->gid, f->op, cred->egid);
 413	case AUDIT_COMPARE_GID_TO_SGID:
 414		return audit_gid_comparator(cred->gid, f->op, cred->sgid);
 415	case AUDIT_COMPARE_GID_TO_FSGID:
 416		return audit_gid_comparator(cred->gid, f->op, cred->fsgid);
 417	/* egid comparisons */
 418	case AUDIT_COMPARE_EGID_TO_SGID:
 419		return audit_gid_comparator(cred->egid, f->op, cred->sgid);
 420	case AUDIT_COMPARE_EGID_TO_FSGID:
 421		return audit_gid_comparator(cred->egid, f->op, cred->fsgid);
 422	/* sgid comparison */
 423	case AUDIT_COMPARE_SGID_TO_FSGID:
 424		return audit_gid_comparator(cred->sgid, f->op, cred->fsgid);
 425	default:
 426		WARN(1, "Missing AUDIT_COMPARE define.  Report as a bug\n");
 427		return 0;
 428	}
 429	return 0;
 430}
 431
 432/* Determine if any context name data matches a rule's watch data */
 433/* Compare a task_struct with an audit_rule.  Return 1 on match, 0
 434 * otherwise.
 435 *
 436 * If task_creation is true, this is an explicit indication that we are
 437 * filtering a task rule at task creation time.  This and tsk == current are
 438 * the only situations where tsk->cred may be accessed without an rcu read lock.
 439 */
 440static int audit_filter_rules(struct task_struct *tsk,
 441			      struct audit_krule *rule,
 442			      struct audit_context *ctx,
 443			      struct audit_names *name,
 444			      enum audit_state *state,
 445			      bool task_creation)
 446{
 447	const struct cred *cred;
 448	int i, need_sid = 1;
 449	u32 sid;
 450	unsigned int sessionid;
 451
 452	cred = rcu_dereference_check(tsk->cred, tsk == current || task_creation);
 453
 454	for (i = 0; i < rule->field_count; i++) {
 455		struct audit_field *f = &rule->fields[i];
 456		struct audit_names *n;
 457		int result = 0;
 458		pid_t pid;
 459
 460		switch (f->type) {
 461		case AUDIT_PID:
 462			pid = task_tgid_nr(tsk);
 463			result = audit_comparator(pid, f->op, f->val);
 464			break;
 465		case AUDIT_PPID:
 466			if (ctx) {
 467				if (!ctx->ppid)
 468					ctx->ppid = task_ppid_nr(tsk);
 469				result = audit_comparator(ctx->ppid, f->op, f->val);
 470			}
 471			break;
 472		case AUDIT_EXE:
 473			result = audit_exe_compare(tsk, rule->exe);
 474			break;
 475		case AUDIT_UID:
 476			result = audit_uid_comparator(cred->uid, f->op, f->uid);
 477			break;
 478		case AUDIT_EUID:
 479			result = audit_uid_comparator(cred->euid, f->op, f->uid);
 480			break;
 481		case AUDIT_SUID:
 482			result = audit_uid_comparator(cred->suid, f->op, f->uid);
 483			break;
 484		case AUDIT_FSUID:
 485			result = audit_uid_comparator(cred->fsuid, f->op, f->uid);
 486			break;
 487		case AUDIT_GID:
 488			result = audit_gid_comparator(cred->gid, f->op, f->gid);
 489			if (f->op == Audit_equal) {
 490				if (!result)
 491					result = in_group_p(f->gid);
 492			} else if (f->op == Audit_not_equal) {
 493				if (result)
 494					result = !in_group_p(f->gid);
 495			}
 496			break;
 497		case AUDIT_EGID:
 498			result = audit_gid_comparator(cred->egid, f->op, f->gid);
 499			if (f->op == Audit_equal) {
 500				if (!result)
 501					result = in_egroup_p(f->gid);
 502			} else if (f->op == Audit_not_equal) {
 503				if (result)
 504					result = !in_egroup_p(f->gid);
 505			}
 506			break;
 507		case AUDIT_SGID:
 508			result = audit_gid_comparator(cred->sgid, f->op, f->gid);
 509			break;
 510		case AUDIT_FSGID:
 511			result = audit_gid_comparator(cred->fsgid, f->op, f->gid);
 512			break;
 513		case AUDIT_SESSIONID:
 514			sessionid = audit_get_sessionid(current);
 515			result = audit_comparator(sessionid, f->op, f->val);
 516			break;
 517		case AUDIT_PERS:
 518			result = audit_comparator(tsk->personality, f->op, f->val);
 519			break;
 520		case AUDIT_ARCH:
 521			if (ctx)
 522				result = audit_comparator(ctx->arch, f->op, f->val);
 523			break;
 524
 525		case AUDIT_EXIT:
 526			if (ctx && ctx->return_valid)
 527				result = audit_comparator(ctx->return_code, f->op, f->val);
 528			break;
 529		case AUDIT_SUCCESS:
 530			if (ctx && ctx->return_valid) {
 531				if (f->val)
 532					result = audit_comparator(ctx->return_valid, f->op, AUDITSC_SUCCESS);
 533				else
 534					result = audit_comparator(ctx->return_valid, f->op, AUDITSC_FAILURE);
 535			}
 536			break;
 537		case AUDIT_DEVMAJOR:
 538			if (name) {
 539				if (audit_comparator(MAJOR(name->dev), f->op, f->val) ||
 540				    audit_comparator(MAJOR(name->rdev), f->op, f->val))
 541					++result;
 542			} else if (ctx) {
 543				list_for_each_entry(n, &ctx->names_list, list) {
 544					if (audit_comparator(MAJOR(n->dev), f->op, f->val) ||
 545					    audit_comparator(MAJOR(n->rdev), f->op, f->val)) {
 546						++result;
 547						break;
 548					}
 549				}
 550			}
 551			break;
 552		case AUDIT_DEVMINOR:
 553			if (name) {
 554				if (audit_comparator(MINOR(name->dev), f->op, f->val) ||
 555				    audit_comparator(MINOR(name->rdev), f->op, f->val))
 556					++result;
 557			} else if (ctx) {
 558				list_for_each_entry(n, &ctx->names_list, list) {
 559					if (audit_comparator(MINOR(n->dev), f->op, f->val) ||
 560					    audit_comparator(MINOR(n->rdev), f->op, f->val)) {
 561						++result;
 562						break;
 563					}
 564				}
 565			}
 566			break;
 567		case AUDIT_INODE:
 568			if (name)
 569				result = audit_comparator(name->ino, f->op, f->val);
 570			else if (ctx) {
 571				list_for_each_entry(n, &ctx->names_list, list) {
 572					if (audit_comparator(n->ino, f->op, f->val)) {
 573						++result;
 574						break;
 575					}
 576				}
 577			}
 578			break;
 579		case AUDIT_OBJ_UID:
 580			if (name) {
 581				result = audit_uid_comparator(name->uid, f->op, f->uid);
 582			} else if (ctx) {
 583				list_for_each_entry(n, &ctx->names_list, list) {
 584					if (audit_uid_comparator(n->uid, f->op, f->uid)) {
 585						++result;
 586						break;
 587					}
 588				}
 589			}
 590			break;
 591		case AUDIT_OBJ_GID:
 592			if (name) {
 593				result = audit_gid_comparator(name->gid, f->op, f->gid);
 594			} else if (ctx) {
 595				list_for_each_entry(n, &ctx->names_list, list) {
 596					if (audit_gid_comparator(n->gid, f->op, f->gid)) {
 597						++result;
 598						break;
 599					}
 600				}
 601			}
 602			break;
 603		case AUDIT_WATCH:
 604			if (name)
 605				result = audit_watch_compare(rule->watch, name->ino, name->dev);
 606			break;
 607		case AUDIT_DIR:
 608			if (ctx)
 609				result = match_tree_refs(ctx, rule->tree);
 610			break;
 611		case AUDIT_LOGINUID:
 612			result = audit_uid_comparator(tsk->loginuid, f->op, f->uid);
 613			break;
 614		case AUDIT_LOGINUID_SET:
 615			result = audit_comparator(audit_loginuid_set(tsk), f->op, f->val);
 616			break;
 617		case AUDIT_SUBJ_USER:
 618		case AUDIT_SUBJ_ROLE:
 619		case AUDIT_SUBJ_TYPE:
 620		case AUDIT_SUBJ_SEN:
 621		case AUDIT_SUBJ_CLR:
 622			/* NOTE: this may return negative values indicating
 623			   a temporary error.  We simply treat this as a
 624			   match for now to avoid losing information that
 625			   may be wanted.   An error message will also be
 626			   logged upon error */
 627			if (f->lsm_rule) {
 628				if (need_sid) {
 629					security_task_getsecid(tsk, &sid);
 630					need_sid = 0;
 631				}
 632				result = security_audit_rule_match(sid, f->type,
 633				                                  f->op,
 634				                                  f->lsm_rule,
 635				                                  ctx);
 636			}
 637			break;
 638		case AUDIT_OBJ_USER:
 639		case AUDIT_OBJ_ROLE:
 640		case AUDIT_OBJ_TYPE:
 641		case AUDIT_OBJ_LEV_LOW:
 642		case AUDIT_OBJ_LEV_HIGH:
 643			/* The above note for AUDIT_SUBJ_USER...AUDIT_SUBJ_CLR
 644			   also applies here */
 645			if (f->lsm_rule) {
 646				/* Find files that match */
 647				if (name) {
 648					result = security_audit_rule_match(
 649					           name->osid, f->type, f->op,
 650					           f->lsm_rule, ctx);
 651				} else if (ctx) {
 652					list_for_each_entry(n, &ctx->names_list, list) {
 653						if (security_audit_rule_match(n->osid, f->type,
 654									      f->op, f->lsm_rule,
 655									      ctx)) {
 656							++result;
 657							break;
 658						}
 659					}
 660				}
 661				/* Find ipc objects that match */
 662				if (!ctx || ctx->type != AUDIT_IPC)
 663					break;
 664				if (security_audit_rule_match(ctx->ipc.osid,
 665							      f->type, f->op,
 666							      f->lsm_rule, ctx))
 667					++result;
 668			}
 669			break;
 670		case AUDIT_ARG0:
 671		case AUDIT_ARG1:
 672		case AUDIT_ARG2:
 673		case AUDIT_ARG3:
 674			if (ctx)
 675				result = audit_comparator(ctx->argv[f->type-AUDIT_ARG0], f->op, f->val);
 676			break;
 677		case AUDIT_FILTERKEY:
 678			/* ignore this field for filtering */
 679			result = 1;
 680			break;
 681		case AUDIT_PERM:
 682			result = audit_match_perm(ctx, f->val);
 683			break;
 684		case AUDIT_FILETYPE:
 685			result = audit_match_filetype(ctx, f->val);
 686			break;
 687		case AUDIT_FIELD_COMPARE:
 688			result = audit_field_compare(tsk, cred, f, ctx, name);
 689			break;
 690		}
 691		if (!result)
 692			return 0;
 693	}
 694
 695	if (ctx) {
 696		if (rule->prio <= ctx->prio)
 697			return 0;
 698		if (rule->filterkey) {
 699			kfree(ctx->filterkey);
 700			ctx->filterkey = kstrdup(rule->filterkey, GFP_ATOMIC);
 701		}
 702		ctx->prio = rule->prio;
 703	}
 704	switch (rule->action) {
 705	case AUDIT_NEVER:
 706		*state = AUDIT_DISABLED;
 707		break;
 708	case AUDIT_ALWAYS:
 709		*state = AUDIT_RECORD_CONTEXT;
 710		break;
 711	}
 712	return 1;
 713}
 714
 715/* At process creation time, we can determine if system-call auditing is
 716 * completely disabled for this task.  Since we only have the task
 717 * structure at this point, we can only check uid and gid.
 718 */
 719static enum audit_state audit_filter_task(struct task_struct *tsk, char **key)
 720{
 721	struct audit_entry *e;
 722	enum audit_state   state;
 723
 724	rcu_read_lock();
 725	list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_TASK], list) {
 726		if (audit_filter_rules(tsk, &e->rule, NULL, NULL,
 727				       &state, true)) {
 728			if (state == AUDIT_RECORD_CONTEXT)
 729				*key = kstrdup(e->rule.filterkey, GFP_ATOMIC);
 730			rcu_read_unlock();
 731			return state;
 732		}
 733	}
 734	rcu_read_unlock();
 735	return AUDIT_BUILD_CONTEXT;
 736}
 737
 738static int audit_in_mask(const struct audit_krule *rule, unsigned long val)
 739{
 740	int word, bit;
 741
 742	if (val > 0xffffffff)
 743		return false;
 744
 745	word = AUDIT_WORD(val);
 746	if (word >= AUDIT_BITMASK_SIZE)
 747		return false;
 748
 749	bit = AUDIT_BIT(val);
 750
 751	return rule->mask[word] & bit;
 752}
 753
 754/* At syscall entry and exit time, this filter is called if the
 755 * audit_state is not low enough that auditing cannot take place, but is
 756 * also not high enough that we already know we have to write an audit
 757 * record (i.e., the state is AUDIT_SETUP_CONTEXT or AUDIT_BUILD_CONTEXT).
 758 */
 759static enum audit_state audit_filter_syscall(struct task_struct *tsk,
 760					     struct audit_context *ctx,
 761					     struct list_head *list)
 762{
 763	struct audit_entry *e;
 764	enum audit_state state;
 765
 766	if (auditd_test_task(tsk))
 767		return AUDIT_DISABLED;
 768
 769	rcu_read_lock();
 770	if (!list_empty(list)) {
 771		list_for_each_entry_rcu(e, list, list) {
 772			if (audit_in_mask(&e->rule, ctx->major) &&
 773			    audit_filter_rules(tsk, &e->rule, ctx, NULL,
 774					       &state, false)) {
 775				rcu_read_unlock();
 776				ctx->current_state = state;
 777				return state;
 778			}
 779		}
 780	}
 781	rcu_read_unlock();
 782	return AUDIT_BUILD_CONTEXT;
 783}
 784
 785/*
 786 * Given an audit_name check the inode hash table to see if they match.
 787 * Called holding the rcu read lock to protect the use of audit_inode_hash
 788 */
 789static int audit_filter_inode_name(struct task_struct *tsk,
 790				   struct audit_names *n,
 791				   struct audit_context *ctx) {
 792	int h = audit_hash_ino((u32)n->ino);
 793	struct list_head *list = &audit_inode_hash[h];
 794	struct audit_entry *e;
 795	enum audit_state state;
 796
 797	if (list_empty(list))
 798		return 0;
 799
 800	list_for_each_entry_rcu(e, list, list) {
 801		if (audit_in_mask(&e->rule, ctx->major) &&
 802		    audit_filter_rules(tsk, &e->rule, ctx, n, &state, false)) {
 803			ctx->current_state = state;
 804			return 1;
 805		}
 806	}
 807
 808	return 0;
 809}
 810
 811/* At syscall exit time, this filter is called if any audit_names have been
 812 * collected during syscall processing.  We only check rules in sublists at hash
 813 * buckets applicable to the inode numbers in audit_names.
 814 * Regarding audit_state, same rules apply as for audit_filter_syscall().
 815 */
 816void audit_filter_inodes(struct task_struct *tsk, struct audit_context *ctx)
 817{
 818	struct audit_names *n;
 819
 820	if (auditd_test_task(tsk))
 821		return;
 822
 823	rcu_read_lock();
 824
 825	list_for_each_entry(n, &ctx->names_list, list) {
 826		if (audit_filter_inode_name(tsk, n, ctx))
 827			break;
 828	}
 829	rcu_read_unlock();
 830}
 831
 832/* Transfer the audit context pointer to the caller, clearing it in the tsk's struct */
 833static inline struct audit_context *audit_take_context(struct task_struct *tsk,
 834						      int return_valid,
 835						      long return_code)
 836{
 837	struct audit_context *context = tsk->audit_context;
 838
 839	if (!context)
 840		return NULL;
 841	context->return_valid = return_valid;
 842
 843	/*
 844	 * we need to fix up the return code in the audit logs if the actual
 845	 * return codes are later going to be fixed up by the arch specific
 846	 * signal handlers
 847	 *
 848	 * This is actually a test for:
 849	 * (rc == ERESTARTSYS ) || (rc == ERESTARTNOINTR) ||
 850	 * (rc == ERESTARTNOHAND) || (rc == ERESTART_RESTARTBLOCK)
 851	 *
 852	 * but is faster than a bunch of ||
 853	 */
 854	if (unlikely(return_code <= -ERESTARTSYS) &&
 855	    (return_code >= -ERESTART_RESTARTBLOCK) &&
 856	    (return_code != -ENOIOCTLCMD))
 857		context->return_code = -EINTR;
 858	else
 859		context->return_code  = return_code;
 860
 861	if (context->in_syscall && !context->dummy) {
 862		audit_filter_syscall(tsk, context, &audit_filter_list[AUDIT_FILTER_EXIT]);
 863		audit_filter_inodes(tsk, context);
 864	}
 865
 866	tsk->audit_context = NULL;
 867	return context;
 868}
 869
 870static inline void audit_proctitle_free(struct audit_context *context)
 871{
 872	kfree(context->proctitle.value);
 873	context->proctitle.value = NULL;
 874	context->proctitle.len = 0;
 875}
 876
 877static inline void audit_free_names(struct audit_context *context)
 878{
 879	struct audit_names *n, *next;
 880
 881	list_for_each_entry_safe(n, next, &context->names_list, list) {
 882		list_del(&n->list);
 883		if (n->name)
 884			putname(n->name);
 885		if (n->should_free)
 886			kfree(n);
 887	}
 888	context->name_count = 0;
 889	path_put(&context->pwd);
 890	context->pwd.dentry = NULL;
 891	context->pwd.mnt = NULL;
 892}
 893
 894static inline void audit_free_aux(struct audit_context *context)
 895{
 896	struct audit_aux_data *aux;
 897
 898	while ((aux = context->aux)) {
 899		context->aux = aux->next;
 900		kfree(aux);
 901	}
 902	while ((aux = context->aux_pids)) {
 903		context->aux_pids = aux->next;
 904		kfree(aux);
 905	}
 906}
 907
 908static inline struct audit_context *audit_alloc_context(enum audit_state state)
 909{
 910	struct audit_context *context;
 911
 912	context = kzalloc(sizeof(*context), GFP_KERNEL);
 913	if (!context)
 914		return NULL;
 915	context->state = state;
 916	context->prio = state == AUDIT_RECORD_CONTEXT ? ~0ULL : 0;
 917	INIT_LIST_HEAD(&context->killed_trees);
 918	INIT_LIST_HEAD(&context->names_list);
 919	return context;
 920}
 921
 922/**
 923 * audit_alloc - allocate an audit context block for a task
 924 * @tsk: task
 925 *
 926 * Filter on the task information and allocate a per-task audit context
 927 * if necessary.  Doing so turns on system call auditing for the
 928 * specified task.  This is called from copy_process, so no lock is
 929 * needed.
 930 */
 931int audit_alloc(struct task_struct *tsk)
 932{
 933	struct audit_context *context;
 934	enum audit_state     state;
 935	char *key = NULL;
 936
 937	if (likely(!audit_ever_enabled))
 938		return 0; /* Return if not auditing. */
 939
 940	state = audit_filter_task(tsk, &key);
 941	if (state == AUDIT_DISABLED) {
 942		clear_tsk_thread_flag(tsk, TIF_SYSCALL_AUDIT);
 943		return 0;
 944	}
 945
 946	if (!(context = audit_alloc_context(state))) {
 947		kfree(key);
 948		audit_log_lost("out of memory in audit_alloc");
 949		return -ENOMEM;
 950	}
 951	context->filterkey = key;
 952
 953	tsk->audit_context  = context;
 954	set_tsk_thread_flag(tsk, TIF_SYSCALL_AUDIT);
 955	return 0;
 956}
 957
 958static inline void audit_free_context(struct audit_context *context)
 959{
 960	audit_free_names(context);
 961	unroll_tree_refs(context, NULL, 0);
 962	free_tree_refs(context);
 963	audit_free_aux(context);
 964	kfree(context->filterkey);
 965	kfree(context->sockaddr);
 966	audit_proctitle_free(context);
 967	kfree(context);
 968}
 969
 970static int audit_log_pid_context(struct audit_context *context, pid_t pid,
 971				 kuid_t auid, kuid_t uid, unsigned int sessionid,
 972				 u32 sid, char *comm)
 973{
 974	struct audit_buffer *ab;
 975	char *ctx = NULL;
 976	u32 len;
 977	int rc = 0;
 978
 979	ab = audit_log_start(context, GFP_KERNEL, AUDIT_OBJ_PID);
 980	if (!ab)
 981		return rc;
 982
 983	audit_log_format(ab, "opid=%d oauid=%d ouid=%d oses=%d", pid,
 984			 from_kuid(&init_user_ns, auid),
 985			 from_kuid(&init_user_ns, uid), sessionid);
 986	if (sid) {
 987		if (security_secid_to_secctx(sid, &ctx, &len)) {
 988			audit_log_format(ab, " obj=(none)");
 989			rc = 1;
 990		} else {
 991			audit_log_format(ab, " obj=%s", ctx);
 992			security_release_secctx(ctx, len);
 993		}
 994	}
 995	audit_log_format(ab, " ocomm=");
 996	audit_log_untrustedstring(ab, comm);
 997	audit_log_end(ab);
 998
 999	return rc;
1000}
1001
1002static void audit_log_execve_info(struct audit_context *context,
1003				  struct audit_buffer **ab)
1004{
1005	long len_max;
1006	long len_rem;
1007	long len_full;
1008	long len_buf;
1009	long len_abuf = 0;
1010	long len_tmp;
1011	bool require_data;
1012	bool encode;
1013	unsigned int iter;
1014	unsigned int arg;
1015	char *buf_head;
1016	char *buf;
1017	const char __user *p = (const char __user *)current->mm->arg_start;
 
 
 
 
 
 
 
 
 
 
1018
1019	/* NOTE: this buffer needs to be large enough to hold all the non-arg
1020	 *       data we put in the audit record for this argument (see the
1021	 *       code below) ... at this point in time 96 is plenty */
1022	char abuf[96];
1023
1024	/* NOTE: we set MAX_EXECVE_AUDIT_LEN to a rather arbitrary limit, the
1025	 *       current value of 7500 is not as important as the fact that it
1026	 *       is less than 8k, a setting of 7500 gives us plenty of wiggle
1027	 *       room if we go over a little bit in the logging below */
1028	WARN_ON_ONCE(MAX_EXECVE_AUDIT_LEN > 7500);
1029	len_max = MAX_EXECVE_AUDIT_LEN;
1030
1031	/* scratch buffer to hold the userspace args */
1032	buf_head = kmalloc(MAX_EXECVE_AUDIT_LEN + 1, GFP_KERNEL);
1033	if (!buf_head) {
1034		audit_panic("out of memory for argv string");
1035		return;
1036	}
1037	buf = buf_head;
1038
1039	audit_log_format(*ab, "argc=%d", context->execve.argc);
 
 
 
 
 
 
 
 
 
1040
1041	len_rem = len_max;
1042	len_buf = 0;
1043	len_full = 0;
1044	require_data = true;
1045	encode = false;
1046	iter = 0;
1047	arg = 0;
1048	do {
1049		/* NOTE: we don't ever want to trust this value for anything
1050		 *       serious, but the audit record format insists we
1051		 *       provide an argument length for really long arguments,
1052		 *       e.g. > MAX_EXECVE_AUDIT_LEN, so we have no choice but
1053		 *       to use strncpy_from_user() to obtain this value for
1054		 *       recording in the log, although we don't use it
1055		 *       anywhere here to avoid a double-fetch problem */
1056		if (len_full == 0)
1057			len_full = strnlen_user(p, MAX_ARG_STRLEN) - 1;
1058
1059		/* read more data from userspace */
1060		if (require_data) {
1061			/* can we make more room in the buffer? */
1062			if (buf != buf_head) {
1063				memmove(buf_head, buf, len_buf);
1064				buf = buf_head;
1065			}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1066
1067			/* fetch as much as we can of the argument */
1068			len_tmp = strncpy_from_user(&buf_head[len_buf], p,
1069						    len_max - len_buf);
1070			if (len_tmp == -EFAULT) {
1071				/* unable to copy from userspace */
1072				send_sig(SIGKILL, current, 0);
1073				goto out;
1074			} else if (len_tmp == (len_max - len_buf)) {
1075				/* buffer is not large enough */
1076				require_data = true;
1077				/* NOTE: if we are going to span multiple
1078				 *       buffers force the encoding so we stand
1079				 *       a chance at a sane len_full value and
1080				 *       consistent record encoding */
1081				encode = true;
1082				len_full = len_full * 2;
1083				p += len_tmp;
1084			} else {
1085				require_data = false;
1086				if (!encode)
1087					encode = audit_string_contains_control(
1088								buf, len_tmp);
1089				/* try to use a trusted value for len_full */
1090				if (len_full < len_max)
1091					len_full = (encode ?
1092						    len_tmp * 2 : len_tmp);
1093				p += len_tmp + 1;
1094			}
1095			len_buf += len_tmp;
1096			buf_head[len_buf] = '\0';
1097
1098			/* length of the buffer in the audit record? */
1099			len_abuf = (encode ? len_buf * 2 : len_buf + 2);
1100		}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1101
1102		/* write as much as we can to the audit log */
1103		if (len_buf > 0) {
1104			/* NOTE: some magic numbers here - basically if we
1105			 *       can't fit a reasonable amount of data into the
1106			 *       existing audit buffer, flush it and start with
1107			 *       a new buffer */
1108			if ((sizeof(abuf) + 8) > len_rem) {
1109				len_rem = len_max;
1110				audit_log_end(*ab);
1111				*ab = audit_log_start(context,
1112						      GFP_KERNEL, AUDIT_EXECVE);
1113				if (!*ab)
1114					goto out;
1115			}
1116
1117			/* create the non-arg portion of the arg record */
1118			len_tmp = 0;
1119			if (require_data || (iter > 0) ||
1120			    ((len_abuf + sizeof(abuf)) > len_rem)) {
1121				if (iter == 0) {
1122					len_tmp += snprintf(&abuf[len_tmp],
1123							sizeof(abuf) - len_tmp,
1124							" a%d_len=%lu",
1125							arg, len_full);
1126				}
1127				len_tmp += snprintf(&abuf[len_tmp],
1128						    sizeof(abuf) - len_tmp,
1129						    " a%d[%d]=", arg, iter++);
1130			} else
1131				len_tmp += snprintf(&abuf[len_tmp],
1132						    sizeof(abuf) - len_tmp,
1133						    " a%d=", arg);
1134			WARN_ON(len_tmp >= sizeof(abuf));
1135			abuf[sizeof(abuf) - 1] = '\0';
1136
1137			/* log the arg in the audit record */
1138			audit_log_format(*ab, "%s", abuf);
1139			len_rem -= len_tmp;
1140			len_tmp = len_buf;
1141			if (encode) {
1142				if (len_abuf > len_rem)
1143					len_tmp = len_rem / 2; /* encoding */
1144				audit_log_n_hex(*ab, buf, len_tmp);
1145				len_rem -= len_tmp * 2;
1146				len_abuf -= len_tmp * 2;
1147			} else {
1148				if (len_abuf > len_rem)
1149					len_tmp = len_rem - 2; /* quotes */
1150				audit_log_n_string(*ab, buf, len_tmp);
1151				len_rem -= len_tmp + 2;
1152				/* don't subtract the "2" because we still need
1153				 * to add quotes to the remaining string */
1154				len_abuf -= len_tmp;
1155			}
1156			len_buf -= len_tmp;
1157			buf += len_tmp;
1158		}
1159
1160		/* ready to move to the next argument? */
1161		if ((len_buf == 0) && !require_data) {
1162			arg++;
1163			iter = 0;
1164			len_full = 0;
1165			require_data = true;
1166			encode = false;
1167		}
1168	} while (arg < context->execve.argc);
1169
1170	/* NOTE: the caller handles the final audit_log_end() call */
1171
1172out:
1173	kfree(buf_head);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1174}
1175
1176static void show_special(struct audit_context *context, int *call_panic)
1177{
1178	struct audit_buffer *ab;
1179	int i;
1180
1181	ab = audit_log_start(context, GFP_KERNEL, context->type);
1182	if (!ab)
1183		return;
1184
1185	switch (context->type) {
1186	case AUDIT_SOCKETCALL: {
1187		int nargs = context->socketcall.nargs;
1188		audit_log_format(ab, "nargs=%d", nargs);
1189		for (i = 0; i < nargs; i++)
1190			audit_log_format(ab, " a%d=%lx", i,
1191				context->socketcall.args[i]);
1192		break; }
1193	case AUDIT_IPC: {
1194		u32 osid = context->ipc.osid;
1195
1196		audit_log_format(ab, "ouid=%u ogid=%u mode=%#ho",
1197				 from_kuid(&init_user_ns, context->ipc.uid),
1198				 from_kgid(&init_user_ns, context->ipc.gid),
1199				 context->ipc.mode);
1200		if (osid) {
1201			char *ctx = NULL;
1202			u32 len;
1203			if (security_secid_to_secctx(osid, &ctx, &len)) {
1204				audit_log_format(ab, " osid=%u", osid);
1205				*call_panic = 1;
1206			} else {
1207				audit_log_format(ab, " obj=%s", ctx);
1208				security_release_secctx(ctx, len);
1209			}
1210		}
1211		if (context->ipc.has_perm) {
1212			audit_log_end(ab);
1213			ab = audit_log_start(context, GFP_KERNEL,
1214					     AUDIT_IPC_SET_PERM);
1215			if (unlikely(!ab))
1216				return;
1217			audit_log_format(ab,
1218				"qbytes=%lx ouid=%u ogid=%u mode=%#ho",
1219				context->ipc.qbytes,
1220				context->ipc.perm_uid,
1221				context->ipc.perm_gid,
1222				context->ipc.perm_mode);
1223		}
1224		break; }
1225	case AUDIT_MQ_OPEN:
1226		audit_log_format(ab,
1227			"oflag=0x%x mode=%#ho mq_flags=0x%lx mq_maxmsg=%ld "
1228			"mq_msgsize=%ld mq_curmsgs=%ld",
1229			context->mq_open.oflag, context->mq_open.mode,
1230			context->mq_open.attr.mq_flags,
1231			context->mq_open.attr.mq_maxmsg,
1232			context->mq_open.attr.mq_msgsize,
1233			context->mq_open.attr.mq_curmsgs);
1234		break;
1235	case AUDIT_MQ_SENDRECV:
1236		audit_log_format(ab,
1237			"mqdes=%d msg_len=%zd msg_prio=%u "
1238			"abs_timeout_sec=%lld abs_timeout_nsec=%ld",
1239			context->mq_sendrecv.mqdes,
1240			context->mq_sendrecv.msg_len,
1241			context->mq_sendrecv.msg_prio,
1242			(long long) context->mq_sendrecv.abs_timeout.tv_sec,
1243			context->mq_sendrecv.abs_timeout.tv_nsec);
1244		break;
1245	case AUDIT_MQ_NOTIFY:
1246		audit_log_format(ab, "mqdes=%d sigev_signo=%d",
1247				context->mq_notify.mqdes,
1248				context->mq_notify.sigev_signo);
1249		break;
1250	case AUDIT_MQ_GETSETATTR: {
1251		struct mq_attr *attr = &context->mq_getsetattr.mqstat;
1252		audit_log_format(ab,
1253			"mqdes=%d mq_flags=0x%lx mq_maxmsg=%ld mq_msgsize=%ld "
1254			"mq_curmsgs=%ld ",
1255			context->mq_getsetattr.mqdes,
1256			attr->mq_flags, attr->mq_maxmsg,
1257			attr->mq_msgsize, attr->mq_curmsgs);
1258		break; }
1259	case AUDIT_CAPSET:
1260		audit_log_format(ab, "pid=%d", context->capset.pid);
1261		audit_log_cap(ab, "cap_pi", &context->capset.cap.inheritable);
1262		audit_log_cap(ab, "cap_pp", &context->capset.cap.permitted);
1263		audit_log_cap(ab, "cap_pe", &context->capset.cap.effective);
1264		audit_log_cap(ab, "cap_pa", &context->capset.cap.ambient);
1265		break;
1266	case AUDIT_MMAP:
1267		audit_log_format(ab, "fd=%d flags=0x%x", context->mmap.fd,
1268				 context->mmap.flags);
1269		break;
1270	case AUDIT_EXECVE:
1271		audit_log_execve_info(context, &ab);
1272		break;
1273	case AUDIT_KERN_MODULE:
1274		audit_log_format(ab, "name=");
1275		audit_log_untrustedstring(ab, context->module.name);
1276		kfree(context->module.name);
1277		break;
1278	}
1279	audit_log_end(ab);
1280}
1281
1282static inline int audit_proctitle_rtrim(char *proctitle, int len)
1283{
1284	char *end = proctitle + len - 1;
1285	while (end > proctitle && !isprint(*end))
1286		end--;
1287
1288	/* catch the case where proctitle is only 1 non-print character */
1289	len = end - proctitle + 1;
1290	len -= isprint(proctitle[len-1]) == 0;
1291	return len;
1292}
1293
1294static void audit_log_proctitle(struct task_struct *tsk,
1295			 struct audit_context *context)
1296{
1297	int res;
1298	char *buf;
1299	char *msg = "(null)";
1300	int len = strlen(msg);
1301	struct audit_buffer *ab;
1302
1303	ab = audit_log_start(context, GFP_KERNEL, AUDIT_PROCTITLE);
1304	if (!ab)
1305		return;	/* audit_panic or being filtered */
1306
1307	audit_log_format(ab, "proctitle=");
1308
1309	/* Not  cached */
1310	if (!context->proctitle.value) {
1311		buf = kmalloc(MAX_PROCTITLE_AUDIT_LEN, GFP_KERNEL);
1312		if (!buf)
1313			goto out;
1314		/* Historically called this from procfs naming */
1315		res = get_cmdline(tsk, buf, MAX_PROCTITLE_AUDIT_LEN);
1316		if (res == 0) {
1317			kfree(buf);
1318			goto out;
1319		}
1320		res = audit_proctitle_rtrim(buf, res);
1321		if (res == 0) {
1322			kfree(buf);
1323			goto out;
1324		}
1325		context->proctitle.value = buf;
1326		context->proctitle.len = res;
1327	}
1328	msg = context->proctitle.value;
1329	len = context->proctitle.len;
1330out:
1331	audit_log_n_untrustedstring(ab, msg, len);
1332	audit_log_end(ab);
1333}
1334
1335static void audit_log_exit(struct audit_context *context, struct task_struct *tsk)
1336{
1337	int i, call_panic = 0;
1338	struct audit_buffer *ab;
1339	struct audit_aux_data *aux;
1340	struct audit_names *n;
1341
1342	/* tsk == current */
1343	context->personality = tsk->personality;
1344
1345	ab = audit_log_start(context, GFP_KERNEL, AUDIT_SYSCALL);
1346	if (!ab)
1347		return;		/* audit_panic has been called */
1348	audit_log_format(ab, "arch=%x syscall=%d",
1349			 context->arch, context->major);
1350	if (context->personality != PER_LINUX)
1351		audit_log_format(ab, " per=%lx", context->personality);
1352	if (context->return_valid)
1353		audit_log_format(ab, " success=%s exit=%ld",
1354				 (context->return_valid==AUDITSC_SUCCESS)?"yes":"no",
1355				 context->return_code);
1356
1357	audit_log_format(ab,
1358			 " a0=%lx a1=%lx a2=%lx a3=%lx items=%d",
1359			 context->argv[0],
1360			 context->argv[1],
1361			 context->argv[2],
1362			 context->argv[3],
1363			 context->name_count);
1364
1365	audit_log_task_info(ab, tsk);
1366	audit_log_key(ab, context->filterkey);
1367	audit_log_end(ab);
1368
1369	for (aux = context->aux; aux; aux = aux->next) {
1370
1371		ab = audit_log_start(context, GFP_KERNEL, aux->type);
1372		if (!ab)
1373			continue; /* audit_panic has been called */
1374
1375		switch (aux->type) {
1376
1377		case AUDIT_BPRM_FCAPS: {
1378			struct audit_aux_data_bprm_fcaps *axs = (void *)aux;
1379			audit_log_format(ab, "fver=%x", axs->fcap_ver);
1380			audit_log_cap(ab, "fp", &axs->fcap.permitted);
1381			audit_log_cap(ab, "fi", &axs->fcap.inheritable);
1382			audit_log_format(ab, " fe=%d", axs->fcap.fE);
1383			audit_log_cap(ab, "old_pp", &axs->old_pcap.permitted);
1384			audit_log_cap(ab, "old_pi", &axs->old_pcap.inheritable);
1385			audit_log_cap(ab, "old_pe", &axs->old_pcap.effective);
1386			audit_log_cap(ab, "old_pa", &axs->old_pcap.ambient);
1387			audit_log_cap(ab, "pp", &axs->new_pcap.permitted);
1388			audit_log_cap(ab, "pi", &axs->new_pcap.inheritable);
1389			audit_log_cap(ab, "pe", &axs->new_pcap.effective);
1390			audit_log_cap(ab, "pa", &axs->new_pcap.ambient);
1391			break; }
1392
1393		}
1394		audit_log_end(ab);
1395	}
1396
1397	if (context->type)
1398		show_special(context, &call_panic);
1399
1400	if (context->fds[0] >= 0) {
1401		ab = audit_log_start(context, GFP_KERNEL, AUDIT_FD_PAIR);
1402		if (ab) {
1403			audit_log_format(ab, "fd0=%d fd1=%d",
1404					context->fds[0], context->fds[1]);
1405			audit_log_end(ab);
1406		}
1407	}
1408
1409	if (context->sockaddr_len) {
1410		ab = audit_log_start(context, GFP_KERNEL, AUDIT_SOCKADDR);
1411		if (ab) {
1412			audit_log_format(ab, "saddr=");
1413			audit_log_n_hex(ab, (void *)context->sockaddr,
1414					context->sockaddr_len);
1415			audit_log_end(ab);
1416		}
1417	}
1418
1419	for (aux = context->aux_pids; aux; aux = aux->next) {
1420		struct audit_aux_data_pids *axs = (void *)aux;
1421
1422		for (i = 0; i < axs->pid_count; i++)
1423			if (audit_log_pid_context(context, axs->target_pid[i],
1424						  axs->target_auid[i],
1425						  axs->target_uid[i],
1426						  axs->target_sessionid[i],
1427						  axs->target_sid[i],
1428						  axs->target_comm[i]))
1429				call_panic = 1;
1430	}
1431
1432	if (context->target_pid &&
1433	    audit_log_pid_context(context, context->target_pid,
1434				  context->target_auid, context->target_uid,
1435				  context->target_sessionid,
1436				  context->target_sid, context->target_comm))
1437			call_panic = 1;
1438
1439	if (context->pwd.dentry && context->pwd.mnt) {
1440		ab = audit_log_start(context, GFP_KERNEL, AUDIT_CWD);
1441		if (ab) {
1442			audit_log_d_path(ab, "cwd=", &context->pwd);
1443			audit_log_end(ab);
1444		}
1445	}
1446
1447	i = 0;
1448	list_for_each_entry(n, &context->names_list, list) {
1449		if (n->hidden)
1450			continue;
1451		audit_log_name(context, n, NULL, i++, &call_panic);
1452	}
1453
1454	audit_log_proctitle(tsk, context);
1455
1456	/* Send end of event record to help user space know we are finished */
1457	ab = audit_log_start(context, GFP_KERNEL, AUDIT_EOE);
1458	if (ab)
1459		audit_log_end(ab);
1460	if (call_panic)
1461		audit_panic("error converting sid to string");
1462}
1463
1464/**
1465 * __audit_free - free a per-task audit context
1466 * @tsk: task whose audit context block to free
1467 *
1468 * Called from copy_process and do_exit
1469 */
1470void __audit_free(struct task_struct *tsk)
1471{
1472	struct audit_context *context;
1473
1474	context = audit_take_context(tsk, 0, 0);
1475	if (!context)
1476		return;
1477
1478	/* Check for system calls that do not go through the exit
1479	 * function (e.g., exit_group), then free context block.
1480	 * We use GFP_ATOMIC here because we might be doing this
1481	 * in the context of the idle thread */
1482	/* that can happen only if we are called from do_exit() */
1483	if (context->in_syscall && context->current_state == AUDIT_RECORD_CONTEXT)
1484		audit_log_exit(context, tsk);
1485	if (!list_empty(&context->killed_trees))
1486		audit_kill_trees(&context->killed_trees);
1487
1488	audit_free_context(context);
1489}
1490
1491/**
1492 * __audit_syscall_entry - fill in an audit record at syscall entry
1493 * @major: major syscall type (function)
1494 * @a1: additional syscall register 1
1495 * @a2: additional syscall register 2
1496 * @a3: additional syscall register 3
1497 * @a4: additional syscall register 4
1498 *
1499 * Fill in audit context at syscall entry.  This only happens if the
1500 * audit context was created when the task was created and the state or
1501 * filters demand the audit context be built.  If the state from the
1502 * per-task filter or from the per-syscall filter is AUDIT_RECORD_CONTEXT,
1503 * then the record will be written at syscall exit time (otherwise, it
1504 * will only be written if another part of the kernel requests that it
1505 * be written).
1506 */
1507void __audit_syscall_entry(int major, unsigned long a1, unsigned long a2,
1508			   unsigned long a3, unsigned long a4)
1509{
1510	struct task_struct *tsk = current;
1511	struct audit_context *context = tsk->audit_context;
1512	enum audit_state     state;
1513
1514	if (!audit_enabled || !context)
1515		return;
1516
1517	BUG_ON(context->in_syscall || context->name_count);
1518
1519	state = context->state;
1520	if (state == AUDIT_DISABLED)
1521		return;
1522
1523	context->dummy = !audit_n_rules;
1524	if (!context->dummy && state == AUDIT_BUILD_CONTEXT) {
1525		context->prio = 0;
1526		if (auditd_test_task(tsk))
1527			return;
1528	}
1529
1530	context->arch	    = syscall_get_arch();
1531	context->major      = major;
1532	context->argv[0]    = a1;
1533	context->argv[1]    = a2;
1534	context->argv[2]    = a3;
1535	context->argv[3]    = a4;
 
 
 
 
 
 
 
 
 
 
1536	context->serial     = 0;
1537	context->ctime = current_kernel_time64();
1538	context->in_syscall = 1;
1539	context->current_state  = state;
1540	context->ppid       = 0;
1541}
1542
1543/**
1544 * __audit_syscall_exit - deallocate audit context after a system call
1545 * @success: success value of the syscall
1546 * @return_code: return value of the syscall
1547 *
1548 * Tear down after system call.  If the audit context has been marked as
1549 * auditable (either because of the AUDIT_RECORD_CONTEXT state from
1550 * filtering, or because some other part of the kernel wrote an audit
1551 * message), then write out the syscall information.  In call cases,
1552 * free the names stored from getname().
1553 */
1554void __audit_syscall_exit(int success, long return_code)
1555{
1556	struct task_struct *tsk = current;
1557	struct audit_context *context;
1558
1559	if (success)
1560		success = AUDITSC_SUCCESS;
1561	else
1562		success = AUDITSC_FAILURE;
1563
1564	context = audit_take_context(tsk, success, return_code);
1565	if (!context)
1566		return;
1567
1568	if (context->in_syscall && context->current_state == AUDIT_RECORD_CONTEXT)
1569		audit_log_exit(context, tsk);
1570
1571	context->in_syscall = 0;
1572	context->prio = context->state == AUDIT_RECORD_CONTEXT ? ~0ULL : 0;
1573
1574	if (!list_empty(&context->killed_trees))
1575		audit_kill_trees(&context->killed_trees);
1576
1577	audit_free_names(context);
1578	unroll_tree_refs(context, NULL, 0);
1579	audit_free_aux(context);
1580	context->aux = NULL;
1581	context->aux_pids = NULL;
1582	context->target_pid = 0;
1583	context->target_sid = 0;
1584	context->sockaddr_len = 0;
1585	context->type = 0;
1586	context->fds[0] = -1;
1587	if (context->state != AUDIT_RECORD_CONTEXT) {
1588		kfree(context->filterkey);
1589		context->filterkey = NULL;
1590	}
1591	tsk->audit_context = context;
1592}
1593
1594static inline void handle_one(const struct inode *inode)
1595{
1596#ifdef CONFIG_AUDIT_TREE
1597	struct audit_context *context;
1598	struct audit_tree_refs *p;
1599	struct audit_chunk *chunk;
1600	int count;
1601	if (likely(!inode->i_fsnotify_marks))
1602		return;
1603	context = current->audit_context;
1604	p = context->trees;
1605	count = context->tree_count;
1606	rcu_read_lock();
1607	chunk = audit_tree_lookup(inode);
1608	rcu_read_unlock();
1609	if (!chunk)
1610		return;
1611	if (likely(put_tree_ref(context, chunk)))
1612		return;
1613	if (unlikely(!grow_tree_refs(context))) {
1614		pr_warn("out of memory, audit has lost a tree reference\n");
1615		audit_set_auditable(context);
1616		audit_put_chunk(chunk);
1617		unroll_tree_refs(context, p, count);
1618		return;
1619	}
1620	put_tree_ref(context, chunk);
1621#endif
1622}
1623
1624static void handle_path(const struct dentry *dentry)
1625{
1626#ifdef CONFIG_AUDIT_TREE
1627	struct audit_context *context;
1628	struct audit_tree_refs *p;
1629	const struct dentry *d, *parent;
1630	struct audit_chunk *drop;
1631	unsigned long seq;
1632	int count;
1633
1634	context = current->audit_context;
1635	p = context->trees;
1636	count = context->tree_count;
1637retry:
1638	drop = NULL;
1639	d = dentry;
1640	rcu_read_lock();
1641	seq = read_seqbegin(&rename_lock);
1642	for(;;) {
1643		struct inode *inode = d_backing_inode(d);
1644		if (inode && unlikely(inode->i_fsnotify_marks)) {
1645			struct audit_chunk *chunk;
1646			chunk = audit_tree_lookup(inode);
1647			if (chunk) {
1648				if (unlikely(!put_tree_ref(context, chunk))) {
1649					drop = chunk;
1650					break;
1651				}
1652			}
1653		}
1654		parent = d->d_parent;
1655		if (parent == d)
1656			break;
1657		d = parent;
1658	}
1659	if (unlikely(read_seqretry(&rename_lock, seq) || drop)) {  /* in this order */
1660		rcu_read_unlock();
1661		if (!drop) {
1662			/* just a race with rename */
1663			unroll_tree_refs(context, p, count);
1664			goto retry;
1665		}
1666		audit_put_chunk(drop);
1667		if (grow_tree_refs(context)) {
1668			/* OK, got more space */
1669			unroll_tree_refs(context, p, count);
1670			goto retry;
1671		}
1672		/* too bad */
1673		pr_warn("out of memory, audit has lost a tree reference\n");
1674		unroll_tree_refs(context, p, count);
1675		audit_set_auditable(context);
1676		return;
1677	}
1678	rcu_read_unlock();
1679#endif
1680}
1681
1682static struct audit_names *audit_alloc_name(struct audit_context *context,
1683						unsigned char type)
1684{
1685	struct audit_names *aname;
1686
1687	if (context->name_count < AUDIT_NAMES) {
1688		aname = &context->preallocated_names[context->name_count];
1689		memset(aname, 0, sizeof(*aname));
1690	} else {
1691		aname = kzalloc(sizeof(*aname), GFP_NOFS);
1692		if (!aname)
1693			return NULL;
1694		aname->should_free = true;
1695	}
1696
1697	aname->ino = AUDIT_INO_UNSET;
1698	aname->type = type;
1699	list_add_tail(&aname->list, &context->names_list);
1700
1701	context->name_count++;
1702	return aname;
1703}
1704
1705/**
1706 * __audit_reusename - fill out filename with info from existing entry
1707 * @uptr: userland ptr to pathname
1708 *
1709 * Search the audit_names list for the current audit context. If there is an
1710 * existing entry with a matching "uptr" then return the filename
1711 * associated with that audit_name. If not, return NULL.
1712 */
1713struct filename *
1714__audit_reusename(const __user char *uptr)
1715{
1716	struct audit_context *context = current->audit_context;
1717	struct audit_names *n;
1718
1719	list_for_each_entry(n, &context->names_list, list) {
1720		if (!n->name)
1721			continue;
1722		if (n->name->uptr == uptr) {
1723			n->name->refcnt++;
1724			return n->name;
1725		}
1726	}
1727	return NULL;
1728}
1729
1730/**
1731 * __audit_getname - add a name to the list
1732 * @name: name to add
1733 *
1734 * Add a name to the list of audit names for this context.
1735 * Called from fs/namei.c:getname().
1736 */
1737void __audit_getname(struct filename *name)
1738{
1739	struct audit_context *context = current->audit_context;
1740	struct audit_names *n;
1741
1742	if (!context->in_syscall)
1743		return;
1744
1745	n = audit_alloc_name(context, AUDIT_TYPE_UNKNOWN);
1746	if (!n)
1747		return;
1748
1749	n->name = name;
1750	n->name_len = AUDIT_NAME_FULL;
1751	name->aname = n;
1752	name->refcnt++;
1753
1754	if (!context->pwd.dentry)
1755		get_fs_pwd(current->fs, &context->pwd);
1756}
1757
1758/**
1759 * __audit_inode - store the inode and device from a lookup
1760 * @name: name being audited
1761 * @dentry: dentry being audited
1762 * @flags: attributes for this particular entry
1763 */
1764void __audit_inode(struct filename *name, const struct dentry *dentry,
1765		   unsigned int flags)
1766{
1767	struct audit_context *context = current->audit_context;
1768	struct inode *inode = d_backing_inode(dentry);
1769	struct audit_names *n;
1770	bool parent = flags & AUDIT_INODE_PARENT;
1771
1772	if (!context->in_syscall)
1773		return;
1774
1775	if (!name)
1776		goto out_alloc;
1777
1778	/*
1779	 * If we have a pointer to an audit_names entry already, then we can
1780	 * just use it directly if the type is correct.
1781	 */
1782	n = name->aname;
1783	if (n) {
1784		if (parent) {
1785			if (n->type == AUDIT_TYPE_PARENT ||
1786			    n->type == AUDIT_TYPE_UNKNOWN)
1787				goto out;
1788		} else {
1789			if (n->type != AUDIT_TYPE_PARENT)
1790				goto out;
1791		}
1792	}
1793
1794	list_for_each_entry_reverse(n, &context->names_list, list) {
1795		if (n->ino) {
1796			/* valid inode number, use that for the comparison */
1797			if (n->ino != inode->i_ino ||
1798			    n->dev != inode->i_sb->s_dev)
1799				continue;
1800		} else if (n->name) {
1801			/* inode number has not been set, check the name */
1802			if (strcmp(n->name->name, name->name))
1803				continue;
1804		} else
1805			/* no inode and no name (?!) ... this is odd ... */
1806			continue;
1807
1808		/* match the correct record type */
1809		if (parent) {
1810			if (n->type == AUDIT_TYPE_PARENT ||
1811			    n->type == AUDIT_TYPE_UNKNOWN)
1812				goto out;
1813		} else {
1814			if (n->type != AUDIT_TYPE_PARENT)
1815				goto out;
1816		}
1817	}
1818
1819out_alloc:
1820	/* unable to find an entry with both a matching name and type */
1821	n = audit_alloc_name(context, AUDIT_TYPE_UNKNOWN);
1822	if (!n)
1823		return;
1824	if (name) {
1825		n->name = name;
1826		name->refcnt++;
1827	}
1828
1829out:
1830	if (parent) {
1831		n->name_len = n->name ? parent_len(n->name->name) : AUDIT_NAME_FULL;
1832		n->type = AUDIT_TYPE_PARENT;
1833		if (flags & AUDIT_INODE_HIDDEN)
1834			n->hidden = true;
1835	} else {
1836		n->name_len = AUDIT_NAME_FULL;
1837		n->type = AUDIT_TYPE_NORMAL;
1838	}
1839	handle_path(dentry);
1840	audit_copy_inode(n, dentry, inode);
1841}
1842
1843void __audit_file(const struct file *file)
1844{
1845	__audit_inode(NULL, file->f_path.dentry, 0);
1846}
1847
1848/**
1849 * __audit_inode_child - collect inode info for created/removed objects
1850 * @parent: inode of dentry parent
1851 * @dentry: dentry being audited
1852 * @type:   AUDIT_TYPE_* value that we're looking for
1853 *
1854 * For syscalls that create or remove filesystem objects, audit_inode
1855 * can only collect information for the filesystem object's parent.
1856 * This call updates the audit context with the child's information.
1857 * Syscalls that create a new filesystem object must be hooked after
1858 * the object is created.  Syscalls that remove a filesystem object
1859 * must be hooked prior, in order to capture the target inode during
1860 * unsuccessful attempts.
1861 */
1862void __audit_inode_child(struct inode *parent,
1863			 const struct dentry *dentry,
1864			 const unsigned char type)
1865{
1866	struct audit_context *context = current->audit_context;
1867	struct inode *inode = d_backing_inode(dentry);
1868	const char *dname = dentry->d_name.name;
1869	struct audit_names *n, *found_parent = NULL, *found_child = NULL;
1870	struct audit_entry *e;
1871	struct list_head *list = &audit_filter_list[AUDIT_FILTER_FS];
1872	int i;
1873
1874	if (!context->in_syscall)
1875		return;
1876
1877	rcu_read_lock();
1878	if (!list_empty(list)) {
1879		list_for_each_entry_rcu(e, list, list) {
1880			for (i = 0; i < e->rule.field_count; i++) {
1881				struct audit_field *f = &e->rule.fields[i];
1882
1883				if (f->type == AUDIT_FSTYPE) {
1884					if (audit_comparator(parent->i_sb->s_magic,
1885					    f->op, f->val)) {
1886						if (e->rule.action == AUDIT_NEVER) {
1887							rcu_read_unlock();
1888							return;
1889						}
1890					}
1891				}
1892			}
1893		}
1894	}
1895	rcu_read_unlock();
1896
1897	if (inode)
1898		handle_one(inode);
1899
1900	/* look for a parent entry first */
1901	list_for_each_entry(n, &context->names_list, list) {
1902		if (!n->name ||
1903		    (n->type != AUDIT_TYPE_PARENT &&
1904		     n->type != AUDIT_TYPE_UNKNOWN))
1905			continue;
1906
1907		if (n->ino == parent->i_ino && n->dev == parent->i_sb->s_dev &&
1908		    !audit_compare_dname_path(dname,
1909					      n->name->name, n->name_len)) {
1910			if (n->type == AUDIT_TYPE_UNKNOWN)
1911				n->type = AUDIT_TYPE_PARENT;
1912			found_parent = n;
1913			break;
1914		}
1915	}
1916
1917	/* is there a matching child entry? */
1918	list_for_each_entry(n, &context->names_list, list) {
1919		/* can only match entries that have a name */
1920		if (!n->name ||
1921		    (n->type != type && n->type != AUDIT_TYPE_UNKNOWN))
1922			continue;
1923
1924		if (!strcmp(dname, n->name->name) ||
1925		    !audit_compare_dname_path(dname, n->name->name,
1926						found_parent ?
1927						found_parent->name_len :
1928						AUDIT_NAME_FULL)) {
1929			if (n->type == AUDIT_TYPE_UNKNOWN)
1930				n->type = type;
1931			found_child = n;
1932			break;
1933		}
1934	}
1935
1936	if (!found_parent) {
1937		/* create a new, "anonymous" parent record */
1938		n = audit_alloc_name(context, AUDIT_TYPE_PARENT);
1939		if (!n)
1940			return;
1941		audit_copy_inode(n, NULL, parent);
1942	}
1943
1944	if (!found_child) {
1945		found_child = audit_alloc_name(context, type);
1946		if (!found_child)
1947			return;
1948
1949		/* Re-use the name belonging to the slot for a matching parent
1950		 * directory. All names for this context are relinquished in
1951		 * audit_free_names() */
1952		if (found_parent) {
1953			found_child->name = found_parent->name;
1954			found_child->name_len = AUDIT_NAME_FULL;
1955			found_child->name->refcnt++;
1956		}
1957	}
1958
1959	if (inode)
1960		audit_copy_inode(found_child, dentry, inode);
1961	else
1962		found_child->ino = AUDIT_INO_UNSET;
1963}
1964EXPORT_SYMBOL_GPL(__audit_inode_child);
1965
1966/**
1967 * auditsc_get_stamp - get local copies of audit_context values
1968 * @ctx: audit_context for the task
1969 * @t: timespec64 to store time recorded in the audit_context
1970 * @serial: serial value that is recorded in the audit_context
1971 *
1972 * Also sets the context as auditable.
1973 */
1974int auditsc_get_stamp(struct audit_context *ctx,
1975		       struct timespec64 *t, unsigned int *serial)
1976{
1977	if (!ctx->in_syscall)
1978		return 0;
1979	if (!ctx->serial)
1980		ctx->serial = audit_serial();
1981	t->tv_sec  = ctx->ctime.tv_sec;
1982	t->tv_nsec = ctx->ctime.tv_nsec;
1983	*serial    = ctx->serial;
1984	if (!ctx->prio) {
1985		ctx->prio = 1;
1986		ctx->current_state = AUDIT_RECORD_CONTEXT;
1987	}
1988	return 1;
1989}
1990
1991/* global counter which is incremented every time something logs in */
1992static atomic_t session_id = ATOMIC_INIT(0);
1993
1994static int audit_set_loginuid_perm(kuid_t loginuid)
1995{
1996	/* if we are unset, we don't need privs */
1997	if (!audit_loginuid_set(current))
1998		return 0;
1999	/* if AUDIT_FEATURE_LOGINUID_IMMUTABLE means never ever allow a change*/
2000	if (is_audit_feature_set(AUDIT_FEATURE_LOGINUID_IMMUTABLE))
2001		return -EPERM;
2002	/* it is set, you need permission */
2003	if (!capable(CAP_AUDIT_CONTROL))
2004		return -EPERM;
2005	/* reject if this is not an unset and we don't allow that */
2006	if (is_audit_feature_set(AUDIT_FEATURE_ONLY_UNSET_LOGINUID) && uid_valid(loginuid))
2007		return -EPERM;
2008	return 0;
2009}
2010
2011static void audit_log_set_loginuid(kuid_t koldloginuid, kuid_t kloginuid,
2012				   unsigned int oldsessionid, unsigned int sessionid,
2013				   int rc)
2014{
2015	struct audit_buffer *ab;
2016	uid_t uid, oldloginuid, loginuid;
2017	struct tty_struct *tty;
2018
2019	if (!audit_enabled)
2020		return;
2021
2022	ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_LOGIN);
2023	if (!ab)
2024		return;
2025
2026	uid = from_kuid(&init_user_ns, task_uid(current));
2027	oldloginuid = from_kuid(&init_user_ns, koldloginuid);
2028	loginuid = from_kuid(&init_user_ns, kloginuid),
2029	tty = audit_get_tty(current);
2030
2031	audit_log_format(ab, "pid=%d uid=%u", task_tgid_nr(current), uid);
 
 
 
2032	audit_log_task_context(ab);
2033	audit_log_format(ab, " old-auid=%u auid=%u tty=%s old-ses=%u ses=%u res=%d",
2034			 oldloginuid, loginuid, tty ? tty_name(tty) : "(none)",
2035			 oldsessionid, sessionid, !rc);
2036	audit_put_tty(tty);
2037	audit_log_end(ab);
2038}
2039
2040/**
2041 * audit_set_loginuid - set current task's audit_context loginuid
2042 * @loginuid: loginuid value
2043 *
2044 * Returns 0.
2045 *
2046 * Called (set) from fs/proc/base.c::proc_loginuid_write().
2047 */
2048int audit_set_loginuid(kuid_t loginuid)
2049{
2050	struct task_struct *task = current;
2051	unsigned int oldsessionid, sessionid = (unsigned int)-1;
2052	kuid_t oldloginuid;
2053	int rc;
2054
2055	oldloginuid = audit_get_loginuid(current);
2056	oldsessionid = audit_get_sessionid(current);
2057
2058	rc = audit_set_loginuid_perm(loginuid);
2059	if (rc)
2060		goto out;
2061
2062	/* are we setting or clearing? */
2063	if (uid_valid(loginuid)) {
2064		sessionid = (unsigned int)atomic_inc_return(&session_id);
2065		if (unlikely(sessionid == (unsigned int)-1))
2066			sessionid = (unsigned int)atomic_inc_return(&session_id);
2067	}
2068
2069	task->sessionid = sessionid;
2070	task->loginuid = loginuid;
2071out:
2072	audit_log_set_loginuid(oldloginuid, loginuid, oldsessionid, sessionid, rc);
2073	return rc;
2074}
2075
2076/**
2077 * __audit_mq_open - record audit data for a POSIX MQ open
2078 * @oflag: open flag
2079 * @mode: mode bits
2080 * @attr: queue attributes
2081 *
2082 */
2083void __audit_mq_open(int oflag, umode_t mode, struct mq_attr *attr)
2084{
2085	struct audit_context *context = current->audit_context;
2086
2087	if (attr)
2088		memcpy(&context->mq_open.attr, attr, sizeof(struct mq_attr));
2089	else
2090		memset(&context->mq_open.attr, 0, sizeof(struct mq_attr));
2091
2092	context->mq_open.oflag = oflag;
2093	context->mq_open.mode = mode;
2094
2095	context->type = AUDIT_MQ_OPEN;
2096}
2097
2098/**
2099 * __audit_mq_sendrecv - record audit data for a POSIX MQ timed send/receive
2100 * @mqdes: MQ descriptor
2101 * @msg_len: Message length
2102 * @msg_prio: Message priority
2103 * @abs_timeout: Message timeout in absolute time
2104 *
2105 */
2106void __audit_mq_sendrecv(mqd_t mqdes, size_t msg_len, unsigned int msg_prio,
2107			const struct timespec64 *abs_timeout)
2108{
2109	struct audit_context *context = current->audit_context;
2110	struct timespec64 *p = &context->mq_sendrecv.abs_timeout;
2111
2112	if (abs_timeout)
2113		memcpy(p, abs_timeout, sizeof(*p));
2114	else
2115		memset(p, 0, sizeof(*p));
2116
2117	context->mq_sendrecv.mqdes = mqdes;
2118	context->mq_sendrecv.msg_len = msg_len;
2119	context->mq_sendrecv.msg_prio = msg_prio;
2120
2121	context->type = AUDIT_MQ_SENDRECV;
2122}
2123
2124/**
2125 * __audit_mq_notify - record audit data for a POSIX MQ notify
2126 * @mqdes: MQ descriptor
2127 * @notification: Notification event
2128 *
2129 */
2130
2131void __audit_mq_notify(mqd_t mqdes, const struct sigevent *notification)
2132{
2133	struct audit_context *context = current->audit_context;
2134
2135	if (notification)
2136		context->mq_notify.sigev_signo = notification->sigev_signo;
2137	else
2138		context->mq_notify.sigev_signo = 0;
2139
2140	context->mq_notify.mqdes = mqdes;
2141	context->type = AUDIT_MQ_NOTIFY;
2142}
2143
2144/**
2145 * __audit_mq_getsetattr - record audit data for a POSIX MQ get/set attribute
2146 * @mqdes: MQ descriptor
2147 * @mqstat: MQ flags
2148 *
2149 */
2150void __audit_mq_getsetattr(mqd_t mqdes, struct mq_attr *mqstat)
2151{
2152	struct audit_context *context = current->audit_context;
2153	context->mq_getsetattr.mqdes = mqdes;
2154	context->mq_getsetattr.mqstat = *mqstat;
2155	context->type = AUDIT_MQ_GETSETATTR;
2156}
2157
2158/**
2159 * __audit_ipc_obj - record audit data for ipc object
2160 * @ipcp: ipc permissions
2161 *
2162 */
2163void __audit_ipc_obj(struct kern_ipc_perm *ipcp)
2164{
2165	struct audit_context *context = current->audit_context;
2166	context->ipc.uid = ipcp->uid;
2167	context->ipc.gid = ipcp->gid;
2168	context->ipc.mode = ipcp->mode;
2169	context->ipc.has_perm = 0;
2170	security_ipc_getsecid(ipcp, &context->ipc.osid);
2171	context->type = AUDIT_IPC;
2172}
2173
2174/**
2175 * __audit_ipc_set_perm - record audit data for new ipc permissions
2176 * @qbytes: msgq bytes
2177 * @uid: msgq user id
2178 * @gid: msgq group id
2179 * @mode: msgq mode (permissions)
2180 *
2181 * Called only after audit_ipc_obj().
2182 */
2183void __audit_ipc_set_perm(unsigned long qbytes, uid_t uid, gid_t gid, umode_t mode)
2184{
2185	struct audit_context *context = current->audit_context;
2186
2187	context->ipc.qbytes = qbytes;
2188	context->ipc.perm_uid = uid;
2189	context->ipc.perm_gid = gid;
2190	context->ipc.perm_mode = mode;
2191	context->ipc.has_perm = 1;
2192}
2193
2194void __audit_bprm(struct linux_binprm *bprm)
2195{
2196	struct audit_context *context = current->audit_context;
2197
2198	context->type = AUDIT_EXECVE;
2199	context->execve.argc = bprm->argc;
2200}
2201
2202
2203/**
2204 * __audit_socketcall - record audit data for sys_socketcall
2205 * @nargs: number of args, which should not be more than AUDITSC_ARGS.
2206 * @args: args array
2207 *
2208 */
2209int __audit_socketcall(int nargs, unsigned long *args)
2210{
2211	struct audit_context *context = current->audit_context;
2212
2213	if (nargs <= 0 || nargs > AUDITSC_ARGS || !args)
2214		return -EINVAL;
2215	context->type = AUDIT_SOCKETCALL;
2216	context->socketcall.nargs = nargs;
2217	memcpy(context->socketcall.args, args, nargs * sizeof(unsigned long));
2218	return 0;
2219}
2220
2221/**
2222 * __audit_fd_pair - record audit data for pipe and socketpair
2223 * @fd1: the first file descriptor
2224 * @fd2: the second file descriptor
2225 *
2226 */
2227void __audit_fd_pair(int fd1, int fd2)
2228{
2229	struct audit_context *context = current->audit_context;
2230	context->fds[0] = fd1;
2231	context->fds[1] = fd2;
2232}
2233
2234/**
2235 * __audit_sockaddr - record audit data for sys_bind, sys_connect, sys_sendto
2236 * @len: data length in user space
2237 * @a: data address in kernel space
2238 *
2239 * Returns 0 for success or NULL context or < 0 on error.
2240 */
2241int __audit_sockaddr(int len, void *a)
2242{
2243	struct audit_context *context = current->audit_context;
2244
2245	if (!context->sockaddr) {
2246		void *p = kmalloc(sizeof(struct sockaddr_storage), GFP_KERNEL);
2247		if (!p)
2248			return -ENOMEM;
2249		context->sockaddr = p;
2250	}
2251
2252	context->sockaddr_len = len;
2253	memcpy(context->sockaddr, a, len);
2254	return 0;
2255}
2256
2257void __audit_ptrace(struct task_struct *t)
2258{
2259	struct audit_context *context = current->audit_context;
2260
2261	context->target_pid = task_tgid_nr(t);
2262	context->target_auid = audit_get_loginuid(t);
2263	context->target_uid = task_uid(t);
2264	context->target_sessionid = audit_get_sessionid(t);
2265	security_task_getsecid(t, &context->target_sid);
2266	memcpy(context->target_comm, t->comm, TASK_COMM_LEN);
2267}
2268
2269/**
2270 * audit_signal_info - record signal info for shutting down audit subsystem
2271 * @sig: signal value
2272 * @t: task being signaled
2273 *
2274 * If the audit subsystem is being terminated, record the task (pid)
2275 * and uid that is doing that.
2276 */
2277int audit_signal_info(int sig, struct task_struct *t)
2278{
2279	struct audit_aux_data_pids *axp;
2280	struct task_struct *tsk = current;
2281	struct audit_context *ctx = tsk->audit_context;
2282	kuid_t uid = current_uid(), t_uid = task_uid(t);
2283
2284	if (auditd_test_task(t) &&
2285	    (sig == SIGTERM || sig == SIGHUP ||
2286	     sig == SIGUSR1 || sig == SIGUSR2)) {
2287		audit_sig_pid = task_tgid_nr(tsk);
2288		if (uid_valid(tsk->loginuid))
2289			audit_sig_uid = tsk->loginuid;
2290		else
2291			audit_sig_uid = uid;
2292		security_task_getsecid(tsk, &audit_sig_sid);
 
 
2293	}
2294
2295	if (!audit_signals || audit_dummy_context())
2296		return 0;
2297
2298	/* optimize the common case by putting first signal recipient directly
2299	 * in audit_context */
2300	if (!ctx->target_pid) {
2301		ctx->target_pid = task_tgid_nr(t);
2302		ctx->target_auid = audit_get_loginuid(t);
2303		ctx->target_uid = t_uid;
2304		ctx->target_sessionid = audit_get_sessionid(t);
2305		security_task_getsecid(t, &ctx->target_sid);
2306		memcpy(ctx->target_comm, t->comm, TASK_COMM_LEN);
2307		return 0;
2308	}
2309
2310	axp = (void *)ctx->aux_pids;
2311	if (!axp || axp->pid_count == AUDIT_AUX_PIDS) {
2312		axp = kzalloc(sizeof(*axp), GFP_ATOMIC);
2313		if (!axp)
2314			return -ENOMEM;
2315
2316		axp->d.type = AUDIT_OBJ_PID;
2317		axp->d.next = ctx->aux_pids;
2318		ctx->aux_pids = (void *)axp;
2319	}
2320	BUG_ON(axp->pid_count >= AUDIT_AUX_PIDS);
2321
2322	axp->target_pid[axp->pid_count] = task_tgid_nr(t);
2323	axp->target_auid[axp->pid_count] = audit_get_loginuid(t);
2324	axp->target_uid[axp->pid_count] = t_uid;
2325	axp->target_sessionid[axp->pid_count] = audit_get_sessionid(t);
2326	security_task_getsecid(t, &axp->target_sid[axp->pid_count]);
2327	memcpy(axp->target_comm[axp->pid_count], t->comm, TASK_COMM_LEN);
2328	axp->pid_count++;
2329
2330	return 0;
2331}
2332
2333/**
2334 * __audit_log_bprm_fcaps - store information about a loading bprm and relevant fcaps
2335 * @bprm: pointer to the bprm being processed
2336 * @new: the proposed new credentials
2337 * @old: the old credentials
2338 *
2339 * Simply check if the proc already has the caps given by the file and if not
2340 * store the priv escalation info for later auditing at the end of the syscall
2341 *
2342 * -Eric
2343 */
2344int __audit_log_bprm_fcaps(struct linux_binprm *bprm,
2345			   const struct cred *new, const struct cred *old)
2346{
2347	struct audit_aux_data_bprm_fcaps *ax;
2348	struct audit_context *context = current->audit_context;
2349	struct cpu_vfs_cap_data vcaps;
2350
2351	ax = kmalloc(sizeof(*ax), GFP_KERNEL);
2352	if (!ax)
2353		return -ENOMEM;
2354
2355	ax->d.type = AUDIT_BPRM_FCAPS;
2356	ax->d.next = context->aux;
2357	context->aux = (void *)ax;
2358
2359	get_vfs_caps_from_disk(bprm->file->f_path.dentry, &vcaps);
2360
2361	ax->fcap.permitted = vcaps.permitted;
2362	ax->fcap.inheritable = vcaps.inheritable;
2363	ax->fcap.fE = !!(vcaps.magic_etc & VFS_CAP_FLAGS_EFFECTIVE);
2364	ax->fcap_ver = (vcaps.magic_etc & VFS_CAP_REVISION_MASK) >> VFS_CAP_REVISION_SHIFT;
2365
2366	ax->old_pcap.permitted   = old->cap_permitted;
2367	ax->old_pcap.inheritable = old->cap_inheritable;
2368	ax->old_pcap.effective   = old->cap_effective;
2369	ax->old_pcap.ambient     = old->cap_ambient;
2370
2371	ax->new_pcap.permitted   = new->cap_permitted;
2372	ax->new_pcap.inheritable = new->cap_inheritable;
2373	ax->new_pcap.effective   = new->cap_effective;
2374	ax->new_pcap.ambient     = new->cap_ambient;
2375	return 0;
2376}
2377
2378/**
2379 * __audit_log_capset - store information about the arguments to the capset syscall
2380 * @new: the new credentials
2381 * @old: the old (current) credentials
2382 *
2383 * Record the arguments userspace sent to sys_capset for later printing by the
2384 * audit system if applicable
2385 */
2386void __audit_log_capset(const struct cred *new, const struct cred *old)
2387{
2388	struct audit_context *context = current->audit_context;
2389	context->capset.pid = task_tgid_nr(current);
2390	context->capset.cap.effective   = new->cap_effective;
2391	context->capset.cap.inheritable = new->cap_effective;
2392	context->capset.cap.permitted   = new->cap_permitted;
2393	context->capset.cap.ambient     = new->cap_ambient;
2394	context->type = AUDIT_CAPSET;
2395}
2396
2397void __audit_mmap_fd(int fd, int flags)
2398{
2399	struct audit_context *context = current->audit_context;
2400	context->mmap.fd = fd;
2401	context->mmap.flags = flags;
2402	context->type = AUDIT_MMAP;
2403}
2404
2405void __audit_log_kern_module(char *name)
2406{
2407	struct audit_context *context = current->audit_context;
2408
2409	context->module.name = kmalloc(strlen(name) + 1, GFP_KERNEL);
2410	strcpy(context->module.name, name);
2411	context->type = AUDIT_KERN_MODULE;
2412}
2413
2414void __audit_fanotify(unsigned int response)
2415{
2416	audit_log(current->audit_context, GFP_KERNEL,
2417		AUDIT_FANOTIFY,	"resp=%u", response);
2418}
2419
2420static void audit_log_task(struct audit_buffer *ab)
2421{
2422	kuid_t auid, uid;
2423	kgid_t gid;
2424	unsigned int sessionid;
2425	char comm[sizeof(current->comm)];
2426
2427	auid = audit_get_loginuid(current);
2428	sessionid = audit_get_sessionid(current);
2429	current_uid_gid(&uid, &gid);
2430
2431	audit_log_format(ab, "auid=%u uid=%u gid=%u ses=%u",
2432			 from_kuid(&init_user_ns, auid),
2433			 from_kuid(&init_user_ns, uid),
2434			 from_kgid(&init_user_ns, gid),
2435			 sessionid);
2436	audit_log_task_context(ab);
2437	audit_log_format(ab, " pid=%d comm=", task_tgid_nr(current));
2438	audit_log_untrustedstring(ab, get_task_comm(comm, current));
2439	audit_log_d_path_exe(ab, current->mm);
2440}
2441
2442/**
2443 * audit_core_dumps - record information about processes that end abnormally
2444 * @signr: signal value
2445 *
2446 * If a process ends with a core dump, something fishy is going on and we
2447 * should record the event for investigation.
2448 */
2449void audit_core_dumps(long signr)
2450{
2451	struct audit_buffer *ab;
2452
2453	if (!audit_enabled)
2454		return;
2455
2456	if (signr == SIGQUIT)	/* don't care for those */
2457		return;
2458
2459	ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_ANOM_ABEND);
2460	if (unlikely(!ab))
2461		return;
2462	audit_log_task(ab);
2463	audit_log_format(ab, " sig=%ld res=1", signr);
2464	audit_log_end(ab);
2465}
2466
2467void __audit_seccomp(unsigned long syscall, long signr, int code)
2468{
2469	struct audit_buffer *ab;
2470
2471	ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_SECCOMP);
2472	if (unlikely(!ab))
2473		return;
2474	audit_log_task(ab);
2475	audit_log_format(ab, " sig=%ld arch=%x syscall=%ld compat=%d ip=0x%lx code=0x%x",
2476			 signr, syscall_get_arch(), syscall,
2477			 in_compat_syscall(), KSTK_EIP(current), code);
2478	audit_log_end(ab);
2479}
2480
2481struct list_head *audit_killed_trees(void)
2482{
2483	struct audit_context *ctx = current->audit_context;
2484	if (likely(!ctx || !ctx->in_syscall))
2485		return NULL;
2486	return &ctx->killed_trees;
2487}