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v4.17
 
   1/* auditfilter.c -- filtering of audit events
   2 *
   3 * Copyright 2003-2004 Red Hat, Inc.
   4 * Copyright 2005 Hewlett-Packard Development Company, L.P.
   5 * Copyright 2005 IBM Corporation
   6 *
   7 * This program is free software; you can redistribute it and/or modify
   8 * it under the terms of the GNU General Public License as published by
   9 * the Free Software Foundation; either version 2 of the License, or
  10 * (at your option) any later version.
  11 *
  12 * This program is distributed in the hope that it will be useful,
  13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 * GNU General Public License for more details.
  16 *
  17 * You should have received a copy of the GNU General Public License
  18 * along with this program; if not, write to the Free Software
  19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  20 */
  21
  22#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  23
  24#include <linux/kernel.h>
  25#include <linux/audit.h>
  26#include <linux/kthread.h>
  27#include <linux/mutex.h>
  28#include <linux/fs.h>
  29#include <linux/namei.h>
  30#include <linux/netlink.h>
  31#include <linux/sched.h>
  32#include <linux/slab.h>
  33#include <linux/security.h>
  34#include <net/net_namespace.h>
  35#include <net/sock.h>
  36#include "audit.h"
  37
  38/*
  39 * Locking model:
  40 *
  41 * audit_filter_mutex:
  42 *		Synchronizes writes and blocking reads of audit's filterlist
  43 *		data.  Rcu is used to traverse the filterlist and access
  44 *		contents of structs audit_entry, audit_watch and opaque
  45 *		LSM rules during filtering.  If modified, these structures
  46 *		must be copied and replace their counterparts in the filterlist.
  47 *		An audit_parent struct is not accessed during filtering, so may
  48 *		be written directly provided audit_filter_mutex is held.
  49 */
  50
  51/* Audit filter lists, defined in <linux/audit.h> */
  52struct list_head audit_filter_list[AUDIT_NR_FILTERS] = {
  53	LIST_HEAD_INIT(audit_filter_list[0]),
  54	LIST_HEAD_INIT(audit_filter_list[1]),
  55	LIST_HEAD_INIT(audit_filter_list[2]),
  56	LIST_HEAD_INIT(audit_filter_list[3]),
  57	LIST_HEAD_INIT(audit_filter_list[4]),
  58	LIST_HEAD_INIT(audit_filter_list[5]),
  59	LIST_HEAD_INIT(audit_filter_list[6]),
  60#if AUDIT_NR_FILTERS != 7
 
  61#error Fix audit_filter_list initialiser
  62#endif
  63};
  64static struct list_head audit_rules_list[AUDIT_NR_FILTERS] = {
  65	LIST_HEAD_INIT(audit_rules_list[0]),
  66	LIST_HEAD_INIT(audit_rules_list[1]),
  67	LIST_HEAD_INIT(audit_rules_list[2]),
  68	LIST_HEAD_INIT(audit_rules_list[3]),
  69	LIST_HEAD_INIT(audit_rules_list[4]),
  70	LIST_HEAD_INIT(audit_rules_list[5]),
  71	LIST_HEAD_INIT(audit_rules_list[6]),
 
  72};
  73
  74DEFINE_MUTEX(audit_filter_mutex);
  75
  76static void audit_free_lsm_field(struct audit_field *f)
  77{
  78	switch (f->type) {
  79	case AUDIT_SUBJ_USER:
  80	case AUDIT_SUBJ_ROLE:
  81	case AUDIT_SUBJ_TYPE:
  82	case AUDIT_SUBJ_SEN:
  83	case AUDIT_SUBJ_CLR:
  84	case AUDIT_OBJ_USER:
  85	case AUDIT_OBJ_ROLE:
  86	case AUDIT_OBJ_TYPE:
  87	case AUDIT_OBJ_LEV_LOW:
  88	case AUDIT_OBJ_LEV_HIGH:
  89		kfree(f->lsm_str);
  90		security_audit_rule_free(f->lsm_rule);
  91	}
  92}
  93
  94static inline void audit_free_rule(struct audit_entry *e)
  95{
  96	int i;
  97	struct audit_krule *erule = &e->rule;
  98
  99	/* some rules don't have associated watches */
 100	if (erule->watch)
 101		audit_put_watch(erule->watch);
 102	if (erule->fields)
 103		for (i = 0; i < erule->field_count; i++)
 104			audit_free_lsm_field(&erule->fields[i]);
 105	kfree(erule->fields);
 106	kfree(erule->filterkey);
 107	kfree(e);
 108}
 109
 110void audit_free_rule_rcu(struct rcu_head *head)
 111{
 112	struct audit_entry *e = container_of(head, struct audit_entry, rcu);
 113	audit_free_rule(e);
 114}
 115
 116/* Initialize an audit filterlist entry. */
 117static inline struct audit_entry *audit_init_entry(u32 field_count)
 118{
 119	struct audit_entry *entry;
 120	struct audit_field *fields;
 121
 122	entry = kzalloc(sizeof(*entry), GFP_KERNEL);
 123	if (unlikely(!entry))
 124		return NULL;
 125
 126	fields = kcalloc(field_count, sizeof(*fields), GFP_KERNEL);
 127	if (unlikely(!fields)) {
 128		kfree(entry);
 129		return NULL;
 130	}
 131	entry->rule.fields = fields;
 132
 133	return entry;
 134}
 135
 136/* Unpack a filter field's string representation from user-space
 137 * buffer. */
 138char *audit_unpack_string(void **bufp, size_t *remain, size_t len)
 139{
 140	char *str;
 141
 142	if (!*bufp || (len == 0) || (len > *remain))
 143		return ERR_PTR(-EINVAL);
 144
 145	/* Of the currently implemented string fields, PATH_MAX
 146	 * defines the longest valid length.
 147	 */
 148	if (len > PATH_MAX)
 149		return ERR_PTR(-ENAMETOOLONG);
 150
 151	str = kmalloc(len + 1, GFP_KERNEL);
 152	if (unlikely(!str))
 153		return ERR_PTR(-ENOMEM);
 154
 155	memcpy(str, *bufp, len);
 156	str[len] = 0;
 157	*bufp += len;
 158	*remain -= len;
 159
 160	return str;
 161}
 162
 163/* Translate an inode field to kernel representation. */
 164static inline int audit_to_inode(struct audit_krule *krule,
 165				 struct audit_field *f)
 166{
 167	if (krule->listnr != AUDIT_FILTER_EXIT ||
 
 168	    krule->inode_f || krule->watch || krule->tree ||
 169	    (f->op != Audit_equal && f->op != Audit_not_equal))
 170		return -EINVAL;
 171
 172	krule->inode_f = f;
 173	return 0;
 174}
 175
 176static __u32 *classes[AUDIT_SYSCALL_CLASSES];
 177
 178int __init audit_register_class(int class, unsigned *list)
 179{
 180	__u32 *p = kcalloc(AUDIT_BITMASK_SIZE, sizeof(__u32), GFP_KERNEL);
 181	if (!p)
 182		return -ENOMEM;
 183	while (*list != ~0U) {
 184		unsigned n = *list++;
 185		if (n >= AUDIT_BITMASK_SIZE * 32 - AUDIT_SYSCALL_CLASSES) {
 186			kfree(p);
 187			return -EINVAL;
 188		}
 189		p[AUDIT_WORD(n)] |= AUDIT_BIT(n);
 190	}
 191	if (class >= AUDIT_SYSCALL_CLASSES || classes[class]) {
 192		kfree(p);
 193		return -EINVAL;
 194	}
 195	classes[class] = p;
 196	return 0;
 197}
 198
 199int audit_match_class(int class, unsigned syscall)
 200{
 201	if (unlikely(syscall >= AUDIT_BITMASK_SIZE * 32))
 202		return 0;
 203	if (unlikely(class >= AUDIT_SYSCALL_CLASSES || !classes[class]))
 204		return 0;
 205	return classes[class][AUDIT_WORD(syscall)] & AUDIT_BIT(syscall);
 206}
 207
 208#ifdef CONFIG_AUDITSYSCALL
 209static inline int audit_match_class_bits(int class, u32 *mask)
 210{
 211	int i;
 212
 213	if (classes[class]) {
 214		for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
 215			if (mask[i] & classes[class][i])
 216				return 0;
 217	}
 218	return 1;
 219}
 220
 221static int audit_match_signal(struct audit_entry *entry)
 222{
 223	struct audit_field *arch = entry->rule.arch_f;
 224
 225	if (!arch) {
 226		/* When arch is unspecified, we must check both masks on biarch
 227		 * as syscall number alone is ambiguous. */
 228		return (audit_match_class_bits(AUDIT_CLASS_SIGNAL,
 229					       entry->rule.mask) &&
 230			audit_match_class_bits(AUDIT_CLASS_SIGNAL_32,
 231					       entry->rule.mask));
 232	}
 233
 234	switch(audit_classify_arch(arch->val)) {
 235	case 0: /* native */
 236		return (audit_match_class_bits(AUDIT_CLASS_SIGNAL,
 237					       entry->rule.mask));
 238	case 1: /* 32bit on biarch */
 239		return (audit_match_class_bits(AUDIT_CLASS_SIGNAL_32,
 240					       entry->rule.mask));
 241	default:
 242		return 1;
 243	}
 244}
 245#endif
 246
 247/* Common user-space to kernel rule translation. */
 248static inline struct audit_entry *audit_to_entry_common(struct audit_rule_data *rule)
 249{
 250	unsigned listnr;
 251	struct audit_entry *entry;
 252	int i, err;
 253
 254	err = -EINVAL;
 255	listnr = rule->flags & ~AUDIT_FILTER_PREPEND;
 256	switch(listnr) {
 257	default:
 258		goto exit_err;
 259#ifdef CONFIG_AUDITSYSCALL
 260	case AUDIT_FILTER_ENTRY:
 261		pr_err("AUDIT_FILTER_ENTRY is deprecated\n");
 262		goto exit_err;
 263	case AUDIT_FILTER_EXIT:
 
 264	case AUDIT_FILTER_TASK:
 265#endif
 266	case AUDIT_FILTER_USER:
 267	case AUDIT_FILTER_TYPE:
 268	case AUDIT_FILTER_FS:
 269		;
 270	}
 271	if (unlikely(rule->action == AUDIT_POSSIBLE)) {
 272		pr_err("AUDIT_POSSIBLE is deprecated\n");
 273		goto exit_err;
 274	}
 275	if (rule->action != AUDIT_NEVER && rule->action != AUDIT_ALWAYS)
 276		goto exit_err;
 277	if (rule->field_count > AUDIT_MAX_FIELDS)
 278		goto exit_err;
 279
 280	err = -ENOMEM;
 281	entry = audit_init_entry(rule->field_count);
 282	if (!entry)
 283		goto exit_err;
 284
 285	entry->rule.flags = rule->flags & AUDIT_FILTER_PREPEND;
 286	entry->rule.listnr = listnr;
 287	entry->rule.action = rule->action;
 288	entry->rule.field_count = rule->field_count;
 289
 290	for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
 291		entry->rule.mask[i] = rule->mask[i];
 292
 293	for (i = 0; i < AUDIT_SYSCALL_CLASSES; i++) {
 294		int bit = AUDIT_BITMASK_SIZE * 32 - i - 1;
 295		__u32 *p = &entry->rule.mask[AUDIT_WORD(bit)];
 296		__u32 *class;
 297
 298		if (!(*p & AUDIT_BIT(bit)))
 299			continue;
 300		*p &= ~AUDIT_BIT(bit);
 301		class = classes[i];
 302		if (class) {
 303			int j;
 304			for (j = 0; j < AUDIT_BITMASK_SIZE; j++)
 305				entry->rule.mask[j] |= class[j];
 306		}
 307	}
 308
 309	return entry;
 310
 311exit_err:
 312	return ERR_PTR(err);
 313}
 314
 315static u32 audit_ops[] =
 316{
 317	[Audit_equal] = AUDIT_EQUAL,
 318	[Audit_not_equal] = AUDIT_NOT_EQUAL,
 319	[Audit_bitmask] = AUDIT_BIT_MASK,
 320	[Audit_bittest] = AUDIT_BIT_TEST,
 321	[Audit_lt] = AUDIT_LESS_THAN,
 322	[Audit_gt] = AUDIT_GREATER_THAN,
 323	[Audit_le] = AUDIT_LESS_THAN_OR_EQUAL,
 324	[Audit_ge] = AUDIT_GREATER_THAN_OR_EQUAL,
 325};
 326
 327static u32 audit_to_op(u32 op)
 328{
 329	u32 n;
 330	for (n = Audit_equal; n < Audit_bad && audit_ops[n] != op; n++)
 331		;
 332	return n;
 333}
 334
 335/* check if an audit field is valid */
 336static int audit_field_valid(struct audit_entry *entry, struct audit_field *f)
 337{
 338	switch(f->type) {
 339	case AUDIT_MSGTYPE:
 340		if (entry->rule.listnr != AUDIT_FILTER_TYPE &&
 341		    entry->rule.listnr != AUDIT_FILTER_USER)
 342			return -EINVAL;
 343		break;
 344	case AUDIT_FSTYPE:
 345		if (entry->rule.listnr != AUDIT_FILTER_FS)
 346			return -EINVAL;
 347		break;
 
 
 
 
 348	}
 349
 350	switch(entry->rule.listnr) {
 351	case AUDIT_FILTER_FS:
 352		switch(f->type) {
 353		case AUDIT_FSTYPE:
 354		case AUDIT_FILTERKEY:
 355			break;
 356		default:
 357			return -EINVAL;
 358		}
 359	}
 360
 361	switch(f->type) {
 362	default:
 363		return -EINVAL;
 
 
 
 
 
 
 
 364	case AUDIT_UID:
 365	case AUDIT_EUID:
 366	case AUDIT_SUID:
 367	case AUDIT_FSUID:
 368	case AUDIT_LOGINUID:
 369	case AUDIT_OBJ_UID:
 370	case AUDIT_GID:
 371	case AUDIT_EGID:
 372	case AUDIT_SGID:
 373	case AUDIT_FSGID:
 374	case AUDIT_OBJ_GID:
 375	case AUDIT_PID:
 376	case AUDIT_PERS:
 377	case AUDIT_MSGTYPE:
 378	case AUDIT_PPID:
 379	case AUDIT_DEVMAJOR:
 380	case AUDIT_DEVMINOR:
 381	case AUDIT_EXIT:
 382	case AUDIT_SUCCESS:
 383	case AUDIT_INODE:
 384	case AUDIT_SESSIONID:
 
 
 
 
 
 385		/* bit ops are only useful on syscall args */
 386		if (f->op == Audit_bitmask || f->op == Audit_bittest)
 387			return -EINVAL;
 388		break;
 389	case AUDIT_ARG0:
 390	case AUDIT_ARG1:
 391	case AUDIT_ARG2:
 392	case AUDIT_ARG3:
 393	case AUDIT_SUBJ_USER:
 394	case AUDIT_SUBJ_ROLE:
 395	case AUDIT_SUBJ_TYPE:
 396	case AUDIT_SUBJ_SEN:
 397	case AUDIT_SUBJ_CLR:
 398	case AUDIT_OBJ_USER:
 399	case AUDIT_OBJ_ROLE:
 400	case AUDIT_OBJ_TYPE:
 401	case AUDIT_OBJ_LEV_LOW:
 402	case AUDIT_OBJ_LEV_HIGH:
 403	case AUDIT_WATCH:
 404	case AUDIT_DIR:
 405	case AUDIT_FILTERKEY:
 406		break;
 407	case AUDIT_LOGINUID_SET:
 408		if ((f->val != 0) && (f->val != 1))
 409			return -EINVAL;
 410	/* FALL THROUGH */
 411	case AUDIT_ARCH:
 412	case AUDIT_FSTYPE:
 
 
 
 
 
 413		if (f->op != Audit_not_equal && f->op != Audit_equal)
 414			return -EINVAL;
 415		break;
 
 
 
 
 
 
 
 
 
 
 
 416	case AUDIT_PERM:
 417		if (f->val & ~15)
 418			return -EINVAL;
 419		break;
 420	case AUDIT_FILETYPE:
 421		if (f->val & ~S_IFMT)
 422			return -EINVAL;
 423		break;
 424	case AUDIT_FIELD_COMPARE:
 425		if (f->val > AUDIT_MAX_FIELD_COMPARE)
 426			return -EINVAL;
 427		break;
 428	case AUDIT_EXE:
 429		if (f->op != Audit_equal)
 430			return -EINVAL;
 431		if (entry->rule.listnr != AUDIT_FILTER_EXIT)
 432			return -EINVAL;
 433		break;
 
 
 434	}
 
 435	return 0;
 436}
 437
 438/* Translate struct audit_rule_data to kernel's rule representation. */
 439static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data,
 440					       size_t datasz)
 441{
 442	int err = 0;
 443	struct audit_entry *entry;
 444	void *bufp;
 445	size_t remain = datasz - sizeof(struct audit_rule_data);
 446	int i;
 447	char *str;
 448	struct audit_fsnotify_mark *audit_mark;
 449
 450	entry = audit_to_entry_common(data);
 451	if (IS_ERR(entry))
 452		goto exit_nofree;
 453
 454	bufp = data->buf;
 455	for (i = 0; i < data->field_count; i++) {
 456		struct audit_field *f = &entry->rule.fields[i];
 
 457
 458		err = -EINVAL;
 459
 460		f->op = audit_to_op(data->fieldflags[i]);
 461		if (f->op == Audit_bad)
 462			goto exit_free;
 463
 464		f->type = data->fields[i];
 465		f->val = data->values[i];
 466
 467		/* Support legacy tests for a valid loginuid */
 468		if ((f->type == AUDIT_LOGINUID) && (f->val == AUDIT_UID_UNSET)) {
 469			f->type = AUDIT_LOGINUID_SET;
 470			f->val = 0;
 471			entry->rule.pflags |= AUDIT_LOGINUID_LEGACY;
 472		}
 473
 474		err = audit_field_valid(entry, f);
 475		if (err)
 476			goto exit_free;
 477
 478		err = -EINVAL;
 479		switch (f->type) {
 480		case AUDIT_LOGINUID:
 481		case AUDIT_UID:
 482		case AUDIT_EUID:
 483		case AUDIT_SUID:
 484		case AUDIT_FSUID:
 485		case AUDIT_OBJ_UID:
 486			f->uid = make_kuid(current_user_ns(), f->val);
 487			if (!uid_valid(f->uid))
 488				goto exit_free;
 489			break;
 490		case AUDIT_GID:
 491		case AUDIT_EGID:
 492		case AUDIT_SGID:
 493		case AUDIT_FSGID:
 494		case AUDIT_OBJ_GID:
 495			f->gid = make_kgid(current_user_ns(), f->val);
 496			if (!gid_valid(f->gid))
 497				goto exit_free;
 498			break;
 499		case AUDIT_ARCH:
 
 500			entry->rule.arch_f = f;
 501			break;
 502		case AUDIT_SUBJ_USER:
 503		case AUDIT_SUBJ_ROLE:
 504		case AUDIT_SUBJ_TYPE:
 505		case AUDIT_SUBJ_SEN:
 506		case AUDIT_SUBJ_CLR:
 507		case AUDIT_OBJ_USER:
 508		case AUDIT_OBJ_ROLE:
 509		case AUDIT_OBJ_TYPE:
 510		case AUDIT_OBJ_LEV_LOW:
 511		case AUDIT_OBJ_LEV_HIGH:
 512			str = audit_unpack_string(&bufp, &remain, f->val);
 513			if (IS_ERR(str))
 
 514				goto exit_free;
 515			entry->rule.buflen += f->val;
 516
 
 517			err = security_audit_rule_init(f->type, f->op, str,
 518						       (void **)&f->lsm_rule);
 519			/* Keep currently invalid fields around in case they
 520			 * become valid after a policy reload. */
 521			if (err == -EINVAL) {
 522				pr_warn("audit rule for LSM \'%s\' is invalid\n",
 523					str);
 524				err = 0;
 525			}
 526			if (err) {
 527				kfree(str);
 528				goto exit_free;
 529			} else
 530				f->lsm_str = str;
 531			break;
 532		case AUDIT_WATCH:
 533			str = audit_unpack_string(&bufp, &remain, f->val);
 534			if (IS_ERR(str))
 
 535				goto exit_free;
 536			entry->rule.buflen += f->val;
 537
 538			err = audit_to_watch(&entry->rule, str, f->val, f->op);
 539			if (err) {
 540				kfree(str);
 541				goto exit_free;
 542			}
 
 543			break;
 544		case AUDIT_DIR:
 545			str = audit_unpack_string(&bufp, &remain, f->val);
 546			if (IS_ERR(str))
 
 547				goto exit_free;
 548			entry->rule.buflen += f->val;
 549
 550			err = audit_make_tree(&entry->rule, str, f->op);
 551			kfree(str);
 552			if (err)
 553				goto exit_free;
 
 554			break;
 555		case AUDIT_INODE:
 
 556			err = audit_to_inode(&entry->rule, f);
 557			if (err)
 558				goto exit_free;
 559			break;
 560		case AUDIT_FILTERKEY:
 561			if (entry->rule.filterkey || f->val > AUDIT_MAX_KEY_LEN)
 562				goto exit_free;
 563			str = audit_unpack_string(&bufp, &remain, f->val);
 564			if (IS_ERR(str))
 
 565				goto exit_free;
 566			entry->rule.buflen += f->val;
 
 567			entry->rule.filterkey = str;
 568			break;
 569		case AUDIT_EXE:
 570			if (entry->rule.exe || f->val > PATH_MAX)
 571				goto exit_free;
 572			str = audit_unpack_string(&bufp, &remain, f->val);
 573			if (IS_ERR(str)) {
 574				err = PTR_ERR(str);
 575				goto exit_free;
 576			}
 577			entry->rule.buflen += f->val;
 578
 579			audit_mark = audit_alloc_mark(&entry->rule, str, f->val);
 580			if (IS_ERR(audit_mark)) {
 581				kfree(str);
 582				err = PTR_ERR(audit_mark);
 583				goto exit_free;
 584			}
 
 585			entry->rule.exe = audit_mark;
 586			break;
 
 
 
 587		}
 588	}
 589
 590	if (entry->rule.inode_f && entry->rule.inode_f->op == Audit_not_equal)
 591		entry->rule.inode_f = NULL;
 592
 593exit_nofree:
 594	return entry;
 595
 596exit_free:
 597	if (entry->rule.tree)
 598		audit_put_tree(entry->rule.tree); /* that's the temporary one */
 599	if (entry->rule.exe)
 600		audit_remove_mark(entry->rule.exe); /* that's the template one */
 601	audit_free_rule(entry);
 602	return ERR_PTR(err);
 603}
 604
 605/* Pack a filter field's string representation into data block. */
 606static inline size_t audit_pack_string(void **bufp, const char *str)
 607{
 608	size_t len = strlen(str);
 609
 610	memcpy(*bufp, str, len);
 611	*bufp += len;
 612
 613	return len;
 614}
 615
 616/* Translate kernel rule representation to struct audit_rule_data. */
 617static struct audit_rule_data *audit_krule_to_data(struct audit_krule *krule)
 618{
 619	struct audit_rule_data *data;
 620	void *bufp;
 621	int i;
 622
 623	data = kmalloc(sizeof(*data) + krule->buflen, GFP_KERNEL);
 624	if (unlikely(!data))
 625		return NULL;
 626	memset(data, 0, sizeof(*data));
 627
 628	data->flags = krule->flags | krule->listnr;
 629	data->action = krule->action;
 630	data->field_count = krule->field_count;
 631	bufp = data->buf;
 632	for (i = 0; i < data->field_count; i++) {
 633		struct audit_field *f = &krule->fields[i];
 634
 635		data->fields[i] = f->type;
 636		data->fieldflags[i] = audit_ops[f->op];
 637		switch(f->type) {
 638		case AUDIT_SUBJ_USER:
 639		case AUDIT_SUBJ_ROLE:
 640		case AUDIT_SUBJ_TYPE:
 641		case AUDIT_SUBJ_SEN:
 642		case AUDIT_SUBJ_CLR:
 643		case AUDIT_OBJ_USER:
 644		case AUDIT_OBJ_ROLE:
 645		case AUDIT_OBJ_TYPE:
 646		case AUDIT_OBJ_LEV_LOW:
 647		case AUDIT_OBJ_LEV_HIGH:
 648			data->buflen += data->values[i] =
 649				audit_pack_string(&bufp, f->lsm_str);
 650			break;
 651		case AUDIT_WATCH:
 652			data->buflen += data->values[i] =
 653				audit_pack_string(&bufp,
 654						  audit_watch_path(krule->watch));
 655			break;
 656		case AUDIT_DIR:
 657			data->buflen += data->values[i] =
 658				audit_pack_string(&bufp,
 659						  audit_tree_path(krule->tree));
 660			break;
 661		case AUDIT_FILTERKEY:
 662			data->buflen += data->values[i] =
 663				audit_pack_string(&bufp, krule->filterkey);
 664			break;
 665		case AUDIT_EXE:
 666			data->buflen += data->values[i] =
 667				audit_pack_string(&bufp, audit_mark_path(krule->exe));
 668			break;
 669		case AUDIT_LOGINUID_SET:
 670			if (krule->pflags & AUDIT_LOGINUID_LEGACY && !f->val) {
 671				data->fields[i] = AUDIT_LOGINUID;
 672				data->values[i] = AUDIT_UID_UNSET;
 673				break;
 674			}
 675			/* fallthrough if set */
 676		default:
 677			data->values[i] = f->val;
 678		}
 679	}
 680	for (i = 0; i < AUDIT_BITMASK_SIZE; i++) data->mask[i] = krule->mask[i];
 
 681
 682	return data;
 683}
 684
 685/* Compare two rules in kernel format.  Considered success if rules
 686 * don't match. */
 687static int audit_compare_rule(struct audit_krule *a, struct audit_krule *b)
 688{
 689	int i;
 690
 691	if (a->flags != b->flags ||
 692	    a->pflags != b->pflags ||
 693	    a->listnr != b->listnr ||
 694	    a->action != b->action ||
 695	    a->field_count != b->field_count)
 696		return 1;
 697
 698	for (i = 0; i < a->field_count; i++) {
 699		if (a->fields[i].type != b->fields[i].type ||
 700		    a->fields[i].op != b->fields[i].op)
 701			return 1;
 702
 703		switch(a->fields[i].type) {
 704		case AUDIT_SUBJ_USER:
 705		case AUDIT_SUBJ_ROLE:
 706		case AUDIT_SUBJ_TYPE:
 707		case AUDIT_SUBJ_SEN:
 708		case AUDIT_SUBJ_CLR:
 709		case AUDIT_OBJ_USER:
 710		case AUDIT_OBJ_ROLE:
 711		case AUDIT_OBJ_TYPE:
 712		case AUDIT_OBJ_LEV_LOW:
 713		case AUDIT_OBJ_LEV_HIGH:
 714			if (strcmp(a->fields[i].lsm_str, b->fields[i].lsm_str))
 715				return 1;
 716			break;
 717		case AUDIT_WATCH:
 718			if (strcmp(audit_watch_path(a->watch),
 719				   audit_watch_path(b->watch)))
 720				return 1;
 721			break;
 722		case AUDIT_DIR:
 723			if (strcmp(audit_tree_path(a->tree),
 724				   audit_tree_path(b->tree)))
 725				return 1;
 726			break;
 727		case AUDIT_FILTERKEY:
 728			/* both filterkeys exist based on above type compare */
 729			if (strcmp(a->filterkey, b->filterkey))
 730				return 1;
 731			break;
 732		case AUDIT_EXE:
 733			/* both paths exist based on above type compare */
 734			if (strcmp(audit_mark_path(a->exe),
 735				   audit_mark_path(b->exe)))
 736				return 1;
 737			break;
 738		case AUDIT_UID:
 739		case AUDIT_EUID:
 740		case AUDIT_SUID:
 741		case AUDIT_FSUID:
 742		case AUDIT_LOGINUID:
 743		case AUDIT_OBJ_UID:
 744			if (!uid_eq(a->fields[i].uid, b->fields[i].uid))
 745				return 1;
 746			break;
 747		case AUDIT_GID:
 748		case AUDIT_EGID:
 749		case AUDIT_SGID:
 750		case AUDIT_FSGID:
 751		case AUDIT_OBJ_GID:
 752			if (!gid_eq(a->fields[i].gid, b->fields[i].gid))
 753				return 1;
 754			break;
 755		default:
 756			if (a->fields[i].val != b->fields[i].val)
 757				return 1;
 758		}
 759	}
 760
 761	for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
 762		if (a->mask[i] != b->mask[i])
 763			return 1;
 764
 765	return 0;
 766}
 767
 768/* Duplicate LSM field information.  The lsm_rule is opaque, so must be
 769 * re-initialized. */
 770static inline int audit_dupe_lsm_field(struct audit_field *df,
 771					   struct audit_field *sf)
 772{
 773	int ret = 0;
 774	char *lsm_str;
 775
 776	/* our own copy of lsm_str */
 777	lsm_str = kstrdup(sf->lsm_str, GFP_KERNEL);
 778	if (unlikely(!lsm_str))
 779		return -ENOMEM;
 780	df->lsm_str = lsm_str;
 781
 782	/* our own (refreshed) copy of lsm_rule */
 783	ret = security_audit_rule_init(df->type, df->op, df->lsm_str,
 784				       (void **)&df->lsm_rule);
 785	/* Keep currently invalid fields around in case they
 786	 * become valid after a policy reload. */
 787	if (ret == -EINVAL) {
 788		pr_warn("audit rule for LSM \'%s\' is invalid\n",
 789			df->lsm_str);
 790		ret = 0;
 791	}
 792
 793	return ret;
 794}
 795
 796/* Duplicate an audit rule.  This will be a deep copy with the exception
 797 * of the watch - that pointer is carried over.  The LSM specific fields
 798 * will be updated in the copy.  The point is to be able to replace the old
 799 * rule with the new rule in the filterlist, then free the old rule.
 800 * The rlist element is undefined; list manipulations are handled apart from
 801 * the initial copy. */
 802struct audit_entry *audit_dupe_rule(struct audit_krule *old)
 803{
 804	u32 fcount = old->field_count;
 805	struct audit_entry *entry;
 806	struct audit_krule *new;
 807	char *fk;
 808	int i, err = 0;
 809
 810	entry = audit_init_entry(fcount);
 811	if (unlikely(!entry))
 812		return ERR_PTR(-ENOMEM);
 813
 814	new = &entry->rule;
 815	new->flags = old->flags;
 816	new->pflags = old->pflags;
 817	new->listnr = old->listnr;
 818	new->action = old->action;
 819	for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
 820		new->mask[i] = old->mask[i];
 821	new->prio = old->prio;
 822	new->buflen = old->buflen;
 823	new->inode_f = old->inode_f;
 824	new->field_count = old->field_count;
 825
 826	/*
 827	 * note that we are OK with not refcounting here; audit_match_tree()
 828	 * never dereferences tree and we can't get false positives there
 829	 * since we'd have to have rule gone from the list *and* removed
 830	 * before the chunks found by lookup had been allocated, i.e. before
 831	 * the beginning of list scan.
 832	 */
 833	new->tree = old->tree;
 834	memcpy(new->fields, old->fields, sizeof(struct audit_field) * fcount);
 835
 836	/* deep copy this information, updating the lsm_rule fields, because
 837	 * the originals will all be freed when the old rule is freed. */
 838	for (i = 0; i < fcount; i++) {
 839		switch (new->fields[i].type) {
 840		case AUDIT_SUBJ_USER:
 841		case AUDIT_SUBJ_ROLE:
 842		case AUDIT_SUBJ_TYPE:
 843		case AUDIT_SUBJ_SEN:
 844		case AUDIT_SUBJ_CLR:
 845		case AUDIT_OBJ_USER:
 846		case AUDIT_OBJ_ROLE:
 847		case AUDIT_OBJ_TYPE:
 848		case AUDIT_OBJ_LEV_LOW:
 849		case AUDIT_OBJ_LEV_HIGH:
 850			err = audit_dupe_lsm_field(&new->fields[i],
 851						       &old->fields[i]);
 852			break;
 853		case AUDIT_FILTERKEY:
 854			fk = kstrdup(old->filterkey, GFP_KERNEL);
 855			if (unlikely(!fk))
 856				err = -ENOMEM;
 857			else
 858				new->filterkey = fk;
 859			break;
 860		case AUDIT_EXE:
 861			err = audit_dupe_exe(new, old);
 862			break;
 863		}
 864		if (err) {
 865			if (new->exe)
 866				audit_remove_mark(new->exe);
 867			audit_free_rule(entry);
 868			return ERR_PTR(err);
 869		}
 870	}
 871
 872	if (old->watch) {
 873		audit_get_watch(old->watch);
 874		new->watch = old->watch;
 875	}
 876
 877	return entry;
 878}
 879
 880/* Find an existing audit rule.
 881 * Caller must hold audit_filter_mutex to prevent stale rule data. */
 882static struct audit_entry *audit_find_rule(struct audit_entry *entry,
 883					   struct list_head **p)
 884{
 885	struct audit_entry *e, *found = NULL;
 886	struct list_head *list;
 887	int h;
 888
 889	if (entry->rule.inode_f) {
 890		h = audit_hash_ino(entry->rule.inode_f->val);
 891		*p = list = &audit_inode_hash[h];
 892	} else if (entry->rule.watch) {
 893		/* we don't know the inode number, so must walk entire hash */
 894		for (h = 0; h < AUDIT_INODE_BUCKETS; h++) {
 895			list = &audit_inode_hash[h];
 896			list_for_each_entry(e, list, list)
 897				if (!audit_compare_rule(&entry->rule, &e->rule)) {
 898					found = e;
 899					goto out;
 900				}
 901		}
 902		goto out;
 903	} else {
 904		*p = list = &audit_filter_list[entry->rule.listnr];
 905	}
 906
 907	list_for_each_entry(e, list, list)
 908		if (!audit_compare_rule(&entry->rule, &e->rule)) {
 909			found = e;
 910			goto out;
 911		}
 912
 913out:
 914	return found;
 915}
 916
 917static u64 prio_low = ~0ULL/2;
 918static u64 prio_high = ~0ULL/2 - 1;
 919
 920/* Add rule to given filterlist if not a duplicate. */
 921static inline int audit_add_rule(struct audit_entry *entry)
 922{
 923	struct audit_entry *e;
 924	struct audit_watch *watch = entry->rule.watch;
 925	struct audit_tree *tree = entry->rule.tree;
 926	struct list_head *list;
 927	int err = 0;
 928#ifdef CONFIG_AUDITSYSCALL
 929	int dont_count = 0;
 930
 931	/* If any of these, don't count towards total */
 932	switch(entry->rule.listnr) {
 933	case AUDIT_FILTER_USER:
 934	case AUDIT_FILTER_TYPE:
 935	case AUDIT_FILTER_FS:
 936		dont_count = 1;
 937	}
 938#endif
 939
 940	mutex_lock(&audit_filter_mutex);
 941	e = audit_find_rule(entry, &list);
 942	if (e) {
 943		mutex_unlock(&audit_filter_mutex);
 944		err = -EEXIST;
 945		/* normally audit_add_tree_rule() will free it on failure */
 946		if (tree)
 947			audit_put_tree(tree);
 948		return err;
 949	}
 950
 951	if (watch) {
 952		/* audit_filter_mutex is dropped and re-taken during this call */
 953		err = audit_add_watch(&entry->rule, &list);
 954		if (err) {
 955			mutex_unlock(&audit_filter_mutex);
 956			/*
 957			 * normally audit_add_tree_rule() will free it
 958			 * on failure
 959			 */
 960			if (tree)
 961				audit_put_tree(tree);
 962			return err;
 963		}
 964	}
 965	if (tree) {
 966		err = audit_add_tree_rule(&entry->rule);
 967		if (err) {
 968			mutex_unlock(&audit_filter_mutex);
 969			return err;
 970		}
 971	}
 972
 973	entry->rule.prio = ~0ULL;
 974	if (entry->rule.listnr == AUDIT_FILTER_EXIT) {
 
 975		if (entry->rule.flags & AUDIT_FILTER_PREPEND)
 976			entry->rule.prio = ++prio_high;
 977		else
 978			entry->rule.prio = --prio_low;
 979	}
 980
 981	if (entry->rule.flags & AUDIT_FILTER_PREPEND) {
 982		list_add(&entry->rule.list,
 983			 &audit_rules_list[entry->rule.listnr]);
 984		list_add_rcu(&entry->list, list);
 985		entry->rule.flags &= ~AUDIT_FILTER_PREPEND;
 986	} else {
 987		list_add_tail(&entry->rule.list,
 988			      &audit_rules_list[entry->rule.listnr]);
 989		list_add_tail_rcu(&entry->list, list);
 990	}
 991#ifdef CONFIG_AUDITSYSCALL
 992	if (!dont_count)
 993		audit_n_rules++;
 994
 995	if (!audit_match_signal(entry))
 996		audit_signals++;
 997#endif
 998	mutex_unlock(&audit_filter_mutex);
 999
1000	return err;
1001}
1002
1003/* Remove an existing rule from filterlist. */
1004int audit_del_rule(struct audit_entry *entry)
1005{
1006	struct audit_entry  *e;
1007	struct audit_tree *tree = entry->rule.tree;
1008	struct list_head *list;
1009	int ret = 0;
1010#ifdef CONFIG_AUDITSYSCALL
1011	int dont_count = 0;
1012
1013	/* If any of these, don't count towards total */
1014	switch(entry->rule.listnr) {
1015	case AUDIT_FILTER_USER:
1016	case AUDIT_FILTER_TYPE:
1017	case AUDIT_FILTER_FS:
1018		dont_count = 1;
1019	}
1020#endif
1021
1022	mutex_lock(&audit_filter_mutex);
1023	e = audit_find_rule(entry, &list);
1024	if (!e) {
1025		ret = -ENOENT;
1026		goto out;
1027	}
1028
1029	if (e->rule.watch)
1030		audit_remove_watch_rule(&e->rule);
1031
1032	if (e->rule.tree)
1033		audit_remove_tree_rule(&e->rule);
1034
1035	if (e->rule.exe)
1036		audit_remove_mark_rule(&e->rule);
1037
1038#ifdef CONFIG_AUDITSYSCALL
1039	if (!dont_count)
1040		audit_n_rules--;
1041
1042	if (!audit_match_signal(entry))
1043		audit_signals--;
1044#endif
1045
1046	list_del_rcu(&e->list);
1047	list_del(&e->rule.list);
1048	call_rcu(&e->rcu, audit_free_rule_rcu);
1049
1050out:
1051	mutex_unlock(&audit_filter_mutex);
1052
1053	if (tree)
1054		audit_put_tree(tree);	/* that's the temporary one */
1055
1056	return ret;
1057}
1058
1059/* List rules using struct audit_rule_data. */
1060static void audit_list_rules(int seq, struct sk_buff_head *q)
1061{
1062	struct sk_buff *skb;
1063	struct audit_krule *r;
1064	int i;
1065
1066	/* This is a blocking read, so use audit_filter_mutex instead of rcu
1067	 * iterator to sync with list writers. */
1068	for (i=0; i<AUDIT_NR_FILTERS; i++) {
1069		list_for_each_entry(r, &audit_rules_list[i], list) {
1070			struct audit_rule_data *data;
1071
1072			data = audit_krule_to_data(r);
1073			if (unlikely(!data))
1074				break;
1075			skb = audit_make_reply(seq, AUDIT_LIST_RULES, 0, 1,
1076					       data,
1077					       sizeof(*data) + data->buflen);
1078			if (skb)
1079				skb_queue_tail(q, skb);
1080			kfree(data);
1081		}
1082	}
1083	skb = audit_make_reply(seq, AUDIT_LIST_RULES, 1, 1, NULL, 0);
1084	if (skb)
1085		skb_queue_tail(q, skb);
1086}
1087
1088/* Log rule additions and removals */
1089static void audit_log_rule_change(char *action, struct audit_krule *rule, int res)
1090{
1091	struct audit_buffer *ab;
1092	uid_t loginuid = from_kuid(&init_user_ns, audit_get_loginuid(current));
1093	unsigned int sessionid = audit_get_sessionid(current);
1094
1095	if (!audit_enabled)
1096		return;
1097
1098	ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
1099	if (!ab)
1100		return;
1101	audit_log_format(ab, "auid=%u ses=%u" ,loginuid, sessionid);
1102	audit_log_task_context(ab);
1103	audit_log_format(ab, " op=%s", action);
1104	audit_log_key(ab, rule->filterkey);
1105	audit_log_format(ab, " list=%d res=%d", rule->listnr, res);
1106	audit_log_end(ab);
1107}
1108
1109/**
1110 * audit_rule_change - apply all rules to the specified message type
1111 * @type: audit message type
1112 * @seq: netlink audit message sequence (serial) number
1113 * @data: payload data
1114 * @datasz: size of payload data
1115 */
1116int audit_rule_change(int type, int seq, void *data, size_t datasz)
1117{
1118	int err = 0;
1119	struct audit_entry *entry;
1120
1121	entry = audit_data_to_entry(data, datasz);
1122	if (IS_ERR(entry))
1123		return PTR_ERR(entry);
1124
1125	switch (type) {
1126	case AUDIT_ADD_RULE:
 
 
 
1127		err = audit_add_rule(entry);
1128		audit_log_rule_change("add_rule", &entry->rule, !err);
1129		break;
1130	case AUDIT_DEL_RULE:
 
 
 
1131		err = audit_del_rule(entry);
1132		audit_log_rule_change("remove_rule", &entry->rule, !err);
1133		break;
1134	default:
1135		err = -EINVAL;
1136		WARN_ON(1);
 
1137	}
1138
1139	if (err || type == AUDIT_DEL_RULE) {
1140		if (entry->rule.exe)
1141			audit_remove_mark(entry->rule.exe);
1142		audit_free_rule(entry);
1143	}
1144
1145	return err;
1146}
1147
1148/**
1149 * audit_list_rules_send - list the audit rules
1150 * @request_skb: skb of request we are replying to (used to target the reply)
1151 * @seq: netlink audit message sequence (serial) number
1152 */
1153int audit_list_rules_send(struct sk_buff *request_skb, int seq)
1154{
1155	u32 portid = NETLINK_CB(request_skb).portid;
1156	struct net *net = sock_net(NETLINK_CB(request_skb).sk);
1157	struct task_struct *tsk;
1158	struct audit_netlink_list *dest;
1159	int err = 0;
1160
1161	/* We can't just spew out the rules here because we might fill
1162	 * the available socket buffer space and deadlock waiting for
1163	 * auditctl to read from it... which isn't ever going to
1164	 * happen if we're actually running in the context of auditctl
1165	 * trying to _send_ the stuff */
1166
1167	dest = kmalloc(sizeof(struct audit_netlink_list), GFP_KERNEL);
1168	if (!dest)
1169		return -ENOMEM;
1170	dest->net = get_net(net);
1171	dest->portid = portid;
1172	skb_queue_head_init(&dest->q);
1173
1174	mutex_lock(&audit_filter_mutex);
1175	audit_list_rules(seq, &dest->q);
1176	mutex_unlock(&audit_filter_mutex);
1177
1178	tsk = kthread_run(audit_send_list, dest, "audit_send_list");
1179	if (IS_ERR(tsk)) {
1180		skb_queue_purge(&dest->q);
 
1181		kfree(dest);
1182		err = PTR_ERR(tsk);
1183	}
1184
1185	return err;
1186}
1187
1188int audit_comparator(u32 left, u32 op, u32 right)
1189{
1190	switch (op) {
1191	case Audit_equal:
1192		return (left == right);
1193	case Audit_not_equal:
1194		return (left != right);
1195	case Audit_lt:
1196		return (left < right);
1197	case Audit_le:
1198		return (left <= right);
1199	case Audit_gt:
1200		return (left > right);
1201	case Audit_ge:
1202		return (left >= right);
1203	case Audit_bitmask:
1204		return (left & right);
1205	case Audit_bittest:
1206		return ((left & right) == right);
1207	default:
1208		BUG();
1209		return 0;
1210	}
1211}
1212
1213int audit_uid_comparator(kuid_t left, u32 op, kuid_t right)
1214{
1215	switch (op) {
1216	case Audit_equal:
1217		return uid_eq(left, right);
1218	case Audit_not_equal:
1219		return !uid_eq(left, right);
1220	case Audit_lt:
1221		return uid_lt(left, right);
1222	case Audit_le:
1223		return uid_lte(left, right);
1224	case Audit_gt:
1225		return uid_gt(left, right);
1226	case Audit_ge:
1227		return uid_gte(left, right);
1228	case Audit_bitmask:
1229	case Audit_bittest:
1230	default:
1231		BUG();
1232		return 0;
1233	}
1234}
1235
1236int audit_gid_comparator(kgid_t left, u32 op, kgid_t right)
1237{
1238	switch (op) {
1239	case Audit_equal:
1240		return gid_eq(left, right);
1241	case Audit_not_equal:
1242		return !gid_eq(left, right);
1243	case Audit_lt:
1244		return gid_lt(left, right);
1245	case Audit_le:
1246		return gid_lte(left, right);
1247	case Audit_gt:
1248		return gid_gt(left, right);
1249	case Audit_ge:
1250		return gid_gte(left, right);
1251	case Audit_bitmask:
1252	case Audit_bittest:
1253	default:
1254		BUG();
1255		return 0;
1256	}
1257}
1258
1259/**
1260 * parent_len - find the length of the parent portion of a pathname
1261 * @path: pathname of which to determine length
1262 */
1263int parent_len(const char *path)
1264{
1265	int plen;
1266	const char *p;
1267
1268	plen = strlen(path);
1269
1270	if (plen == 0)
1271		return plen;
1272
1273	/* disregard trailing slashes */
1274	p = path + plen - 1;
1275	while ((*p == '/') && (p > path))
1276		p--;
1277
1278	/* walk backward until we find the next slash or hit beginning */
1279	while ((*p != '/') && (p > path))
1280		p--;
1281
1282	/* did we find a slash? Then increment to include it in path */
1283	if (*p == '/')
1284		p++;
1285
1286	return p - path;
1287}
1288
1289/**
1290 * audit_compare_dname_path - compare given dentry name with last component in
1291 * 			      given path. Return of 0 indicates a match.
1292 * @dname:	dentry name that we're comparing
1293 * @path:	full pathname that we're comparing
1294 * @parentlen:	length of the parent if known. Passing in AUDIT_NAME_FULL
1295 * 		here indicates that we must compute this value.
1296 */
1297int audit_compare_dname_path(const char *dname, const char *path, int parentlen)
1298{
1299	int dlen, pathlen;
1300	const char *p;
1301
1302	dlen = strlen(dname);
1303	pathlen = strlen(path);
1304	if (pathlen < dlen)
1305		return 1;
1306
1307	parentlen = parentlen == AUDIT_NAME_FULL ? parent_len(path) : parentlen;
1308	if (pathlen - parentlen != dlen)
1309		return 1;
1310
1311	p = path + parentlen;
1312
1313	return strncmp(p, dname, dlen);
1314}
1315
1316int audit_filter(int msgtype, unsigned int listtype)
1317{
1318	struct audit_entry *e;
1319	int ret = 1; /* Audit by default */
1320
1321	rcu_read_lock();
1322	if (list_empty(&audit_filter_list[listtype]))
1323		goto unlock_and_return;
1324	list_for_each_entry_rcu(e, &audit_filter_list[listtype], list) {
1325		int i, result = 0;
1326
1327		for (i = 0; i < e->rule.field_count; i++) {
1328			struct audit_field *f = &e->rule.fields[i];
1329			pid_t pid;
1330			u32 sid;
1331
1332			switch (f->type) {
1333			case AUDIT_PID:
1334				pid = task_pid_nr(current);
1335				result = audit_comparator(pid, f->op, f->val);
1336				break;
1337			case AUDIT_UID:
1338				result = audit_uid_comparator(current_uid(), f->op, f->uid);
1339				break;
1340			case AUDIT_GID:
1341				result = audit_gid_comparator(current_gid(), f->op, f->gid);
1342				break;
1343			case AUDIT_LOGINUID:
1344				result = audit_uid_comparator(audit_get_loginuid(current),
1345							      f->op, f->uid);
1346				break;
1347			case AUDIT_LOGINUID_SET:
1348				result = audit_comparator(audit_loginuid_set(current),
1349							  f->op, f->val);
1350				break;
1351			case AUDIT_MSGTYPE:
1352				result = audit_comparator(msgtype, f->op, f->val);
1353				break;
1354			case AUDIT_SUBJ_USER:
1355			case AUDIT_SUBJ_ROLE:
1356			case AUDIT_SUBJ_TYPE:
1357			case AUDIT_SUBJ_SEN:
1358			case AUDIT_SUBJ_CLR:
1359				if (f->lsm_rule) {
1360					security_task_getsecid(current, &sid);
1361					result = security_audit_rule_match(sid,
1362							f->type, f->op, f->lsm_rule, NULL);
1363				}
1364				break;
 
 
 
 
 
1365			default:
1366				goto unlock_and_return;
1367			}
1368			if (result < 0) /* error */
1369				goto unlock_and_return;
1370			if (!result)
1371				break;
1372		}
1373		if (result > 0) {
1374			if (e->rule.action == AUDIT_NEVER || listtype == AUDIT_FILTER_TYPE)
1375				ret = 0;
1376			break;
1377		}
1378	}
1379unlock_and_return:
1380	rcu_read_unlock();
1381	return ret;
1382}
1383
1384static int update_lsm_rule(struct audit_krule *r)
1385{
1386	struct audit_entry *entry = container_of(r, struct audit_entry, rule);
1387	struct audit_entry *nentry;
1388	int err = 0;
1389
1390	if (!security_audit_rule_known(r))
1391		return 0;
1392
1393	nentry = audit_dupe_rule(r);
1394	if (entry->rule.exe)
1395		audit_remove_mark(entry->rule.exe);
1396	if (IS_ERR(nentry)) {
1397		/* save the first error encountered for the
1398		 * return value */
1399		err = PTR_ERR(nentry);
1400		audit_panic("error updating LSM filters");
1401		if (r->watch)
1402			list_del(&r->rlist);
1403		list_del_rcu(&entry->list);
1404		list_del(&r->list);
1405	} else {
1406		if (r->watch || r->tree)
1407			list_replace_init(&r->rlist, &nentry->rule.rlist);
1408		list_replace_rcu(&entry->list, &nentry->list);
1409		list_replace(&r->list, &nentry->rule.list);
1410	}
1411	call_rcu(&entry->rcu, audit_free_rule_rcu);
1412
1413	return err;
1414}
1415
1416/* This function will re-initialize the lsm_rule field of all applicable rules.
1417 * It will traverse the filter lists serarching for rules that contain LSM
1418 * specific filter fields.  When such a rule is found, it is copied, the
1419 * LSM field is re-initialized, and the old rule is replaced with the
1420 * updated rule. */
1421int audit_update_lsm_rules(void)
1422{
1423	struct audit_krule *r, *n;
1424	int i, err = 0;
1425
1426	/* audit_filter_mutex synchronizes the writers */
1427	mutex_lock(&audit_filter_mutex);
1428
1429	for (i = 0; i < AUDIT_NR_FILTERS; i++) {
1430		list_for_each_entry_safe(r, n, &audit_rules_list[i], list) {
1431			int res = update_lsm_rule(r);
1432			if (!err)
1433				err = res;
1434		}
1435	}
1436	mutex_unlock(&audit_filter_mutex);
1437
1438	return err;
1439}
v6.9.4
   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/* auditfilter.c -- filtering of audit events
   3 *
   4 * Copyright 2003-2004 Red Hat, Inc.
   5 * Copyright 2005 Hewlett-Packard Development Company, L.P.
   6 * Copyright 2005 IBM Corporation
 
 
 
 
 
 
 
 
 
 
 
 
 
 
   7 */
   8
   9#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  10
  11#include <linux/kernel.h>
  12#include <linux/audit.h>
  13#include <linux/kthread.h>
  14#include <linux/mutex.h>
  15#include <linux/fs.h>
  16#include <linux/namei.h>
  17#include <linux/netlink.h>
  18#include <linux/sched.h>
  19#include <linux/slab.h>
  20#include <linux/security.h>
  21#include <net/net_namespace.h>
  22#include <net/sock.h>
  23#include "audit.h"
  24
  25/*
  26 * Locking model:
  27 *
  28 * audit_filter_mutex:
  29 *		Synchronizes writes and blocking reads of audit's filterlist
  30 *		data.  Rcu is used to traverse the filterlist and access
  31 *		contents of structs audit_entry, audit_watch and opaque
  32 *		LSM rules during filtering.  If modified, these structures
  33 *		must be copied and replace their counterparts in the filterlist.
  34 *		An audit_parent struct is not accessed during filtering, so may
  35 *		be written directly provided audit_filter_mutex is held.
  36 */
  37
  38/* Audit filter lists, defined in <linux/audit.h> */
  39struct list_head audit_filter_list[AUDIT_NR_FILTERS] = {
  40	LIST_HEAD_INIT(audit_filter_list[0]),
  41	LIST_HEAD_INIT(audit_filter_list[1]),
  42	LIST_HEAD_INIT(audit_filter_list[2]),
  43	LIST_HEAD_INIT(audit_filter_list[3]),
  44	LIST_HEAD_INIT(audit_filter_list[4]),
  45	LIST_HEAD_INIT(audit_filter_list[5]),
  46	LIST_HEAD_INIT(audit_filter_list[6]),
  47	LIST_HEAD_INIT(audit_filter_list[7]),
  48#if AUDIT_NR_FILTERS != 8
  49#error Fix audit_filter_list initialiser
  50#endif
  51};
  52static struct list_head audit_rules_list[AUDIT_NR_FILTERS] = {
  53	LIST_HEAD_INIT(audit_rules_list[0]),
  54	LIST_HEAD_INIT(audit_rules_list[1]),
  55	LIST_HEAD_INIT(audit_rules_list[2]),
  56	LIST_HEAD_INIT(audit_rules_list[3]),
  57	LIST_HEAD_INIT(audit_rules_list[4]),
  58	LIST_HEAD_INIT(audit_rules_list[5]),
  59	LIST_HEAD_INIT(audit_rules_list[6]),
  60	LIST_HEAD_INIT(audit_rules_list[7]),
  61};
  62
  63DEFINE_MUTEX(audit_filter_mutex);
  64
  65static void audit_free_lsm_field(struct audit_field *f)
  66{
  67	switch (f->type) {
  68	case AUDIT_SUBJ_USER:
  69	case AUDIT_SUBJ_ROLE:
  70	case AUDIT_SUBJ_TYPE:
  71	case AUDIT_SUBJ_SEN:
  72	case AUDIT_SUBJ_CLR:
  73	case AUDIT_OBJ_USER:
  74	case AUDIT_OBJ_ROLE:
  75	case AUDIT_OBJ_TYPE:
  76	case AUDIT_OBJ_LEV_LOW:
  77	case AUDIT_OBJ_LEV_HIGH:
  78		kfree(f->lsm_str);
  79		security_audit_rule_free(f->lsm_rule);
  80	}
  81}
  82
  83static inline void audit_free_rule(struct audit_entry *e)
  84{
  85	int i;
  86	struct audit_krule *erule = &e->rule;
  87
  88	/* some rules don't have associated watches */
  89	if (erule->watch)
  90		audit_put_watch(erule->watch);
  91	if (erule->fields)
  92		for (i = 0; i < erule->field_count; i++)
  93			audit_free_lsm_field(&erule->fields[i]);
  94	kfree(erule->fields);
  95	kfree(erule->filterkey);
  96	kfree(e);
  97}
  98
  99void audit_free_rule_rcu(struct rcu_head *head)
 100{
 101	struct audit_entry *e = container_of(head, struct audit_entry, rcu);
 102	audit_free_rule(e);
 103}
 104
 105/* Initialize an audit filterlist entry. */
 106static inline struct audit_entry *audit_init_entry(u32 field_count)
 107{
 108	struct audit_entry *entry;
 109	struct audit_field *fields;
 110
 111	entry = kzalloc(sizeof(*entry), GFP_KERNEL);
 112	if (unlikely(!entry))
 113		return NULL;
 114
 115	fields = kcalloc(field_count, sizeof(*fields), GFP_KERNEL);
 116	if (unlikely(!fields)) {
 117		kfree(entry);
 118		return NULL;
 119	}
 120	entry->rule.fields = fields;
 121
 122	return entry;
 123}
 124
 125/* Unpack a filter field's string representation from user-space
 126 * buffer. */
 127char *audit_unpack_string(void **bufp, size_t *remain, size_t len)
 128{
 129	char *str;
 130
 131	if (!*bufp || (len == 0) || (len > *remain))
 132		return ERR_PTR(-EINVAL);
 133
 134	/* Of the currently implemented string fields, PATH_MAX
 135	 * defines the longest valid length.
 136	 */
 137	if (len > PATH_MAX)
 138		return ERR_PTR(-ENAMETOOLONG);
 139
 140	str = kmalloc(len + 1, GFP_KERNEL);
 141	if (unlikely(!str))
 142		return ERR_PTR(-ENOMEM);
 143
 144	memcpy(str, *bufp, len);
 145	str[len] = 0;
 146	*bufp += len;
 147	*remain -= len;
 148
 149	return str;
 150}
 151
 152/* Translate an inode field to kernel representation. */
 153static inline int audit_to_inode(struct audit_krule *krule,
 154				 struct audit_field *f)
 155{
 156	if ((krule->listnr != AUDIT_FILTER_EXIT &&
 157	     krule->listnr != AUDIT_FILTER_URING_EXIT) ||
 158	    krule->inode_f || krule->watch || krule->tree ||
 159	    (f->op != Audit_equal && f->op != Audit_not_equal))
 160		return -EINVAL;
 161
 162	krule->inode_f = f;
 163	return 0;
 164}
 165
 166static __u32 *classes[AUDIT_SYSCALL_CLASSES];
 167
 168int __init audit_register_class(int class, unsigned *list)
 169{
 170	__u32 *p = kcalloc(AUDIT_BITMASK_SIZE, sizeof(__u32), GFP_KERNEL);
 171	if (!p)
 172		return -ENOMEM;
 173	while (*list != ~0U) {
 174		unsigned n = *list++;
 175		if (n >= AUDIT_BITMASK_SIZE * 32 - AUDIT_SYSCALL_CLASSES) {
 176			kfree(p);
 177			return -EINVAL;
 178		}
 179		p[AUDIT_WORD(n)] |= AUDIT_BIT(n);
 180	}
 181	if (class >= AUDIT_SYSCALL_CLASSES || classes[class]) {
 182		kfree(p);
 183		return -EINVAL;
 184	}
 185	classes[class] = p;
 186	return 0;
 187}
 188
 189int audit_match_class(int class, unsigned syscall)
 190{
 191	if (unlikely(syscall >= AUDIT_BITMASK_SIZE * 32))
 192		return 0;
 193	if (unlikely(class >= AUDIT_SYSCALL_CLASSES || !classes[class]))
 194		return 0;
 195	return classes[class][AUDIT_WORD(syscall)] & AUDIT_BIT(syscall);
 196}
 197
 198#ifdef CONFIG_AUDITSYSCALL
 199static inline int audit_match_class_bits(int class, u32 *mask)
 200{
 201	int i;
 202
 203	if (classes[class]) {
 204		for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
 205			if (mask[i] & classes[class][i])
 206				return 0;
 207	}
 208	return 1;
 209}
 210
 211static int audit_match_signal(struct audit_entry *entry)
 212{
 213	struct audit_field *arch = entry->rule.arch_f;
 214
 215	if (!arch) {
 216		/* When arch is unspecified, we must check both masks on biarch
 217		 * as syscall number alone is ambiguous. */
 218		return (audit_match_class_bits(AUDIT_CLASS_SIGNAL,
 219					       entry->rule.mask) &&
 220			audit_match_class_bits(AUDIT_CLASS_SIGNAL_32,
 221					       entry->rule.mask));
 222	}
 223
 224	switch (audit_classify_arch(arch->val)) {
 225	case 0: /* native */
 226		return (audit_match_class_bits(AUDIT_CLASS_SIGNAL,
 227					       entry->rule.mask));
 228	case 1: /* 32bit on biarch */
 229		return (audit_match_class_bits(AUDIT_CLASS_SIGNAL_32,
 230					       entry->rule.mask));
 231	default:
 232		return 1;
 233	}
 234}
 235#endif
 236
 237/* Common user-space to kernel rule translation. */
 238static inline struct audit_entry *audit_to_entry_common(struct audit_rule_data *rule)
 239{
 240	unsigned listnr;
 241	struct audit_entry *entry;
 242	int i, err;
 243
 244	err = -EINVAL;
 245	listnr = rule->flags & ~AUDIT_FILTER_PREPEND;
 246	switch (listnr) {
 247	default:
 248		goto exit_err;
 249#ifdef CONFIG_AUDITSYSCALL
 250	case AUDIT_FILTER_ENTRY:
 251		pr_err("AUDIT_FILTER_ENTRY is deprecated\n");
 252		goto exit_err;
 253	case AUDIT_FILTER_EXIT:
 254	case AUDIT_FILTER_URING_EXIT:
 255	case AUDIT_FILTER_TASK:
 256#endif
 257	case AUDIT_FILTER_USER:
 258	case AUDIT_FILTER_EXCLUDE:
 259	case AUDIT_FILTER_FS:
 260		;
 261	}
 262	if (unlikely(rule->action == AUDIT_POSSIBLE)) {
 263		pr_err("AUDIT_POSSIBLE is deprecated\n");
 264		goto exit_err;
 265	}
 266	if (rule->action != AUDIT_NEVER && rule->action != AUDIT_ALWAYS)
 267		goto exit_err;
 268	if (rule->field_count > AUDIT_MAX_FIELDS)
 269		goto exit_err;
 270
 271	err = -ENOMEM;
 272	entry = audit_init_entry(rule->field_count);
 273	if (!entry)
 274		goto exit_err;
 275
 276	entry->rule.flags = rule->flags & AUDIT_FILTER_PREPEND;
 277	entry->rule.listnr = listnr;
 278	entry->rule.action = rule->action;
 279	entry->rule.field_count = rule->field_count;
 280
 281	for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
 282		entry->rule.mask[i] = rule->mask[i];
 283
 284	for (i = 0; i < AUDIT_SYSCALL_CLASSES; i++) {
 285		int bit = AUDIT_BITMASK_SIZE * 32 - i - 1;
 286		__u32 *p = &entry->rule.mask[AUDIT_WORD(bit)];
 287		__u32 *class;
 288
 289		if (!(*p & AUDIT_BIT(bit)))
 290			continue;
 291		*p &= ~AUDIT_BIT(bit);
 292		class = classes[i];
 293		if (class) {
 294			int j;
 295			for (j = 0; j < AUDIT_BITMASK_SIZE; j++)
 296				entry->rule.mask[j] |= class[j];
 297		}
 298	}
 299
 300	return entry;
 301
 302exit_err:
 303	return ERR_PTR(err);
 304}
 305
 306static u32 audit_ops[] =
 307{
 308	[Audit_equal] = AUDIT_EQUAL,
 309	[Audit_not_equal] = AUDIT_NOT_EQUAL,
 310	[Audit_bitmask] = AUDIT_BIT_MASK,
 311	[Audit_bittest] = AUDIT_BIT_TEST,
 312	[Audit_lt] = AUDIT_LESS_THAN,
 313	[Audit_gt] = AUDIT_GREATER_THAN,
 314	[Audit_le] = AUDIT_LESS_THAN_OR_EQUAL,
 315	[Audit_ge] = AUDIT_GREATER_THAN_OR_EQUAL,
 316};
 317
 318static u32 audit_to_op(u32 op)
 319{
 320	u32 n;
 321	for (n = Audit_equal; n < Audit_bad && audit_ops[n] != op; n++)
 322		;
 323	return n;
 324}
 325
 326/* check if an audit field is valid */
 327static int audit_field_valid(struct audit_entry *entry, struct audit_field *f)
 328{
 329	switch (f->type) {
 330	case AUDIT_MSGTYPE:
 331		if (entry->rule.listnr != AUDIT_FILTER_EXCLUDE &&
 332		    entry->rule.listnr != AUDIT_FILTER_USER)
 333			return -EINVAL;
 334		break;
 335	case AUDIT_FSTYPE:
 336		if (entry->rule.listnr != AUDIT_FILTER_FS)
 337			return -EINVAL;
 338		break;
 339	case AUDIT_PERM:
 340		if (entry->rule.listnr == AUDIT_FILTER_URING_EXIT)
 341			return -EINVAL;
 342		break;
 343	}
 344
 345	switch (entry->rule.listnr) {
 346	case AUDIT_FILTER_FS:
 347		switch (f->type) {
 348		case AUDIT_FSTYPE:
 349		case AUDIT_FILTERKEY:
 350			break;
 351		default:
 352			return -EINVAL;
 353		}
 354	}
 355
 356	/* Check for valid field type and op */
 357	switch (f->type) {
 358	case AUDIT_ARG0:
 359	case AUDIT_ARG1:
 360	case AUDIT_ARG2:
 361	case AUDIT_ARG3:
 362	case AUDIT_PERS: /* <uapi/linux/personality.h> */
 363	case AUDIT_DEVMINOR:
 364		/* all ops are valid */
 365		break;
 366	case AUDIT_UID:
 367	case AUDIT_EUID:
 368	case AUDIT_SUID:
 369	case AUDIT_FSUID:
 370	case AUDIT_LOGINUID:
 371	case AUDIT_OBJ_UID:
 372	case AUDIT_GID:
 373	case AUDIT_EGID:
 374	case AUDIT_SGID:
 375	case AUDIT_FSGID:
 376	case AUDIT_OBJ_GID:
 377	case AUDIT_PID:
 
 378	case AUDIT_MSGTYPE:
 379	case AUDIT_PPID:
 380	case AUDIT_DEVMAJOR:
 
 381	case AUDIT_EXIT:
 382	case AUDIT_SUCCESS:
 383	case AUDIT_INODE:
 384	case AUDIT_SESSIONID:
 385	case AUDIT_SUBJ_SEN:
 386	case AUDIT_SUBJ_CLR:
 387	case AUDIT_OBJ_LEV_LOW:
 388	case AUDIT_OBJ_LEV_HIGH:
 389	case AUDIT_SADDR_FAM:
 390		/* bit ops are only useful on syscall args */
 391		if (f->op == Audit_bitmask || f->op == Audit_bittest)
 392			return -EINVAL;
 393		break;
 
 
 
 
 394	case AUDIT_SUBJ_USER:
 395	case AUDIT_SUBJ_ROLE:
 396	case AUDIT_SUBJ_TYPE:
 
 
 397	case AUDIT_OBJ_USER:
 398	case AUDIT_OBJ_ROLE:
 399	case AUDIT_OBJ_TYPE:
 
 
 400	case AUDIT_WATCH:
 401	case AUDIT_DIR:
 402	case AUDIT_FILTERKEY:
 
 403	case AUDIT_LOGINUID_SET:
 
 
 
 404	case AUDIT_ARCH:
 405	case AUDIT_FSTYPE:
 406	case AUDIT_PERM:
 407	case AUDIT_FILETYPE:
 408	case AUDIT_FIELD_COMPARE:
 409	case AUDIT_EXE:
 410		/* only equal and not equal valid ops */
 411		if (f->op != Audit_not_equal && f->op != Audit_equal)
 412			return -EINVAL;
 413		break;
 414	default:
 415		/* field not recognized */
 416		return -EINVAL;
 417	}
 418
 419	/* Check for select valid field values */
 420	switch (f->type) {
 421	case AUDIT_LOGINUID_SET:
 422		if ((f->val != 0) && (f->val != 1))
 423			return -EINVAL;
 424		break;
 425	case AUDIT_PERM:
 426		if (f->val & ~15)
 427			return -EINVAL;
 428		break;
 429	case AUDIT_FILETYPE:
 430		if (f->val & ~S_IFMT)
 431			return -EINVAL;
 432		break;
 433	case AUDIT_FIELD_COMPARE:
 434		if (f->val > AUDIT_MAX_FIELD_COMPARE)
 435			return -EINVAL;
 436		break;
 437	case AUDIT_SADDR_FAM:
 438		if (f->val >= AF_MAX)
 
 
 439			return -EINVAL;
 440		break;
 441	default:
 442		break;
 443	}
 444
 445	return 0;
 446}
 447
 448/* Translate struct audit_rule_data to kernel's rule representation. */
 449static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data,
 450					       size_t datasz)
 451{
 452	int err = 0;
 453	struct audit_entry *entry;
 454	void *bufp;
 455	size_t remain = datasz - sizeof(struct audit_rule_data);
 456	int i;
 457	char *str;
 458	struct audit_fsnotify_mark *audit_mark;
 459
 460	entry = audit_to_entry_common(data);
 461	if (IS_ERR(entry))
 462		goto exit_nofree;
 463
 464	bufp = data->buf;
 465	for (i = 0; i < data->field_count; i++) {
 466		struct audit_field *f = &entry->rule.fields[i];
 467		u32 f_val;
 468
 469		err = -EINVAL;
 470
 471		f->op = audit_to_op(data->fieldflags[i]);
 472		if (f->op == Audit_bad)
 473			goto exit_free;
 474
 475		f->type = data->fields[i];
 476		f_val = data->values[i];
 477
 478		/* Support legacy tests for a valid loginuid */
 479		if ((f->type == AUDIT_LOGINUID) && (f_val == AUDIT_UID_UNSET)) {
 480			f->type = AUDIT_LOGINUID_SET;
 481			f_val = 0;
 482			entry->rule.pflags |= AUDIT_LOGINUID_LEGACY;
 483		}
 484
 485		err = audit_field_valid(entry, f);
 486		if (err)
 487			goto exit_free;
 488
 489		err = -EINVAL;
 490		switch (f->type) {
 491		case AUDIT_LOGINUID:
 492		case AUDIT_UID:
 493		case AUDIT_EUID:
 494		case AUDIT_SUID:
 495		case AUDIT_FSUID:
 496		case AUDIT_OBJ_UID:
 497			f->uid = make_kuid(current_user_ns(), f_val);
 498			if (!uid_valid(f->uid))
 499				goto exit_free;
 500			break;
 501		case AUDIT_GID:
 502		case AUDIT_EGID:
 503		case AUDIT_SGID:
 504		case AUDIT_FSGID:
 505		case AUDIT_OBJ_GID:
 506			f->gid = make_kgid(current_user_ns(), f_val);
 507			if (!gid_valid(f->gid))
 508				goto exit_free;
 509			break;
 510		case AUDIT_ARCH:
 511			f->val = f_val;
 512			entry->rule.arch_f = f;
 513			break;
 514		case AUDIT_SUBJ_USER:
 515		case AUDIT_SUBJ_ROLE:
 516		case AUDIT_SUBJ_TYPE:
 517		case AUDIT_SUBJ_SEN:
 518		case AUDIT_SUBJ_CLR:
 519		case AUDIT_OBJ_USER:
 520		case AUDIT_OBJ_ROLE:
 521		case AUDIT_OBJ_TYPE:
 522		case AUDIT_OBJ_LEV_LOW:
 523		case AUDIT_OBJ_LEV_HIGH:
 524			str = audit_unpack_string(&bufp, &remain, f_val);
 525			if (IS_ERR(str)) {
 526				err = PTR_ERR(str);
 527				goto exit_free;
 528			}
 529			entry->rule.buflen += f_val;
 530			f->lsm_str = str;
 531			err = security_audit_rule_init(f->type, f->op, str,
 532						       (void **)&f->lsm_rule);
 533			/* Keep currently invalid fields around in case they
 534			 * become valid after a policy reload. */
 535			if (err == -EINVAL) {
 536				pr_warn("audit rule for LSM \'%s\' is invalid\n",
 537					str);
 538				err = 0;
 539			} else if (err)
 
 
 540				goto exit_free;
 
 
 541			break;
 542		case AUDIT_WATCH:
 543			str = audit_unpack_string(&bufp, &remain, f_val);
 544			if (IS_ERR(str)) {
 545				err = PTR_ERR(str);
 546				goto exit_free;
 547			}
 548			err = audit_to_watch(&entry->rule, str, f_val, f->op);
 
 549			if (err) {
 550				kfree(str);
 551				goto exit_free;
 552			}
 553			entry->rule.buflen += f_val;
 554			break;
 555		case AUDIT_DIR:
 556			str = audit_unpack_string(&bufp, &remain, f_val);
 557			if (IS_ERR(str)) {
 558				err = PTR_ERR(str);
 559				goto exit_free;
 560			}
 
 561			err = audit_make_tree(&entry->rule, str, f->op);
 562			kfree(str);
 563			if (err)
 564				goto exit_free;
 565			entry->rule.buflen += f_val;
 566			break;
 567		case AUDIT_INODE:
 568			f->val = f_val;
 569			err = audit_to_inode(&entry->rule, f);
 570			if (err)
 571				goto exit_free;
 572			break;
 573		case AUDIT_FILTERKEY:
 574			if (entry->rule.filterkey || f_val > AUDIT_MAX_KEY_LEN)
 575				goto exit_free;
 576			str = audit_unpack_string(&bufp, &remain, f_val);
 577			if (IS_ERR(str)) {
 578				err = PTR_ERR(str);
 579				goto exit_free;
 580			}
 581			entry->rule.buflen += f_val;
 582			entry->rule.filterkey = str;
 583			break;
 584		case AUDIT_EXE:
 585			if (entry->rule.exe || f_val > PATH_MAX)
 586				goto exit_free;
 587			str = audit_unpack_string(&bufp, &remain, f_val);
 588			if (IS_ERR(str)) {
 589				err = PTR_ERR(str);
 590				goto exit_free;
 591			}
 592			audit_mark = audit_alloc_mark(&entry->rule, str, f_val);
 
 
 593			if (IS_ERR(audit_mark)) {
 594				kfree(str);
 595				err = PTR_ERR(audit_mark);
 596				goto exit_free;
 597			}
 598			entry->rule.buflen += f_val;
 599			entry->rule.exe = audit_mark;
 600			break;
 601		default:
 602			f->val = f_val;
 603			break;
 604		}
 605	}
 606
 607	if (entry->rule.inode_f && entry->rule.inode_f->op == Audit_not_equal)
 608		entry->rule.inode_f = NULL;
 609
 610exit_nofree:
 611	return entry;
 612
 613exit_free:
 614	if (entry->rule.tree)
 615		audit_put_tree(entry->rule.tree); /* that's the temporary one */
 616	if (entry->rule.exe)
 617		audit_remove_mark(entry->rule.exe); /* that's the template one */
 618	audit_free_rule(entry);
 619	return ERR_PTR(err);
 620}
 621
 622/* Pack a filter field's string representation into data block. */
 623static inline size_t audit_pack_string(void **bufp, const char *str)
 624{
 625	size_t len = strlen(str);
 626
 627	memcpy(*bufp, str, len);
 628	*bufp += len;
 629
 630	return len;
 631}
 632
 633/* Translate kernel rule representation to struct audit_rule_data. */
 634static struct audit_rule_data *audit_krule_to_data(struct audit_krule *krule)
 635{
 636	struct audit_rule_data *data;
 637	void *bufp;
 638	int i;
 639
 640	data = kmalloc(struct_size(data, buf, krule->buflen), GFP_KERNEL);
 641	if (unlikely(!data))
 642		return NULL;
 643	memset(data, 0, sizeof(*data));
 644
 645	data->flags = krule->flags | krule->listnr;
 646	data->action = krule->action;
 647	data->field_count = krule->field_count;
 648	bufp = data->buf;
 649	for (i = 0; i < data->field_count; i++) {
 650		struct audit_field *f = &krule->fields[i];
 651
 652		data->fields[i] = f->type;
 653		data->fieldflags[i] = audit_ops[f->op];
 654		switch (f->type) {
 655		case AUDIT_SUBJ_USER:
 656		case AUDIT_SUBJ_ROLE:
 657		case AUDIT_SUBJ_TYPE:
 658		case AUDIT_SUBJ_SEN:
 659		case AUDIT_SUBJ_CLR:
 660		case AUDIT_OBJ_USER:
 661		case AUDIT_OBJ_ROLE:
 662		case AUDIT_OBJ_TYPE:
 663		case AUDIT_OBJ_LEV_LOW:
 664		case AUDIT_OBJ_LEV_HIGH:
 665			data->buflen += data->values[i] =
 666				audit_pack_string(&bufp, f->lsm_str);
 667			break;
 668		case AUDIT_WATCH:
 669			data->buflen += data->values[i] =
 670				audit_pack_string(&bufp,
 671						  audit_watch_path(krule->watch));
 672			break;
 673		case AUDIT_DIR:
 674			data->buflen += data->values[i] =
 675				audit_pack_string(&bufp,
 676						  audit_tree_path(krule->tree));
 677			break;
 678		case AUDIT_FILTERKEY:
 679			data->buflen += data->values[i] =
 680				audit_pack_string(&bufp, krule->filterkey);
 681			break;
 682		case AUDIT_EXE:
 683			data->buflen += data->values[i] =
 684				audit_pack_string(&bufp, audit_mark_path(krule->exe));
 685			break;
 686		case AUDIT_LOGINUID_SET:
 687			if (krule->pflags & AUDIT_LOGINUID_LEGACY && !f->val) {
 688				data->fields[i] = AUDIT_LOGINUID;
 689				data->values[i] = AUDIT_UID_UNSET;
 690				break;
 691			}
 692			fallthrough;	/* if set */
 693		default:
 694			data->values[i] = f->val;
 695		}
 696	}
 697	for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
 698		data->mask[i] = krule->mask[i];
 699
 700	return data;
 701}
 702
 703/* Compare two rules in kernel format.  Considered success if rules
 704 * don't match. */
 705static int audit_compare_rule(struct audit_krule *a, struct audit_krule *b)
 706{
 707	int i;
 708
 709	if (a->flags != b->flags ||
 710	    a->pflags != b->pflags ||
 711	    a->listnr != b->listnr ||
 712	    a->action != b->action ||
 713	    a->field_count != b->field_count)
 714		return 1;
 715
 716	for (i = 0; i < a->field_count; i++) {
 717		if (a->fields[i].type != b->fields[i].type ||
 718		    a->fields[i].op != b->fields[i].op)
 719			return 1;
 720
 721		switch (a->fields[i].type) {
 722		case AUDIT_SUBJ_USER:
 723		case AUDIT_SUBJ_ROLE:
 724		case AUDIT_SUBJ_TYPE:
 725		case AUDIT_SUBJ_SEN:
 726		case AUDIT_SUBJ_CLR:
 727		case AUDIT_OBJ_USER:
 728		case AUDIT_OBJ_ROLE:
 729		case AUDIT_OBJ_TYPE:
 730		case AUDIT_OBJ_LEV_LOW:
 731		case AUDIT_OBJ_LEV_HIGH:
 732			if (strcmp(a->fields[i].lsm_str, b->fields[i].lsm_str))
 733				return 1;
 734			break;
 735		case AUDIT_WATCH:
 736			if (strcmp(audit_watch_path(a->watch),
 737				   audit_watch_path(b->watch)))
 738				return 1;
 739			break;
 740		case AUDIT_DIR:
 741			if (strcmp(audit_tree_path(a->tree),
 742				   audit_tree_path(b->tree)))
 743				return 1;
 744			break;
 745		case AUDIT_FILTERKEY:
 746			/* both filterkeys exist based on above type compare */
 747			if (strcmp(a->filterkey, b->filterkey))
 748				return 1;
 749			break;
 750		case AUDIT_EXE:
 751			/* both paths exist based on above type compare */
 752			if (strcmp(audit_mark_path(a->exe),
 753				   audit_mark_path(b->exe)))
 754				return 1;
 755			break;
 756		case AUDIT_UID:
 757		case AUDIT_EUID:
 758		case AUDIT_SUID:
 759		case AUDIT_FSUID:
 760		case AUDIT_LOGINUID:
 761		case AUDIT_OBJ_UID:
 762			if (!uid_eq(a->fields[i].uid, b->fields[i].uid))
 763				return 1;
 764			break;
 765		case AUDIT_GID:
 766		case AUDIT_EGID:
 767		case AUDIT_SGID:
 768		case AUDIT_FSGID:
 769		case AUDIT_OBJ_GID:
 770			if (!gid_eq(a->fields[i].gid, b->fields[i].gid))
 771				return 1;
 772			break;
 773		default:
 774			if (a->fields[i].val != b->fields[i].val)
 775				return 1;
 776		}
 777	}
 778
 779	for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
 780		if (a->mask[i] != b->mask[i])
 781			return 1;
 782
 783	return 0;
 784}
 785
 786/* Duplicate LSM field information.  The lsm_rule is opaque, so must be
 787 * re-initialized. */
 788static inline int audit_dupe_lsm_field(struct audit_field *df,
 789					   struct audit_field *sf)
 790{
 791	int ret;
 792	char *lsm_str;
 793
 794	/* our own copy of lsm_str */
 795	lsm_str = kstrdup(sf->lsm_str, GFP_KERNEL);
 796	if (unlikely(!lsm_str))
 797		return -ENOMEM;
 798	df->lsm_str = lsm_str;
 799
 800	/* our own (refreshed) copy of lsm_rule */
 801	ret = security_audit_rule_init(df->type, df->op, df->lsm_str,
 802				       (void **)&df->lsm_rule);
 803	/* Keep currently invalid fields around in case they
 804	 * become valid after a policy reload. */
 805	if (ret == -EINVAL) {
 806		pr_warn("audit rule for LSM \'%s\' is invalid\n",
 807			df->lsm_str);
 808		ret = 0;
 809	}
 810
 811	return ret;
 812}
 813
 814/* Duplicate an audit rule.  This will be a deep copy with the exception
 815 * of the watch - that pointer is carried over.  The LSM specific fields
 816 * will be updated in the copy.  The point is to be able to replace the old
 817 * rule with the new rule in the filterlist, then free the old rule.
 818 * The rlist element is undefined; list manipulations are handled apart from
 819 * the initial copy. */
 820struct audit_entry *audit_dupe_rule(struct audit_krule *old)
 821{
 822	u32 fcount = old->field_count;
 823	struct audit_entry *entry;
 824	struct audit_krule *new;
 825	char *fk;
 826	int i, err = 0;
 827
 828	entry = audit_init_entry(fcount);
 829	if (unlikely(!entry))
 830		return ERR_PTR(-ENOMEM);
 831
 832	new = &entry->rule;
 833	new->flags = old->flags;
 834	new->pflags = old->pflags;
 835	new->listnr = old->listnr;
 836	new->action = old->action;
 837	for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
 838		new->mask[i] = old->mask[i];
 839	new->prio = old->prio;
 840	new->buflen = old->buflen;
 841	new->inode_f = old->inode_f;
 842	new->field_count = old->field_count;
 843
 844	/*
 845	 * note that we are OK with not refcounting here; audit_match_tree()
 846	 * never dereferences tree and we can't get false positives there
 847	 * since we'd have to have rule gone from the list *and* removed
 848	 * before the chunks found by lookup had been allocated, i.e. before
 849	 * the beginning of list scan.
 850	 */
 851	new->tree = old->tree;
 852	memcpy(new->fields, old->fields, sizeof(struct audit_field) * fcount);
 853
 854	/* deep copy this information, updating the lsm_rule fields, because
 855	 * the originals will all be freed when the old rule is freed. */
 856	for (i = 0; i < fcount; i++) {
 857		switch (new->fields[i].type) {
 858		case AUDIT_SUBJ_USER:
 859		case AUDIT_SUBJ_ROLE:
 860		case AUDIT_SUBJ_TYPE:
 861		case AUDIT_SUBJ_SEN:
 862		case AUDIT_SUBJ_CLR:
 863		case AUDIT_OBJ_USER:
 864		case AUDIT_OBJ_ROLE:
 865		case AUDIT_OBJ_TYPE:
 866		case AUDIT_OBJ_LEV_LOW:
 867		case AUDIT_OBJ_LEV_HIGH:
 868			err = audit_dupe_lsm_field(&new->fields[i],
 869						       &old->fields[i]);
 870			break;
 871		case AUDIT_FILTERKEY:
 872			fk = kstrdup(old->filterkey, GFP_KERNEL);
 873			if (unlikely(!fk))
 874				err = -ENOMEM;
 875			else
 876				new->filterkey = fk;
 877			break;
 878		case AUDIT_EXE:
 879			err = audit_dupe_exe(new, old);
 880			break;
 881		}
 882		if (err) {
 883			if (new->exe)
 884				audit_remove_mark(new->exe);
 885			audit_free_rule(entry);
 886			return ERR_PTR(err);
 887		}
 888	}
 889
 890	if (old->watch) {
 891		audit_get_watch(old->watch);
 892		new->watch = old->watch;
 893	}
 894
 895	return entry;
 896}
 897
 898/* Find an existing audit rule.
 899 * Caller must hold audit_filter_mutex to prevent stale rule data. */
 900static struct audit_entry *audit_find_rule(struct audit_entry *entry,
 901					   struct list_head **p)
 902{
 903	struct audit_entry *e, *found = NULL;
 904	struct list_head *list;
 905	int h;
 906
 907	if (entry->rule.inode_f) {
 908		h = audit_hash_ino(entry->rule.inode_f->val);
 909		*p = list = &audit_inode_hash[h];
 910	} else if (entry->rule.watch) {
 911		/* we don't know the inode number, so must walk entire hash */
 912		for (h = 0; h < AUDIT_INODE_BUCKETS; h++) {
 913			list = &audit_inode_hash[h];
 914			list_for_each_entry(e, list, list)
 915				if (!audit_compare_rule(&entry->rule, &e->rule)) {
 916					found = e;
 917					goto out;
 918				}
 919		}
 920		goto out;
 921	} else {
 922		*p = list = &audit_filter_list[entry->rule.listnr];
 923	}
 924
 925	list_for_each_entry(e, list, list)
 926		if (!audit_compare_rule(&entry->rule, &e->rule)) {
 927			found = e;
 928			goto out;
 929		}
 930
 931out:
 932	return found;
 933}
 934
 935static u64 prio_low = ~0ULL/2;
 936static u64 prio_high = ~0ULL/2 - 1;
 937
 938/* Add rule to given filterlist if not a duplicate. */
 939static inline int audit_add_rule(struct audit_entry *entry)
 940{
 941	struct audit_entry *e;
 942	struct audit_watch *watch = entry->rule.watch;
 943	struct audit_tree *tree = entry->rule.tree;
 944	struct list_head *list;
 945	int err = 0;
 946#ifdef CONFIG_AUDITSYSCALL
 947	int dont_count = 0;
 948
 949	/* If any of these, don't count towards total */
 950	switch (entry->rule.listnr) {
 951	case AUDIT_FILTER_USER:
 952	case AUDIT_FILTER_EXCLUDE:
 953	case AUDIT_FILTER_FS:
 954		dont_count = 1;
 955	}
 956#endif
 957
 958	mutex_lock(&audit_filter_mutex);
 959	e = audit_find_rule(entry, &list);
 960	if (e) {
 961		mutex_unlock(&audit_filter_mutex);
 962		err = -EEXIST;
 963		/* normally audit_add_tree_rule() will free it on failure */
 964		if (tree)
 965			audit_put_tree(tree);
 966		return err;
 967	}
 968
 969	if (watch) {
 970		/* audit_filter_mutex is dropped and re-taken during this call */
 971		err = audit_add_watch(&entry->rule, &list);
 972		if (err) {
 973			mutex_unlock(&audit_filter_mutex);
 974			/*
 975			 * normally audit_add_tree_rule() will free it
 976			 * on failure
 977			 */
 978			if (tree)
 979				audit_put_tree(tree);
 980			return err;
 981		}
 982	}
 983	if (tree) {
 984		err = audit_add_tree_rule(&entry->rule);
 985		if (err) {
 986			mutex_unlock(&audit_filter_mutex);
 987			return err;
 988		}
 989	}
 990
 991	entry->rule.prio = ~0ULL;
 992	if (entry->rule.listnr == AUDIT_FILTER_EXIT ||
 993	    entry->rule.listnr == AUDIT_FILTER_URING_EXIT) {
 994		if (entry->rule.flags & AUDIT_FILTER_PREPEND)
 995			entry->rule.prio = ++prio_high;
 996		else
 997			entry->rule.prio = --prio_low;
 998	}
 999
1000	if (entry->rule.flags & AUDIT_FILTER_PREPEND) {
1001		list_add(&entry->rule.list,
1002			 &audit_rules_list[entry->rule.listnr]);
1003		list_add_rcu(&entry->list, list);
1004		entry->rule.flags &= ~AUDIT_FILTER_PREPEND;
1005	} else {
1006		list_add_tail(&entry->rule.list,
1007			      &audit_rules_list[entry->rule.listnr]);
1008		list_add_tail_rcu(&entry->list, list);
1009	}
1010#ifdef CONFIG_AUDITSYSCALL
1011	if (!dont_count)
1012		audit_n_rules++;
1013
1014	if (!audit_match_signal(entry))
1015		audit_signals++;
1016#endif
1017	mutex_unlock(&audit_filter_mutex);
1018
1019	return err;
1020}
1021
1022/* Remove an existing rule from filterlist. */
1023int audit_del_rule(struct audit_entry *entry)
1024{
1025	struct audit_entry  *e;
1026	struct audit_tree *tree = entry->rule.tree;
1027	struct list_head *list;
1028	int ret = 0;
1029#ifdef CONFIG_AUDITSYSCALL
1030	int dont_count = 0;
1031
1032	/* If any of these, don't count towards total */
1033	switch (entry->rule.listnr) {
1034	case AUDIT_FILTER_USER:
1035	case AUDIT_FILTER_EXCLUDE:
1036	case AUDIT_FILTER_FS:
1037		dont_count = 1;
1038	}
1039#endif
1040
1041	mutex_lock(&audit_filter_mutex);
1042	e = audit_find_rule(entry, &list);
1043	if (!e) {
1044		ret = -ENOENT;
1045		goto out;
1046	}
1047
1048	if (e->rule.watch)
1049		audit_remove_watch_rule(&e->rule);
1050
1051	if (e->rule.tree)
1052		audit_remove_tree_rule(&e->rule);
1053
1054	if (e->rule.exe)
1055		audit_remove_mark_rule(&e->rule);
1056
1057#ifdef CONFIG_AUDITSYSCALL
1058	if (!dont_count)
1059		audit_n_rules--;
1060
1061	if (!audit_match_signal(entry))
1062		audit_signals--;
1063#endif
1064
1065	list_del_rcu(&e->list);
1066	list_del(&e->rule.list);
1067	call_rcu(&e->rcu, audit_free_rule_rcu);
1068
1069out:
1070	mutex_unlock(&audit_filter_mutex);
1071
1072	if (tree)
1073		audit_put_tree(tree);	/* that's the temporary one */
1074
1075	return ret;
1076}
1077
1078/* List rules using struct audit_rule_data. */
1079static void audit_list_rules(int seq, struct sk_buff_head *q)
1080{
1081	struct sk_buff *skb;
1082	struct audit_krule *r;
1083	int i;
1084
1085	/* This is a blocking read, so use audit_filter_mutex instead of rcu
1086	 * iterator to sync with list writers. */
1087	for (i = 0; i < AUDIT_NR_FILTERS; i++) {
1088		list_for_each_entry(r, &audit_rules_list[i], list) {
1089			struct audit_rule_data *data;
1090
1091			data = audit_krule_to_data(r);
1092			if (unlikely(!data))
1093				break;
1094			skb = audit_make_reply(seq, AUDIT_LIST_RULES, 0, 1,
1095					       data,
1096					       struct_size(data, buf, data->buflen));
1097			if (skb)
1098				skb_queue_tail(q, skb);
1099			kfree(data);
1100		}
1101	}
1102	skb = audit_make_reply(seq, AUDIT_LIST_RULES, 1, 1, NULL, 0);
1103	if (skb)
1104		skb_queue_tail(q, skb);
1105}
1106
1107/* Log rule additions and removals */
1108static void audit_log_rule_change(char *action, struct audit_krule *rule, int res)
1109{
1110	struct audit_buffer *ab;
 
 
1111
1112	if (!audit_enabled)
1113		return;
1114
1115	ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_CONFIG_CHANGE);
1116	if (!ab)
1117		return;
1118	audit_log_session_info(ab);
1119	audit_log_task_context(ab);
1120	audit_log_format(ab, " op=%s", action);
1121	audit_log_key(ab, rule->filterkey);
1122	audit_log_format(ab, " list=%d res=%d", rule->listnr, res);
1123	audit_log_end(ab);
1124}
1125
1126/**
1127 * audit_rule_change - apply all rules to the specified message type
1128 * @type: audit message type
1129 * @seq: netlink audit message sequence (serial) number
1130 * @data: payload data
1131 * @datasz: size of payload data
1132 */
1133int audit_rule_change(int type, int seq, void *data, size_t datasz)
1134{
1135	int err = 0;
1136	struct audit_entry *entry;
1137
 
 
 
 
1138	switch (type) {
1139	case AUDIT_ADD_RULE:
1140		entry = audit_data_to_entry(data, datasz);
1141		if (IS_ERR(entry))
1142			return PTR_ERR(entry);
1143		err = audit_add_rule(entry);
1144		audit_log_rule_change("add_rule", &entry->rule, !err);
1145		break;
1146	case AUDIT_DEL_RULE:
1147		entry = audit_data_to_entry(data, datasz);
1148		if (IS_ERR(entry))
1149			return PTR_ERR(entry);
1150		err = audit_del_rule(entry);
1151		audit_log_rule_change("remove_rule", &entry->rule, !err);
1152		break;
1153	default:
 
1154		WARN_ON(1);
1155		return -EINVAL;
1156	}
1157
1158	if (err || type == AUDIT_DEL_RULE) {
1159		if (entry->rule.exe)
1160			audit_remove_mark(entry->rule.exe);
1161		audit_free_rule(entry);
1162	}
1163
1164	return err;
1165}
1166
1167/**
1168 * audit_list_rules_send - list the audit rules
1169 * @request_skb: skb of request we are replying to (used to target the reply)
1170 * @seq: netlink audit message sequence (serial) number
1171 */
1172int audit_list_rules_send(struct sk_buff *request_skb, int seq)
1173{
 
 
1174	struct task_struct *tsk;
1175	struct audit_netlink_list *dest;
 
1176
1177	/* We can't just spew out the rules here because we might fill
1178	 * the available socket buffer space and deadlock waiting for
1179	 * auditctl to read from it... which isn't ever going to
1180	 * happen if we're actually running in the context of auditctl
1181	 * trying to _send_ the stuff */
1182
1183	dest = kmalloc(sizeof(*dest), GFP_KERNEL);
1184	if (!dest)
1185		return -ENOMEM;
1186	dest->net = get_net(sock_net(NETLINK_CB(request_skb).sk));
1187	dest->portid = NETLINK_CB(request_skb).portid;
1188	skb_queue_head_init(&dest->q);
1189
1190	mutex_lock(&audit_filter_mutex);
1191	audit_list_rules(seq, &dest->q);
1192	mutex_unlock(&audit_filter_mutex);
1193
1194	tsk = kthread_run(audit_send_list_thread, dest, "audit_send_list");
1195	if (IS_ERR(tsk)) {
1196		skb_queue_purge(&dest->q);
1197		put_net(dest->net);
1198		kfree(dest);
1199		return PTR_ERR(tsk);
1200	}
1201
1202	return 0;
1203}
1204
1205int audit_comparator(u32 left, u32 op, u32 right)
1206{
1207	switch (op) {
1208	case Audit_equal:
1209		return (left == right);
1210	case Audit_not_equal:
1211		return (left != right);
1212	case Audit_lt:
1213		return (left < right);
1214	case Audit_le:
1215		return (left <= right);
1216	case Audit_gt:
1217		return (left > right);
1218	case Audit_ge:
1219		return (left >= right);
1220	case Audit_bitmask:
1221		return (left & right);
1222	case Audit_bittest:
1223		return ((left & right) == right);
1224	default:
 
1225		return 0;
1226	}
1227}
1228
1229int audit_uid_comparator(kuid_t left, u32 op, kuid_t right)
1230{
1231	switch (op) {
1232	case Audit_equal:
1233		return uid_eq(left, right);
1234	case Audit_not_equal:
1235		return !uid_eq(left, right);
1236	case Audit_lt:
1237		return uid_lt(left, right);
1238	case Audit_le:
1239		return uid_lte(left, right);
1240	case Audit_gt:
1241		return uid_gt(left, right);
1242	case Audit_ge:
1243		return uid_gte(left, right);
1244	case Audit_bitmask:
1245	case Audit_bittest:
1246	default:
 
1247		return 0;
1248	}
1249}
1250
1251int audit_gid_comparator(kgid_t left, u32 op, kgid_t right)
1252{
1253	switch (op) {
1254	case Audit_equal:
1255		return gid_eq(left, right);
1256	case Audit_not_equal:
1257		return !gid_eq(left, right);
1258	case Audit_lt:
1259		return gid_lt(left, right);
1260	case Audit_le:
1261		return gid_lte(left, right);
1262	case Audit_gt:
1263		return gid_gt(left, right);
1264	case Audit_ge:
1265		return gid_gte(left, right);
1266	case Audit_bitmask:
1267	case Audit_bittest:
1268	default:
 
1269		return 0;
1270	}
1271}
1272
1273/**
1274 * parent_len - find the length of the parent portion of a pathname
1275 * @path: pathname of which to determine length
1276 */
1277int parent_len(const char *path)
1278{
1279	int plen;
1280	const char *p;
1281
1282	plen = strlen(path);
1283
1284	if (plen == 0)
1285		return plen;
1286
1287	/* disregard trailing slashes */
1288	p = path + plen - 1;
1289	while ((*p == '/') && (p > path))
1290		p--;
1291
1292	/* walk backward until we find the next slash or hit beginning */
1293	while ((*p != '/') && (p > path))
1294		p--;
1295
1296	/* did we find a slash? Then increment to include it in path */
1297	if (*p == '/')
1298		p++;
1299
1300	return p - path;
1301}
1302
1303/**
1304 * audit_compare_dname_path - compare given dentry name with last component in
1305 * 			      given path. Return of 0 indicates a match.
1306 * @dname:	dentry name that we're comparing
1307 * @path:	full pathname that we're comparing
1308 * @parentlen:	length of the parent if known. Passing in AUDIT_NAME_FULL
1309 * 		here indicates that we must compute this value.
1310 */
1311int audit_compare_dname_path(const struct qstr *dname, const char *path, int parentlen)
1312{
1313	int dlen, pathlen;
1314	const char *p;
1315
1316	dlen = dname->len;
1317	pathlen = strlen(path);
1318	if (pathlen < dlen)
1319		return 1;
1320
1321	parentlen = parentlen == AUDIT_NAME_FULL ? parent_len(path) : parentlen;
1322	if (pathlen - parentlen != dlen)
1323		return 1;
1324
1325	p = path + parentlen;
1326
1327	return strncmp(p, dname->name, dlen);
1328}
1329
1330int audit_filter(int msgtype, unsigned int listtype)
1331{
1332	struct audit_entry *e;
1333	int ret = 1; /* Audit by default */
1334
1335	rcu_read_lock();
 
 
1336	list_for_each_entry_rcu(e, &audit_filter_list[listtype], list) {
1337		int i, result = 0;
1338
1339		for (i = 0; i < e->rule.field_count; i++) {
1340			struct audit_field *f = &e->rule.fields[i];
1341			pid_t pid;
1342			u32 sid;
1343
1344			switch (f->type) {
1345			case AUDIT_PID:
1346				pid = task_pid_nr(current);
1347				result = audit_comparator(pid, f->op, f->val);
1348				break;
1349			case AUDIT_UID:
1350				result = audit_uid_comparator(current_uid(), f->op, f->uid);
1351				break;
1352			case AUDIT_GID:
1353				result = audit_gid_comparator(current_gid(), f->op, f->gid);
1354				break;
1355			case AUDIT_LOGINUID:
1356				result = audit_uid_comparator(audit_get_loginuid(current),
1357							      f->op, f->uid);
1358				break;
1359			case AUDIT_LOGINUID_SET:
1360				result = audit_comparator(audit_loginuid_set(current),
1361							  f->op, f->val);
1362				break;
1363			case AUDIT_MSGTYPE:
1364				result = audit_comparator(msgtype, f->op, f->val);
1365				break;
1366			case AUDIT_SUBJ_USER:
1367			case AUDIT_SUBJ_ROLE:
1368			case AUDIT_SUBJ_TYPE:
1369			case AUDIT_SUBJ_SEN:
1370			case AUDIT_SUBJ_CLR:
1371				if (f->lsm_rule) {
1372					security_current_getsecid_subj(&sid);
1373					result = security_audit_rule_match(sid,
1374						   f->type, f->op, f->lsm_rule);
1375				}
1376				break;
1377			case AUDIT_EXE:
1378				result = audit_exe_compare(current, e->rule.exe);
1379				if (f->op == Audit_not_equal)
1380					result = !result;
1381				break;
1382			default:
1383				goto unlock_and_return;
1384			}
1385			if (result < 0) /* error */
1386				goto unlock_and_return;
1387			if (!result)
1388				break;
1389		}
1390		if (result > 0) {
1391			if (e->rule.action == AUDIT_NEVER || listtype == AUDIT_FILTER_EXCLUDE)
1392				ret = 0;
1393			break;
1394		}
1395	}
1396unlock_and_return:
1397	rcu_read_unlock();
1398	return ret;
1399}
1400
1401static int update_lsm_rule(struct audit_krule *r)
1402{
1403	struct audit_entry *entry = container_of(r, struct audit_entry, rule);
1404	struct audit_entry *nentry;
1405	int err = 0;
1406
1407	if (!security_audit_rule_known(r))
1408		return 0;
1409
1410	nentry = audit_dupe_rule(r);
1411	if (entry->rule.exe)
1412		audit_remove_mark(entry->rule.exe);
1413	if (IS_ERR(nentry)) {
1414		/* save the first error encountered for the
1415		 * return value */
1416		err = PTR_ERR(nentry);
1417		audit_panic("error updating LSM filters");
1418		if (r->watch)
1419			list_del(&r->rlist);
1420		list_del_rcu(&entry->list);
1421		list_del(&r->list);
1422	} else {
1423		if (r->watch || r->tree)
1424			list_replace_init(&r->rlist, &nentry->rule.rlist);
1425		list_replace_rcu(&entry->list, &nentry->list);
1426		list_replace(&r->list, &nentry->rule.list);
1427	}
1428	call_rcu(&entry->rcu, audit_free_rule_rcu);
1429
1430	return err;
1431}
1432
1433/* This function will re-initialize the lsm_rule field of all applicable rules.
1434 * It will traverse the filter lists serarching for rules that contain LSM
1435 * specific filter fields.  When such a rule is found, it is copied, the
1436 * LSM field is re-initialized, and the old rule is replaced with the
1437 * updated rule. */
1438int audit_update_lsm_rules(void)
1439{
1440	struct audit_krule *r, *n;
1441	int i, err = 0;
1442
1443	/* audit_filter_mutex synchronizes the writers */
1444	mutex_lock(&audit_filter_mutex);
1445
1446	for (i = 0; i < AUDIT_NR_FILTERS; i++) {
1447		list_for_each_entry_safe(r, n, &audit_rules_list[i], list) {
1448			int res = update_lsm_rule(r);
1449			if (!err)
1450				err = res;
1451		}
1452	}
1453	mutex_unlock(&audit_filter_mutex);
1454
1455	return err;
1456}