blob: 5d5424b51b746fe64a38bde879d985e6e6780284 [file] [log] [blame]
Dave Jones199a9af2006-09-29 01:59:00 -07001/*
2 * Copyright 2006, Red Hat, Inc., Dave Jones
3 * Released under the General Public License (GPL).
4 *
Kees Cookd7c81672016-08-17 14:42:08 -07005 * This file contains the linked list validation for DEBUG_LIST.
Dave Jones199a9af2006-09-29 01:59:00 -07006 */
7
Paul Gortmaker8bc3bcc2011-11-16 21:29:17 -05008#include <linux/export.h>
Dave Jones199a9af2006-09-29 01:59:00 -07009#include <linux/list.h>
Paul Gortmaker50af5ea2012-01-20 18:35:53 -050010#include <linux/bug.h>
Paul Gortmakerb116ee42012-01-20 18:46:49 -050011#include <linux/kernel.h>
Dave Jones559f9ba2012-03-14 22:17:39 -040012#include <linux/rculist.h>
Dave Jones199a9af2006-09-29 01:59:00 -070013
14/*
Kees Cookd7c81672016-08-17 14:42:08 -070015 * Check that the data structures for the list manipulations are reasonably
16 * valid. Failures here indicate memory corruption (and possibly an exploit
17 * attempt).
Dave Jones199a9af2006-09-29 01:59:00 -070018 */
19
Kees Cookd7c81672016-08-17 14:42:08 -070020bool __list_add_valid(struct list_head *new, struct list_head *prev,
21 struct list_head *next)
Dave Jones199a9af2006-09-29 01:59:00 -070022{
Kees Cook85caa952017-02-24 15:00:38 -080023 if (CHECK_DATA_CORRUPTION(next->prev != prev,
Matthew Wilcox68c1f082018-04-10 16:33:06 -070024 "list_add corruption. next->prev should be prev (%px), but was %px. (next=%px).\n",
Kees Cook85caa952017-02-24 15:00:38 -080025 prev, next->prev, next) ||
26 CHECK_DATA_CORRUPTION(prev->next != next,
Matthew Wilcox68c1f082018-04-10 16:33:06 -070027 "list_add corruption. prev->next should be next (%px), but was %px. (prev=%px).\n",
Kees Cook85caa952017-02-24 15:00:38 -080028 next, prev->next, prev) ||
29 CHECK_DATA_CORRUPTION(new == prev || new == next,
Matthew Wilcox68c1f082018-04-10 16:33:06 -070030 "list_add double add: new=%px, prev=%px, next=%px.\n",
Kees Cook85caa952017-02-24 15:00:38 -080031 new, prev, next))
32 return false;
Kees Cookde54ebbe2016-08-17 14:42:11 -070033
Kees Cookd7c81672016-08-17 14:42:08 -070034 return true;
Dave Jones199a9af2006-09-29 01:59:00 -070035}
Kees Cookd7c81672016-08-17 14:42:08 -070036EXPORT_SYMBOL(__list_add_valid);
Dave Jones199a9af2006-09-29 01:59:00 -070037
Kees Cook0cd340d2016-08-17 14:42:10 -070038bool __list_del_entry_valid(struct list_head *entry)
Linus Torvalds3c18d4d2011-02-18 11:32:28 -080039{
40 struct list_head *prev, *next;
41
42 prev = entry->prev;
43 next = entry->next;
44
Kees Cook85caa952017-02-24 15:00:38 -080045 if (CHECK_DATA_CORRUPTION(next == LIST_POISON1,
Matthew Wilcox68c1f082018-04-10 16:33:06 -070046 "list_del corruption, %px->next is LIST_POISON1 (%px)\n",
Kees Cook85caa952017-02-24 15:00:38 -080047 entry, LIST_POISON1) ||
48 CHECK_DATA_CORRUPTION(prev == LIST_POISON2,
Matthew Wilcox68c1f082018-04-10 16:33:06 -070049 "list_del corruption, %px->prev is LIST_POISON2 (%px)\n",
Kees Cook85caa952017-02-24 15:00:38 -080050 entry, LIST_POISON2) ||
51 CHECK_DATA_CORRUPTION(prev->next != entry,
Matthew Wilcox68c1f082018-04-10 16:33:06 -070052 "list_del corruption. prev->next should be %px, but was %px\n",
Kees Cook85caa952017-02-24 15:00:38 -080053 entry, prev->next) ||
54 CHECK_DATA_CORRUPTION(next->prev != entry,
Matthew Wilcox68c1f082018-04-10 16:33:06 -070055 "list_del corruption. next->prev should be %px, but was %px\n",
Kees Cook85caa952017-02-24 15:00:38 -080056 entry, next->prev))
57 return false;
58
Kees Cook0cd340d2016-08-17 14:42:10 -070059 return true;
Linus Torvalds3c18d4d2011-02-18 11:32:28 -080060
Linus Torvalds3c18d4d2011-02-18 11:32:28 -080061}
Kees Cook0cd340d2016-08-17 14:42:10 -070062EXPORT_SYMBOL(__list_del_entry_valid);