Dave Jones | 199a9af | 2006-09-29 01:59:00 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright 2006, Red Hat, Inc., Dave Jones |
| 3 | * Released under the General Public License (GPL). |
| 4 | * |
Kees Cook | 791e53f | 2016-08-17 14:42:08 -0700 | [diff] [blame] | 5 | * This file contains the linked list validation for DEBUG_LIST. |
Dave Jones | 199a9af | 2006-09-29 01:59:00 -0700 | [diff] [blame] | 6 | */ |
| 7 | |
Paul Gortmaker | 8bc3bcc | 2011-11-16 21:29:17 -0500 | [diff] [blame] | 8 | #include <linux/export.h> |
Dave Jones | 199a9af | 2006-09-29 01:59:00 -0700 | [diff] [blame] | 9 | #include <linux/list.h> |
Paul Gortmaker | 50af5ea | 2012-01-20 18:35:53 -0500 | [diff] [blame] | 10 | #include <linux/bug.h> |
Paul Gortmaker | b116ee4 | 2012-01-20 18:46:49 -0500 | [diff] [blame] | 11 | #include <linux/kernel.h> |
Dave Jones | 559f9ba | 2012-03-14 22:17:39 -0400 | [diff] [blame] | 12 | #include <linux/rculist.h> |
Syed Rameez Mustafa | cf9c1e4 | 2013-07-15 11:52:09 -0700 | [diff] [blame] | 13 | #include <linux/bug.h> |
Dave Jones | 199a9af | 2006-09-29 01:59:00 -0700 | [diff] [blame] | 14 | |
| 15 | /* |
Kees Cook | 791e53f | 2016-08-17 14:42:08 -0700 | [diff] [blame] | 16 | * Check that the data structures for the list manipulations are reasonably |
| 17 | * valid. Failures here indicate memory corruption (and possibly an exploit |
| 18 | * attempt). |
Dave Jones | 199a9af | 2006-09-29 01:59:00 -0700 | [diff] [blame] | 19 | */ |
| 20 | |
Kees Cook | 791e53f | 2016-08-17 14:42:08 -0700 | [diff] [blame] | 21 | bool __list_add_valid(struct list_head *new, struct list_head *prev, |
| 22 | struct list_head *next) |
Dave Jones | 199a9af | 2006-09-29 01:59:00 -0700 | [diff] [blame] | 23 | { |
Syed Rameez Mustafa | cf9c1e4 | 2013-07-15 11:52:09 -0700 | [diff] [blame] | 24 | |
Kees Cook | eb235bf | 2017-02-24 15:00:38 -0800 | [diff] [blame] | 25 | if (CHECK_DATA_CORRUPTION(next->prev != prev, |
Minming Qi | 2e316b4 | 2018-11-07 13:12:49 +0800 | [diff] [blame] | 26 | "list_add corruption. next->prev should be prev (%p), but was %p. (next=%p).\n", |
| 27 | prev, next->prev, next) || |
| 28 | CHECK_DATA_CORRUPTION(prev->next != next, |
| 29 | "list_add corruption. prev->next should be next (%p), but was %p. (prev=%p).\n", |
| 30 | next, prev->next, prev) || |
| 31 | CHECK_DATA_CORRUPTION(new == prev || new == next, |
| 32 | "list_add double add: new=%p, prev=%p, next=%p.\n", |
| 33 | new, prev, next)) |
| 34 | return false; |
Syed Rameez Mustafa | cf9c1e4 | 2013-07-15 11:52:09 -0700 | [diff] [blame] | 35 | |
Dave Jones | 199a9af | 2006-09-29 01:59:00 -0700 | [diff] [blame] | 36 | next->prev = new; |
| 37 | new->next = next; |
| 38 | new->prev = prev; |
Paul E. McKenney | 1c97be6 | 2015-09-20 22:02:17 -0700 | [diff] [blame] | 39 | WRITE_ONCE(prev->next, new); |
Dave Jones | 199a9af | 2006-09-29 01:59:00 -0700 | [diff] [blame] | 40 | |
Kees Cook | 791e53f | 2016-08-17 14:42:08 -0700 | [diff] [blame] | 41 | return true; |
Dave Jones | 199a9af | 2006-09-29 01:59:00 -0700 | [diff] [blame] | 42 | } |
Kees Cook | 791e53f | 2016-08-17 14:42:08 -0700 | [diff] [blame] | 43 | EXPORT_SYMBOL(__list_add_valid); |
Dave Jones | 199a9af | 2006-09-29 01:59:00 -0700 | [diff] [blame] | 44 | |
Kees Cook | ca48e8c | 2016-08-17 14:42:10 -0700 | [diff] [blame] | 45 | bool __list_del_entry_valid(struct list_head *entry) |
Linus Torvalds | 3c18d4d | 2011-02-18 11:32:28 -0800 | [diff] [blame] | 46 | { |
| 47 | struct list_head *prev, *next; |
| 48 | |
| 49 | prev = entry->prev; |
| 50 | next = entry->next; |
| 51 | |
Kees Cook | eb235bf | 2017-02-24 15:00:38 -0800 | [diff] [blame] | 52 | if (CHECK_DATA_CORRUPTION(next == LIST_POISON1, |
| 53 | "list_del corruption, %p->next is LIST_POISON1 (%p)\n", |
| 54 | entry, LIST_POISON1) || |
| 55 | CHECK_DATA_CORRUPTION(prev == LIST_POISON2, |
| 56 | "list_del corruption, %p->prev is LIST_POISON2 (%p)\n", |
| 57 | entry, LIST_POISON2) || |
| 58 | CHECK_DATA_CORRUPTION(prev->next != entry, |
| 59 | "list_del corruption. prev->next should be %p, but was %p\n", |
| 60 | entry, prev->next) || |
| 61 | CHECK_DATA_CORRUPTION(next->prev != entry, |
| 62 | "list_del corruption. next->prev should be %p, but was %p\n", |
| 63 | entry, next->prev)) |
| 64 | return false; |
Linus Torvalds | 3c18d4d | 2011-02-18 11:32:28 -0800 | [diff] [blame] | 65 | |
Kees Cook | ca48e8c | 2016-08-17 14:42:10 -0700 | [diff] [blame] | 66 | return true; |
Linus Torvalds | 3c18d4d | 2011-02-18 11:32:28 -0800 | [diff] [blame] | 67 | |
Dave Jones | 199a9af | 2006-09-29 01:59:00 -0700 | [diff] [blame] | 68 | } |
Kees Cook | ca48e8c | 2016-08-17 14:42:10 -0700 | [diff] [blame] | 69 | EXPORT_SYMBOL(__list_del_entry_valid); |