mirror of
https://github.com/torvalds/linux
synced 2024-07-22 11:10:46 +00:00
0cd340dcb0
Similar to the list_add() debug consolidation, this commit consolidates the debug checking performed during CONFIG_DEBUG_LIST into a new __list_del_entry_valid() function, and stops list updates when corruption is found. Refactored from same hardening in PaX and Grsecurity. Signed-off-by: Kees Cook <keescook@chromium.org> Acked-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by: Rik van Riel <riel@redhat.com>
73 lines
1.9 KiB
C
73 lines
1.9 KiB
C
/*
|
|
* Copyright 2006, Red Hat, Inc., Dave Jones
|
|
* Released under the General Public License (GPL).
|
|
*
|
|
* This file contains the linked list validation for DEBUG_LIST.
|
|
*/
|
|
|
|
#include <linux/export.h>
|
|
#include <linux/list.h>
|
|
#include <linux/bug.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/rculist.h>
|
|
|
|
/*
|
|
* Check that the data structures for the list manipulations are reasonably
|
|
* valid. Failures here indicate memory corruption (and possibly an exploit
|
|
* attempt).
|
|
*/
|
|
|
|
bool __list_add_valid(struct list_head *new, struct list_head *prev,
|
|
struct list_head *next)
|
|
{
|
|
if (unlikely(next->prev != prev)) {
|
|
WARN(1, "list_add corruption. next->prev should be prev (%p), but was %p. (next=%p).\n",
|
|
prev, next->prev, next);
|
|
return false;
|
|
}
|
|
if (unlikely(prev->next != next)) {
|
|
WARN(1, "list_add corruption. prev->next should be next (%p), but was %p. (prev=%p).\n",
|
|
next, prev->next, prev);
|
|
return false;
|
|
}
|
|
if (unlikely(new == prev || new == next)) {
|
|
WARN(1, "list_add double add: new=%p, prev=%p, next=%p.\n",
|
|
new, prev, next);
|
|
return false;
|
|
}
|
|
return true;
|
|
}
|
|
EXPORT_SYMBOL(__list_add_valid);
|
|
|
|
bool __list_del_entry_valid(struct list_head *entry)
|
|
{
|
|
struct list_head *prev, *next;
|
|
|
|
prev = entry->prev;
|
|
next = entry->next;
|
|
|
|
if (unlikely(next == LIST_POISON1)) {
|
|
WARN(1, "list_del corruption, %p->next is LIST_POISON1 (%p)\n",
|
|
entry, LIST_POISON1);
|
|
return false;
|
|
}
|
|
if (unlikely(prev == LIST_POISON2)) {
|
|
WARN(1, "list_del corruption, %p->prev is LIST_POISON2 (%p)\n",
|
|
entry, LIST_POISON2);
|
|
return false;
|
|
}
|
|
if (unlikely(prev->next != entry)) {
|
|
WARN(1, "list_del corruption. prev->next should be %p, but was %p\n",
|
|
entry, prev->next);
|
|
return false;
|
|
}
|
|
if (unlikely(next->prev != entry)) {
|
|
WARN(1, "list_del corruption. next->prev should be %p, but was %p\n",
|
|
entry, next->prev);
|
|
return false;
|
|
}
|
|
return true;
|
|
|
|
}
|
|
EXPORT_SYMBOL(__list_del_entry_valid);
|