Commit f015ac3e authored Sep 30, 2010 by Don Mullis Committed by Linus Torvalds Oct 01, 2010

lib/list_sort: do not pass bad pointers to cmp callback



If the original list is a POT in length, the first callback from line 73
will pass a==b both pointing to the original list_head.  This is dangerous
because the 'list_sort()' user can use 'container_of()' and accesses the
"containing" object, which does not necessary exist for the list head.  So
the user can access RAM which does not belong to him.  If this is a write
access, we can end up with memory corruption.

Signed-off-by: Don Mullis <don.mullis@gmail.com>
Tested-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 982f7c2b

lib/list_sort.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -70,7 +70,7 @@ static void merge_and_restore_back_links(void *priv,
		* element comparison is needed, so the client's cmp()
		* routine can invoke cond_resched() periodically.
		*/
		(*cmp)(priv, tail, tail);
		(*cmp)(priv, tail->next, tail->next);

		tail->next->prev = tail;
		tail = tail->next;