Commit 51b73dab authored Mar 11, 2016 by Matthew Dawson Committed by Alex Shi Apr 11, 2016

mm/mempool: avoid KASAN marking mempool poison checks as use-after-free



When removing an element from the mempool, mark it as unpoisoned in KASAN
before verifying its contents for SLUB/SLAB debugging.  Otherwise KASAN
will flag the reads checking the element use-after-free writes as
use-after-free reads.

Signed-off-by: Matthew Dawson <matthew@mjdsystems.ca>
Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit 7640131032db9118a78af715ac77ba2debeeb17c)
Signed-off-by: Alex Shi <alex.shi@linaro.org>

parent 07a0301e

mm/mempool.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -135,8 +135,8 @@ static void remove_element(mempool_t pool)
		void *element = pool->elements[--pool->curr_nr];

		BUG_ON(pool->curr_nr < 0);
		check_element(pool, element);
		kasan_unpoison_element(pool, element);
		check_element(pool, element);
		return element;
		}