* [PATCH] mm/mempool: Avoid KASAN marking mempool posion checks as use-after-free
@ 2016-03-09 6:16 ` Matthew Dawson
0 siblings, 0 replies; 4+ messages in thread
From: Matthew Dawson @ 2016-03-09 6:16 UTC (permalink / raw)
To: linux-mm; +Cc: linux-kernel
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>
---
mm/mempool.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/mm/mempool.c b/mm/mempool.c
index 004d42b..7924f4f 100644
--- a/mm/mempool.c
+++ b/mm/mempool.c
@@ -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;
}
--
2.7.1
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^ permalink raw reply related [flat|nested] 4+ messages in thread
* [PATCH] mm/mempool: Avoid KASAN marking mempool posion checks as use-after-free
@ 2016-03-09 6:16 ` Matthew Dawson
0 siblings, 0 replies; 4+ messages in thread
From: Matthew Dawson @ 2016-03-09 6:16 UTC (permalink / raw)
To: linux-mm; +Cc: linux-kernel
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>
---
mm/mempool.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/mm/mempool.c b/mm/mempool.c
index 004d42b..7924f4f 100644
--- a/mm/mempool.c
+++ b/mm/mempool.c
@@ -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;
}
--
2.7.1
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH] mm/mempool: Avoid KASAN marking mempool posion checks as use-after-free
2016-03-09 6:16 ` Matthew Dawson
@ 2016-03-10 13:55 ` Andrey Ryabinin
-1 siblings, 0 replies; 4+ messages in thread
From: Andrey Ryabinin @ 2016-03-10 13:55 UTC (permalink / raw)
To: Matthew Dawson, linux-mm; +Cc: linux-kernel, Andrew Morton
On 03/09/2016 09:16 AM, Matthew Dawson wrote:
> 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>
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To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
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^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] mm/mempool: Avoid KASAN marking mempool posion checks as use-after-free
@ 2016-03-10 13:55 ` Andrey Ryabinin
0 siblings, 0 replies; 4+ messages in thread
From: Andrey Ryabinin @ 2016-03-10 13:55 UTC (permalink / raw)
To: Matthew Dawson, linux-mm; +Cc: linux-kernel, Andrew Morton
On 03/09/2016 09:16 AM, Matthew Dawson wrote:
> 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>
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2016-03-10 13:56 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
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2016-03-09 6:16 [PATCH] mm/mempool: Avoid KASAN marking mempool posion checks as use-after-free Matthew Dawson
2016-03-09 6:16 ` Matthew Dawson
2016-03-10 13:55 ` Andrey Ryabinin
2016-03-10 13:55 ` Andrey Ryabinin
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