This is a note to let you know that I've just added the patch titled
mm/mempool: avoid KASAN marking mempool poison checks as use-after-free
to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
mm-mempool-avoid-kasan-marking-mempool-poison-checks-as-use-after-free.patch
and it can be found in the queue-4.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 7640131032db9118a78af715ac77ba2debeeb17c Mon Sep 17 00:00:00 2001
From: Matthew Dawson <matthew@xxxxxxxxxxxxx>
Date: Fri, 11 Mar 2016 13:08:07 -0800
Subject: mm/mempool: avoid KASAN marking mempool poison checks as use-after-free
From: Matthew Dawson <matthew@xxxxxxxxxxxxx>
commit 7640131032db9118a78af715ac77ba2debeeb17c upstream.
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@xxxxxxxxxxxxx>
Acked-by: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Andrii Bordunov <aborduno@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
mm/mempool.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/mm/mempool.c
+++ b/mm/mempool.c
@@ -135,8 +135,8 @@ static void *remove_element(mempool_t *p
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;
}
Patches currently in stable-queue which might be from matthew@xxxxxxxxxxxxx are
queue-4.4/mm-mempool-avoid-kasan-marking-mempool-poison-checks-as-use-after-free.patch