Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:52886 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753612AbdHKVID (ORCPT ); Fri, 11 Aug 2017 17:08:03 -0400 Subject: Patch "mm/mempool: avoid KASAN marking mempool poison checks as use-after-free" has been added to the 4.4-stable tree To: matthew@mjdsystems.ca, aborduno@cisco.com, akpm@linux-foundation.org, aryabinin@virtuozzo.com, gregkh@linuxfoundation.org, torvalds@linux-foundation.org Cc: , From: Date: Fri, 11 Aug 2017 14:07:55 -0700 Message-ID: <150248567520683@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: 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 know about it. >From 7640131032db9118a78af715ac77ba2debeeb17c Mon Sep 17 00:00:00 2001 From: Matthew Dawson 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 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 Acked-by: Andrey Ryabinin Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Cc: Andrii Bordunov Signed-off-by: Greg Kroah-Hartman --- 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@mjdsystems.ca are queue-4.4/mm-mempool-avoid-kasan-marking-mempool-poison-checks-as-use-after-free.patch