Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755792AbaBEUvO (ORCPT ); Wed, 5 Feb 2014 15:51:14 -0500 Received: from mail.windriver.com ([147.11.1.11]:54982 "EHLO mail.windriver.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754762AbaBEUGD (ORCPT ); Wed, 5 Feb 2014 15:06:03 -0500 From: Paul Gortmaker To: , CC: Takamori Yamaguchi , Aaditya Kumar , Andrew Morton , Linus Torvalds , Paul Gortmaker Subject: [v2.6.34-stable 102/213] mm: bugfix: set current->reclaim_state to NULL while returning from kswapd() Date: Wed, 5 Feb 2014 15:00:57 -0500 Message-ID: <1391630568-49251-103-git-send-email-paul.gortmaker@windriver.com> X-Mailer: git-send-email 1.8.5.2 In-Reply-To: <1391630568-49251-1-git-send-email-paul.gortmaker@windriver.com> References: <1391630568-49251-1-git-send-email-paul.gortmaker@windriver.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Takamori Yamaguchi ------------------- This is a commit scheduled for the next v2.6.34 longterm release. http://git.kernel.org/?p=linux/kernel/git/paulg/longterm-queue-2.6.34.git If you see a problem with using this for longterm, please comment. ------------------- commit b0a8cc58e6b9aaae3045752059e5e6260c0b94bc upstream. In kswapd(), set current->reclaim_state to NULL before returning, as current->reclaim_state holds reference to variable on kswapd()'s stack. In rare cases, while returning from kswapd() during memory offlining, __free_slab() and freepages() can access the dangling pointer of current->reclaim_state. Signed-off-by: Takamori Yamaguchi Signed-off-by: Aaditya Kumar Acked-by: David Rientjes Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Paul Gortmaker --- mm/vmscan.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/mm/vmscan.c b/mm/vmscan.c index 5c4620600333..365a899bcae0 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -2341,6 +2341,8 @@ static int kswapd(void *p) if (!ret) balance_pgdat(pgdat, order); } + + current->reclaim_state = NULL; return 0; } -- 1.8.5.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/