From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932876AbcBIULj (ORCPT ); Tue, 9 Feb 2016 15:11:39 -0500 Received: from mail-wm0-f41.google.com ([74.125.82.41]:34666 "EHLO mail-wm0-f41.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932751AbcBIULd (ORCPT ); Tue, 9 Feb 2016 15:11:33 -0500 From: Rasmus Villemoes To: Andrew Morton , Johannes Weiner , Michal Hocko , Vladimir Davydov , "David S. Miller" , Rasmus Villemoes Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [PATCH 5/5] mm/backing-dev.c: fix error path in wb_init() Date: Tue, 9 Feb 2016 21:11:16 +0100 Message-Id: <1455048677-19882-6-git-send-email-linux@rasmusvillemoes.dk> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1455048677-19882-1-git-send-email-linux@rasmusvillemoes.dk> References: <1455048677-19882-1-git-send-email-linux@rasmusvillemoes.dk> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org We need to use post-decrement to get percpu_counter_destroy() called on &wb->stat[0]. Moreover, the pre-decremebt would cause infinite out-of-bounds accesses if the setup code failed at i==0. Signed-off-by: Rasmus Villemoes --- mm/backing-dev.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/backing-dev.c b/mm/backing-dev.c index cc5d29d2da9b..723f3e624b9a 100644 --- a/mm/backing-dev.c +++ b/mm/backing-dev.c @@ -328,7 +328,7 @@ static int wb_init(struct bdi_writeback *wb, struct backing_dev_info *bdi, return 0; out_destroy_stat: - while (--i) + while (i--) percpu_counter_destroy(&wb->stat[i]); fprop_local_destroy_percpu(&wb->completions); out_put_cong: -- 2.1.4 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f43.google.com (mail-wm0-f43.google.com [74.125.82.43]) by kanga.kvack.org (Postfix) with ESMTP id B208A6B0009 for ; Tue, 9 Feb 2016 15:11:33 -0500 (EST) Received: by mail-wm0-f43.google.com with SMTP id 128so91021wmz.1 for ; Tue, 09 Feb 2016 12:11:33 -0800 (PST) Received: from mail-wm0-x22e.google.com (mail-wm0-x22e.google.com. [2a00:1450:400c:c09::22e]) by mx.google.com with ESMTPS id c2si51128437wjb.214.2016.02.09.12.11.32 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 09 Feb 2016 12:11:32 -0800 (PST) Received: by mail-wm0-x22e.google.com with SMTP id g62so38798476wme.0 for ; Tue, 09 Feb 2016 12:11:32 -0800 (PST) From: Rasmus Villemoes Subject: [PATCH 5/5] mm/backing-dev.c: fix error path in wb_init() Date: Tue, 9 Feb 2016 21:11:16 +0100 Message-Id: <1455048677-19882-6-git-send-email-linux@rasmusvillemoes.dk> In-Reply-To: <1455048677-19882-1-git-send-email-linux@rasmusvillemoes.dk> References: <1455048677-19882-1-git-send-email-linux@rasmusvillemoes.dk> Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton , Johannes Weiner , Michal Hocko , Vladimir Davydov , "David S. Miller" , Rasmus Villemoes Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org We need to use post-decrement to get percpu_counter_destroy() called on &wb->stat[0]. Moreover, the pre-decremebt would cause infinite out-of-bounds accesses if the setup code failed at i==0. Signed-off-by: Rasmus Villemoes --- mm/backing-dev.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/backing-dev.c b/mm/backing-dev.c index cc5d29d2da9b..723f3e624b9a 100644 --- a/mm/backing-dev.c +++ b/mm/backing-dev.c @@ -328,7 +328,7 @@ static int wb_init(struct bdi_writeback *wb, struct backing_dev_info *bdi, return 0; out_destroy_stat: - while (--i) + while (i--) percpu_counter_destroy(&wb->stat[i]); fprop_local_destroy_percpu(&wb->completions); out_put_cong: -- 2.1.4 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org