From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753731AbbBKQnv (ORCPT ); Wed, 11 Feb 2015 11:43:51 -0500 Received: from mail-ie0-f170.google.com ([209.85.223.170]:33951 "EHLO mail-ie0-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752952AbbBKQnu (ORCPT ); Wed, 11 Feb 2015 11:43:50 -0500 Message-ID: <54DB86C5.4090607@kernel.dk> Date: Wed, 11 Feb 2015 09:43:49 -0700 From: Jens Axboe User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.4.0 MIME-Version: 1.0 To: Tony Battersby , linux-scsi@vger.kernel.org, "James E.J. Bottomley" , Christoph Hellwig CC: linux-kernel@vger.kernel.org Subject: Re: [PATCH] blk-mq: fix double-free in error path References: <54DB841E.6030108@cybernetics.com> In-Reply-To: <54DB841E.6030108@cybernetics.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 02/11/2015 09:32 AM, Tony Battersby wrote: > If the allocation of bt->bs fails, then bt->map can be freed twice, once > in blk_mq_init_bitmap_tags() -> bt_alloc(), and once in > blk_mq_init_bitmap_tags() -> bt_free(). Fix by setting the pointer to > NULL after the first free. > > Cc: > Signed-off-by: Tony Battersby > --- > > For inclusion in kernel 3.20. > > --- linux-3.19.0/block/blk-mq-tag.c.orig 2015-02-08 21:54:22.000000000 -0500 > +++ linux-3.19.0/block/blk-mq-tag.c 2015-02-10 09:42:38.000000000 -0500 > @@ -509,6 +509,7 @@ static int bt_alloc(struct blk_mq_bitmap > bt->bs = kzalloc(BT_WAIT_QUEUES * sizeof(*bt->bs), GFP_KERNEL); > if (!bt->bs) { > kfree(bt->map); > + bt->map = NULL; > return -ENOMEM; > } Thanks Tony, applied. -- Jens Axboe