From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755582AbaEAPRf (ORCPT ); Thu, 1 May 2014 11:17:35 -0400 Received: from mail-pa0-f48.google.com ([209.85.220.48]:44469 "EHLO mail-pa0-f48.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753225AbaEAPRd (ORCPT ); Thu, 1 May 2014 11:17:33 -0400 Message-ID: <53626583.5030604@kernel.dk> Date: Thu, 01 May 2014 09:17:23 -0600 From: Jens Axboe User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.4.0 MIME-Version: 1.0 To: Ming Lei , linux-kernel@vger.kernel.org CC: Christoph Hellwig Subject: Re: [PATCH] block: null_blk: fix use after free References: <1398928356-24390-1-git-send-email-tom.leiming@gmail.com> In-Reply-To: <1398928356-24390-1-git-send-email-tom.leiming@gmail.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 05/01/2014 01:12 AM, Ming Lei wrote: > entry(cmd->ll_list) may belong to new request once end_cmd() > returns, so fix the bug with the patch. > > Without the change, it is easy to observe oops when > doing null_blk(timer) test. > > Signed-off-by: Ming Lei > --- > drivers/block/null_blk.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/block/null_blk.c b/drivers/block/null_blk.c > index 8e7e3a0..e932398 100644 > --- a/drivers/block/null_blk.c > +++ b/drivers/block/null_blk.c > @@ -203,8 +203,8 @@ static enum hrtimer_restart null_cmd_timer_expired(struct hrtimer *timer) > entry = llist_reverse_order(entry); > do { > cmd = container_of(entry, struct nullb_cmd, ll_list); > - end_cmd(cmd); > entry = entry->next; > + end_cmd(cmd); > } while (entry); > } Good catch, applied. -- Jens Axboe