From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Message-ID: <54202F75.8080401@kernel.dk> Date: Mon, 22 Sep 2014 08:17:25 -0600 From: Jens Axboe MIME-Version: 1.0 To: Christian Borntraeger , tom.leiming@gmail.com CC: David Hildenbrand , kvm@vger.kernel.org, stable@vger.kernel.org, rusty@rustcorp.com.au, virtualization@lists.linux-foundation.org, mst@redhat.com, linux-kernel@vger.kernel.org, ppinatti@linux.vnet.ibm.com Subject: Re: [PATCH] blk-mq: Avoid race condition with uninitialized requests References: <1411031071-40390-1-git-send-email-dahi@linux.vnet.ibm.com> <1411031071-40390-2-git-send-email-dahi@linux.vnet.ibm.com> <54202EF8.4080909@de.ibm.com> In-Reply-To: <54202EF8.4080909@de.ibm.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: kvm-owner@vger.kernel.org List-ID: On 2014-09-22 08:15, Christian Borntraeger wrote: > On 09/18/2014 11:04 AM, David Hildenbrand wrote: >> This patch should fix the bug reported in https://lkml.org/lkml/2014/9/11/249. >> >> We have to initialize at least the atomic_flags and the cmd_flags when >> allocating storage for the requests. >> >> Otherwise blk_mq_timeout_check() might dereference uninitialized pointers when >> racing with the creation of a request. >> >> Also move the reset of cmd_flags for the initializing code to the point where a >> request is freed. So we will never end up with pending flush request indicators >> that might trigger dereferences of invalid pointers in blk_mq_timeout_check(). >> >> Cc: stable@vger.kernel.org >> Signed-off-by: David Hildenbrand > > Acked-by: Christian Borntraeger > > Can you please add > Reported-by: Paulo De Rezende Pinatti > Tested-by: Paulo De Rezende Pinatti > > as Paulo did the testing work? > > We thing this patch is fine and should go upstream. I might have to pick'n rebase the series, in which case I'll add it. But I already queued it up last week, so if I don't, then I can't easily add it. I wish the git notes wasn't such a horrible and unusable hack, so we had a chance to annotate commits without having to rewrite history... -- Jens Axboe