From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752390AbdEJIDd (ORCPT ); Wed, 10 May 2017 04:03:33 -0400 Received: from mx2.suse.de ([195.135.220.15]:46293 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751363AbdEJIDa (ORCPT ); Wed, 10 May 2017 04:03:30 -0400 Subject: Re: [PATCH v2] scsi: sg: don't return bogus Sg_requests To: Johannes Thumshirn , "Martin K . Petersen" Cc: James Bottomley , Andrey Konovalov , Linux Kernel Mailinglist , Linux SCSI Mailinglist , Christoph Hellwig , Doug Gilbert References: <20170510075340.12125-1-jthumshirn@suse.de> From: Hannes Reinecke Message-ID: Date: Wed, 10 May 2017 10:03:27 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.1.0 MIME-Version: 1.0 In-Reply-To: <20170510075340.12125-1-jthumshirn@suse.de> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 05/10/2017 09:53 AM, Johannes Thumshirn wrote: > If the list search in sg_get_rq_mark() fails to find a valid request, we > return a bogus element. This then can later lead to a GPF in sg_remove_scat(). > > So don't return bogus Sg_requests in sg_get_rq_mark() but NULL in case the > list search doesn't find a valid request. > > Signed-off-by: Johannes Thumshirn > Reported-by: Andrey Konovalov > Cc: Hannes Reinecke > Cc: Christoph Hellwig > Cc: Doug Gilbert > --- > Changes to v1: > * Directly return found element within the loop (Hannes) > > drivers/scsi/sg.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c > index 0a38ba01b7b4..82c33a6edbea 100644 > --- a/drivers/scsi/sg.c > +++ b/drivers/scsi/sg.c > @@ -2074,11 +2074,12 @@ sg_get_rq_mark(Sg_fd * sfp, int pack_id) > if ((1 == resp->done) && (!resp->sg_io_owned) && > ((-1 == pack_id) || (resp->header.pack_id == pack_id))) { > resp->done = 2; /* guard against other readers */ > - break; > + write_unlock_irqrestore(&sfp->rq_list_lock, iflags); > + return resp; > } > } > write_unlock_irqrestore(&sfp->rq_list_lock, iflags); > - return resp; > + return NULL; > } > > /* always adds to end of list */ > Better. Reviewed-by: Hannes Reinecke Cheers, Hannes -- Dr. Hannes Reinecke Teamlead Storage & Networking hare@suse.de +49 911 74053 688 SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg GF: F. Imendörffer, J. Smithard, J. Guild, D. Upmanyu, G. Norton HRB 21284 (AG Nürnberg)