From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759786Ab3GaNZs (ORCPT ); Wed, 31 Jul 2013 09:25:48 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:46913 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759699Ab3GaNZp (ORCPT ); Wed, 31 Jul 2013 09:25:45 -0400 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Martin K. Petersen" , "James Bottomley" , "Ewan D. Milne" Date: Wed, 31 Jul 2013 15:23:09 +0200 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [68/84] [SCSI] sd: fix crash when UA received on DIF enabled device In-Reply-To: X-SA-Exim-Connect-IP: 151.216.67.181 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.2.50-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: "Ewan D. Milne" commit 085b513f97d8d799d28491239be4b451bcd8c2c5 upstream. sd_prep_fn will allocate a larger CDB for the command via mempool_alloc for devices using DIF type 2 protection. This CDB was being freed in sd_done, which results in a kernel crash if the command is retried due to a UNIT ATTENTION. This change moves the code to free the larger CDB into sd_unprep_fn instead, which is invoked after the request is complete. It is no longer necessary to call scsi_print_command separately for this case as the ->cmnd will no longer be NULL in the normal code path. Also removed conditional test for DIF type 2 when freeing the larger CDB because the protection_type could have been changed via sysfs while the command was executing. Signed-off-by: Ewan D. Milne Acked-by: Martin K. Petersen Signed-off-by: James Bottomley Signed-off-by: Ben Hutchings --- drivers/scsi/sd.c | 22 +++++++--------------- 1 file changed, 7 insertions(+), 15 deletions(-) --- a/drivers/scsi/sd.c +++ b/drivers/scsi/sd.c @@ -641,10 +641,17 @@ static int scsi_setup_flush_cmnd(struct static void sd_unprep_fn(struct request_queue *q, struct request *rq) { + struct scsi_cmnd *SCpnt = rq->special; + if (rq->cmd_flags & REQ_DISCARD) { free_page((unsigned long)rq->buffer); rq->buffer = NULL; } + if (SCpnt->cmnd != rq->cmd) { + mempool_free(SCpnt->cmnd, sd_cdb_pool); + SCpnt->cmnd = NULL; + SCpnt->cmd_len = 0; + } } /** @@ -1452,21 +1459,6 @@ static int sd_done(struct scsi_cmnd *SCp if (rq_data_dir(SCpnt->request) == READ && scsi_prot_sg_count(SCpnt)) sd_dif_complete(SCpnt, good_bytes); - if (scsi_host_dif_capable(sdkp->device->host, sdkp->protection_type) - == SD_DIF_TYPE2_PROTECTION && SCpnt->cmnd != SCpnt->request->cmd) { - - /* We have to print a failed command here as the - * extended CDB gets freed before scsi_io_completion() - * is called. - */ - if (result) - scsi_print_command(SCpnt); - - mempool_free(SCpnt->cmnd, sd_cdb_pool); - SCpnt->cmnd = NULL; - SCpnt->cmd_len = 0; - } - return good_bytes; }