From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:47719 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755506AbcGYVlz (ORCPT ); Mon, 25 Jul 2016 17:41:55 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Helge Deller , James Bottomley , Johannes Thumshirn , "Ewan D. Milne" , Christoph Hellwig , "Martin K. Petersen" Subject: [PATCH 4.6 192/203] 53c700: fix BUG on untagged commands Date: Mon, 25 Jul 2016 13:56:47 -0700 Message-Id: <20160725203437.243650037@linuxfoundation.org> In-Reply-To: <20160725203429.221747288@linuxfoundation.org> References: <20160725203429.221747288@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: James Bottomley commit 8beb330044d0d1878c7b92290e91c0b889e92633 upstream. The untagged command case in the 53c700 driver has been broken since host wide tags were enabled because the replaced scsi_find_tag() function had a special case for the tag value SCSI_NO_TAG to retrieve sdev->current_cmnd. The replacement function scsi_host_find_tag() has no such special case and returns NULL causing untagged commands to trigger a BUG() in the driver. Inspection shows that the 53c700 is the only driver using this SCSI_NO_TAG case, so a local fix in the driver suffices to fix this problem globally. Fixes: 64d513ac31b - "scsi: use host wide tags by default" Reported-by: Helge Deller Tested-by: Helge Deller Signed-off-by: James Bottomley Reviewed-by: Johannes Thumshirn Reviewed-by: Ewan D. Milne Acked-by: Christoph Hellwig Signed-off-by: Martin K. Petersen Signed-off-by: Greg Kroah-Hartman --- drivers/scsi/53c700.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/drivers/scsi/53c700.c +++ b/drivers/scsi/53c700.c @@ -1122,7 +1122,7 @@ process_script_interrupt(__u32 dsps, __u } else { struct scsi_cmnd *SCp; - SCp = scsi_host_find_tag(SDp->host, SCSI_NO_TAG); + SCp = SDp->current_cmnd; if(unlikely(SCp == NULL)) { sdev_printk(KERN_ERR, SDp, "no saved request for untagged cmd\n"); @@ -1826,7 +1826,7 @@ NCR_700_queuecommand_lck(struct scsi_cmn slot->tag, slot); } else { slot->tag = SCSI_NO_TAG; - /* must populate current_cmnd for scsi_host_find_tag to work */ + /* save current command for reselection */ SCp->device->current_cmnd = SCp; } /* sanity check: some of the commands generated by the mid-layer