From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756555AbcGGHk4 (ORCPT ); Thu, 7 Jul 2016 03:40:56 -0400 Received: from prv-mh.provo.novell.com ([137.65.248.74]:44725 "EHLO prv-mh.provo.novell.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756371AbcGGHkz convert rfc822-to-8bit (ORCPT ); Thu, 7 Jul 2016 03:40:55 -0400 Message-Id: <577E23A602000078000FBE15@prv-mh.provo.novell.com> X-Mailer: Novell GroupWise Internet Agent 14.2.0 Date: Thu, 07 Jul 2016 01:40:54 -0600 From: "Jan Beulich" To: "Roger Pau Monne" , "Konrad Rzeszutek Wilk" Cc: , Subject: [PATCH] xen-blkfront: avoid NULL de-reference in CDROM ioctl handling Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 8BIT Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The ioctl can be called prior to full device setup having completed. Signed-off-by: Jan Beulich --- drivers/block/xen-blkfront.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) --- 4.7-rc6-xen.orig/drivers/block/xen-blkfront.c +++ 4.7-rc6-xen/drivers/block/xen-blkfront.c @@ -496,12 +496,10 @@ static int blkif_ioctl(struct block_devi return -EFAULT; return 0; - case CDROM_GET_CAPABILITY: { - struct gendisk *gd = info->gd; - if (gd->flags & GENHD_FL_CD) + case CDROM_GET_CAPABILITY: + if (info->gd && (info->gd->flags & GENHD_FL_CD)) return 0; return -EINVAL; - } default: /*printk(KERN_ALERT "ioctl %08x not supported by Xen blkdev\n",