Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755056AbbKWN1B (ORCPT ); Mon, 23 Nov 2015 08:27:01 -0500 Received: from mx2.suse.de ([195.135.220.15]:59319 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754136AbbKWNJk (ORCPT ); Mon, 23 Nov 2015 08:09:40 -0500 X-Amavis-Alert: BAD HEADER SECTION, Duplicate header field: "References" From: Jiri Slaby To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Cathy Avery , Konrad Rzeszutek Wilk , Jiri Slaby Subject: [PATCH 3.12 18/72] xen-blkfront: check for null drvdata in blkback_changed (XenbusStateClosing) Date: Mon, 23 Nov 2015 14:08:40 +0100 Message-Id: <54001184d4c2f4660a783437d318d3868239690a.1448283890.git.jslaby@suse.cz> X-Mailer: git-send-email 2.6.3 In-Reply-To: References: In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1460 Lines: 43 From: Cathy Avery 3.12-stable review patch. If anyone has any objections, please let me know. =============== commit a54c8f0f2d7df525ff997e2afe71866a1a013064 upstream. xen-blkfront will crash if the check to talk_to_blkback() in blkback_changed()(XenbusStateInitWait) returns an error. The driver data is freed and info is set to NULL. Later during the close process via talk_to_blkback's call to xenbus_dev_fatal() the null pointer is passed to and dereference in blkfront_closing. Signed-off-by: Cathy Avery Signed-off-by: Konrad Rzeszutek Wilk Signed-off-by: Jiri Slaby --- drivers/block/xen-blkfront.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c index 7d0eb3f8d629..0b6932c376fb 100644 --- a/drivers/block/xen-blkfront.c +++ b/drivers/block/xen-blkfront.c @@ -1965,7 +1965,8 @@ static void blkback_changed(struct xenbus_device *dev, break; /* Missed the backend's Closing state -- fallthrough */ case XenbusStateClosing: - blkfront_closing(info); + if (info) + blkfront_closing(info); break; } } -- 2.6.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/