From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758361AbcB1PoQ (ORCPT ); Sun, 28 Feb 2016 10:44:16 -0500 Received: from mx1.redhat.com ([209.132.183.28]:38914 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757868AbcB1PoO (ORCPT ); Sun, 28 Feb 2016 10:44:14 -0500 Date: Sun, 28 Feb 2016 17:44:09 +0200 From: "Michael S. Tsirkin" To: linux-kernel@vger.kernel.org Cc: stable@vger.kernel.org, Wim Van Sebroeck , Guenter Roeck , linux-watchdog@vger.kernel.org, Dan Carpenter Subject: [PATCH for-4.5] watchdog/rc32434_wdt: fix ioctl error handling Message-ID: <1456674185-24670-1-git-send-email-mst@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline X-Mutt-Fcc: =sent X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.39]); Sun, 28 Feb 2016 15:44:14 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Calling return copy_to_user(...) in an ioctl will not do the right thing if there's a pagefault: copy_to_user returns the number of bytes not copied in this case. Fix up watchdog/rc32434_wdt to do return copy_to_user(...)) ? -EFAULT : 0; instead. Cc: stable@vger.kernel.org Signed-off-by: Michael S. Tsirkin --- Untested. drivers/watchdog/rc32434_wdt.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/watchdog/rc32434_wdt.c b/drivers/watchdog/rc32434_wdt.c index 71e78ef..3a75f3b 100644 --- a/drivers/watchdog/rc32434_wdt.c +++ b/drivers/watchdog/rc32434_wdt.c @@ -237,7 +237,7 @@ static long rc32434_wdt_ioctl(struct file *file, unsigned int cmd, return -EINVAL; /* Fall through */ case WDIOC_GETTIMEOUT: - return copy_to_user(argp, &timeout, sizeof(int)); + return copy_to_user(argp, &timeout, sizeof(int)) ? -EFAULT : 0; default: return -ENOTTY; } -- MST