From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753375AbcFEKZl (ORCPT ); Sun, 5 Jun 2016 06:25:41 -0400 Received: from wtarreau.pck.nerim.net ([62.212.114.60]:22142 "EHLO 1wt.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752261AbcFEKZf (ORCPT ); Sun, 5 Jun 2016 06:25:35 -0400 From: Willy Tarreau To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: "Michael S. Tsirkin" , Guenter Roeck , Wim Van Sebroeck , Willy Tarreau Subject: [PATCH 3.10 035/143] watchdog: rc32434_wdt: fix ioctl error handling Date: Sun, 5 Jun 2016 12:18:58 +0200 Message-Id: <1465122046-9645-36-git-send-email-w@1wt.eu> X-Mailer: git-send-email 2.8.0.rc2.1.gbe9624a In-Reply-To: <1465122046-9645-1-git-send-email-w@1wt.eu> References: <1465122046-9645-1-git-send-email-w@1wt.eu> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: "Michael S. Tsirkin" commit 10e7ac22cdd4d211cef99afcb9371b70cb175be6 upstream. 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 Signed-off-by: Guenter Roeck Signed-off-by: Wim Van Sebroeck Signed-off-by: Willy Tarreau --- 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 f78bc00..ea8f582 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; } -- 2.8.0.rc2.1.gbe9624a