From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933006AbaLBEEn (ORCPT ); Mon, 1 Dec 2014 23:04:43 -0500 Received: from userp1040.oracle.com ([156.151.31.81]:34600 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932974AbaLBEEe (ORCPT ); Mon, 1 Dec 2014 23:04:34 -0500 From: Sasha Levin To: linux-kernel@vger.kernel.org Cc: Sasha Levin , John Stultz , Thomas Gleixner Subject: [PATCH] time: settimeofday: validate the values of tv fomr user Date: Mon, 1 Dec 2014 23:04:09 -0500 Message-Id: <1417493050-13594-5-git-send-email-sasha.levin@oracle.com> X-Mailer: git-send-email 2.1.0 In-Reply-To: <1417493050-13594-1-git-send-email-sasha.levin@oracle.com> References: <1417493050-13594-1-git-send-email-sasha.levin@oracle.com> X-Source-IP: ucsinet22.oracle.com [156.151.31.94] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org An unvalidated user input is multiplied by a constant, which can result in an undefined behaviour for large values. While this is validated later, we should avoid triggering undefined behaviour. Signed-off-by: Sasha Levin --- kernel/time/time.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/kernel/time/time.c b/kernel/time/time.c index 9ec4fa5..6f53df7 100644 --- a/kernel/time/time.c +++ b/kernel/time/time.c @@ -200,6 +200,10 @@ SYSCALL_DEFINE2(settimeofday, struct timeval __user *, tv, if (tv) { if (copy_from_user(&user_tv, tv, sizeof(*tv))) return -EFAULT; + + if (user_tv.tv_usec > USEC_PER_SEC || user_tv.tv_usec < 0) + return -EINVAL; + new_ts.tv_sec = user_tv.tv_sec; new_ts.tv_nsec = user_tv.tv_usec * NSEC_PER_USEC; } -- 1.7.10.4