From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752530AbaLDAZ1 (ORCPT ); Wed, 3 Dec 2014 19:25:27 -0500 Received: from userp1040.oracle.com ([156.151.31.81]:45355 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751030AbaLDAZ0 (ORCPT ); Wed, 3 Dec 2014 19:25:26 -0500 From: Sasha Levin To: linux-kernel@vger.kernel.org Cc: Sasha Levin , John Stultz , Thomas Gleixner Subject: [PATCH] time: adjtimex: validate the ADJ_FREQUENCY case Date: Wed, 3 Dec 2014 19:25:05 -0500 Message-Id: <1417652705-1959-1-git-send-email-sasha.levin@oracle.com> X-Mailer: git-send-email 2.1.0 X-Source-IP: acsinet22.oracle.com [141.146.126.238] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Verify that the frequency value from userspace is valid and makes sense. Unverified values can cause overflows later on. Signed-off-by: Sasha Levin --- kernel/time/ntp.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c index 87a346f..54828cf 100644 --- a/kernel/time/ntp.c +++ b/kernel/time/ntp.c @@ -633,6 +633,15 @@ int ntp_validate_timex(struct timex *txc) if ((txc->modes & ADJ_SETOFFSET) && (!capable(CAP_SYS_TIME))) return -EPERM; + if (txc->modes & ADJ_FREQUENCY) { + if (!capable(CAP_SYS_TIME)) + return -EPERM; + if (txc->freq < 0) + return -EINVAL; + if (LONG_MAX / PPM_SCALE < txc->freq) + return -EINVAL; + } + return 0; } -- 1.7.10.4