From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932745Ab2JAXAt (ORCPT ); Mon, 1 Oct 2012 19:00:49 -0400 Received: from 1wt.eu ([62.212.114.60]:35215 "EHLO 1wt.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932707Ab2JAXAm (ORCPT ); Mon, 1 Oct 2012 19:00:42 -0400 Message-Id: <20121001225200.194544970@1wt.eu> User-Agent: quilt/0.48-1 Date: Tue, 02 Oct 2012 00:52:58 +0200 From: Willy Tarreau To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Sasha Levin , johnstul@us.ibm.com, Thomas Gleixner , Greg Kroah-Hartman , Willy Tarreau Subject: [ 061/180] ntp: Fix integer overflow when setting time In-Reply-To: <6a854f579a99b4fe2efaca1057e8ae22@local> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.32-longterm review patch. If anyone has any objections, please let me know. ------------------ From: Sasha Levin commit a078c6d0e6288fad6d83fb6d5edd91ddb7b6ab33 upstream. 'long secs' is passed as divisor to div_s64, which accepts a 32bit divisor. On 64bit machines that value is trimmed back from 8 bytes back to 4, causing a divide by zero when the number is bigger than (1 << 32) - 1 and all 32 lower bits are 0. Use div64_long() instead. Signed-off-by: Sasha Levin Cc: johnstul@us.ibm.com Link: http://lkml.kernel.org/r/1331829374-31543-2-git-send-email-levinsasha928@gmail.com Signed-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman [WT: div64_long() does not exist on 2.6.32 and needs a deeper backport than desired. Instead, address the issue by controlling that the divisor is correct for use as an s32 divisor] Signed-off-by: Willy Tarreau --- kernel/time/ntp.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c index c1c36a2..26472a7 100644 --- a/kernel/time/ntp.c +++ b/kernel/time/ntp.c @@ -106,7 +106,7 @@ static inline s64 ntp_update_offset_fll(s64 offset64, long secs) { time_status &= ~STA_MODE; - if (secs < MINSEC) + if ((s32)secs < MINSEC) return 0; if (!(time_status & STA_FLL) && (secs <= MAXSEC)) -- 1.7.2.1.45.g54fbc