From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9DD95C6778A for ; Mon, 2 Jul 2018 09:38:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 635F025475 for ; Mon, 2 Jul 2018 09:38:14 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 635F025475 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=zytor.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754580AbeGBJiN (ORCPT ); Mon, 2 Jul 2018 05:38:13 -0400 Received: from terminus.zytor.com ([198.137.202.136]:48147 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753529AbeGBJiJ (ORCPT ); Mon, 2 Jul 2018 05:38:09 -0400 Received: from terminus.zytor.com (localhost [127.0.0.1]) by terminus.zytor.com (8.15.2/8.15.2) with ESMTPS id w629c4DT4024422 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Mon, 2 Jul 2018 02:38:04 -0700 Received: (from tipbot@localhost) by terminus.zytor.com (8.15.2/8.15.2/Submit) id w629c4PD4024419; Mon, 2 Jul 2018 02:38:04 -0700 Date: Mon, 2 Jul 2018 02:38:04 -0700 X-Authentication-Warning: terminus.zytor.com: tipbot set sender to tipbot@zytor.com using -f From: tip-bot for Thomas Gleixner Message-ID: Cc: hpa@zytor.com, tglx@linutronix.de, linux-kernel@vger.kernel.org, mingo@kernel.org, icytxw@gmail.com, john.stultz@linaro.org Reply-To: john.stultz@linaro.org, icytxw@gmail.com, mingo@kernel.org, linux-kernel@vger.kernel.org, tglx@linutronix.de, hpa@zytor.com In-Reply-To: References: To: linux-tip-commits@vger.kernel.org Subject: [tip:timers/core] alarmtimer: Prevent overflow for relative nanosleep Git-Commit-ID: 5f936e19cc0ef97dbe3a56e9498922ad5ba1edef X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 5f936e19cc0ef97dbe3a56e9498922ad5ba1edef Gitweb: https://git.kernel.org/tip/5f936e19cc0ef97dbe3a56e9498922ad5ba1edef Author: Thomas Gleixner AuthorDate: Mon, 2 Jul 2018 09:34:29 +0200 Committer: Thomas Gleixner CommitDate: Mon, 2 Jul 2018 11:33:26 +0200 alarmtimer: Prevent overflow for relative nanosleep Air Icy reported: UBSAN: Undefined behaviour in kernel/time/alarmtimer.c:811:7 signed integer overflow: 1529859276030040771 + 9223372036854775807 cannot be represented in type 'long long int' Call Trace: alarm_timer_nsleep+0x44c/0x510 kernel/time/alarmtimer.c:811 __do_sys_clock_nanosleep kernel/time/posix-timers.c:1235 [inline] __se_sys_clock_nanosleep kernel/time/posix-timers.c:1213 [inline] __x64_sys_clock_nanosleep+0x326/0x4e0 kernel/time/posix-timers.c:1213 do_syscall_64+0xb8/0x3a0 arch/x86/entry/common.c:290 alarm_timer_nsleep() uses ktime_add() to add the current time and the relative expiry value. ktime_add() has no sanity checks so the addition can overflow when the relative timeout is large enough. Use ktime_add_safe() which has the necessary sanity checks in place and limits the result to the valid range. Fixes: 9a7adcf5c6de ("timers: Posix interface for alarm-timers") Reported-by: Team OWL337 Signed-off-by: Thomas Gleixner Cc: John Stultz Link: https://lkml.kernel.org/r/alpine.DEB.2.21.1807020926360.1595@nanos.tec.linutronix.de --- kernel/time/alarmtimer.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/kernel/time/alarmtimer.c b/kernel/time/alarmtimer.c index 78a3cc555823..fa5de5e8de61 100644 --- a/kernel/time/alarmtimer.c +++ b/kernel/time/alarmtimer.c @@ -808,7 +808,8 @@ static int alarm_timer_nsleep(const clockid_t which_clock, int flags, /* Convert (if necessary) to absolute time */ if (flags != TIMER_ABSTIME) { ktime_t now = alarm_bases[type].gettime(); - exp = ktime_add(now, exp); + + exp = ktime_add_safe(now, exp); } ret = alarmtimer_do_nsleep(&alarm, exp, type);