Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754364AbbLERLE (ORCPT ); Sat, 5 Dec 2015 12:11:04 -0500 Received: from www.linutronix.de ([62.245.132.108]:53357 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754120AbbLERLC (ORCPT ); Sat, 5 Dec 2015 12:11:02 -0500 Date: Sat, 5 Dec 2015 18:10:13 +0100 (CET) From: Thomas Gleixner To: Sasha Levin cc: john.stultz@linaro.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] time: verify time values in adjtimex ADJ_SETOFFSET to avoid overflow In-Reply-To: <1449198571-21133-1-git-send-email-sasha.levin@oracle.com> Message-ID: References: <1449198571-21133-1-git-send-email-sasha.levin@oracle.com> User-Agent: Alpine 2.11 (DEB 23 2013-08-11) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001,URIBL_BLOCKED=0.001 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1092 Lines: 33 On Thu, 3 Dec 2015, Sasha Levin wrote: > Make sure the tv_usec makes sense. We might multiply them later which can > cause an overflow and undefined behavior. > > Signed-off-by: Sasha Levin > --- > kernel/time/timekeeping.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c > index d563c19..aa3c1c2 100644 > --- a/kernel/time/timekeeping.c > +++ b/kernel/time/timekeeping.c > @@ -1987,6 +1987,10 @@ int do_adjtimex(struct timex *txc) > > if (txc->modes & ADJ_SETOFFSET) { > struct timespec delta; > + > + if (txc->time.tv_usec >= USEC_PER_SEC || txc->time.tv_usec <= -USEC_PER_SEC) > + return -EINVAL; That's not a canonical timeval. timeval_valid() is what you want to check it. Or has adjtimex some magic exception here? Thanks, tglx -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/