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From: Sasha Levin <sasha.levin@oracle.com>
To: john.stultz@linaro.org, tglx@linutronix.de
Cc: linux-kernel@vger.kernel.org, Sasha Levin <sasha.levin@oracle.com>
Subject: [PATCH] time: verify time values in adjtimex ADJ_SETOFFSET to avoid overflow
Date: Thu,  3 Dec 2015 22:09:31 -0500	[thread overview]
Message-ID: <1449198571-21133-1-git-send-email-sasha.levin@oracle.com> (raw)

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 <sasha.levin@oracle.com>
---
 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;
+
 		delta.tv_sec  = txc->time.tv_sec;
 		delta.tv_nsec = txc->time.tv_usec;
 		if (!(txc->modes & ADJ_NANO))
-- 
1.7.10.4


             reply	other threads:[~2015-12-04  3:09 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-12-04  3:09 Sasha Levin [this message]
2015-12-04 20:27 ` John Stultz
2015-12-05 17:10 ` Thomas Gleixner
2015-12-06  0:15   ` Sasha Levin
2015-12-06  9:07     ` Thomas Gleixner
2015-12-06 22:11       ` Richard Cochran
2015-12-07 19:54         ` John Stultz
2015-12-07 20:11           ` [RFC][PATCH -reworked] time: Verify " John Stultz
2015-12-07 20:13             ` John Stultz
2015-12-07 20:16               ` Thomas Gleixner
2015-12-07 20:15           ` [PATCH] time: verify " Thomas Gleixner
2015-12-07 20:19             ` John Stultz
2015-12-07 20:23             ` John Stultz

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