From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-sn1nam02on0109.outbound.protection.outlook.com ([104.47.36.109]:7623 "EHLO NAM02-SN1-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1032212AbeCAPaP (ORCPT ); Thu, 1 Mar 2018 10:30:15 -0500 From: Sasha Levin To: "stable@vger.kernel.org" , "stable-commits@vger.kernel.org" CC: Li Jinyue , Thomas Gleixner , Sasha Levin Subject: [added to the 4.1 stable tree] futex: Prevent overflow by strengthen input validation Date: Thu, 1 Mar 2018 15:24:20 +0000 Message-ID: <20180301152116.1486-181-alexander.levin@microsoft.com> References: <20180301152116.1486-1-alexander.levin@microsoft.com> In-Reply-To: <20180301152116.1486-1-alexander.levin@microsoft.com> Content-Language: en-US Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org List-ID: From: Li Jinyue This patch has been added to the 4.1 stable tree. If you have any objections, please let us know. =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D [ Upstream commit fbe0e839d1e22d88810f3ee3e2f1479be4c0aa4a ] UBSAN reports signed integer overflow in kernel/futex.c: UBSAN: Undefined behaviour in kernel/futex.c:2041:18 signed integer overflow: 0 - -2147483648 cannot be represented in type 'int' Add a sanity check to catch negative values of nr_wake and nr_requeue. Signed-off-by: Li Jinyue Signed-off-by: Thomas Gleixner Cc: peterz@infradead.org Cc: dvhart@infradead.org Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/1513242294-31786-1-git-send-email-lijinyue@= huawei.com Signed-off-by: Sasha Levin --- kernel/futex.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/kernel/futex.c b/kernel/futex.c index 959cc4fc6de5..4195616b27d9 100644 --- a/kernel/futex.c +++ b/kernel/futex.c @@ -1514,6 +1514,9 @@ static int futex_requeue(u32 __user *uaddr1, unsigned= int flags, struct futex_hash_bucket *hb1, *hb2; struct futex_q *this, *next; =20 + if (nr_wake < 0 || nr_requeue < 0) + return -EINVAL; + if (requeue_pi) { /* * Requeue PI only works on two distinct uaddrs. This --=20 2.14.1