From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:58546 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751409AbeAVIld (ORCPT ); Mon, 22 Jan 2018 03:41:33 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Li Jinyue , Thomas Gleixner , peterz@infradead.org, dvhart@infradead.org Subject: [PATCH 4.4 22/53] futex: Prevent overflow by strengthen input validation Date: Mon, 22 Jan 2018 09:40:14 +0100 Message-Id: <20180122083911.235536031@linuxfoundation.org> In-Reply-To: <20180122083910.299610926@linuxfoundation.org> References: <20180122083910.299610926@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Li Jinyue commit fbe0e839d1e22d88810f3ee3e2f1479be4c0aa4a upstream. 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 Link: https://lkml.kernel.org/r/1513242294-31786-1-git-send-email-lijinyue@huawei.com Signed-off-by: Greg Kroah-Hartman --- kernel/futex.c | 3 +++ 1 file changed, 3 insertions(+) --- a/kernel/futex.c +++ b/kernel/futex.c @@ -1621,6 +1621,9 @@ static int futex_requeue(u32 __user *uad struct futex_q *this, *next; WAKE_Q(wake_q); + if (nr_wake < 0 || nr_requeue < 0) + return -EINVAL; + if (requeue_pi) { /* * Requeue PI only works on two distinct uaddrs. This