From 3a1525ec2f10feaa2855e91e848ea7f94b6f6943 Mon Sep 17 00:00:00 2001 From: Li Jinyue <lijinyue@huawei.com> Date: Thu, 14 Dec 2017 17:04:54 +0800 Subject: [PATCH] futex: Prevent overflow by strengthen input validation 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. Bug: 76106267 Signed-off-by: Li Jinyue <lijinyue@huawei.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> 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 <gregkh@linuxfoundation.org> Change-Id: Ib103517371e2691bbfb795fa8f199f6dae35c12e --- kernel/futex.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/kernel/futex.c b/kernel/futex.c index 776c359ec004..14474bfb1699 100644 --- a/kernel/futex.c +++ b/kernel/futex.c @@ -1705,6 +1705,9 @@ static int futex_requeue(u32 __user *uaddr1, unsigned int flags, 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 -- GitLab