This is a note to let you know that I've just added the patch titled
futex: Prevent overflow by strengthen input validation
to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
futex-prevent-overflow-by-strengthen-input-validation.patch
and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From fbe0e839d1e22d88810f3ee3e2f1479be4c0aa4a Mon Sep 17 00:00:00 2001
From: Li Jinyue <lijinyue@xxxxxxxxxx>
Date: Thu, 14 Dec 2017 17:04:54 +0800
Subject: futex: Prevent overflow by strengthen input validation
From: Li Jinyue <lijinyue@xxxxxxxxxx>
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 <lijinyue@xxxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: peterz@xxxxxxxxxxxxx
Cc: dvhart@xxxxxxxxxxxxx
Link: https://lkml.kernel.org/r/1513242294-31786-1-git-send-email-lijinyue@xxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
kernel/futex.c | 3 +++
1 file changed, 3 insertions(+)
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -1711,6 +1711,9 @@ 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
Patches currently in stable-queue which might be from lijinyue@xxxxxxxxxx are
queue-4.9/futex-prevent-overflow-by-strengthen-input-validation.patch