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 3.18-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-3.18 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 @@ -1514,6 +1514,9 @@ static int futex_requeue(u32 __user *uad struct futex_hash_bucket *hb1, *hb2; struct futex_q *this, *next; + 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-3.18/futex-prevent-overflow-by-strengthen-input-validation.patch