Subject: size overflow in function qdisc_tree_decrease_qlen net/sched/sch_api.c

From: Daniele Fucini <[email-masked]>
Date: Tue, 1 Dec 2015 02:00:05 +0100

Hello,

I'm using a Grsecurity patched kernel (version 4.2.6-201511282239) and
I'm getting system freezes due to PaX detecting a size overflow in
function qdisc_tree_decrease_qlen net/sched/sch_api.c:769 whenever I use
Transmission BitTorrent client.

On the Grsecurity forum I was told it's probably an unintended integer
underflow that I should report upstream.

Here's the relevant log:
https://gist.github.com/cf54ccbb12ea65e146d4

And here's the thread on Grsecurity forum:
https://forums.grsecurity.net/viewtopic.php?f=3&t=4327

Let me know if there's any other information you need to help debug
this.

Daniele