Re: net/llc: BUG in llc_sap_state_process/skb_set_owner_r

From: Eric Dumazet
Date: Sun Feb 12 2017 - 12:11:17 EST


On Sun, Feb 12, 2017 at 8:44 AM, Andrey Konovalov <andreyknvl@xxxxxxxxxx> wrote:
> Hi,
>
> I've got the following error report while fuzzing the kernel with syzkaller.
>
> On commit 926af6273fc683cd98cd0ce7bf0d04a02eed6742.
>
> A reproducer and .config are attached

Thanks for the report.

llc sets skb->sk without corresponding skb->destructor.

This is considered invalid by our current standards.

As I added the sanity check in skb_destructor() back in linux-3.12
(!!!), I will send the corresponding LLC fix.

( commit 376c7311bdb6efea3322310333576a04d73fbe4c )