Re: kernel panic: stack is corrupted in udp4_lib_lookup2

From: Stefano Brivio
Date: Fri Jan 04 2019 - 05:54:48 EST


On Fri, 4 Jan 2019 11:32:12 +0100
Dmitry Vyukov <dvyukov@xxxxxxxxxx> wrote:

> On Thu, Jan 3, 2019 at 10:54 PM Stefano Brivio <sbrivio@xxxxxxxxxx> wrote:
> >
> > On Thu, 3 Jan 2019 15:15:06 -0600
> > Willem de Bruijn <willemdebruijn.kernel@xxxxxxxxx> wrote:
> >
> > > syzbot generated stack traces with
> > >
> > > [ 183.517380] udpv6_err+0x46/0x60
> > > [ 183.520739] ? __udp6_lib_err+0x1890/0x1890
> > > [ 183.525054] gue6_err_proto_handler+0x199/0x280
> >
> > Where? I can't find that in any logs linked from the dashboard at
> > https://syzkaller.appspot.com/bug?extid=4ad25edc7a33e4ab91e0 :(
>
> Stefano, there are these 4 bugs reported that have similarly looking
> reproducers involving udp sockets and that crash modes that looks like
> stack corruption/overflow:
>
> https://syzkaller.appspot.com/bug?extid=14005fa30c9a07192934
> https://syzkaller.appspot.com/bug?extid=d14090007dc9ba5fa9b7
> https://syzkaller.appspot.com/bug?extid=137ed32ec9a6d5b0d5fe
> https://syzkaller.appspot.com/bug?id=d5bc3e0c66d200d72216ab343a67c4327e4a3452
>
> Are these the same bug as this?

Judging from the reproducers for the first three, they seem to be. I
guess I can trigger tests also for those by sending a (sharp)syz
test ... e-mail with the patch to the Reported-by: addresses, right?

And the three reports you pointed out from the pile of corrupted
reports also seem to match, others look unrelated.

--
Stefano