Re: possible deadlock in rtnl_lock (3)

From: Paolo Abeni
Date: Wed Feb 07 2018 - 04:08:17 EST


On Tue, 2018-02-06 at 19:00 +0100, Dmitry Vyukov wrote:
> On Tue, Feb 6, 2018 at 6:58 PM, syzbot
> <syzbot+63682ce11532e0da2b9d@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
> > Hello,
> >
> > syzbot hit the following crash on net-next commit
> > 617aebe6a97efa539cc4b8a52adccd89596e6be0 (Sun Feb 4 00:25:42 2018 +0000)
> > Merge tag 'usercopy-v4.16-rc1' of
> > git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux
> >
> > So far this crash happened 2510 times on net-next, upstream.
> > C reproducer is attached.
> > syzkaller reproducer is attached.
> > Raw console output is attached.
> > compiler: gcc (GCC) 7.1.1 20170620
> > .config is attached.
> >
> > IMPORTANT: if you fix the bug, please add the following tag to the commit:
> > Reported-by: syzbot+63682ce11532e0da2b9d@xxxxxxxxxxxxxxxxxxxxxxxxx
> > It will help syzbot understand when the bug is fixed. See footer for
> > details.
> > If you forward the report, please keep this part and the footer.
>
>
> Paolo, was this also fixed by "netfilter: on sockopt() acquire sock
> lock only in the required scope"?

I *think* this is fixed by the above commit, anyway I'll probably be
unable to verify such statement soon.

Thanks,

Paolo