Re: INFO: rcu detected stall in pfkey_sendmsg

[Florian Westphal]

Dmitry Vyukov <dvyukov@xxxxxxxxxx> wrote:
> On Wed, Dec 19, 2018 at 7:37 PM syzbot
> <syzbot+e1d3a7522b4d05aeede4@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
> >
> > Hello,
> >
> > syzbot found the following crash on:
> >
> > HEAD commit:    a26d94bff4d5 net: bridge: remove unneeded variable 'err'
> > git tree:       net-next
> > console output: https://syzkaller.appspot.com/x/log.txt?x=14c7a4cd400000
> > kernel config:  https://syzkaller.appspot.com/x/.config?x=d9655b05acfc97ff
> > dashboard link: https://syzkaller.appspot.com/bug?extid=e1d3a7522b4d05aeede4
> > compiler:       gcc (GCC) 8.0.1 20180413 (experimental)
> >
> > Unfortunately, I don't have any reproducer for this crash yet.
> 
> +Florian, this looks related to:
> INFO: rcu detected stall in xfrm_hash_rebuild
> https://syzkaller.appspot.com/bug?id=62ee9df6b17e143dcd22a6bc5383c1b4ba797c8c
> https://groups.google.com/forum/#!msg/syzkaller-bugs/4yD3ts-wWRA/63scKqSyDAAJ
> 
> Should we dup them?

No, not yet anyway.  First report triggers rcu stall during hash
rebuild, this looks like stall is directly on insertion.

(Could obviously still be same bug).