Re: WARNING: possible recursive locking detected

From: Julian Anastasov
Date: Wed Apr 11 2018 - 15:45:52 EST



Hello,

On Wed, 11 Apr 2018, Dmitry Vyukov wrote:

> On Wed, Apr 11, 2018 at 4:02 PM, syzbot
> <syzbot+3c43eecd7745a5ce1640@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
> > Hello,
> >
> > syzbot hit the following crash on upstream commit
> > b284d4d5a6785f8cd07eda2646a95782373cd01e (Tue Apr 10 19:25:30 2018 +0000)
> > Merge tag 'ceph-for-4.17-rc1' of git://github.com/ceph/ceph-client
> > syzbot dashboard link:
> > https://syzkaller.appspot.com/bug?extid=3c43eecd7745a5ce1640
> >
> > So far this crash happened 3 times on upstream.
> > C reproducer: https://syzkaller.appspot.com/x/repro.c?id=5103706542440448
> > syzkaller reproducer:
> > https://syzkaller.appspot.com/x/repro.syz?id=5641659786199040
> > Raw console output:
> > https://syzkaller.appspot.com/x/log.txt?id=5099510896263168
> > Kernel config:
> > https://syzkaller.appspot.com/x/.config?id=-1223000601505858474
> > compiler: gcc (GCC) 8.0.1 20180301 (experimental)
> >
> > IMPORTANT: if you fix the bug, please add the following tag to the commit:
> > Reported-by: syzbot+3c43eecd7745a5ce1640@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.
>
> #syz dup: possible deadlock in rtnl_lock (5)

Yes, patch is now in the "nf" tree, so all these
lockups around start_sync_thread should be resolved soon...

> > IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id =
> > 0
> > IPVS: stopping backup sync thread 4546 ...
> >
> > ============================================
> > IPVS: stopping backup sync thread 4559 ...
> > WARNING: possible recursive locking detected

Regards

--
Julian Anastasov <ja@xxxxxx>