Re: WARNING: ODEBUG bug in netdev_freemem (2)

From: Thomas Gleixner
Date: Mon Jun 24 2019 - 05:34:24 EST


On Mon, 24 Jun 2019, syzbot wrote:

> Hello,
>
> syzbot found the following crash on:
>
> HEAD commit: fd6b99fa Merge branch 'akpm' (patches from Andrew)
> git tree: upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=144de256a00000
> kernel config: https://syzkaller.appspot.com/x/.config?x=fa9f7e1b6a8bb586
> dashboard link: https://syzkaller.appspot.com/bug?extid=c4521ac872a4ccc3afec
> compiler: gcc (GCC) 9.0.0 20181231 (experimental)
>
> Unfortunately, I don't have any reproducer for this crash yet.
>
> IMPORTANT: if you fix the bug, please add the following tag to the commit:
> Reported-by: syzbot+c4521ac872a4ccc3afec@xxxxxxxxxxxxxxxxxxxxxxxxx
>
> device hsr_slave_0 left promiscuous mode
> team0 (unregistering): Port device team_slave_1 removed
> team0 (unregistering): Port device team_slave_0 removed
> bond0 (unregistering): Releasing backup interface bond_slave_1
> bond0 (unregistering): Releasing backup interface bond_slave_0
> bond0 (unregistering): Released all slaves
> ------------[ cut here ]------------
> ODEBUG: free active (active state 0) object type: timer_list hint:
> delayed_work_timer_fn+0x0/0x90 arch/x86/include/asm/paravirt.h:767

One of the cleaned up devices has left an active timer which belongs to a
delayed work. That's all I can decode out of that splat. :(

Thanks,

tglx