Re: unregister_netdevice: waiting for DEV to become free (2)

From: Toke HÃiland-JÃrgensen
Date: Wed Oct 16 2019 - 06:34:51 EST


Alexei Starovoitov <alexei.starovoitov@xxxxxxxxx> writes:

> On Fri, Oct 11, 2019 at 3:15 AM Tetsuo Handa
> <penguin-kernel@xxxxxxxxxxxxxxxxxxx> wrote:
>>
>> Hello.
>>
>> I noticed that syzbot is reporting that refcount incremented by bpf(BPF_MAP_UPDATE_ELEM)
>> syscall is not decremented when unregister_netdevice() is called. Is this a BPF bug?
>
> Jesper, Toke,
> please take a look.

Yeah, that unregister notification handler definitely looks broken for
hashmaps; I'll send a patch :)

-Toke