Re: net: SOFTIRQ-safe -> SOFTIRQ-unsafe lock order detected in skb_array_produce

Dmitry Vyukov
2017-02-09T18:05:06Z

On Thu, Feb 9, 2017 at 6:50 PM, Michael S. Tsirkin <mst@redhat.com> wrote:
> On Thu, Feb 09, 2017 at 11:49:30AM +0100, Dmitry Vyukov wrote:
>> On Thu, Feb 9, 2017 at 11:02 AM, Jason Wang <jasowang@redhat.com> wrote:
>> >
>> >
>> > ----- Original Message -----
>> >> Hello,
>> >>
>> >> I've got the following report while running syzkaller fuzzer on mmotm
>> >> (git://git.kernel.org/pub/scm/linux/kernel/git/mhocko/mm.git)
>> >> remotes/mmotm/auto-latest ee4ba7533626ba7bf2f8b992266467ac9fdc045e:
>> >>
>> >
>> > [...]
>> >
>> >>
>> >> other info that might help us debug this:
>> >>
>> >> Possible interrupt unsafe locking scenario:
>> >>
>> >> CPU0 CPU1
>> >> ---- ----
>> >> lock(&(&r->consumer_lock)->rlock);
>> >> local_irq_disable();
>> >> lock(&(&r->producer_lock)->rlock);
>> >> lock(&(&r->consumer_lock)->rlock);
>> >> <Interrupt>
>> >> lock(&(&r->producer_lock)->rlock);
>> >>
>> >
>> > Thanks a lot for the testing.
>> >
>> > Looks like we could address this by using skb_array_consume_bh() instead.
>> >
>> > Could you pls verify if the following patch works?
>>
>> No, I can't test it, sorry. This happened once on bots. And bots
>> currently test only upstream versions.
>
> Which trees are tested? Will linux-next help?

Linus tree, linux-next and mmotm at the moment.