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

[Jason Wang]

On 2017年02月09日 18:49, Dmitry Vyukov wrote:

On Thu, Feb 9, 2017 at 11:02 AM, Jason Wang<jasow...@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.

No problem, will try to test my self.

Thanks