Subject: Re: [syzbot] INFO: rcu detected stall in net_tx_action

From: Ming Lei <[email-masked]>
Date: Thu, 28 Jul 2022 00:00:07 +0800

On Tue, Jul 26, 2022 at 08:50:09AM -0700, syzbot wrote:
> syzbot suspects this issue was fixed by commit:
> 
> commit 0a9a25ca78437b39e691bcc3dc8240455b803d8d
> Author: Ming Lei <[email-masked]>
> Date:   Fri Mar 18 13:01:43 2022 +0000
> 
>     block: let blkcg_gq grab request queue's refcnt
> 
> bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=1004f05a080000
> start commit:   d6765985a42a Revert "be2net: disable bh with spin_lock in ..
> git tree:       net
> kernel config:  https://syzkaller.appspot.com/x/.config?x=7ca96a2d153c74b0
> dashboard link: https://syzkaller.appspot.com/bug?extid=3ba0493d523d007b3819
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=14c9edc8300000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=172463c8300000
> 

The bad commit has been fixed by the following patch:

d578c770c852 block: avoid calling blkg_free() in atomic context

Thanks, 
Ming