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

From: Ming Lei
Date: Wed Jul 27 2022 - 12:00:32 EST


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 <ming.lei@xxxxxxxxxx>
> 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