References: <CABcoxUayum5oOqFMMqAeWuS8+EzojquSOSyDA3J_2omY=2EeAg@mail.gmail.com>
User-agent: mu4e 1.6.10; emacs 28.2
From:   Jakub Sitnicki <jakub@cloudflare.com>
To:     Hsin-Wei Hung <hsinweih@uci.edu>
Cc:     John Fastabend <john.fastabend@gmail.com>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>, netdev@vger.kernel.org,
        bpf@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: A potential deadlock in sockhash map
Date:   Thu, 23 Feb 2023 14:17:54 +0100
In-reply-to: <CABcoxUayum5oOqFMMqAeWuS8+EzojquSOSyDA3J_2omY=2EeAg@mail.gmail.com>
Message-ID: <87a614h62a.fsf@cloudflare.com>
MIME-Version: 1.0
Content-Type: text/plain
Precedence: bulk

Hi,

On Mon, Feb 20, 2023 at 07:39 AM -06, Hsin-Wei Hung wrote:
> I think my previous report got blocked since it contained HTML
> subparts so I am sending it again. Our bpf runtime fuzzer (a
> customized syzkaller) triggered a lockdep warning in the bpf subsystem
> indicating a potential deadlock. We are able to trigger this bug on
> v5.15.25 and v5.19. The following code is a BPF PoC, and the lockdep
> warning is attached at the end.

Not sure if you've seen John's reply to the previous report:

https://lore.kernel.org/all/63dddcc92fc31_6bb15208e9@john.notmuch/

Are you also fuzzing any newer kernel versions? Or was v5.19 the latest?

Did syzkaller find a reproducer?

Thanks,
Jakub