MIME-Version: 1.0
From:   kvartet <xyru1999@gmail.com>
Date:   Tue, 4 Jan 2022 16:42:42 +0800
Message-ID: <CAFkrUshXhoAttBomV3ngTa2rWUebiKOb4D2QkXMrL+YB05Bx_g@mail.gmail.com>
Subject: INFO: task hung in sit_exit_batch_net
To:     davem@davemloft.net, yoshfuji@linux-ipv6.org, dsahern@kernel.org,
        kuba@kernel.org, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com
Cc:     sunhao.th@gmail.com
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

Hello,

When using Syzkaller to fuzz the latest Linux kernel, the following
crash was triggered.

HEAD commit: a7904a538933 Linux 5.16-rc6
git tree: upstream
console output: https://paste.ubuntu.com/p/b8pTJKKYkB/plain/
kernel config: https://paste.ubuntu.com/p/FDDNHDxtwz/plain/

Sorry, I don't have a reproducer for this crash, hope the symbolized
report can help.
If you fix this issue, please add the following tag to the commit:
Reported-by: Yiru Xu <xyru1999@gmail.com>


INFO: task kworker/u8:6:11437 blocked for more than 143 seconds.
      Not tainted 5.16.0-rc6 #9
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:6    state:D stack:26360 pid:11437 ppid:     2 flags:0x00004000
Workqueue: netns cleanup_net
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:4972 [inline]
 __schedule+0xcd9/0x2530 kernel/sched/core.c:6253
 schedule+0xd2/0x260 kernel/sched/core.c:6326
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6385
 __mutex_lock_common kernel/locking/mutex.c:680 [inline]
 __mutex_lock+0xc48/0x1610 kernel/locking/mutex.c:740
 sit_exit_batch_net+0x88/0x770 net/ipv6/sit.c:1946
 ops_exit_list.isra.0+0x103/0x150 net/core/net_namespace.c:171
 cleanup_net+0x511/0xa90 net/core/net_namespace.c:593
 process_one_work+0x9df/0x16d0 kernel/workqueue.c:2298
 worker_thread+0x90/0xed0 kernel/workqueue.c:2445


Best Regards,
Yiru