Re: INFO: task hung in add_one_compat_dev

[Lee Jones]

On Tue, 04 Jan 2022, kvartet wrote:

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

Why was this sent to me?

> HEAD commit: a7904a538933 Linux 5.16-rc6
> git tree: upstream
> console output: https://paste.ubuntu.com/p/b6z4q5NnV6/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@xxxxxxxxx>
> 
> 
> INFO: task syz-executor.5:32436 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:syz-executor.5  state:D stack:24768 pid:32436 ppid:  6788 flags:0x00004000
> 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
>  add_one_compat_dev drivers/infiniband/core/device.c:942 [inline]
>  add_one_compat_dev+0xea/0x7f0 drivers/infiniband/core/device.c:919
>  rdma_dev_init_net+0x28b/0x480 drivers/infiniband/core/device.c:1184
>  ops_init+0xaf/0x420 net/core/net_namespace.c:140
>  setup_net+0x415/0xa40 net/core/net_namespace.c:326
>  copy_net_ns+0x2d9/0x660 net/core/net_namespace.c:470
>  create_new_namespaces.isra.0+0x3cb/0xae0 kernel/nsproxy.c:110
>  copy_namespaces+0x391/0x450 kernel/nsproxy.c:178
>  copy_process+0x2d37/0x73e0 kernel/fork.c:2194
>  kernel_clone+0xe7/0x10c0 kernel/fork.c:2582
>  __do_sys_clone3+0x1c9/0x2e0 kernel/fork.c:2857
>  do_syscall_x64 arch/x86/entry/common.c:50 [inline]
>  do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
>  entry_SYSCALL_64_after_hwframe+0x44/0xae
> RIP: 0033:0x7ff4fe91489d
> RSP: 002b:00007ff4fd285c28 EFLAGS: 00000246 ORIG_RAX: 00000000000001b3
> RAX: ffffffffffffffda RBX: 00007ff4fea33f60 RCX: 00007ff4fe91489d
> RDX: 0000000000000000 RSI: 0000000000000058 RDI: 0000000020000440
> RBP: 00007ff4fe98100d R08: 0000000000000000 R09: 0000000000000000
> R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
> R13: 00007fff3b67e98f R14: 00007ff4fea33f60 R15: 00007ff4fd285dc0

-- 
Lee Jones [李琼斯]
Principal Technical Lead - Developer Services
Linaro.org │ Open source software for Arm SoCs
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