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 <20210913135459.GA120302@rowland.harvard.edu>
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From:   Hao Sun <sunhao.th@gmail.com>
Date:   Sat, 18 Sep 2021 09:56:52 +0800
Message-ID: <CACkBjsZcg0B=tF8cr54VqaJMVURD9R463epZqRQfesnoY=+L8g@mail.gmail.com>
Subject: Re: INFO: task hung in hub_port_init
To:     Alan Stern <stern@rowland.harvard.edu>
Cc:     Greg KH <gregkh@linuxfoundation.org>, linux-usb@vger.kernel.org,
        a.darwish@linutronix.de, johan@kernel.org,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        oneukum@suse.com
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Hi Alan,

Alan Stern <stern@rowland.harvard.edu> =E4=BA=8E2021=E5=B9=B49=E6=9C=8813=
=E6=97=A5=E5=91=A8=E4=B8=80 =E4=B8=8B=E5=8D=889:55=E5=86=99=E9=81=93=EF=BC=
=9A
>
> On Mon, Sep 13, 2021 at 11:13:15AM +0800, Hao Sun wrote:
> > Hello,
> >
> > When using Healer to fuzz the Linux kernel, the following crash was tri=
ggered.
> >
> > HEAD commit: ac08b1c68d1b Merge tag 'pci-v5.15-changes'
> > git tree: upstream
> > console output:
> > https://drive.google.com/file/d/1ZeDIMe-DoY3fB32j2p5ifgpq-Lc5N74I/view?=
usp=3Dsharing
> > kernel config: https://drive.google.com/file/d/1qrJUXD8ZIeAkg-xojzDpp04=
v9MtQ8RR6/view?usp=3Dsharing
> > Syzlang reproducer:
> > https://drive.google.com/file/d/1tZe8VmXfxoPqlNpzpGOd-e5WCSWgbkxB/view?=
usp=3Dsharing
> > Similar report:
> > https://groups.google.com/g/syzkaller-bugs/c/zX55CUzjBOY/m/uf91r0XqAgAJ
> >
> > Sorry, I don't have a C reproducer for this crash but have a Syzlang
> > reproducer. Also, hope the symbolized report can help.
> > Here are the instructions on how to execute Syzlang prog:
> > https://github.com/google/syzkaller/blob/master/docs/executing_syzkalle=
r_programs.md
> >
> > If you fix this issue, please add the following tag to the commit:
> > Reported-by: Hao Sun <sunhao.th@gmail.com>
>
> There's not much hope of finding the cause of a problem like this
> without seeing the kernel log.
>

Healer found another Syzlang prog to reproduce this task hang:
https://paste.ubuntu.com/p/HCNYbKJYtx/

Also here is a very simple script to execute the reproducer:
https://paste.ubuntu.com/p/ZTGmvFSP6d/

The `syz-execprog` and `syz-executor` are needed, so please build
Syzkaller first before running the script.
Hope this can help to find the root cause of the problem.

Regards
Hao