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Subject: Re: =?UTF-8?Q?=E5=9B=9E=E5=A4=8D=3A?= drivers/char: suspected
 null-pointer dereference problem in handle_control_message
From:   Amit Shah <amit@infradead.org>
To:     YE Chengfeng <cyeaa@connect.ust.hk>,
        "amit@kernel.org" <amit@kernel.org>,
        "arnd@arndb.de" <arnd@arndb.de>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Date:   Thu, 28 Oct 2021 13:54:49 +0200
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On Tue, 2021-10-26 at 11:51 +0000, YE Chengfeng wrote:
> Thanks for your reply.
> 
> Agree with you, seems that the branch at #line 1573 already handles this situation.
> 
> Another question, is it possible that port->name is null when show_port_name is invoked? I don't see any null-check there, could it be a null-dereference problem at #line 1282? Link is below.
> https://github.com/torvalds/linux/blob/master/drivers/char/virtio_console.c#L1282

Why don't you try it?

It's certainly possible that a port doesn't have a name.