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Date: Wed, 19 Aug 2026 14:40:19 +0200
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: Runyu Xiao <runyu.xiao@seu.edu.cn>
Cc: Rui Miguel Silva <rmfrfs@gmail.com>, Johan Hovold <johan@kernel.org>,
	Alex Elder <elder@kernel.org>,
	Kris Huang <huang_kris@projectara.com>,
	greybus-dev <greybus-dev@lists.linaro.org>,
	linux-staging <linux-staging@lists.linux.dev>,
	linux-kernel <linux-kernel@vger.kernel.org>,
	stable <stable@vger.kernel.org>, Jianhao Xu <jianhao.xu@seu.edu.cn>
Subject: Re: [PATCH] staging: greybus: light: initialize channel lock before
 registration
Message-ID: <2026081946-hamstring-sly-8c39@gregkh>
References: <20260818142020.1989539-1-runyu.xiao@seu.edu.cn>
 <2026081801-arguable-gosling-c590@gregkh>
 <ANAASQBEK9Ye2X-O4oze*arv.3.1787142765226.Hmail.220255722@seu.edu.cn>
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On Wed, Aug 19, 2026 at 08:32:45PM +0800, Runyu Xiao wrote:
> On Tue, Aug 18, 2026 at 20:23:10 +0200, Greg Kroah-Hartman wrote:
> > How was this found and tested?
> 
> 
> Found by code inspection: gb_lights_channel_register() publishes the
> LED class device and its brightness callback before
> mutex_init(&light->channels[i].lock) runs, so a concurrent brightness
> update can take an uninitialized mutex.

<snip>

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greg k-h