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Date: Wed, 11 Mar 2026 13:14:00 +0100
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: Fan Wu <fanwu01@zju.edu.cn>
Cc: Johan Hovold <johan@kernel.org>, linux-usb@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH] USB: serial: opticon: fix UAF in write callback during
 port removal
Message-ID: <2026031137-amply-cardboard-581c@gregkh>
References: <aa_c0B9E7MPm_yqL@hovoldconsulting.com>
 <20260309142757.589802-1-fanwu01@zju.edu.cn>
 <20260310170424.19817-1-fanwu01@zju.edu.cn>
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In-Reply-To: <20260310170424.19817-1-fanwu01@zju.edu.cn>

On Tue, Mar 10, 2026 at 05:04:24PM +0000, Fan Wu wrote:
> On Tue, Mar 10, 2026 at 09:56:48 +0100, Johan Hovold wrote:
> > How was this potential issue found? Are you using some kind of LLM or
> > other tool?
> 
> Hi Johan,
> 
> Thanks for the explanation. You're right — I missed the lifecycle guarantees
> provided by usb_serial_disconnect(), and since opticon_close() already handles
> the URB cleanup, this report is a false positive.
> 
> I'm currently researching static analysis techniques (CodeQL combined with LLM
> assistance) for detecting UAF bugs, particularly around cross-entry lifetimes.
> In this case, the analysis missed the subsystem-level guarantee that close runs
> before remove.

As is required, you always have to document this type of thing in the
changelog text.

thanks,

greg k-h