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Date: Thu, 23 Jan 2025 07:12:01 -0800
From: Jakub Kicinski <kuba@kernel.org>
To: Gui-Dong Han <2045gemini@gmail.com>
Cc: 3chas3@gmail.com, linux-atm-general@lists.sourceforge.net,
 netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
 baijiaju1990@gmail.com, horms@kernel.org, stable@vger.kernel.org
Subject: Re: [PATCH v2] atm/fore200e: Fix possible data race in
 fore200e_open()
Message-ID: <20250123071201.3d38d8f6@kernel.org>
In-Reply-To: <20250122023745.584995-1-2045gemini@gmail.com>
References: <20250122023745.584995-1-2045gemini@gmail.com>
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On Wed, 22 Jan 2025 02:37:45 +0000 Gui-Dong Han wrote:
> Protect access to fore200e->available_cell_rate with rate_mtx lock to
> prevent potential data race.
> 
> In this case, since the update depends on a prior read, a data race
> could lead to a wrong fore200e.available_cell_rate value.
> 
> The field fore200e.available_cell_rate is generally protected by the lock
> fore200e.rate_mtx when accessed. In all other read and write cases, this
> field is consistently protected by the lock, except for this case and
> during initialization.

Please describe the call paths which interact to cause the race.