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Message-ID: <c2b7264f-c533-2d80-e41e-a7019aefb602@datenfreihafen.org>
Date:   Sat, 7 Oct 2023 20:42:46 +0200
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Subject: Re: [PATCH] [v4] ieee802154: ca8210: Fix a potential UAF in
 ca8210_probe
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To:     Dinghao Liu <dinghao.liu@zju.edu.cn>
Cc:     stable@vger.kernel.org, Alexander Aring <alex.aring@gmail.com>,
        Miquel Raynal <miquel.raynal@bootlin.com>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>,
        Harry Morris <harrymorris12@gmail.com>,
        Marcel Holtmann <marcel@holtmann.org>,
        linux-wpan@vger.kernel.org, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org
References: <20231007033049.22353-1-dinghao.liu@zju.edu.cn>
From:   Stefan Schmidt <stefan@datenfreihafen.org>
In-Reply-To: <20231007033049.22353-1-dinghao.liu@zju.edu.cn>
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Hello.

On 07.10.23 05:30, Dinghao Liu wrote:
> If of_clk_add_provider() fails in ca8210_register_ext_clock(),
> it calls clk_unregister() to release priv->clk and returns an
> error. However, the caller ca8210_probe() then calls ca8210_remove(),
> where priv->clk is freed again in ca8210_unregister_ext_clock(). In
> this case, a use-after-free may happen in the second time we call
> clk_unregister().
> 
> Fix this by removing the first clk_unregister(). Also, priv->clk could
> be an error code on failure of clk_register_fixed_rate(). Use
> IS_ERR_OR_NULL to catch this case in ca8210_unregister_ext_clock().
> 
> Fixes: ded845a781a5 ("ieee802154: Add CA8210 IEEE 802.15.4 device driver")
> Signed-off-by: Dinghao Liu <dinghao.liu@zju.edu.cn>
> ---
> 
> Changelog:
> 
> v2: -Remove the first clk_unregister() instead of nulling priv->clk.
> 
> v3: -Simplify ca8210_register_ext_clock().
>      -Add a ';' after return in ca8210_unregister_ext_clock().
> 
> v4: -Remove an unused variable 'ret'.


This patch has been applied to the wpan tree and will be
part of the next pull request to net. Thanks!

regards
Stefan Schmidt