Re: [PATCH] [v4] ieee802154: ca8210: Fix a potential UAF in ca8210_probe

[Stefan Schmidt <stefan@datenfreihafen.org>]

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