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Date: Thu, 13 Jun 2024 15:31:50 +0300
From: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
To: Javier Carrasco <javier.carrasco.cruz@gmail.com>
Cc: Heikki Krogerus <heikki.krogerus@linux.intel.com>, 
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, 
	stable@vger.kernel.org
Subject: Re: [PATCH] usb: typec: ucsi: glink: fix child node release in probe
 function
Message-ID: <fuoqdo3s7vxjb4edctkgmvqmzd4bcivos2crotbl6iyhjtylii@jyqk26c7quxd>
References: <20240613-ucsi-glink-release-node-v1-1-f7629a56f70a@gmail.com>
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In-Reply-To: <20240613-ucsi-glink-release-node-v1-1-f7629a56f70a@gmail.com>

On Thu, Jun 13, 2024 at 02:14:48PM +0200, Javier Carrasco wrote:
> The device_for_each_child_node() macro requires explicit calls to
> fwnode_handle_put() in all early exits of the loop if the child node is
> not required outside. Otherwise, the child node's refcount is not
> decremented and the resource is not released.
> 
> The current implementation of pmic_glink_ucsi_probe() makes use of the
> device_for_each_child_node(), but does not release the child node on
> early returns. Add the missing calls to fwnode_handle_put().
> 
> Cc: stable@vger.kernel.org
> Fixes: c6165ed2f425 ("usb: ucsi: glink: use the connector orientation GPIO to provide switch events")
> Signed-off-by: Javier Carrasco <javier.carrasco.cruz@gmail.com>
> ---
> This case would be a great opportunity for the recently introduced
> device_for_each_child_node_scoped(), but given that it has not been
> released yet, the traditional approach has been used to account for
> stable kernels (bug introduced with v6.7). A second patch to clean
> this up with that macro is ready to be sent once this fix is applied,
> so this kind of problem does not arise if more early returns are added.
> 
> This issue has been found while analyzing the code and not tested with
> hardware, only compiled and checked with static analysis tools. Any
> tests with real hardware are always welcome.
> ---
>  drivers/usb/typec/ucsi/ucsi_glink.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>


-- 
With best wishes
Dmitry