Re: [PATCH] spi: Fix reference count leak in slave_show()

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

On Wed, Mar 19, 2025 at 11:23:04AM +0800, Miaoqian Lin wrote:
> Fix a reference count leak in slave_show() by properly putting the device
> reference obtained from device_find_any_child().
> 
> Fixes: 6c364062bfed ("spi: core: Add support for registering SPI slave controllers")
> Fixes: c21b0837983d ("spi: Use device_find_any_child() instead of custom approach")
> Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
> ---
>  drivers/spi/spi.c | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
> index a7a4647717d4..ff07c87dbadc 100644
> --- a/drivers/spi/spi.c
> +++ b/drivers/spi/spi.c
> @@ -2954,9 +2954,13 @@ static ssize_t slave_show(struct device *dev, struct device_attribute *attr,
>  	struct spi_controller *ctlr = container_of(dev, struct spi_controller,
>  						   dev);
>  	struct device *child;
> +	int ret;
>  
>  	child = device_find_any_child(&ctlr->dev);
> -	return sysfs_emit(buf, "%s\n", child ? to_spi_device(child)->modalias : NULL);
> +	ret = sysfs_emit(buf, "%s\n", child ? to_spi_device(child)->modalias : NULL);
> +	put_device(child);
> +
> +	return ret;
>  }
>  
>  static ssize_t slave_store(struct device *dev, struct device_attribute *attr,
> -- 
> 2.39.5 (Apple Git-154)
> 

Hi,

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