Re: [PATCH 1/2] mfd: twl4030-audio: fix sibling-node lookup

From: Peter Ujfalusi
Date: Mon Nov 13 2017 - 15:15:25 EST


On 11/11/2017 05:38 PM, Johan Hovold wrote:
> A helper purported to look up a child node based on its name was using
> the wrong of-helper and ended up prematurely freeing the parent of-node
> while leaking any matching node.
>
> To make things worse, any matching node would not even necessarily be a
> child node as the whole device tree was searched depth-first starting at
> the parent.

I think it is the same case as with the twl6040, there were no
of_get_child_by_name() when this was done...

Thanks for fixing it!

Acked-by: Peter Ujfalusi <peter.ujfalusi@xxxxxx>

>
> Fixes: 019a7e6b7b31 ("mfd: twl4030-audio: Add DT support")
> Cc: stable <stable@xxxxxxxxxxxxxxx> # 3.7
> Cc: Peter Ujfalusi <peter.ujfalusi@xxxxxx>
> ---
> drivers/mfd/twl4030-audio.c | 9 +++++++--
> 1 file changed, 7 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/mfd/twl4030-audio.c b/drivers/mfd/twl4030-audio.c
> index da16bf45fab4..dc94ffc6321a 100644
> --- a/drivers/mfd/twl4030-audio.c
> +++ b/drivers/mfd/twl4030-audio.c
> @@ -159,13 +159,18 @@ unsigned int twl4030_audio_get_mclk(void)
> EXPORT_SYMBOL_GPL(twl4030_audio_get_mclk);
>
> static bool twl4030_audio_has_codec(struct twl4030_audio_data *pdata,
> - struct device_node *node)
> + struct device_node *parent)
> {
> + struct device_node *node;
> +
> if (pdata && pdata->codec)
> return true;
>
> - if (of_find_node_by_name(node, "codec"))
> + node = of_get_child_by_name(parent, "codec");
> + if (node) {
> + of_node_put(node);
> return true;
> + }
>
> return false;
> }
>


--
PÃter

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