Re: [PATCH v2 1/9] of: add helper to lookup compatible child node

From: Rob Herring
Date: Thu Aug 30 2018 - 11:51:25 EST


On Mon, Aug 27, 2018 at 3:22 AM Johan Hovold <johan@xxxxxxxxxx> wrote:
>
> Add of_get_compatible_child() helper that can be used to lookup
> compatible child nodes.
>
> Several drivers currently use of_find_compatible_node() to lookup child
> nodes while failing to notice that the of_find_ functions search the
> entire tree depth-first (from a given start node) and therefore can
> match unrelated nodes. The fact that these functions also drop a
> reference to the node they start searching from (e.g. the parent node)
> is typically also overlooked, something which can lead to use-after-free
> bugs.
>
> Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>
> ---
> drivers/of/base.c | 25 +++++++++++++++++++++++++
> include/linux/of.h | 8 ++++++++
> 2 files changed, 33 insertions(+)

I've applied this one and plan to send to Linus tomorrow.

Rob