Re: [PATCH][next] drivers: base: swnode: check if swnode is null before dereferencing it

From: Rafael J. Wysocki
Date: Thu Dec 27 2018 - 03:59:57 EST


On Sat, Dec 22, 2018 at 1:43 PM Colin King <colin.king@xxxxxxxxxxxxx> wrote:
>
> From: Colin Ian King <colin.king@xxxxxxxxxxxxx>
>
> The macro to_software_mode can potentially return NULL, so also add
> a null check on the swnode before dereferencing it to avoid any null
> pointer dereferences.
>
> Detected by CoverityScan, CID#1476052 ("Explicit null dereferenced")
>
> Fixes: 59abd83672f7 ("drivers: base: Introducing software nodes to the firmware node framework")
> Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx>
> ---
> drivers/base/swnode.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/base/swnode.c b/drivers/base/swnode.c
> index 306bb93287af..204aa7d049e0 100644
> --- a/drivers/base/swnode.c
> +++ b/drivers/base/swnode.c
> @@ -477,7 +477,8 @@ software_node_get_parent(const struct fwnode_handle *fwnode)
> {
> struct software_node *swnode = to_software_node(fwnode);
>
> - return swnode->parent ? &swnode->parent->fwnode : NULL;
> + return swnode ? (swnode->parent ? &swnode->parent->fwnode : NULL) :
> + NULL;
> }
>
> struct fwnode_handle *
> --

Applied, thanks!