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

From: Rafael J. Wysocki
Date: Thu Dec 27 2018 - 03:59:32 EST


On Sat, Dec 22, 2018 at 1:49 PM Colin King <colin.king@xxxxxxxxxxxxx> wrote:
>
> From: Colin Ian King <colin.king@xxxxxxxxxxxxx>
>
> The pointer p can be potentially null macro to_software_node can return
> null. Add null check on p before dereferencing it to avoid any null
> pointer dereferences.
>
> Detected by CoverityScan, CID#1476039 ("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 | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/base/swnode.c b/drivers/base/swnode.c
> index 204aa7d049e0..89ad8dee6ad5 100644
> --- a/drivers/base/swnode.c
> +++ b/drivers/base/swnode.c
> @@ -488,7 +488,7 @@ software_node_get_next_child(const struct fwnode_handle *fwnode,
> struct software_node *p = to_software_node(fwnode);
> struct software_node *c = to_software_node(child);
>
> - if (list_empty(&p->children) ||
> + if (!p || list_empty(&p->children) ||
> (c && list_is_last(&c->entry, &p->children)))
> return NULL;
>
> --

Applied, thanks!