Re: [PATCH next] drm/amd/display: Fix possible NULL dereference in dc_dmub_srv_cmd_run_list()

[Hamza Mahfooz]

On 4/26/23 15:24, Harshit Mogalapalli wrote:
> We have a NULL check for 'dc_dmub_srv' in dc_dmub_srv_cmd_run_list()
> but we are dereferencing it before checking.
>
> Fix this moving the dereference next to NULL check.
>
> This issue is found with Smatch(static analysis tool).
>
> Fixes: e97cc04fe0fb ("drm/amd/display: refactor dmub commands into single function")
> Signed-off-by: Harshit Mogalapalli <harshit.m.mogalapalli@xxxxxxxxxx>

Applied, thanks!

> ---
> Only compile tested.
> ---
>   drivers/gpu/drm/amd/display/dc/dc_dmub_srv.c | 3 ++-
>   1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/amd/display/dc/dc_dmub_srv.c b/drivers/gpu/drm/amd/display/dc/dc_dmub_srv.c
> index d15ec32243e2..62d3473c32bc 100644
> --- a/drivers/gpu/drm/amd/display/dc/dc_dmub_srv.c
> +++ b/drivers/gpu/drm/amd/display/dc/dc_dmub_srv.c
> @@ -125,7 +125,7 @@ bool dc_dmub_srv_cmd_run(struct dc_dmub_srv *dc_dmub_srv, union dmub_rb_cmd *cmd
>   
>   bool dc_dmub_srv_cmd_run_list(struct dc_dmub_srv *dc_dmub_srv, unsigned int count, union dmub_rb_cmd *cmd_list, enum dm_dmub_wait_type wait_type)
>   {
> -	struct dc_context *dc_ctx = dc_dmub_srv->ctx;
> +	struct dc_context *dc_ctx;
>   	struct dmub_srv *dmub;
>   	enum dmub_status status;
>   	int i;
> @@ -133,6 +133,7 @@ bool dc_dmub_srv_cmd_run_list(struct dc_dmub_srv *dc_dmub_srv, unsigned int coun
>   	if (!dc_dmub_srv || !dc_dmub_srv->dmub)
>   		return false;
>   
> +	dc_ctx = dc_dmub_srv->ctx;
>   	dmub = dc_dmub_srv->dmub;
>   
>   	for (i = 0 ; i < count; i++) {
--
Hamza