diff mbox series

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

Message ID 20230426192413.143971-1-harshit.m.mogalapalli@oracle.com
State New
Headers
Series [next] drm/amd/display: Fix possible NULL dereference in dc_dmub_srv_cmd_run_list() |

Commit Message

Harshit Mogalapalli April 26, 2023, 7:24 p.m. UTC 
  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@oracle.com>
---
Only compile tested.
---
 drivers/gpu/drm/amd/display/dc/dc_dmub_srv.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

Comments

Hamza Mahfooz April 26, 2023, 8:59 p.m. UTC | #1 
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@oracle.com>

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++) {
diff mbox series

Patch

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++) {