* [PATCH] drm/amd/display: Add null pointer check in mod_hdcp_hdcp1_create_session()
@ 2025-07-24 2:36 Chenyuan Yang
2025-08-17 23:57 ` Alex Hung
0 siblings, 1 reply; 2+ messages in thread
From: Chenyuan Yang @ 2025-07-24 2:36 UTC (permalink / raw)
To: harry.wentland, sunpeng.li
Cc: siqueira, alexander.deucher, christian.koenig, airlied, simona,
alex.hung, vulab, Wenjing.Liu, isabel.zhang, amd-gfx, dri-devel,
linux-kernel, Chenyuan Yang
The function mod_hdcp_hdcp1_create_session() calls the function
get_first_active_display(), but does not check its return value.
The return value is a null pointer if the display list is empty.
This will lead to a null pointer dereference.
Add a null pointer check for get_first_active_display() and return
MOD_HDCP_STATUS_DISPLAY_NOT_FOUND if the function return null.
This is similar to the commit c3e9826a2202
("drm/amd/display: Add null pointer check for get_first_active_display()").
Fixes: 2deade5ede56 ("drm/amd/display: Remove hdcp display state with mst fix")
Signed-off-by: Chenyuan Yang <chenyuan0y@gmail.com>
---
drivers/gpu/drm/amd/display/modules/hdcp/hdcp_psp.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/gpu/drm/amd/display/modules/hdcp/hdcp_psp.c b/drivers/gpu/drm/amd/display/modules/hdcp/hdcp_psp.c
index e58e7b93810b..6b7db8ec9a53 100644
--- a/drivers/gpu/drm/amd/display/modules/hdcp/hdcp_psp.c
+++ b/drivers/gpu/drm/amd/display/modules/hdcp/hdcp_psp.c
@@ -260,6 +260,9 @@ enum mod_hdcp_status mod_hdcp_hdcp1_create_session(struct mod_hdcp *hdcp)
return MOD_HDCP_STATUS_FAILURE;
}
+ if (!display)
+ return MOD_HDCP_STATUS_DISPLAY_NOT_FOUND;
+
hdcp_cmd = (struct ta_hdcp_shared_memory *)psp->hdcp_context.context.mem_context.shared_buf;
mutex_lock(&psp->hdcp_context.mutex);
--
2.34.1
^ permalink raw reply related [flat|nested] 2+ messages in thread* Re: [PATCH] drm/amd/display: Add null pointer check in mod_hdcp_hdcp1_create_session()
2025-07-24 2:36 [PATCH] drm/amd/display: Add null pointer check in mod_hdcp_hdcp1_create_session() Chenyuan Yang
@ 2025-08-17 23:57 ` Alex Hung
0 siblings, 0 replies; 2+ messages in thread
From: Alex Hung @ 2025-08-17 23:57 UTC (permalink / raw)
To: Chenyuan Yang, harry.wentland, sunpeng.li
Cc: siqueira, alexander.deucher, christian.koenig, airlied, simona,
vulab, Wenjing.Liu, isabel.zhang, amd-gfx, dri-devel,
linux-kernel
Reviewed-by: Alex Hung <alex.hung@amd.com>
On 7/23/25 20:36, Chenyuan Yang wrote:
> The function mod_hdcp_hdcp1_create_session() calls the function
> get_first_active_display(), but does not check its return value.
> The return value is a null pointer if the display list is empty.
> This will lead to a null pointer dereference.
>
> Add a null pointer check for get_first_active_display() and return
> MOD_HDCP_STATUS_DISPLAY_NOT_FOUND if the function return null.
>
> This is similar to the commit c3e9826a2202
> ("drm/amd/display: Add null pointer check for get_first_active_display()").
>
> Fixes: 2deade5ede56 ("drm/amd/display: Remove hdcp display state with mst fix")
> Signed-off-by: Chenyuan Yang <chenyuan0y@gmail.com>
> ---
> drivers/gpu/drm/amd/display/modules/hdcp/hdcp_psp.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/drivers/gpu/drm/amd/display/modules/hdcp/hdcp_psp.c b/drivers/gpu/drm/amd/display/modules/hdcp/hdcp_psp.c
> index e58e7b93810b..6b7db8ec9a53 100644
> --- a/drivers/gpu/drm/amd/display/modules/hdcp/hdcp_psp.c
> +++ b/drivers/gpu/drm/amd/display/modules/hdcp/hdcp_psp.c
> @@ -260,6 +260,9 @@ enum mod_hdcp_status mod_hdcp_hdcp1_create_session(struct mod_hdcp *hdcp)
> return MOD_HDCP_STATUS_FAILURE;
> }
>
> + if (!display)
> + return MOD_HDCP_STATUS_DISPLAY_NOT_FOUND;
> +
> hdcp_cmd = (struct ta_hdcp_shared_memory *)psp->hdcp_context.context.mem_context.shared_buf;
>
> mutex_lock(&psp->hdcp_context.mutex);
^ permalink raw reply [flat|nested] 2+ messages in thread
end of thread, other threads:[~2025-08-17 23:58 UTC | newest]
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2025-07-24 2:36 [PATCH] drm/amd/display: Add null pointer check in mod_hdcp_hdcp1_create_session() Chenyuan Yang
2025-08-17 23:57 ` Alex Hung
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