6.6-stable review patch. If anyone has any objections, please let me know.
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From: Chenyuan Yang chenyuan0y@gmail.com
[ Upstream commit 7a2ca2ea64b1b63c8baa94a8f5deb70b2248d119 ]
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 Reviewed-by: Alex Hung alex.hung@amd.com Tested-by: Dan Wheeler daniel.wheeler@amd.com Signed-off-by: Alex Deucher alexander.deucher@amd.com (cherry picked from commit 5e43eb3cd731649c4f8b9134f857be62a416c893) Signed-off-by: Sasha Levin sashal@kernel.org --- 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 7f8f127e7722..ab6964ca1c2b 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);