From: Mario Limonciello mario.limonciello@amd.com

[Why] A slab-use-after-free is reported when HDCP is destroyed but the property_validate_dwork queue is still running.

[How] Cancel the delayed work when destroying workqueue.

Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/4006 Fixes: da3fd7ac0bcf ("drm/amd/display: Update CP property based on HW query") Cc: Alex Deucher alexander.deucher@amd.com Cc: stable@vger.kernel.org Reviewed-by: Alex Hung alex.hung@amd.com Signed-off-by: Mario Limonciello mario.limonciello@amd.com Signed-off-by: Tom Chung chiahsuan.chung@amd.com --- drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_hdcp.c | 1 + 1 file changed, 1 insertion(+)

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_hdcp.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_hdcp.c index 8238cfd276be..6a4b5f4d8a9d 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_hdcp.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_hdcp.c @@ -455,6 +455,7 @@ void hdcp_destroy(struct kobject *kobj, struct hdcp_workqueue *hdcp_work) for (i = 0; i < hdcp_work->max_link; i++) { cancel_delayed_work_sync(&hdcp_work[i].callback_dwork); cancel_delayed_work_sync(&hdcp_work[i].watchdog_timer_dwork); + cancel_delayed_work_sync(&hdcp_work[i].property_validate_dwork); }

sysfs_remove_bin_file(kobj, &hdcp_work[0].attr);