From e65e7bea220c3ce8c4c793b4ba35557f4994ab2b Mon Sep 17 00:00:00 2001
From: Mario Limonciello <mario.limonciello@amd.com>
Date: Fri, 28 Feb 2025 13:18:14 -0600
Subject: [PATCH] drm/amd/display: Fix slab-use-after-free on hdcp_work
[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>
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>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit 725a04ba5a95e89c89633d4322430cfbca7ce128)
Cc: stable@vger.kernel.org
---
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 e339c7a8d541c..c0dc232440490 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);
--
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