[PATCH 3/4] drm/panthor: Reset the FW VM to NULL on unplug

[Boris Brezillon]

This way get NULL derefs instead of use-after-free if the FW VM is
referenced after the device has been unplugged.

Signed-off-by: Boris Brezillon <boris.brezil...@collabora.com>
---
 drivers/gpu/drm/panthor/panthor_fw.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/gpu/drm/panthor/panthor_fw.c 
b/drivers/gpu/drm/panthor/panthor_fw.c
index b41685304a83..93165961a6b5 100644
--- a/drivers/gpu/drm/panthor/panthor_fw.c
+++ b/drivers/gpu/drm/panthor/panthor_fw.c
@@ -1141,6 +1141,7 @@ void panthor_fw_unplug(struct panthor_device *ptdev)
         * state to keep the active_refcnt balanced.
         */
        panthor_vm_put(ptdev->fw->vm);
+       ptdev->fw->vm = NULL;
 
        panthor_gpu_power_off(ptdev, L2, ptdev->gpu_info.l2_present, 20000);
 }
-- 
2.44.0