drm/xe: Fix possible UAF in guc_exec_queue_process_msg

Store xe_device ahead of processing message as message can be free'd in
some cases.

v2:
 - Including missing local changes
v3:
 - Resend for CI

Reported-by: kernel test robot <[email protected]>
Reported-by: Dan Carpenter <[email protected]>
Closes: https://lore.kernel.org/r/[email protected]/
Fixes: 55ea73a ("drm/xe: Build PM into GuC CT layer")
Signed-off-by: Matthew Brost <[email protected]>
Reviewed-by: Himal Prasad Ghimiray <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]
(cherry picked from commit 1a394b4)
Signed-off-by: Rodrigo Vivi <[email protected]>

Author: mbrost05

drivers/gpu/drm/xe/xe_guc_submit.c

@@ -1375,6 +1375,8 @@ static void __guc_exec_queue_process_msg_resume(struct xe_sched_msg *msg)
 
 static void guc_exec_queue_process_msg(struct xe_sched_msg *msg)
 {
+	struct xe_device *xe = guc_to_xe(exec_queue_to_guc(msg->private_data));
+
 	trace_xe_sched_msg_recv(msg);
 
 	switch (msg->opcode) {
@@ -1394,7 +1396,7 @@ static void guc_exec_queue_process_msg(struct xe_sched_msg *msg)
 		XE_WARN_ON("Unknown message type");
 	}
 
-	xe_pm_runtime_put(guc_to_xe(exec_queue_to_guc(msg->private_data)));
+	xe_pm_runtime_put(xe);
 }
 
 static const struct drm_sched_backend_ops drm_sched_ops = {