[fixup] check NULL pointer before access (#8573)

Signed-off-by: Shell <[email protected]>

1 files changed, 9 insertions, 2 deletions

diff --git a/src/scheduler_mp.c b/src/scheduler_mp.c
index 1a6c5ae983..7397e1071e 100644
--- a/src/scheduler_mp.c
+++ b/src/scheduler_mp.c
@@ -1255,8 +1255,15 @@ rt_uint16_t rt_critical_level(void)
 
     current_thread = rt_cpu_self()->current_thread;
 
-    /* the necessary memory barrier is done on irq_(dis|en)able */
-    critical_lvl = RT_SCHED_CTX(current_thread).critical_lock_nest;
+    if (current_thread)
+    {
+        /* the necessary memory barrier is done on irq_(dis|en)able */
+        critical_lvl = RT_SCHED_CTX(current_thread).critical_lock_nest;
+    }
+    else
+    {
+        critical_lvl = 0;
+    }
 
     rt_hw_local_irq_enable(level);
     return critical_lvl;