1 files changed, 6 insertions, 1 deletions

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 90d99fb02ae4..53042f118f23 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -1628,8 +1628,13 @@ void ftrace_retfunc_init_task(struct task_struct *t)
 
 void ftrace_retfunc_exit_task(struct task_struct *t)
 {
-        kfree(t->ret_stack);
+        struct ftrace_ret_stack *ret_stack = t->ret_stack;
+
         t->ret_stack = NULL;
+        /* NULL must become visible to IRQs before we free it: */
+        barrier();
+
+        kfree(ret_stack);
 }
 #endif