diff --git a/fs/exec.c b/fs/exec.c
index d0ecea0781f7..dd194923c52c 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -616,6 +616,15 @@ static int de_thread(struct task_struct *tsk)
 		kmem_cache_free(sighand_cachep, newsighand);
 		return -EAGAIN;
 	}
+
+	/*
+	 * child_reaper ignores SIGKILL, change it now.
+	 * Reparenting needs write_lock on tasklist_lock,
+	 * so it is safe to do it under read_lock.
+	 */
+	if (unlikely(current->group_leader == child_reaper))
+		child_reaper = current;
+
 	zap_other_threads(current);
 	read_unlock(&tasklist_lock);
 
@@ -660,23 +669,12 @@ static int de_thread(struct task_struct *tsk)
 		struct dentry *proc_dentry1, *proc_dentry2;
 		unsigned long ptrace;
 
-		leader = current->group_leader;
-		/*
-		 * If our leader is the child_reaper become
-		 * the child_reaper and resend SIGKILL signal.
-		 */
-		if (unlikely(leader == child_reaper)) {
-			write_lock(&tasklist_lock);
-			child_reaper = current;
-			zap_other_threads(current);
-			write_unlock(&tasklist_lock);
-		}
-
 		/*
 		 * Wait for the thread group leader to be a zombie.
 		 * It should already be zombie at this point, most
 		 * of the time.
 		 */
+		leader = current->group_leader;
 		while (leader->exit_state != EXIT_ZOMBIE)
 			yield();