[PATCH] migration: Assign current_migration as NULL after migration

[Keqian Zhu]

In migration_shutdown, global var current_migration is freed but not
assigned to NULL, which may cause heap-use-after-free problem if the
following code logic is abnormal.

Signed-off-by: Keqian Zhu <zhukeqian1@huawei.com>
---
 migration/migration.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/migration/migration.c b/migration/migration.c
index 481a590f72..effffd7332 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -189,6 +189,7 @@ void migration_shutdown(void)
      */
     migrate_fd_cancel(current_migration);
     object_unref(OBJECT(current_migration));
+    current_migration = NULL;
 }
 
 /* For outgoing */
-- 
2.19.1