[PATCH] migration/rdma: Fix cm_event used before being initialized

[Li Zhijian]

A segmentation fault was triggered when i try to abort a postcopy + rdma
migration.

since rdma_ack_cm_event releases a uninitialized cm_event in thise case.

like below:
2496     ret = rdma_get_cm_event(rdma->channel, &cm_event);
2497     if (ret) {
2498         perror("rdma_get_cm_event after rdma_connect");
2499         ERROR(errp, "connecting to destination!");
2500         rdma_ack_cm_event(cm_event); <<<< cause segmentation fault
2501         goto err_rdma_source_connect;
2502     }

Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
---
 migration/rdma.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/migration/rdma.c b/migration/rdma.c
index 00eac34232..2dadb62aed 100644
--- a/migration/rdma.c
+++ b/migration/rdma.c
@@ -2466,7 +2466,7 @@ static int qemu_rdma_connect(RDMAContext *rdma, Error 
**errp)
                                           .private_data = &cap,
                                           .private_data_len = sizeof(cap),
                                         };
-    struct rdma_cm_event *cm_event;
+    struct rdma_cm_event *cm_event = NULL;
     int ret;
 
     /*
-- 
2.30.2