From efb208dc9c3f1e881aecff21fb1c7a7b6b869480 Mon Sep 17 00:00:00 2001 From: Li Zhijian Date: Wed, 19 May 2021 14:47:40 +0800 Subject: [PATCH] migration/rdma: Fix cm_event used before being initialized 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 these 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 } Refer to the rdma_get_cm_event() code, cm_event will be updated/changed only if rdma_get_cm_event() returns 0. So it's okey to remove the ack in error patch. Signed-off-by: Li Zhijian Message-Id: <20210519064740.10828-1-lizhijian@cn.fujitsu.com> Reviewed-by: Dr. David Alan Gilbert Signed-off-by: Dr. David Alan Gilbert --- migration/rdma.c | 1 - 1 file changed, 1 deletion(-) diff --git a/migration/rdma.c b/migration/rdma.c index 00eac34232..41726cc74a 100644 --- a/migration/rdma.c +++ b/migration/rdma.c @@ -2497,7 +2497,6 @@ static int qemu_rdma_connect(RDMAContext *rdma, Error **errp) if (ret) { perror("rdma_get_cm_event after rdma_connect"); ERROR(errp, "connecting to destination!"); - rdma_ack_cm_event(cm_event); goto err_rdma_source_connect; }