vhost: fix fd leak in kick setup

[ upstream commit bc900f8 ]

This patch fixes a file descriptor leak which happens
in the error path of vhost_user_set_vring_kick().

Fixes: 4796ad6 ("examples/vhost: import userspace vhost application")

Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Reviewed-by: Chenbo Xia <chenbo.xia@intel.com>
Reviewed-by: Xueming Li <xuemingl@nvidia.com>

lib/librte_vhost/vhost_user.c

@@ -1844,8 +1844,12 @@ vhost_user_set_vring_kick(struct virtio_net **pdev, struct VhostUserMsg *msg,
 
 	/* Interpret ring addresses only when ring is started. */
 	dev = translate_ring_addresses(dev, file.index);
-	if (!dev)
+	if (!dev) {
+		if (file.fd != VIRTIO_INVALID_EVENTFD)
+			close(file.fd);
+
 		return RTE_VHOST_MSG_RESULT_ERR;
+	}
 
 	*pdev = dev;