Drivers: hv: vmbus: Fix a bug in the error path in vmbus_open()

Correctly rollback state if the failure occurs after we have handed over
the ownership of the buffer to the host.
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Cc: stable@vger.kernel.org
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/hv/channel.c

@@ -137,7 +137,7 @@ int vmbus_open(struct vmbus_channel *newchannel, u32 send_ringbuffer_size,
 			   GFP_KERNEL);
 	if (!open_info) {
 		err = -ENOMEM;
-		goto error0;
+		goto error_gpadl;
 	}
 
 	init_completion(&open_info->waitevent);
@@ -153,7 +153,7 @@ int vmbus_open(struct vmbus_channel *newchannel, u32 send_ringbuffer_size,
 
 	if (userdatalen > MAX_USER_DEFINED_BYTES) {
 		err = -EINVAL;
-		goto error0;
+		goto error_gpadl;
 	}
 
 	if (userdatalen)
@@ -197,6 +197,9 @@ int vmbus_open(struct vmbus_channel *newchannel, u32 send_ringbuffer_size,
 	list_del(&open_info->msglistentry);
 	spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 
+error_gpadl:
+	vmbus_teardown_gpadl(newchannel, newchannel->ringbuffer_gpadlhandle);
+
 error0:
 	free_pages((unsigned long)out,
 		get_order(send_ringbuffer_size + recv_ringbuffer_size));