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

commit 40384e4bbeb9f2651fe9bffc0062d9f31ef625bf upstream.

Correctly rollback state if the failure occurs after we have handed over
the ownership of the buffer to the host.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/hv/channel.c b/drivers/hv/channel.c
index 92f34de..05e6a7d 100644
--- a/drivers/hv/channel.c
+++ b/drivers/hv/channel.c
@@ -169,7 +169,7 @@
 			   GFP_KERNEL);
 	if (!open_info) {
 		err = -ENOMEM;
-		goto error0;
+		goto error_gpadl;
 	}
 
 	init_completion(&open_info->waitevent);
@@ -185,7 +185,7 @@
 
 	if (userdatalen > MAX_USER_DEFINED_BYTES) {
 		err = -EINVAL;
-		goto error0;
+		goto error_gpadl;
 	}
 
 	if (userdatalen)
@@ -226,6 +226,9 @@
 	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));