Drivers: hv: don't leak memory in vmbus_establish_gpadl()

BugLink: http://bugs.launchpad.net/bugs/1650059

In some cases create_gpadl_header() allocates submessages but we never
free them.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 7cc80c98)
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Acked-by: Brad Figg <brad.figg@canonical.com>
Acked-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>

drivers/hv/channel.c

@@ -388,7 +388,7 @@ int vmbus_establish_gpadl(struct vmbus_channel *channel, void *kbuffer,
 	struct vmbus_channel_gpadl_header *gpadlmsg;
 	struct vmbus_channel_gpadl_body *gpadl_body;
 	struct vmbus_channel_msginfo *msginfo = NULL;
-	struct vmbus_channel_msginfo *submsginfo;
+	struct vmbus_channel_msginfo *submsginfo, *tmp;
 	struct list_head *curr;
 	u32 next_gpadl_handle;
 	unsigned long flags;
@@ -445,6 +445,10 @@ int vmbus_establish_gpadl(struct vmbus_channel *channel, void *kbuffer,
 	spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 	list_del(&msginfo->msglistentry);
 	spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
+	list_for_each_entry_safe(submsginfo, tmp, &msginfo->submsglist,
+				 msglistentry) {
+		kfree(submsginfo);
+	}
 
 	kfree(msginfo);
 	return ret;