From 094801214cc5227016728e76c2a28f23f6ee0ed2 Mon Sep 17 00:00:00 2001
From: Dexuan Cui <decui@microsoft.com>
Date: Mon, 14 Dec 2015 16:01:48 -0800
Subject: [PATCH 19/44] Drivers: hv: vmbus: do sanity check of channel state in
 vmbus_close_internal()

This fixes an incorrect assumption of channel state in the function.

Signed-off-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 64b7faf903dae2df94d89edf2c688b16751800e4)
---
 drivers/hv/channel.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/drivers/hv/channel.c b/drivers/hv/channel.c
index d037454fe7b8..b00cdfb725de 100644
--- a/drivers/hv/channel.c
+++ b/drivers/hv/channel.c
@@ -514,6 +514,18 @@ static int vmbus_close_internal(struct vmbus_channel *channel)
 	tasklet = hv_context.event_dpc[channel->target_cpu];
 	tasklet_disable(tasklet);
 
+	/*
+	 * In case a device driver's probe() fails (e.g.,
+	 * util_probe() -> vmbus_open() returns -ENOMEM) and the device is
+	 * rescinded later (e.g., we dynamically disble an Integrated Service
+	 * in Hyper-V Manager), the driver's remove() invokes vmbus_close():
+	 * here we should skip most of the below cleanup work.
+	 */
+	if (channel->state != CHANNEL_OPENED_STATE) {
+		ret = -EINVAL;
+		goto out;
+	}
+
 	channel->state = CHANNEL_OPEN_STATE;
 	channel->sc_creation_callback = NULL;
 	/* Stop callback and cancel the timer asap */
-- 
2.13.0

