From: Dexuan Cui <decui@microsoft.com>
Date: Tue, 15 Dec 2015 00:01:48 +0000 (-0800)
Subject: Drivers: hv: vmbus: do sanity check of channel state in vmbus_close_internal()
X-Git-Tag: v4.13~3859^2~36
X-Git-Url: https://git.proxmox.com/?a=commitdiff_plain;h=64b7faf903dae2df94d89edf2c688b16751800e4;p=mirror_ubuntu-bionic-kernel.git

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>
---

diff --git a/drivers/hv/channel.c b/drivers/hv/channel.c
index f7f3d5ccd6bd..00e1be775908 100644
--- a/drivers/hv/channel.c
+++ b/drivers/hv/channel.c
@@ -512,6 +512,18 @@ 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+	 * rescinded later (e.g., we dynamically disble an Integrated Service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 */