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 f7f3d5c..00e1be7 100644 (file)
--- 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+        * rescinded later (e.g., we dynamically disble an Integrated Service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 */