vmbus: hvsock: add proper sync for vmbus_hvsock_device_unregister()

Without the patch, vmbus_hvsock_device_unregister() can destroy the device
prematurely when close() is called, and can cause NULl dereferencing or
potential data loss (the last portion of the data stream may be dropped
prematurely).

Signed-off-by: Dexuan Cui <[email protected]>
Cc: Haiyang Zhang <[email protected]>
Cc: Stephen Hemminger <[email protected]>
Signed-off-by: K. Y. Srinivasan <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
This commit is contained in:
Dexuan Cui 2017-10-18 02:08:40 -07:00 • committed by Greg Kroah-Hartman
commit 9d35593b4f

View file

@ -937,7 +937,10 @@ void vmbus_hvsock_device_unregister(struct vmbus_channel *channel)
{
BUG_ON(!is_hvsock_channel(channel));
channel->rescind = true;
/* We always get a rescind msg when a connection is closed. */
while (!READ_ONCE(channel->probe_done) || !READ_ONCE(channel->rescind))
msleep(1);
vmbus_device_unregister(channel->device_obj);
}
EXPORT_SYMBOL_GPL(vmbus_hvsock_device_unregister);