RE: [PATCH] Drivers: vmbus: Check for channel allocation before looking up relids

From: Dexuan Cui
Date: Wed Feb 08 2023 - 14:04:44 EST


> From: Mohammed Gamal <mgamal@xxxxxxxxxx>
> Sent: Wednesday, February 8, 2023 3:34 AM
>
> relid2channel() assumes vmbus channel array to be allocated when called.
> However, if the guest receives a vmbus interrupt during driver initialization
> before vmbus_connect() is called or if vmbus_connect() fails, the vmbus
> interrupt service routine is called which in turn calls relid2channel()
> and can cause a null pointer dereference.

Before vmbus_connect() is called or if vmbus_connect() fails, there should
be no VMBus channel related interrupts at all, so relid2channel() can't be
called.

Can you please share the log or at least the crash call-stack?
I'm curious how the crash can happen.