The thing is, Microsoft’s virus-scanning API shouldn’t be able to BSOD anything, no matter what third-party software makes calls to it, or the nature of those calls. They should have implemented some kind of error handler for when the calls are malformed.
So this is really a case of both Crowdstrike and Microsoft fucking up. Crowdstrike shoulders most of the blame, of course, but Microsoft really needs to harden their API to appropriately catch errors, or this will happen again.
I’m an idiot. For some reason, I was thinking about the Windows Defender API, which can be called from third-party applications.
I don’t believe there was any specific API in use here, for virus scanning or not. I suppose maybe the device driver API? I am not a kernel developer so I don’t know if that’s the right term for it.
Crowdstrike’s driver was loaded at boot and caused a null pointer dereference error, inside the kernel. In userspace, when this happens, the kernel is there to catch it so only the application that caused it crashes. In kernelspace, you get a BSOD because there’s really nothing else to do.
