RE: [PATCH] ACPI: scan: Fix a Hyper-V Linux VM panic caused by buffer overflow

[Dexuan Cui]

> From: Michael Kelley <mikelley@xxxxxxxxxxxxx>
> Sent: Tuesday, December 22, 2020 5:56 AM
> From: Dexuan Cui 
> Sent: Thursday, December 17, 2020
> 8:08 PM
> >
> > Linux VM on Hyper-V crashes with the latest mainline:
> > ...
> > --- a/drivers/acpi/scan.c
> > +++ b/drivers/acpi/scan.c
> > @@ -674,7 +674,8 @@ int acpi_device_add(struct acpi_device *device,
> >  	}
> >  	if (!found) {
> >  		acpi_device_bus_id = new_bus_id;
> > -		strcpy(acpi_device_bus_id->bus_id, acpi_device_hid(device));
> > +		strlcpy(acpi_device_bus_id->bus_id, acpi_device_hid(device),
> > +			sizeof(acpi_device_bus_id->bus_id));
> >  		acpi_device_bus_id->instance_no = 0;
> >  		list_add_tail(&acpi_device_bus_id->node, &acpi_bus_id_list);
> >  	}
> 
> Reviewed-by: Michael Kelley <mikelley@xxxxxxxxxxxxx>

Hi, ACPI maintainers,
Would you please take a look at the small fix? Currently the mainline Linux
kernel, running in a VM on Hyper-V, has been broken for almost 3 weeks,
i.e. the VM always panics when it boots.

The patch has already had Michael's Reviewed-by.

BTW, the patch should have a stable tag:
Cc: <stable@xxxxxxxxxxxxxxx>

Or, do you want the patch to go through the Hyper-V tree?
https://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux.git/log/?h=hyperv-fixes

The small patch is unlikely to cause a merge conflict, and it only affects
Linux VMs on Hyper-V so far.

Thanks,
-- Dexuan