Re: [PATCH 8/8] efi: pstore: Add module parameter for setting the record size

From: Kees Cook
Date: Fri Oct 07 2022 - 15:32:42 EST


On Fri, Oct 07, 2022 at 10:45:33AM -0300, Guilherme G. Piccoli wrote:
> On 07/10/2022 10:19, Ard Biesheuvel wrote:
> > [...]
> >
> > OVMF has
> >
> > OvmfPkg/OvmfPkgX64.dsc:
> > gEfiMdeModulePkgTokenSpaceGuid.PcdMaxVariableSize|0x2000
> > OvmfPkg/OvmfPkgX64.dsc:
> > gEfiMdeModulePkgTokenSpaceGuid.PcdMaxVariableSize|0x8400
> >
> > where the first one is without secure boot and the second with secure boot.
> >
> > Interestingly, the default is
> >
> > gEfiMdeModulePkgTokenSpaceGuid.PcdMaxVariableSize|0x400
> >
> > so this is probably where this 1k number comes from. So perhaps it is
> > better to leave it at 1k after all :-(
> >
>
> Oh darn...
>
> So, let's stick with 1024 then? If so, no need for re-submitting right?

Given OVMF showing this as a max, it doesn't seem right to also make
this a minimum? Perhaps choose a different minimum to be enforced.

Also, can you update the commit log with Ard's archeology on
gEfiMdeModulePkgTokenSpaceGuid.PcdMaxVariableSize ?

--
Kees Cook