Re: An actual suggestion (Re: [GIT PULL] Kernel lockdown for secure boot)

David Howells
2018-04-04T22:19:27Z

Jann Horn <jannh@google.com> wrote:

> > Uh, no. bpf, for example, can be used to modify kernel memory.
>
> I'm pretty sure bpf isn't supposed to be able to modify arbitrary
> kernel memory. AFAIU if you can use BPF to write to arbitrary kernel
> memory, that's a bug; with CAP_SYS_ADMIN, you can read from userspace,
> write to userspace, and read from kernelspace, but you shouldn't be
> able to write to kernelspace.

Ah - you may be right. I seem to have misremembered what Joey Lee wrote in
his patch description.

David