Re: [PATCH V40 23/29] bpf: Restrict bpf when kernel lockdown is in confidentiality mode

From: David Howells
Date: Fri Aug 30 2019 - 12:33:03 EST

Matthew Garrett <matthewgarrett@xxxxxxxxxx> wrote:

> From: David Howells <dhowells@xxxxxxxxxx>
> bpf_read() and bpf_read_str() could potentially be abused to (eg) allow
> private keys in kernel memory to be leaked. Disable them if the kernel
> has been locked down in confidentiality mode.
> Suggested-by: Alexei Starovoitov <alexei.starovoitov@xxxxxxxxx>
> Signed-off-by: Matthew Garrett <mjg59@xxxxxxxxxx>
> Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>
> cc: netdev@xxxxxxxxxxxxxxx
> cc: Chun-Yi Lee <jlee@xxxxxxxx>
> cc: Alexei Starovoitov <alexei.starovoitov@xxxxxxxxx>
> Cc: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
> Signed-off-by: James Morris <jmorris@xxxxxxxxx>

Signed-off-by: David Howells <dhowells@xxxxxxxxxx>