Re: [PATCH] lockdown: kexec_file: prevent unsigned kernel image when KEXEC_SIG not enabled

[Coiby Xu]

Hi Mimi,

On Mon, Nov 21, 2022 at 01:23:57PM -0500, Mimi Zohar wrote:
> Hi Coiby,
>
> On Mon, 2022-11-21 at 15:29 +0800, Coiby Xu wrote:
> > A kernel builder may not enable KEXEC_SIG and some architectures like
> > ppc64 simply don't have KEXEC_SIG. In these cases, unless both
> > IMA_ARCH_POLICY and secure boot also enabled, lockdown doesn't prevent
> > unsigned kernel image from being kexec'ed via the kexec_file_load
> > syscall whereas it could prevent one via the kexec_load syscall. Mandate
> > signature verification for those cases.
> >
> > Fixes: 155bdd30af17 ("kexec_file: Restrict at runtime if the kernel is locked down")
> > Cc: Matthew Garrett <mjg59@xxxxxxxxxxxxx>
> > Cc: Jiri Bohac <jbohac@xxxxxxx>
> > Cc: David Howells <dhowells@xxxxxxxxxx>
> > Cc: kexec@xxxxxxxxxxxxxxxxxxx
> > Cc: linux-integrity@xxxxxxxxxxxxxxx
> > Signed-off-by: Coiby Xu <coxu@xxxxxxxxxx>
>
> Other than correcting the function name to mandate_signature_verificati
> on(),

Applied to v2, thanks for correcting me! Btw, I realize I overwrote the
return code of kexec_image_verify_sig with
mandate_signature_verification's. v2 has fixed this issue as well.

> Reviewed-by: Mimi Zohar <zohar@xxxxxxxxxxxxx>

And thanks for the review!

--
Best regards,
Coiby

--
Best regards,
Coiby