On 01/14/19 at 11:10am, Mimi Zohar wrote:
> On Sun, 2019-01-13 at 09:39 +0800, Dave Young wrote:
> > Hi,
> >
> > On 01/11/19 at 11:13am, Mimi Zohar wrote:
> > > On Fri, 2019-01-11 at 21:43 +0800, Dave Young wrote:
> > > [snip]
> > >
> > > > Personally I would like to see platform key separated from integrity.
> > > > But for the kexec_file part I think it is good at least it works with
> > > > this fix.
> > > >
> > > > Acked-by: Dave Young <dyoung@xxxxxxxxxx>
> > >
> > > The original "platform" keyring patches that Nayna posted multiple
> > > times were in the certs directory, but nobody commented/responded. So
> > > she reworked the patches, moving them to the integrity directory and
> > > posted them (cc'ing the kexec mailing list). It's a bit late to be
> > > asking to move it, isn't it?
> >
> > Hmm, apologize for being late, I did not get chance to have a look the
> > old series. Since we have the needs now, it should be still fine
> >
> > Maybe Kairui can check Nayna's old series, see if he can do something
> > again?
>
> Whether the platform keyring is defined in certs/ or in integrity/ the
> keyring id needs to be accessible to the other, without making the
> keyring id global. Moving where the platform keyring is defined is
> not the problem.
Agreed, but just feel kexec depends on IMA sounds not good.
>
> Commit a210fd32a46b ("kexec: add call to LSM hook in original
> kexec_load syscall") introduced a new LSM hook. Assuming
> CONFIG_KEXEC_VERIFY_SIG is enabled, with commit b5ca117365d9 ("ima:
> prevent kexec_load syscall based on runtime secureboot flag") we can
> now block the kexec_load syscall. Without being able to block the
> kexec_load syscall, verifying the kexec image signature via the
> kexec_file_load syscall is kind of pointless.
>
> Unless you're planning on writing an LSM to prevent the kexec_load
> syscall, I assume you'll want to enable integrity anyway.
User can disable kexec_load in kernel config, and only allow
kexec_file_load. But yes, this can be improved separately in case no
IMA enabled.
For the time being we can leave with it and fix like this series do.
>
> Mimi
>
Thanks
Dave
