Messages in this thread | | | Subject | Re: [PATCH] lockdown: kexec_file: prevent unsigned kernel image when KEXEC_SIG not enabled | From | Mimi Zohar <> | Date | Mon, 28 Nov 2022 12:16:08 -0500 |
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On Tue, 2022-11-22 at 10:36 +0800, Coiby Xu wrote: > 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@srcf.ucam.org> > >> Cc: Jiri Bohac <jbohac@suse.cz> > >> Cc: David Howells <dhowells@redhat.com> > >> Cc: kexec@lists.infradead.org > >> Cc: linux-integrity@vger.kernel.org > >> Signed-off-by: Coiby Xu <coxu@redhat.com> > > > >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@linux.ibm.com> > > And thanks for the review!
You're welcome.
Without either IMA_ARCH or KEXEC_SIG enabled, the kexec selftest test_kexec_file_load.sh properly failed with "kexec_file_load failed [PASS]", but from the informational messages output, it isn't clear why it failed. This should be corrected.
-- thanks,
Mimi
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