Messages in this thread | | | Date | Fri, 30 Dec 2022 15:00:28 +0800 | From | Coiby Xu <> | Subject | Re: [PATCH] lockdown: kexec_file: prevent unsigned kernel image when KEXEC_SIG not enabled |
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On Mon, Nov 28, 2022 at 12:16:08PM -0500, Mimi Zohar wrote: >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 for the suggestion! I've added some tests in v3 and now the message is "# kexec_file_load failed (missing IMA sig) [PASS]".
> >-- >thanks, > >Mimi >
-- Best regards, Coiby
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