Hi Coiby, On Fri, 2022-12-30 at 14:58 +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. The phrase "unless both IMA_ARCH_POLICY and secure boot also enabled" doesn't reflect the code. IMA could contain a custom policy rule which requires the kexec kernel image signature verification as well. Refer to the comment now in mandate_signature_verification(). thanks, Mimi
