Currently, a problem faced by arm64 is if a kernel image is signed by a MOK key, loading it via the kexec_file_load() system call would be rejected with the error "Lockdown: kexec: kexec of unsigned images is restricted; see man kernel_lockdown.7". This happens because arm64 uses only the primary keyring i.e. the .builtin_trusted_keys keyring that contains only kernel built-in keys to verify the kexec kernel image. MOK keys are loaded into the .platform keyring or/and .machine keyring. The .machine keyring is linked to the secondary keyring i.e. .secondary_trusted_keys keyring when the end-user chooses to trust MOK keys. The platform keyring is exclusively used for kexec kernel image verification and .secondary_trusted_keys together with .builtin_trusted_keys are the system trusted keyrings. So obviously there is no reason to not use .secondary_trusted_keys or .platform keyring for kernel image signature verification. Similarly, s390 only uses platform keyring for kernel image signature verification and built-in keys and secondary keyring are not used. This patch set allows arm64 and s390 to use more system keyrings including the .secondary_trusted_keys and .platform keyring to verify kexec kernel image signature as x86 does. The 3rd arm64 patch depends on the first two patches. The 4th s390 patch can be applied independently. v8: - drop "Cc: stable@xxxxxxxxxxxxxxx" for the first two prerequisite patches [Baoquan] v7: - drop the Fixes tag for the 2nd patch and add patch prerequisites [Baoquan] - improve cover letter v6: - integrate the first three patches of "[PATCH 0/4] Unifrom keyring support across architectures and functions" from Michal [1] - improve commit message [Baoquan, Michal] - directly assign kexec_kernel_verify_pe_sig to kexec_file_ops->verify_sig [Michal] v5: - improve commit message [Baoquan] v4: - fix commit reference format issue and other checkpatch.pl warnings [Baoquan] v3: - s/arch_kexec_kernel_verify_pe_sig/kexec_kernel_verify_pe_sig [Eric] - clean up arch_kexec_kernel_verify_sig [Eric] v2: - only x86_64 and arm64 need to enable PE file signature check [Dave] [1] https://lore.kernel.org/lkml/cover.1644953683.git.msuchanek@xxxxxxx/ Coiby Xu (3): kexec: clean up arch_kexec_kernel_verify_sig kexec, KEYS: make the code in bzImage64_verify_sig generic arm64: kexec_file: use more system keyrings to verify kernel image signature Michal Suchanek (1): kexec, KEYS, s390: Make use of built-in and secondary keyring for signature verification arch/arm64/kernel/kexec_image.c | 11 +----- arch/s390/kernel/machine_kexec_file.c | 18 +++++++--- arch/x86/kernel/kexec-bzimage64.c | 20 +---------- include/linux/kexec.h | 7 ++-- kernel/kexec_file.c | 51 ++++++++++++++++----------- 5 files changed, 50 insertions(+), 57 deletions(-) -- 2.35.3 _______________________________________________ kexec mailing list kexec@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/kexec
