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 image_verify_sig uses only the primary keyring that contains only kernel built-in keys to verify the kexec image.
This patch allows to verify arm64 kernel image signature using not only .builtin_trusted_keys but also .platform and .secondary_trusted_keys keyring.
Fixes: 732b7b93d849 ("arm64: kexec_file: add kernel signature verification support") Cc: stable@vger.kernel.org # 34d5960af253: kexec: clean up arch_kexec_kernel_verify_sig Cc: stable@vger.kernel.org # 83b7bb2d49ae: kexec, KEYS: make the code in bzImage64_verify_sig generic Acked-by: Baoquan He bhe@redhat.com Cc: kexec@lists.infradead.org Cc: keyrings@vger.kernel.org Cc: linux-security-module@vger.kernel.org Co-developed-by: Michal Suchanek msuchanek@suse.de Signed-off-by: Michal Suchanek msuchanek@suse.de Acked-by: Will Deacon will@kernel.org Signed-off-by: Coiby Xu coxu@redhat.com --- arch/arm64/kernel/kexec_image.c | 11 +---------- 1 file changed, 1 insertion(+), 10 deletions(-)
diff --git a/arch/arm64/kernel/kexec_image.c b/arch/arm64/kernel/kexec_image.c index 9ec34690e255..5ed6a585f21f 100644 --- a/arch/arm64/kernel/kexec_image.c +++ b/arch/arm64/kernel/kexec_image.c @@ -14,7 +14,6 @@ #include <linux/kexec.h> #include <linux/pe.h> #include <linux/string.h> -#include <linux/verification.h> #include <asm/byteorder.h> #include <asm/cpufeature.h> #include <asm/image.h> @@ -130,18 +129,10 @@ static void *image_load(struct kimage *image, return NULL; }
-#ifdef CONFIG_KEXEC_IMAGE_VERIFY_SIG -static int image_verify_sig(const char *kernel, unsigned long kernel_len) -{ - return verify_pefile_signature(kernel, kernel_len, NULL, - VERIFYING_KEXEC_PE_SIGNATURE); -} -#endif - const struct kexec_file_ops kexec_image_ops = { .probe = image_probe, .load = image_load, #ifdef CONFIG_KEXEC_IMAGE_VERIFY_SIG - .verify_sig = image_verify_sig, + .verify_sig = kexec_kernel_verify_pe_sig, #endif };