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: sta...@vger.kernel.org # 34d5960af253: kexec: clean up 
arch_kexec_kernel_verify_sig
Cc: sta...@vger.kernel.org # 83b7bb2d49ae: kexec, KEYS: make the code in 
bzImage64_verify_sig generic
Acked-by: Baoquan He <b...@redhat.com>
Cc: kexec@lists.infradead.org
Cc: keyri...@vger.kernel.org
Cc: linux-security-mod...@vger.kernel.org
Co-developed-by: Michal Suchanek <msucha...@suse.de>
Signed-off-by: Michal Suchanek <msucha...@suse.de>
Acked-by: Will Deacon <w...@kernel.org>
Signed-off-by: Coiby Xu <c...@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
 };
-- 
2.35.3


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