[SRU][J][PATCH 3/3] arm64: kexec_file: use more system keyrings to verify kernel image signature

[Chengen Du]

From: Coiby Xu <coxu at redhat.com>

Currently, when loading a kernel image via the kexec_file_load() system
call, arm64 can only use the .builtin_trusted_keys keyring to verify
a signature whereas x86 can use three more keyrings i.e.
.secondary_trusted_keys, .machine and .platform keyrings. For example,
one resulting problem is kexec'ing a kernel image  would be rejected
with the error "Lockdown: kexec: kexec of unsigned images is restricted;
see man kernel_lockdown.7".

This patch set enables arm64 to make use of the same keyrings as x86 to
verify the signature kexec'ed kernel image.

Fixes: 732b7b93d849 ("arm64: kexec_file: add kernel signature verification support")
Cc: stable at vger.kernel.org # 105e10e2cf1c: kexec_file: drop weak attribute from functions
Cc: stable at vger.kernel.org # 34d5960af253: kexec: clean up arch_kexec_kernel_verify_sig
Cc: stable at vger.kernel.org # 83b7bb2d49ae: kexec, KEYS: make the code in bzImage64_verify_sig generic
Acked-by: Baoquan He <bhe at redhat.com>
Cc: kexec at lists.infradead.org
Cc: keyrings at vger.kernel.org
Cc: linux-security-module at vger.kernel.org
Co-developed-by: Michal Suchanek <msuchanek at suse.de>
Signed-off-by: Michal Suchanek <msuchanek at suse.de>
Acked-by: Will Deacon <will at kernel.org>
Signed-off-by: Coiby Xu <coxu at redhat.com>
Signed-off-by: Mimi Zohar <zohar at linux.ibm.com>
(cherry picked from commit 0d519cadf75184a24313568e7f489a7fc9b1be3b)
Signed-off-by: Chengen Du <chengen.du at canonical.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
 };
-- 
2.39.2