Hi Greg,
This patch depends on three prerequisites but 5.18-stable tree has two
prerequisites backported. So the full list of commit ids should be
backported is shown below,
1. c903dae8941d ("kexec, KEYS: make the code in bzImage64_verify_sig generic")
2. 0d519cadf751 ("arm64: kexec_file: use more system keyrings to verify kernel image signature")
$ git checkout -b arm_key_5.18.y stable/linux-5.18.y
Updating files: 100% (43489/43489), done.
branch 'arm_key_5.18.y' set up to track 'stable/linux-5.18.y'.
Switched to a new branch 'arm_key_5.18.y'
$ git cherry-pick c903dae8941d 0d519cadf751
Auto-merging include/linux/kexec.h
Auto-merging kernel/kexec_file.c
[arm_key_5.18.y f3c9c5542700] kexec, KEYS: make the code in bzImage64_verify_sig generic
Date: Thu Jul 14 21:40:25 2022 +0800
3 files changed, 25 insertions(+), 19 deletions(-)
[arm_key_5.18.y 532854860941] arm64: kexec_file: use more system keyrings to verify kernel image signature
Date: Thu Jul 14 21:40:26 2022 +0800
1 file changed, 1 insertion(+), 10 deletions(-)
On Mon, Aug 15, 2022 at 05:33:04PM +0200, gregkh@xxxxxxxxxxxxxxxxxxx wrote:
The patch below does not apply to the 5.18-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@xxxxxxxxxxxxxxx>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 0d519cadf75184a24313568e7f489a7fc9b1be3b Mon Sep 17 00:00:00 2001
From: Coiby Xu <coxu@xxxxxxxxxx>
Date: Thu, 14 Jul 2022 21:40:26 +0800
Subject: [PATCH] arm64: kexec_file: use more system keyrings to verify kernel
image signature
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@xxxxxxxxxxxxxxx # 105e10e2cf1c: kexec_file: drop weak attribute from functions
Cc: stable@xxxxxxxxxxxxxxx # 34d5960af253: kexec: clean up arch_kexec_kernel_verify_sig
Cc: stable@xxxxxxxxxxxxxxx # 83b7bb2d49ae: kexec, KEYS: make the code in bzImage64_verify_sig generic
Acked-by: Baoquan He <bhe@xxxxxxxxxx>
Cc: kexec@xxxxxxxxxxxxxxxxxxx
Cc: keyrings@xxxxxxxxxxxxxxx
Cc: linux-security-module@xxxxxxxxxxxxxxx
Co-developed-by: Michal Suchanek <msuchanek@xxxxxxx>
Signed-off-by: Michal Suchanek <msuchanek@xxxxxxx>
Acked-by: Will Deacon <will@xxxxxxxxxx>
Signed-off-by: Coiby Xu <coxu@xxxxxxxxxx>
Signed-off-by: Mimi Zohar <zohar@xxxxxxxxxxxxx>
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
};
--
Best regards,
Coiby
