[PATCH 5.15 13/14] kexec, KEYS: make the code in bzImage64_verify_sig generic

Greg Kroah-Hartman
2022-08-19T15:42:17Z

From: Coiby Xu <coxu@redhat.com>

commit c903dae8941deb55043ee46ded29e84e97cd84bb upstream.

commit 278311e417be ("kexec, KEYS: Make use of platform keyring for
signature verify") adds platform keyring support on x86 kexec but not
arm64.

The code in bzImage64_verify_sig uses the keys on the
.builtin_trusted_keys, .machine, if configured and enabled,
.secondary_trusted_keys, also if configured, and .platform keyrings
to verify the signed kernel image as PE file.

Cc: kexec@lists.infradead.org
Cc: keyrings@vger.kernel.org
Cc: linux-security-module@vger.kernel.org
Reviewed-by: Michal Suchanek <msuchanek@suse.de>
Signed-off-by: Coiby Xu <coxu@redhat.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/x86/kernel/kexec-bzimage64.c | 20 +-------------------
include/linux/kexec.h | 7 +++++++
kernel/kexec_file.c | 17 +++++++++++++++++
3 files changed, 25 insertions(+), 19 deletions(-)

--- a/arch/x86/kernel/kexec-bzimage64.c
+++ b/arch/x86/kernel/kexec-bzimage64.c
@@ -17,7 +17,6 @@
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/efi.h>
-#include <linux/verification.h>

#include <asm/bootparam.h>
#include <asm/setup.h>
@@ -528,28 +527,11 @@ static int bzImage64_cleanup(void *loade
return 0;
}

-#ifdef CONFIG_KEXEC_BZIMAGE_VERIFY_SIG
-static int bzImage64_verify_sig(const char *kernel, unsigned long kernel_len)
-{
- int ret;
-
- ret = verify_pefile_signature(kernel, kernel_len,
- VERIFY_USE_SECONDARY_KEYRING,
- VERIFYING_KEXEC_PE_SIGNATURE);
- if (ret == -ENOKEY && IS_ENABLED(CONFIG_INTEGRITY_PLATFORM_KEYRING)) {
- ret = verify_pefile_signature(kernel, kernel_len,
- VERIFY_USE_PLATFORM_KEYRING,
- VERIFYING_KEXEC_PE_SIGNATURE);
- }
- return ret;
-}
-#endif
-
const struct kexec_file_ops kexec_bzImage64_ops = {
.probe = bzImage64_probe,
.load = bzImage64_load,
.cleanup = bzImage64_cleanup,
#ifdef CONFIG_KEXEC_BZIMAGE_VERIFY_SIG
- .verify_sig = bzImage64_verify_sig,
+ .verify_sig = kexec_kernel_verify_pe_sig,
#endif
};
--- a/include/linux/kexec.h
+++ b/include/linux/kexec.h
@@ -19,6 +19,7 @@
#include <asm/io.h>

#include <uapi/linux/kexec.h>
+#include <linux/verification.h>

#ifdef CONFIG_KEXEC_CORE
#include <linux/list.h>
@@ -206,6 +207,12 @@ static inline void *arch_kexec_kernel_im
}
#endif

+#ifdef CONFIG_KEXEC_SIG
+#ifdef CONFIG_SIGNED_PE_FILE_VERIFICATION
+int kexec_kernel_verify_pe_sig(const char *kernel, unsigned long kernel_len);
+#endif
+#endif
+
extern int kexec_add_buffer(struct kexec_buf *kbuf);
int kexec_locate_mem_hole(struct kexec_buf *kbuf);

--- a/kernel/kexec_file.c
+++ b/kernel/kexec_file.c
@@ -123,6 +123,23 @@ void kimage_file_post_load_cleanup(struc
}

#ifdef CONFIG_KEXEC_SIG
+#ifdef CONFIG_SIGNED_PE_FILE_VERIFICATION
+int kexec_kernel_verify_pe_sig(const char *kernel, unsigned long kernel_len)
+{
+ int ret;
+
+ ret = verify_pefile_signature(kernel, kernel_len,
+ VERIFY_USE_SECONDARY_KEYRING,
+ VERIFYING_KEXEC_PE_SIGNATURE);
+ if (ret == -ENOKEY && IS_ENABLED(CONFIG_INTEGRITY_PLATFORM_KEYRING)) {
+ ret = verify_pefile_signature(kernel, kernel_len,
+ VERIFY_USE_PLATFORM_KEYRING,
+ VERIFYING_KEXEC_PE_SIGNATURE);
+ }
+ return ret;
+}
+#endif
+
static int kexec_image_verify_sig(struct kimage *image, void *buf,
unsigned long buf_len)
{