[PATCH v9 1/4] kexec: clean up arch_kexec_kernel_verify_sig

[PATCH v9 1/4] kexec: clean up arch_kexec_kernel_verify_sig

[Coiby Xu]

Currently there is no arch-specific implementation of
arch_kexec_kernel_verify_sig. Even if we want to add an implementation
for an architecture in the future, we can simply use "(struct
kexec_file_ops*)->verify_sig". So clean it up.

Note this patch is dependent by later patches so it should backported to
the stable tree as well.

Cc: stable@vger.kernel.org
Suggested-by: Eric W. Biederman <ebiederm@xmission.com>
Reviewed-by: Michal Suchanek <msuchanek@suse.de>
Acked-by: Baoquan He <bhe@redhat.com>
Signed-off-by: Coiby Xu <coxu@redhat.com>
---
 include/linux/kexec.h |  4 ----
 kernel/kexec_file.c   | 34 +++++++++++++---------------------
 2 files changed, 13 insertions(+), 25 deletions(-)

diff --git a/include/linux/kexec.h b/include/linux/kexec.h
index ce6536f1d269..e3125fae1599 100644
--- a/include/linux/kexec.h
+++ b/include/linux/kexec.h
@@ -194,10 +194,6 @@ int arch_kexec_kernel_image_probe(struct kimage *image, void *buf,
 				  unsigned long buf_len);
 void *arch_kexec_kernel_image_load(struct kimage *image);
 int arch_kimage_file_post_load_cleanup(struct kimage *image);
-#ifdef CONFIG_KEXEC_SIG
-int arch_kexec_kernel_verify_sig(struct kimage *image, void *buf,
-				 unsigned long buf_len);
-#endif
 int arch_kexec_locate_mem_hole(struct kexec_buf *kbuf);
 
 extern int kexec_add_buffer(struct kexec_buf *kbuf);
diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c
index 145321a5e798..c7cbadc754a1 100644
--- a/kernel/kexec_file.c
+++ b/kernel/kexec_file.c
@@ -89,25 +89,6 @@ int __weak arch_kimage_file_post_load_cleanup(struct kimage *image)
 	return kexec_image_post_load_cleanup_default(image);
 }
 
-#ifdef CONFIG_KEXEC_SIG
-static int kexec_image_verify_sig_default(struct kimage *image, void *buf,
-					  unsigned long buf_len)
-{
-	if (!image->fops || !image->fops->verify_sig) {
-		pr_debug("kernel loader does not support signature verification.\n");
-		return -EKEYREJECTED;
-	}
-
-	return image->fops->verify_sig(buf, buf_len);
-}
-
-int __weak arch_kexec_kernel_verify_sig(struct kimage *image, void *buf,
-					unsigned long buf_len)
-{
-	return kexec_image_verify_sig_default(image, buf, buf_len);
-}
-#endif
-
 /*
  * Free up memory used by kernel, initrd, and command line. This is temporary
  * memory allocation which is not needed any more after these buffers have
@@ -150,13 +131,24 @@ void kimage_file_post_load_cleanup(struct kimage *image)
 }
 
 #ifdef CONFIG_KEXEC_SIG
+static int kexec_image_verify_sig(struct kimage *image, void *buf,
+		unsigned long buf_len)
+{
+	if (!image->fops || !image->fops->verify_sig) {
+		pr_debug("kernel loader does not support signature verification.\n");
+		return -EKEYREJECTED;
+	}
+
+	return image->fops->verify_sig(buf, buf_len);
+}
+
 static int
 kimage_validate_signature(struct kimage *image)
 {
 	int ret;
 
-	ret = arch_kexec_kernel_verify_sig(image, image->kernel_buf,
-					   image->kernel_buf_len);
+	ret = kexec_image_verify_sig(image, image->kernel_buf,
+				     image->kernel_buf_len);
 	if (ret) {
 
 		if (IS_ENABLED(CONFIG_KEXEC_SIG_FORCE)) {
-- 
2.35.3

[PATCH v9 2/4] kexec, KEYS: make the code in bzImage64_verify_sig generic

[Coiby Xu]

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>
---
 arch/x86/kernel/kexec-bzimage64.c | 20 +-------------------
 include/linux/kexec.h             |  6 ++++++
 kernel/kexec_file.c               | 17 +++++++++++++++++
 3 files changed, 24 insertions(+), 19 deletions(-)

diff --git a/arch/x86/kernel/kexec-bzimage64.c b/arch/x86/kernel/kexec-bzimage64.c
index 170d0fd68b1f..f299b48f9c9f 100644
--- 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 *loader_data)
 	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
 };
diff --git a/include/linux/kexec.h b/include/linux/kexec.h
index e3125fae1599..620018bbc419 100644
--- 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>
 
 /* Location of a reserved region to hold the crash kernel.
  */
@@ -194,6 +195,11 @@ int arch_kexec_kernel_image_probe(struct kimage *image, void *buf,
 				  unsigned long buf_len);
 void *arch_kexec_kernel_image_load(struct kimage *image);
 int arch_kimage_file_post_load_cleanup(struct kimage *image);
+#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
 int arch_kexec_locate_mem_hole(struct kexec_buf *kbuf);
 
 extern int kexec_add_buffer(struct kexec_buf *kbuf);
diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c
index c7cbadc754a1..db6e89128b98 100644
--- a/kernel/kexec_file.c
+++ b/kernel/kexec_file.c
@@ -131,6 +131,23 @@ void kimage_file_post_load_cleanup(struct kimage *image)
 }
 
 #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)
 {
-- 
2.35.3

[PATCH v9 3/4] arm64: kexec_file: use more system keyrings to verify kernel image signature

[Coiby Xu]

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@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
 };
-- 
2.35.3

[PATCH v9 4/4] kexec, KEYS, s390: Make use of built-in and secondary keyring for signature verification

[Coiby Xu]

From: Michal Suchanek <msuchanek@suse.de>

commit e23a8020ce4e ("s390/kexec_file: Signature verification prototype")
adds support for KEXEC_SIG verification with keys from platform keyring
but the built-in keys and secondary keyring are not used.

Add support for the built-in keys and secondary keyring as x86 does.

Fixes: e23a8020ce4e ("s390/kexec_file: Signature verification prototype")
Cc: stable@vger.kernel.org
Cc: Philipp Rudo <prudo@linux.ibm.com>
Cc: kexec@lists.infradead.org
Cc: keyrings@vger.kernel.org
Cc: linux-security-module@vger.kernel.org
Signed-off-by: Michal Suchanek <msuchanek@suse.de>
Reviewed-by: "Lee, Chun-Yi" <jlee@suse.com>
Acked-by: Baoquan He <bhe@redhat.com>
Signed-off-by: Coiby Xu <coxu@redhat.com>
---
 arch/s390/kernel/machine_kexec_file.c | 18 +++++++++++++-----
 1 file changed, 13 insertions(+), 5 deletions(-)

diff --git a/arch/s390/kernel/machine_kexec_file.c b/arch/s390/kernel/machine_kexec_file.c
index 8f43575a4dd3..fc6d5f58debe 100644
--- a/arch/s390/kernel/machine_kexec_file.c
+++ b/arch/s390/kernel/machine_kexec_file.c
@@ -31,6 +31,7 @@ int s390_verify_sig(const char *kernel, unsigned long kernel_len)
 	const unsigned long marker_len = sizeof(MODULE_SIG_STRING) - 1;
 	struct module_signature *ms;
 	unsigned long sig_len;
+	int ret;
 
 	/* Skip signature verification when not secure IPLed. */
 	if (!ipl_secure_flag)
@@ -65,11 +66,18 @@ int s390_verify_sig(const char *kernel, unsigned long kernel_len)
 		return -EBADMSG;
 	}
 
-	return verify_pkcs7_signature(kernel, kernel_len,
-				      kernel + kernel_len, sig_len,
-				      VERIFY_USE_PLATFORM_KEYRING,
-				      VERIFYING_MODULE_SIGNATURE,
-				      NULL, NULL);
+	ret = verify_pkcs7_signature(kernel, kernel_len,
+				     kernel + kernel_len, sig_len,
+				     VERIFY_USE_SECONDARY_KEYRING,
+				     VERIFYING_MODULE_SIGNATURE,
+				     NULL, NULL);
+	if (ret == -ENOKEY && IS_ENABLED(CONFIG_INTEGRITY_PLATFORM_KEYRING))
+		ret = verify_pkcs7_signature(kernel, kernel_len,
+					     kernel + kernel_len, sig_len,
+					     VERIFY_USE_PLATFORM_KEYRING,
+					     VERIFYING_MODULE_SIGNATURE,
+					     NULL, NULL);
+	return ret;
 }
 #endif /* CONFIG_KEXEC_SIG */
 
-- 
2.35.3