[PATCH 1/4] Fix arm64 kexec forbidding kernels signed with keys in the secondary keyring to boot

[PATCH 1/4] Fix arm64 kexec forbidding kernels signed with keys in the secondary keyring to boot

[Michal Suchanek]

commit d3bfe84129f6 ("certs: Add a secondary system keyring that can be added to dynamically")
split of .system_keyring into .builtin_trusted_keys and
.secondary_trusted_keys broke kexec, thereby preventing kernels signed by
keys which are now in the secondary keyring from being kexec'd.

Fix this by passing VERIFY_USE_SECONDARY_KEYRING to
verify_pefile_signature().

Cherry-picked from
commit ea93102f3224 ("Fix kexec forbidding kernels signed with keys in the secondary keyring to boot")

Fixes: 732b7b93d849 ("arm64: kexec_file: add kernel signature verification support")
Cc: kexec at lists.infradead.org
Cc: keyrings at vger.kernel.org
Cc: linux-security-module at vger.kernel.org
Cc: stable at kernel.org
Signed-off-by: Michal Suchanek <msuchanek@suse.de>
---
 arch/arm64/kernel/kexec_image.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/kernel/kexec_image.c b/arch/arm64/kernel/kexec_image.c
index 9ec34690e255..1fbf2ee7c005 100644
--- a/arch/arm64/kernel/kexec_image.c
+++ b/arch/arm64/kernel/kexec_image.c
@@ -133,7 +133,8 @@ static void *image_load(struct kimage *image,
 #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,
+	return verify_pefile_signature(kernel, kernel_len,
+				       VERIFY_USE_SECONDARY_KEYRING,
 				       VERIFYING_KEXEC_PE_SIGNATURE);
 }
 #endif
-- 
2.31.1

[PATCH 1/4] Fix arm64 kexec forbidding kernels signed with keys in the secondary keyring to boot

[joeyli]

On Tue, Feb 15, 2022 at 08:39:38PM +0100, Michal Suchanek wrote:
> commit d3bfe84129f6 ("certs: Add a secondary system keyring that can be added to dynamically")
> split of .system_keyring into .builtin_trusted_keys and
> .secondary_trusted_keys broke kexec, thereby preventing kernels signed by
> keys which are now in the secondary keyring from being kexec'd.
> 
> Fix this by passing VERIFY_USE_SECONDARY_KEYRING to
> verify_pefile_signature().
> 
> Cherry-picked from
> commit ea93102f3224 ("Fix kexec forbidding kernels signed with keys in the secondary keyring to boot")
> 
> Fixes: 732b7b93d849 ("arm64: kexec_file: add kernel signature verification support")
> Cc: kexec at lists.infradead.org
> Cc: keyrings at vger.kernel.org
> Cc: linux-security-module at vger.kernel.org
> Cc: stable at kernel.org
> Signed-off-by: Michal Suchanek <msuchanek@suse.de>

Reviewed-by: "Lee, Chun-Yi" <jlee@suse.com>

> ---
>  arch/arm64/kernel/kexec_image.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/arm64/kernel/kexec_image.c b/arch/arm64/kernel/kexec_image.c
> index 9ec34690e255..1fbf2ee7c005 100644
> --- a/arch/arm64/kernel/kexec_image.c
> +++ b/arch/arm64/kernel/kexec_image.c
> @@ -133,7 +133,8 @@ static void *image_load(struct kimage *image,
>  #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,
> +	return verify_pefile_signature(kernel, kernel_len,
> +				       VERIFY_USE_SECONDARY_KEYRING,
>  				       VERIFYING_KEXEC_PE_SIGNATURE);
>  }
>  #endif
> -- 
> 2.31.1

[PATCH 1/4] Fix arm64 kexec forbidding kernels signed with keys in the secondary keyring to boot

[Baoquan He]

Hi,

On 02/15/22 at 08:39pm, Michal Suchanek wrote:
> commit d3bfe84129f6 ("certs: Add a secondary system keyring that can be added to dynamically")
> split of .system_keyring into .builtin_trusted_keys and
> .secondary_trusted_keys broke kexec, thereby preventing kernels signed by
> keys which are now in the secondary keyring from being kexec'd.
> 
> Fix this by passing VERIFY_USE_SECONDARY_KEYRING to
> verify_pefile_signature().
> 
> Cherry-picked from
> commit ea93102f3224 ("Fix kexec forbidding kernels signed with keys in the secondary keyring to boot")

This line may need a line feed?

The patch 1~3 looks good to me. Coiby encountered the same issue
on arm64, and has posted a patch series to fix that and there's clean up
and code adjustment.

https://lore.kernel.org/all/20220401013118.348084-1-coxu at redhat.com/T/#u

Hi Coiby,

Maybe you can check this patchset, and consider how to integrate your
patches based on this patch 1~/3?

For this patch itself, ack.

Acked-by: Baoquan He <bhe@redhat.com>

> 
> Fixes: 732b7b93d849 ("arm64: kexec_file: add kernel signature verification support")
> Cc: kexec at lists.infradead.org
> Cc: keyrings at vger.kernel.org
> Cc: linux-security-module at vger.kernel.org
> Cc: stable at kernel.org
> Signed-off-by: Michal Suchanek <msuchanek@suse.de>
> ---
>  arch/arm64/kernel/kexec_image.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/arm64/kernel/kexec_image.c b/arch/arm64/kernel/kexec_image.c
> index 9ec34690e255..1fbf2ee7c005 100644
> --- a/arch/arm64/kernel/kexec_image.c
> +++ b/arch/arm64/kernel/kexec_image.c
> @@ -133,7 +133,8 @@ static void *image_load(struct kimage *image,
>  #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,
> +	return verify_pefile_signature(kernel, kernel_len,
> +				       VERIFY_USE_SECONDARY_KEYRING,
>  				       VERIFYING_KEXEC_PE_SIGNATURE);
>  }
>  #endif
> -- 
> 2.31.1
> 

[PATCH 2/4] kexec, KEYS, arm64: Make use of platform keyring for signature verification

[Michal Suchanek]

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

Add platform keyring support on arm64 as well.

Fixes: 278311e417be ("kexec, KEYS: Make use of platform keyring for signature verify")
Cc: kexec at lists.infradead.org
Cc: keyrings at vger.kernel.org
Cc: linux-security-module at vger.kernel.org
Cc: stable at kernel.org
Signed-off-by: Michal Suchanek <msuchanek@suse.de>
---
 arch/arm64/kernel/kexec_image.c | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/arch/arm64/kernel/kexec_image.c b/arch/arm64/kernel/kexec_image.c
index 1fbf2ee7c005..3dee7b2d8336 100644
--- a/arch/arm64/kernel/kexec_image.c
+++ b/arch/arm64/kernel/kexec_image.c
@@ -133,9 +133,17 @@ static void *image_load(struct kimage *image,
 #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,
-				       VERIFY_USE_SECONDARY_KEYRING,
-				       VERIFYING_KEXEC_PE_SIGNATURE);
+	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
 
-- 
2.31.1

[PATCH 2/4] kexec, KEYS, arm64: Make use of platform keyring for signature verification

[joeyli]

On Tue, Feb 15, 2022 at 08:39:39PM +0100, Michal Suchanek wrote:
> commit 278311e417be ("kexec, KEYS: Make use of platform keyring for signature verify")
> adds platform keyring support on x86 kexec but not arm64.
> 
> Add platform keyring support on arm64 as well.
> 
> Fixes: 278311e417be ("kexec, KEYS: Make use of platform keyring for signature verify")
> Cc: kexec at lists.infradead.org
> Cc: keyrings at vger.kernel.org
> Cc: linux-security-module at vger.kernel.org
> Cc: stable at kernel.org
> Signed-off-by: Michal Suchanek <msuchanek@suse.de>

Reviewed-by: "Lee, Chun-Yi" <jlee@suse.com>

> ---
>  arch/arm64/kernel/kexec_image.c | 14 +++++++++++---
>  1 file changed, 11 insertions(+), 3 deletions(-)
> 
> diff --git a/arch/arm64/kernel/kexec_image.c b/arch/arm64/kernel/kexec_image.c
> index 1fbf2ee7c005..3dee7b2d8336 100644
> --- a/arch/arm64/kernel/kexec_image.c
> +++ b/arch/arm64/kernel/kexec_image.c
> @@ -133,9 +133,17 @@ static void *image_load(struct kimage *image,
>  #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,
> -				       VERIFY_USE_SECONDARY_KEYRING,
> -				       VERIFYING_KEXEC_PE_SIGNATURE);
> +	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
>  
> -- 
> 2.31.1

[PATCH 3/4] kexec, KEYS, s390: Make use of built-in and secondary keyring for signature verification

[Michal Suchanek]

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: Philipp Rudo <prudo@linux.ibm.com>
Cc: kexec at lists.infradead.org
Cc: keyrings at vger.kernel.org
Cc: linux-security-module at vger.kernel.org
Cc: stable at kernel.org
Signed-off-by: Michal Suchanek <msuchanek@suse.de>
---
 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 */
 
-- 
2.31.1

[PATCH 3/4] kexec, KEYS, s390: Make use of built-in and secondary keyring for signature verification

[joeyli]

On Tue, Feb 15, 2022 at 08:39:40PM +0100, Michal Suchanek wrote:
> 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: Philipp Rudo <prudo@linux.ibm.com>
> Cc: kexec at lists.infradead.org
> Cc: keyrings at vger.kernel.org
> Cc: linux-security-module at vger.kernel.org
> Cc: stable at kernel.org
> Signed-off-by: Michal Suchanek <msuchanek@suse.de>

Reviewed-by: "Lee, Chun-Yi" <jlee@suse.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 */
>  
> -- 
> 2.31.1

[PATCH 0/4] Unifrom keyring support across architectures and functions

[Coiby Xu]

Hi Michal,

As mentioned by Baoquan, I have a patch set "[PATCH v5 0/3] use more
system keyrings to verify arm64 kdump kernel image signature" [1]. The
differences between your patch set and mine are as follows, 
  - my patch set only adds support for arm64 while yours also extends to
    s390
  - I made the code for verifying signed kernel image as PE file in x86
    public so arm64 can reuse the code as well which seems to be better
    approach
  - I also cleaned up clean up arch_kexec_kernel_verify_sig

Would you mind if I integrate your first 3 patches with mine as follows
  - for arm64, I'll use my version
  - for s390, I'll use your version

For your last patch which allows to use of platform keyring for
signature verification of kernel module, I'll leave it to yourself. How
do you think about it?


[1] https://lore.kernel.org/all/20220401013118.348084-1-coxu at redhat.com/

On Tue, Feb 15, 2022 at 08:39:37PM +0100, Michal Suchanek wrote:
>While testing KEXEC_SIG on powerpc I noticed discrepancy in support for
>different keyrings across architectures and between KEXEC_SIG and
>MODULE_SIG. Fix this by enabling suport for the missing keyrings.
>
>The latter two patches obviously conflict with the ongoing module code
>cleanup. If they turn out desirable I will add them to the other series
>dealing with KEXEC_SIG.
>
>The arm patches can be merged independently.
>
>Thanks
>
>Michal
>
>Michal Suchanek (4):
>  Fix arm64 kexec forbidding kernels signed with keys in the secondary
>    keyring to boot
>  kexec, KEYS, arm64: Make use of platform keyring for signature
>    verification
>  kexec, KEYS, s390: Make use of built-in and secondary keyring for
>    signature verification
>  module, KEYS: Make use of platform keyring for signature verification
>
> arch/arm64/kernel/kexec_image.c       | 13 +++++++++++--
> arch/s390/kernel/machine_kexec_file.c | 18 +++++++++++++-----
> kernel/module_signing.c               | 14 ++++++++++----
> 3 files changed, 34 insertions(+), 11 deletions(-)
>
>-- 
>2.31.1
>

-- 
Best regards,
Coiby

[PATCH 0/4] Unifrom keyring support across architectures and functions

[Michal =?unknown-8bit?q?Such=C3=A1nek?=]

On Fri, Apr 08, 2022 at 03:47:04PM +0800, Coiby Xu wrote:
> Hi Michal,
> 
> As mentioned by Baoquan, I have a patch set "[PATCH v5 0/3] use more
> system keyrings to verify arm64 kdump kernel image signature" [1]. The
> differences between your patch set and mine are as follows,  - my patch set
> only adds support for arm64 while yours also extends to
>    s390
>  - I made the code for verifying signed kernel image as PE file in x86
>    public so arm64 can reuse the code as well which seems to be better
>    approach
>  - I also cleaned up clean up arch_kexec_kernel_verify_sig
> 
> Would you mind if I integrate your first 3 patches with mine as follows
>  - for arm64, I'll use my version
>  - for s390, I'll use your version

Great

less code duplication is always good.

Thanks

Michal

> 
> For your last patch which allows to use of platform keyring for
> signature verification of kernel module, I'll leave it to yourself. How
> do you think about it?
> 
> 
> [1] https://lore.kernel.org/all/20220401013118.348084-1-coxu at redhat.com/
> 
> On Tue, Feb 15, 2022 at 08:39:37PM +0100, Michal Suchanek wrote:
> > While testing KEXEC_SIG on powerpc I noticed discrepancy in support for
> > different keyrings across architectures and between KEXEC_SIG and
> > MODULE_SIG. Fix this by enabling suport for the missing keyrings.
> > 
> > The latter two patches obviously conflict with the ongoing module code
> > cleanup. If they turn out desirable I will add them to the other series
> > dealing with KEXEC_SIG.
> > 
> > The arm patches can be merged independently.
> > 
> > Thanks
> > 
> > Michal
> > 
> > Michal Suchanek (4):
> >  Fix arm64 kexec forbidding kernels signed with keys in the secondary
> >    keyring to boot
> >  kexec, KEYS, arm64: Make use of platform keyring for signature
> >    verification
> >  kexec, KEYS, s390: Make use of built-in and secondary keyring for
> >    signature verification
> >  module, KEYS: Make use of platform keyring for signature verification
> > 
> > arch/arm64/kernel/kexec_image.c       | 13 +++++++++++--
> > arch/s390/kernel/machine_kexec_file.c | 18 +++++++++++++-----
> > kernel/module_signing.c               | 14 ++++++++++----
> > 3 files changed, 34 insertions(+), 11 deletions(-)
> > 
> > -- 
> > 2.31.1
> > 
> 
> -- 
> Best regards,
> Coiby
>