diff mbox series

[v2,1/2] kexec, KEYS: make the code in bzImage64_verify_sig generic

Message ID 20211009095458.297191-2-coxu@redhat.com (mailing list archive)
State New, archived
Headers show
Series use more system keyrings to verify arm64 kdump kernel image signature | expand

Commit Message

Coiby Xu Oct. 9, 2021, 9:54 a.m. UTC
The code in bzImage64_verify_sig could make use of system keyrings including
.buitin_trusted_keys, .secondary_trusted_keys and .platform keyring to verify
signed kernel image as PE file. Make it generic so both x86_64 and arm64 can 
use it.

Signed-off-by: Coiby Xu <coxu@redhat.com>
---
 arch/x86/kernel/kexec-bzimage64.c | 13 +------------
 include/linux/kexec.h             |  3 +++
 kernel/kexec_file.c               | 17 +++++++++++++++++
 3 files changed, 21 insertions(+), 12 deletions(-)

Comments

Eric W. Biederman Oct. 11, 2021, 1:58 p.m. UTC | #1
Coiby Xu <coxu@redhat.com> writes:

> The code in bzImage64_verify_sig could make use of system keyrings including
> .buitin_trusted_keys, .secondary_trusted_keys and .platform keyring to verify
> signed kernel image as PE file. Make it generic so both x86_64 and arm64 can 
> use it.

The naming is problematic.

At a minimum please name the new function kexec_kernel_verify_pe_sig.
AKA what you named it without the "arch_" prefix.  A function named with
an "arch_" prefix  implies that it has an architecture specific
implementation.

It looks like arch_kexec_kernel_verify_sig should be killed as well
as it only has one implementation in the generic code.  And the code
should always call kexec_image_verify_sig_default.  Not that you should
do that but I am pointing it out as it seems that is the bad example you
are copying.

Eric

> Signed-off-by: Coiby Xu <coxu@redhat.com>
> ---
>  arch/x86/kernel/kexec-bzimage64.c | 13 +------------
>  include/linux/kexec.h             |  3 +++
>  kernel/kexec_file.c               | 17 +++++++++++++++++
>  3 files changed, 21 insertions(+), 12 deletions(-)
>
> diff --git a/arch/x86/kernel/kexec-bzimage64.c b/arch/x86/kernel/kexec-bzimage64.c
> index 170d0fd68b1f..4136dd3be5a9 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>
> @@ -531,17 +530,7 @@ static int bzImage64_cleanup(void *loader_data)
>  #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;
> +	return arch_kexec_kernel_verify_pe_sig(kernel, kernel_len);
>  }
>  #endif
>  
> diff --git a/include/linux/kexec.h b/include/linux/kexec.h
> index 0c994ae37729..d45f32336dbe 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>
>  
>  #ifdef CONFIG_KEXEC_CORE
>  #include <linux/list.h>
> @@ -199,6 +200,8 @@ 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);
> +int arch_kexec_kernel_verify_pe_sig(const char *kernel,
> +				    unsigned long kernel_len);
>  #endif
>  int arch_kexec_locate_mem_hole(struct kexec_buf *kbuf);
>  
> diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c
> index 33400ff051a8..0530275b7aa3 100644
> --- a/kernel/kexec_file.c
> +++ b/kernel/kexec_file.c
> @@ -106,6 +106,23 @@ int __weak arch_kexec_kernel_verify_sig(struct kimage *image, void *buf,
>  {
>  	return kexec_image_verify_sig_default(image, buf, buf_len);
>  }
> +
> +#ifdef CONFIG_SIGNED_PE_FILE_VERIFICATION
> +int arch_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
>  #endif
>  
>  /*
Coiby Xu Oct. 12, 2021, 3:53 a.m. UTC | #2
On Mon, Oct 11, 2021 at 08:58:36AM -0500, Eric W. Biederman wrote:
>Coiby Xu <coxu@redhat.com> writes:
>
>> The code in bzImage64_verify_sig could make use of system keyrings including
>> .buitin_trusted_keys, .secondary_trusted_keys and .platform keyring to verify
>> signed kernel image as PE file. Make it generic so both x86_64 and arm64 can
>> use it.
>
>The naming is problematic.
>
>At a minimum please name the new function kexec_kernel_verify_pe_sig.
>AKA what you named it without the "arch_" prefix.  A function named with
>an "arch_" prefix  implies that it has an architecture specific
>implementation.

Thanks for bringing up this issue and providing the fix and the explanation.

>
>It looks like arch_kexec_kernel_verify_sig should be killed as well
>as it only has one implementation in the generic code.  And the code
>should always call kexec_image_verify_sig_default.  Not that you should
>do that but I am pointing it out as it seems that is the bad example you
>are copying.

Yes, you are right about it. This is a leftover issue of commit 
9ec4ecef0af7790551109283ca039a7c52de343c ("kexec_file,x86,powerpc: factor 
out kexec_file_ops functions"),
     
     As arch_kexec_kernel_image_{probe,load}(),
     arch_kimage_file_post_load_cleanup() and arch_kexec_kernel_verify_sig()
     are almost duplicated among architectures, they can be commonalized with
     an architecture-defined kexec_file_ops array.  So let's factor them out.

That commit moves the architecture specific implementation of 
arch_kexec_kernel_verify_sig to kexec_file_ops->verify_sig. So actually 
arch_kexec_kernel_verify_sig should be removed. Then we rename
kexec_image_verify_sig_default to kimage_validate_signature and call 
it in kimage_validate_signature directly. I'll include a new patch to do 
the clean-up work in v3.

>
>Eric
>
>> Signed-off-by: Coiby Xu <coxu@redhat.com>
>> ---
>>  arch/x86/kernel/kexec-bzimage64.c | 13 +------------
>>  include/linux/kexec.h             |  3 +++
>>  kernel/kexec_file.c               | 17 +++++++++++++++++
>>  3 files changed, 21 insertions(+), 12 deletions(-)
>>
>> diff --git a/arch/x86/kernel/kexec-bzimage64.c b/arch/x86/kernel/kexec-bzimage64.c
>> index 170d0fd68b1f..4136dd3be5a9 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>
>> @@ -531,17 +530,7 @@ static int bzImage64_cleanup(void *loader_data)
>>  #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;
>> +	return arch_kexec_kernel_verify_pe_sig(kernel, kernel_len);
>>  }
>>  #endif
>>
>> diff --git a/include/linux/kexec.h b/include/linux/kexec.h
>> index 0c994ae37729..d45f32336dbe 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>
>>
>>  #ifdef CONFIG_KEXEC_CORE
>>  #include <linux/list.h>
>> @@ -199,6 +200,8 @@ 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);
>> +int arch_kexec_kernel_verify_pe_sig(const char *kernel,
>> +				    unsigned long kernel_len);
>>  #endif
>>  int arch_kexec_locate_mem_hole(struct kexec_buf *kbuf);
>>
>> diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c
>> index 33400ff051a8..0530275b7aa3 100644
>> --- a/kernel/kexec_file.c
>> +++ b/kernel/kexec_file.c
>> @@ -106,6 +106,23 @@ int __weak arch_kexec_kernel_verify_sig(struct kimage *image, void *buf,
>>  {
>>  	return kexec_image_verify_sig_default(image, buf, buf_len);
>>  }
>> +
>> +#ifdef CONFIG_SIGNED_PE_FILE_VERIFICATION
>> +int arch_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
>>  #endif
>>
>>  /*
>
diff mbox series

Patch

diff --git a/arch/x86/kernel/kexec-bzimage64.c b/arch/x86/kernel/kexec-bzimage64.c
index 170d0fd68b1f..4136dd3be5a9 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>
@@ -531,17 +530,7 @@  static int bzImage64_cleanup(void *loader_data)
 #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;
+	return arch_kexec_kernel_verify_pe_sig(kernel, kernel_len);
 }
 #endif
 
diff --git a/include/linux/kexec.h b/include/linux/kexec.h
index 0c994ae37729..d45f32336dbe 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>
 
 #ifdef CONFIG_KEXEC_CORE
 #include <linux/list.h>
@@ -199,6 +200,8 @@  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);
+int arch_kexec_kernel_verify_pe_sig(const char *kernel,
+				    unsigned long kernel_len);
 #endif
 int arch_kexec_locate_mem_hole(struct kexec_buf *kbuf);
 
diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c
index 33400ff051a8..0530275b7aa3 100644
--- a/kernel/kexec_file.c
+++ b/kernel/kexec_file.c
@@ -106,6 +106,23 @@  int __weak arch_kexec_kernel_verify_sig(struct kimage *image, void *buf,
 {
 	return kexec_image_verify_sig_default(image, buf, buf_len);
 }
+
+#ifdef CONFIG_SIGNED_PE_FILE_VERIFICATION
+int arch_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
 #endif
 
 /*