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* [PATCH v3] KEYS: trusted: Fix trusted key backends when building as module
@ 2021-07-30  1:28 Andreas Rammhold
  2021-07-30  4:54 ` Sumit Garg
                   ` (2 more replies)
  0 siblings, 3 replies; 12+ messages in thread
From: Andreas Rammhold @ 2021-07-30  1:28 UTC (permalink / raw)
  To: James Bottomley, Jarkko Sakkinen, Mimi Zohar, David Howells,
	James Morris, Serge E. Hallyn, Sumit Garg
  Cc: Ahmad Fatoum, Andreas Rammhold, linux-integrity, keyrings,
	linux-security-module, linux-kernel

Before this commit the kernel could end up with no trusted key sources
even though both of the currently supported backends (TPM and TEE) were
compiled as modules. This manifested in the trusted key type not being
registered at all.

When checking if a CONFIG_… preprocessor variable is defined we only
test for the builtin (=y) case and not the module (=m) case. By using
the IS_REACHABLE() macro we do test for both cases.

Fixes: 5d0682be3189 ("KEYS: trusted: Add generic trusted keys framework")
Signed-off-by: Andreas Rammhold <andreas@rammhold.de>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>

---

v3:
* Fixed patch formatting

v2:
* Fixed commit message
* Switched from IS_DEFINED() to IS_REACHABLE()

 security/keys/trusted-keys/trusted_core.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/security/keys/trusted-keys/trusted_core.c b/security/keys/trusted-keys/trusted_core.c
index d5c891d8d353..5b35f1b87644 100644
--- a/security/keys/trusted-keys/trusted_core.c
+++ b/security/keys/trusted-keys/trusted_core.c
@@ -27,10 +27,10 @@ module_param_named(source, trusted_key_source, charp, 0);
 MODULE_PARM_DESC(source, "Select trusted keys source (tpm or tee)");
 
 static const struct trusted_key_source trusted_key_sources[] = {
-#if defined(CONFIG_TCG_TPM)
+#if IS_REACHABLE(CONFIG_TCG_TPM)
 	{ "tpm", &trusted_key_tpm_ops },
 #endif
-#if defined(CONFIG_TEE)
+#if IS_REACHABLE(CONFIG_TEE)
 	{ "tee", &trusted_key_tee_ops },
 #endif
 };
-- 
2.32.0


^ permalink raw reply	[flat|nested] 12+ messages in thread

* Re: [PATCH v3] KEYS: trusted: Fix trusted key backends when building as module
  2021-07-30  1:28 [PATCH v3] KEYS: trusted: Fix trusted key backends when building as module Andreas Rammhold
@ 2021-07-30  4:54 ` Sumit Garg
  2021-07-30  6:14 ` Ahmad Fatoum
  2021-09-13  7:47 ` Ahmad Fatoum
  2 siblings, 0 replies; 12+ messages in thread
From: Sumit Garg @ 2021-07-30  4:54 UTC (permalink / raw)
  To: Andreas Rammhold
  Cc: James Bottomley, Jarkko Sakkinen, Mimi Zohar, David Howells,
	James Morris, Serge E. Hallyn, Ahmad Fatoum, linux-integrity,
	open list:ASYMMETRIC KEYS, open list:SECURITY SUBSYSTEM,
	Linux Kernel Mailing List

On Fri, 30 Jul 2021 at 06:58, Andreas Rammhold <andreas@rammhold.de> wrote:
>
> Before this commit the kernel could end up with no trusted key sources
> even though both of the currently supported backends (TPM and TEE) were
> compiled as modules. This manifested in the trusted key type not being
> registered at all.
>
> When checking if a CONFIG_… preprocessor variable is defined we only
> test for the builtin (=y) case and not the module (=m) case. By using
> the IS_REACHABLE() macro we do test for both cases.
>
> Fixes: 5d0682be3189 ("KEYS: trusted: Add generic trusted keys framework")
> Signed-off-by: Andreas Rammhold <andreas@rammhold.de>
> Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
>
> ---
>
> v3:
> * Fixed patch formatting
>
> v2:
> * Fixed commit message
> * Switched from IS_DEFINED() to IS_REACHABLE()
>
>  security/keys/trusted-keys/trusted_core.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>

LGTM.

Reviewed-by: Sumit Garg <sumit.garg@linaro.org>

-Sumit

> diff --git a/security/keys/trusted-keys/trusted_core.c b/security/keys/trusted-keys/trusted_core.c
> index d5c891d8d353..5b35f1b87644 100644
> --- a/security/keys/trusted-keys/trusted_core.c
> +++ b/security/keys/trusted-keys/trusted_core.c
> @@ -27,10 +27,10 @@ module_param_named(source, trusted_key_source, charp, 0);
>  MODULE_PARM_DESC(source, "Select trusted keys source (tpm or tee)");
>
>  static const struct trusted_key_source trusted_key_sources[] = {
> -#if defined(CONFIG_TCG_TPM)
> +#if IS_REACHABLE(CONFIG_TCG_TPM)
>         { "tpm", &trusted_key_tpm_ops },
>  #endif
> -#if defined(CONFIG_TEE)
> +#if IS_REACHABLE(CONFIG_TEE)
>         { "tee", &trusted_key_tee_ops },
>  #endif
>  };
> --
> 2.32.0
>

^ permalink raw reply	[flat|nested] 12+ messages in thread

* Re: [PATCH v3] KEYS: trusted: Fix trusted key backends when building as module
  2021-07-30  1:28 [PATCH v3] KEYS: trusted: Fix trusted key backends when building as module Andreas Rammhold
  2021-07-30  4:54 ` Sumit Garg
@ 2021-07-30  6:14 ` Ahmad Fatoum
  2021-09-13  7:47 ` Ahmad Fatoum
  2 siblings, 0 replies; 12+ messages in thread
From: Ahmad Fatoum @ 2021-07-30  6:14 UTC (permalink / raw)
  To: Andreas Rammhold, James Bottomley, Jarkko Sakkinen, Mimi Zohar,
	David Howells, James Morris, Serge E. Hallyn, Sumit Garg
  Cc: linux-integrity, keyrings, linux-security-module, linux-kernel

On 30.07.21 03:28, Andreas Rammhold wrote:
> Before this commit the kernel could end up with no trusted key sources
> even though both of the currently supported backends (TPM and TEE) were
> compiled as modules. This manifested in the trusted key type not being
> registered at all.
> 
> When checking if a CONFIG_… preprocessor variable is defined we only
> test for the builtin (=y) case and not the module (=m) case. By using
> the IS_REACHABLE() macro we do test for both cases.
> 
> Fixes: 5d0682be3189 ("KEYS: trusted: Add generic trusted keys framework")
> Signed-off-by: Andreas Rammhold <andreas@rammhold.de>
> Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>

Reviewed-by: Ahmad Fatoum <a.fatoum@pengutronix.de>

> 
> ---
> 
> v3:
> * Fixed patch formatting
> 
> v2:
> * Fixed commit message
> * Switched from IS_DEFINED() to IS_REACHABLE()
> 
>  security/keys/trusted-keys/trusted_core.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/security/keys/trusted-keys/trusted_core.c b/security/keys/trusted-keys/trusted_core.c
> index d5c891d8d353..5b35f1b87644 100644
> --- a/security/keys/trusted-keys/trusted_core.c
> +++ b/security/keys/trusted-keys/trusted_core.c
> @@ -27,10 +27,10 @@ module_param_named(source, trusted_key_source, charp, 0);
>  MODULE_PARM_DESC(source, "Select trusted keys source (tpm or tee)");
>  
>  static const struct trusted_key_source trusted_key_sources[] = {
> -#if defined(CONFIG_TCG_TPM)
> +#if IS_REACHABLE(CONFIG_TCG_TPM)
>  	{ "tpm", &trusted_key_tpm_ops },
>  #endif
> -#if defined(CONFIG_TEE)
> +#if IS_REACHABLE(CONFIG_TEE)
>  	{ "tee", &trusted_key_tee_ops },
>  #endif
>  };
> 


-- 
Pengutronix e.K.                           |                             |
Steuerwalder Str. 21                       | http://www.pengutronix.de/  |
31137 Hildesheim, Germany                  | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |

^ permalink raw reply	[flat|nested] 12+ messages in thread

* Re: [PATCH v3] KEYS: trusted: Fix trusted key backends when building as module
  2021-07-30  1:28 [PATCH v3] KEYS: trusted: Fix trusted key backends when building as module Andreas Rammhold
  2021-07-30  4:54 ` Sumit Garg
  2021-07-30  6:14 ` Ahmad Fatoum
@ 2021-09-13  7:47 ` Ahmad Fatoum
  2021-09-27  8:51   ` Andreas Rammhold
  2 siblings, 1 reply; 12+ messages in thread
From: Ahmad Fatoum @ 2021-09-13  7:47 UTC (permalink / raw)
  To: Andreas Rammhold, James Bottomley, Jarkko Sakkinen, Mimi Zohar,
	David Howells, James Morris, Serge E. Hallyn, Sumit Garg
  Cc: linux-integrity, keyrings, linux-security-module, linux-kernel

Dear trusted key maintainers,

On 30.07.21 03:28, Andreas Rammhold wrote:
> Before this commit the kernel could end up with no trusted key sources
> even though both of the currently supported backends (TPM and TEE) were
> compiled as modules. This manifested in the trusted key type not being
> registered at all.
> 
> When checking if a CONFIG_… preprocessor variable is defined we only
> test for the builtin (=y) case and not the module (=m) case. By using
> the IS_REACHABLE() macro we do test for both cases.
> 
> Fixes: 5d0682be3189 ("KEYS: trusted: Add generic trusted keys framework")
> Signed-off-by: Andreas Rammhold <andreas@rammhold.de>
> Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Does anyone intend to pick this up?

Cheers,
Ahmad



> 
> ---
> 
> v3:
> * Fixed patch formatting
> 
> v2:
> * Fixed commit message
> * Switched from IS_DEFINED() to IS_REACHABLE()
> 
>  security/keys/trusted-keys/trusted_core.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/security/keys/trusted-keys/trusted_core.c b/security/keys/trusted-keys/trusted_core.c
> index d5c891d8d353..5b35f1b87644 100644
> --- a/security/keys/trusted-keys/trusted_core.c
> +++ b/security/keys/trusted-keys/trusted_core.c
> @@ -27,10 +27,10 @@ module_param_named(source, trusted_key_source, charp, 0);
>  MODULE_PARM_DESC(source, "Select trusted keys source (tpm or tee)");
>  
>  static const struct trusted_key_source trusted_key_sources[] = {
> -#if defined(CONFIG_TCG_TPM)
> +#if IS_REACHABLE(CONFIG_TCG_TPM)
>  	{ "tpm", &trusted_key_tpm_ops },
>  #endif
> -#if defined(CONFIG_TEE)
> +#if IS_REACHABLE(CONFIG_TEE)
>  	{ "tee", &trusted_key_tee_ops },
>  #endif
>  };
> 


-- 
Pengutronix e.K.                           |                             |
Steuerwalder Str. 21                       | http://www.pengutronix.de/  |
31137 Hildesheim, Germany                  | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |

^ permalink raw reply	[flat|nested] 12+ messages in thread

* Re: [PATCH v3] KEYS: trusted: Fix trusted key backends when building as module
  2021-09-13  7:47 ` Ahmad Fatoum
@ 2021-09-27  8:51   ` Andreas Rammhold
  2021-09-27 11:27     ` Mimi Zohar
  0 siblings, 1 reply; 12+ messages in thread
From: Andreas Rammhold @ 2021-09-27  8:51 UTC (permalink / raw)
  To: Ahmad Fatoum
  Cc: Andreas Rammhold, James Bottomley, Jarkko Sakkinen, Mimi Zohar,
	David Howells, James Morris, Serge E. Hallyn, Sumit Garg,
	linux-integrity, keyrings, linux-security-module, linux-kernel

On 09:47 13.09.21, Ahmad Fatoum wrote:
> Dear trusted key maintainers,
> 
> On 30.07.21 03:28, Andreas Rammhold wrote:
> > Before this commit the kernel could end up with no trusted key sources
> > even though both of the currently supported backends (TPM and TEE) were
> > compiled as modules. This manifested in the trusted key type not being
> > registered at all.
> > 
> > When checking if a CONFIG_… preprocessor variable is defined we only
> > test for the builtin (=y) case and not the module (=m) case. By using
> > the IS_REACHABLE() macro we do test for both cases.
> > 
> > Fixes: 5d0682be3189 ("KEYS: trusted: Add generic trusted keys framework")
> > Signed-off-by: Andreas Rammhold <andreas@rammhold.de>
> > Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
> Does anyone intend to pick this up?

Did this end up in any tree by now? I am wondering if I should resend
the patch instead. Perhaps it was just overlooked?


Andi

^ permalink raw reply	[flat|nested] 12+ messages in thread

* Re: [PATCH v3] KEYS: trusted: Fix trusted key backends when building as module
  2021-09-27  8:51   ` Andreas Rammhold
@ 2021-09-27 11:27     ` Mimi Zohar
  2021-09-27 20:08       ` Andreas Rammhold
  0 siblings, 1 reply; 12+ messages in thread
From: Mimi Zohar @ 2021-09-27 11:27 UTC (permalink / raw)
  To: Andreas Rammhold, Ahmad Fatoum
  Cc: James Bottomley, Jarkko Sakkinen, David Howells, James Morris,
	Serge E. Hallyn, Sumit Garg, linux-integrity, keyrings,
	linux-security-module, linux-kernel

On Mon, 2021-09-27 at 10:51 +0200, Andreas Rammhold wrote:
> On 09:47 13.09.21, Ahmad Fatoum wrote:
> > Dear trusted key maintainers,
> > 
> > On 30.07.21 03:28, Andreas Rammhold wrote:
> > > Before this commit the kernel could end up with no trusted key sources
> > > even though both of the currently supported backends (TPM and TEE) were
> > > compiled as modules. This manifested in the trusted key type not being
> > > registered at all.
> > > 
> > > When checking if a CONFIG_… preprocessor variable is defined we only
> > > test for the builtin (=y) case and not the module (=m) case. By using
> > > the IS_REACHABLE() macro we do test for both cases.
> > > 
> > > Fixes: 5d0682be3189 ("KEYS: trusted: Add generic trusted keys framework")
> > > Signed-off-by: Andreas Rammhold <andreas@rammhold.de>
> > > Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
> > Does anyone intend to pick this up?
> 
> Did this end up in any tree by now? I am wondering if I should resend
> the patch instead. Perhaps it was just overlooked?

For EVM environments only using trusted and encrypted keys, not file
signatures, the trusted key is needed to decrypt the "master" key in
order to verify kernel modules.

Mimi



^ permalink raw reply	[flat|nested] 12+ messages in thread

* Re: [PATCH v3] KEYS: trusted: Fix trusted key backends when building as module
  2021-09-27 11:27     ` Mimi Zohar
@ 2021-09-27 20:08       ` Andreas Rammhold
  2021-09-27 20:33         ` Mimi Zohar
  0 siblings, 1 reply; 12+ messages in thread
From: Andreas Rammhold @ 2021-09-27 20:08 UTC (permalink / raw)
  To: Mimi Zohar
  Cc: Andreas Rammhold, Ahmad Fatoum, James Bottomley, Jarkko Sakkinen,
	David Howells, James Morris, Serge E. Hallyn, Sumit Garg,
	linux-integrity, keyrings, linux-security-module, linux-kernel

On 07:27 27.09.21, Mimi Zohar wrote:
> On Mon, 2021-09-27 at 10:51 +0200, Andreas Rammhold wrote:
> > On 09:47 13.09.21, Ahmad Fatoum wrote:
> > > Dear trusted key maintainers,
> > > 
> > > On 30.07.21 03:28, Andreas Rammhold wrote:
> > > > Before this commit the kernel could end up with no trusted key sources
> > > > even though both of the currently supported backends (TPM and TEE) were
> > > > compiled as modules. This manifested in the trusted key type not being
> > > > registered at all.
> > > > 
> > > > When checking if a CONFIG_… preprocessor variable is defined we only
> > > > test for the builtin (=y) case and not the module (=m) case. By using
> > > > the IS_REACHABLE() macro we do test for both cases.
> > > > 
> > > > Fixes: 5d0682be3189 ("KEYS: trusted: Add generic trusted keys framework")
> > > > Signed-off-by: Andreas Rammhold <andreas@rammhold.de>
> > > > Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
> > > Does anyone intend to pick this up?
> > 
> > Did this end up in any tree by now? I am wondering if I should resend
> > the patch instead. Perhaps it was just overlooked?
> 
> For EVM environments only using trusted and encrypted keys, not file
> signatures, the trusted key is needed to decrypt the "master" key in
> order to verify kernel modules.

So what you are saying is that right now (before this patch & after this
patch) you could compile a kernel that wouldn't be able to load any
modules when the trusted keychain part is built as module?


Andi

^ permalink raw reply	[flat|nested] 12+ messages in thread

* Re: [PATCH v3] KEYS: trusted: Fix trusted key backends when building as module
  2021-09-27 20:08       ` Andreas Rammhold
@ 2021-09-27 20:33         ` Mimi Zohar
  2021-09-27 20:55           ` Andreas Rammhold
  0 siblings, 1 reply; 12+ messages in thread
From: Mimi Zohar @ 2021-09-27 20:33 UTC (permalink / raw)
  To: Andreas Rammhold
  Cc: Ahmad Fatoum, James Bottomley, Jarkko Sakkinen, David Howells,
	James Morris, Serge E. Hallyn, Sumit Garg, linux-integrity,
	keyrings, linux-security-module, linux-kernel

On Mon, 2021-09-27 at 22:08 +0200, Andreas Rammhold wrote:
> On 07:27 27.09.21, Mimi Zohar wrote:
> > On Mon, 2021-09-27 at 10:51 +0200, Andreas Rammhold wrote:
> > > On 09:47 13.09.21, Ahmad Fatoum wrote:
> > > > Dear trusted key maintainers,
> > > > 
> > > > On 30.07.21 03:28, Andreas Rammhold wrote:
> > > > > Before this commit the kernel could end up with no trusted key sources
> > > > > even though both of the currently supported backends (TPM and TEE) were
> > > > > compiled as modules. This manifested in the trusted key type not being
> > > > > registered at all.
> > > > > 
> > > > > When checking if a CONFIG_… preprocessor variable is defined we only
> > > > > test for the builtin (=y) case and not the module (=m) case. By using
> > > > > the IS_REACHABLE() macro we do test for both cases.
> > > > > 
> > > > > Fixes: 5d0682be3189 ("KEYS: trusted: Add generic trusted keys framework")
> > > > > Signed-off-by: Andreas Rammhold <andreas@rammhold.de>
> > > > > Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
> > > > Does anyone intend to pick this up?
> > > 
> > > Did this end up in any tree by now? I am wondering if I should resend
> > > the patch instead. Perhaps it was just overlooked?
> > 
> > For EVM environments only using trusted and encrypted keys, not file
> > signatures, the trusted key is needed to decrypt the "master" key in
> > order to verify kernel modules.
> 
> So what you are saying is that right now (before this patch & after this
> patch) you could compile a kernel that wouldn't be able to load any
> modules when the trusted keychain part is built as module?

Before this patch, trusted and encrypted keys are builtin, so verifying
kernel modules with security.evm containing an EVM hmac would succeed. 
Afterwards it would fail, as there's a dependency on the trusted key to
verify the integrity of the trusted key module.

Mimi


^ permalink raw reply	[flat|nested] 12+ messages in thread

* Re: [PATCH v3] KEYS: trusted: Fix trusted key backends when building as module
  2021-09-27 20:33         ` Mimi Zohar
@ 2021-09-27 20:55           ` Andreas Rammhold
  2021-09-27 21:31             ` Mimi Zohar
  0 siblings, 1 reply; 12+ messages in thread
From: Andreas Rammhold @ 2021-09-27 20:55 UTC (permalink / raw)
  To: Mimi Zohar
  Cc: Andreas Rammhold, Ahmad Fatoum, James Bottomley, Jarkko Sakkinen,
	David Howells, James Morris, Serge E. Hallyn, Sumit Garg,
	linux-integrity, keyrings, linux-security-module, linux-kernel

On 16:33 27.09.21, Mimi Zohar wrote:
> On Mon, 2021-09-27 at 22:08 +0200, Andreas Rammhold wrote:
> > On 07:27 27.09.21, Mimi Zohar wrote:
> > > On Mon, 2021-09-27 at 10:51 +0200, Andreas Rammhold wrote:
> > > > On 09:47 13.09.21, Ahmad Fatoum wrote:
> > > > > Dear trusted key maintainers,
> > > > > 
> > > > > On 30.07.21 03:28, Andreas Rammhold wrote:
> > > > > > Before this commit the kernel could end up with no trusted key sources
> > > > > > even though both of the currently supported backends (TPM and TEE) were
> > > > > > compiled as modules. This manifested in the trusted key type not being
> > > > > > registered at all.
> > > > > > 
> > > > > > When checking if a CONFIG_… preprocessor variable is defined we only
> > > > > > test for the builtin (=y) case and not the module (=m) case. By using
> > > > > > the IS_REACHABLE() macro we do test for both cases.
> > > > > > 
> > > > > > Fixes: 5d0682be3189 ("KEYS: trusted: Add generic trusted keys framework")
> > > > > > Signed-off-by: Andreas Rammhold <andreas@rammhold.de>
> > > > > > Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
> > > > > Does anyone intend to pick this up?
> > > > 
> > > > Did this end up in any tree by now? I am wondering if I should resend
> > > > the patch instead. Perhaps it was just overlooked?
> > > 
> > > For EVM environments only using trusted and encrypted keys, not file
> > > signatures, the trusted key is needed to decrypt the "master" key in
> > > order to verify kernel modules.
> > 
> > So what you are saying is that right now (before this patch & after this
> > patch) you could compile a kernel that wouldn't be able to load any
> > modules when the trusted keychain part is built as module?
> 
> Before this patch, trusted and encrypted keys are builtin, so verifying
> kernel modules with security.evm containing an EVM hmac would succeed. 
> Afterwards it would fail, as there's a dependency on the trusted key to
> verify the integrity of the trusted key module.

But building with =m was a valid configuration which is the original
reason for me submitting the patch. So perhaps this should not be
allowed to be a module then?


^ permalink raw reply	[flat|nested] 12+ messages in thread

* Re: [PATCH v3] KEYS: trusted: Fix trusted key backends when building as module
  2021-09-27 20:55           ` Andreas Rammhold
@ 2021-09-27 21:31             ` Mimi Zohar
  2021-10-02 21:47               ` Andreas Rammhold
  0 siblings, 1 reply; 12+ messages in thread
From: Mimi Zohar @ 2021-09-27 21:31 UTC (permalink / raw)
  To: Andreas Rammhold
  Cc: Ahmad Fatoum, James Bottomley, Jarkko Sakkinen, David Howells,
	James Morris, Serge E. Hallyn, Sumit Garg, linux-integrity,
	keyrings, linux-security-module, linux-kernel

On Mon, 2021-09-27 at 22:55 +0200, Andreas Rammhold wrote:
> On 16:33 27.09.21, Mimi Zohar wrote:
> > On Mon, 2021-09-27 at 22:08 +0200, Andreas Rammhold wrote:
> > > On 07:27 27.09.21, Mimi Zohar wrote:
> > > > On Mon, 2021-09-27 at 10:51 +0200, Andreas Rammhold wrote:
> > > > > On 09:47 13.09.21, Ahmad Fatoum wrote:
> > > > > > Dear trusted key maintainers,
> > > > > > 
> > > > > > On 30.07.21 03:28, Andreas Rammhold wrote:
> > > > > > > Before this commit the kernel could end up with no trusted key sources
> > > > > > > even though both of the currently supported backends (TPM and TEE) were
> > > > > > > compiled as modules. This manifested in the trusted key type not being
> > > > > > > registered at all.
> > > > > > > 
> > > > > > > When checking if a CONFIG_… preprocessor variable is defined we only
> > > > > > > test for the builtin (=y) case and not the module (=m) case. By using
> > > > > > > the IS_REACHABLE() macro we do test for both cases.
> > > > > > > 
> > > > > > > Fixes: 5d0682be3189 ("KEYS: trusted: Add generic trusted keys framework")
> > > > > > > Signed-off-by: Andreas Rammhold <andreas@rammhold.de>
> > > > > > > Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
> > > > > > Does anyone intend to pick this up?
> > > > > 
> > > > > Did this end up in any tree by now? I am wondering if I should resend
> > > > > the patch instead. Perhaps it was just overlooked?
> > > > 
> > > > For EVM environments only using trusted and encrypted keys, not file
> > > > signatures, the trusted key is needed to decrypt the "master" key in
> > > > order to verify kernel modules.
> > > 
> > > So what you are saying is that right now (before this patch & after this
> > > patch) you could compile a kernel that wouldn't be able to load any
> > > modules when the trusted keychain part is built as module?
> > 
> > Before this patch, trusted and encrypted keys are builtin, so verifying
> > kernel modules with security.evm containing an EVM hmac would succeed. 
> > Afterwards it would fail, as there's a dependency on the trusted key to
> > verify the integrity of the trusted key module.
> 
> But building with =m was a valid configuration which is the original
> reason for me submitting the patch. So perhaps this should not be
> allowed to be a module then?

My mistake.  Trusted and encrypted key types have always been defined
as tristate.  Only when EVM selects encrypted keys, and by extension
trusted keys, are they builtin.

Mimi


^ permalink raw reply	[flat|nested] 12+ messages in thread

* Re: [PATCH v3] KEYS: trusted: Fix trusted key backends when building as module
  2021-09-27 21:31             ` Mimi Zohar
@ 2021-10-02 21:47               ` Andreas Rammhold
  2021-10-11 10:19                 ` Ahmad Fatoum
  0 siblings, 1 reply; 12+ messages in thread
From: Andreas Rammhold @ 2021-10-02 21:47 UTC (permalink / raw)
  To: Mimi Zohar
  Cc: Ahmad Fatoum, James Bottomley, Jarkko Sakkinen, David Howells,
	James Morris, Serge E. Hallyn, Sumit Garg, linux-integrity,
	keyrings, linux-security-module, linux-kernel

On 17:31 27.09.21, Mimi Zohar wrote:
> On Mon, 2021-09-27 at 22:55 +0200, Andreas Rammhold wrote:
> > On 16:33 27.09.21, Mimi Zohar wrote:
> > > On Mon, 2021-09-27 at 22:08 +0200, Andreas Rammhold wrote:
> > > > On 07:27 27.09.21, Mimi Zohar wrote:
> > > > > On Mon, 2021-09-27 at 10:51 +0200, Andreas Rammhold wrote:
> > > > > > On 09:47 13.09.21, Ahmad Fatoum wrote:
> > > > > > > Dear trusted key maintainers,
> > > > > > > 
> > > > > > > On 30.07.21 03:28, Andreas Rammhold wrote:
> > > > > > > > Before this commit the kernel could end up with no trusted key sources
> > > > > > > > even though both of the currently supported backends (TPM and TEE) were
> > > > > > > > compiled as modules. This manifested in the trusted key type not being
> > > > > > > > registered at all.
> > > > > > > > 
> > > > > > > > When checking if a CONFIG_… preprocessor variable is defined we only
> > > > > > > > test for the builtin (=y) case and not the module (=m) case. By using
> > > > > > > > the IS_REACHABLE() macro we do test for both cases.
> > > > > > > > 
> > > > > > > > Fixes: 5d0682be3189 ("KEYS: trusted: Add generic trusted keys framework")
> > > > > > > > Signed-off-by: Andreas Rammhold <andreas@rammhold.de>
> > > > > > > > Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
> > > > > > > Does anyone intend to pick this up?
> > > > > > 
> > > > > > Did this end up in any tree by now? I am wondering if I should resend
> > > > > > the patch instead. Perhaps it was just overlooked?
> > > > > 
> > > > > For EVM environments only using trusted and encrypted keys, not file
> > > > > signatures, the trusted key is needed to decrypt the "master" key in
> > > > > order to verify kernel modules.
> > > > 
> > > > So what you are saying is that right now (before this patch & after this
> > > > patch) you could compile a kernel that wouldn't be able to load any
> > > > modules when the trusted keychain part is built as module?
> > > 
> > > Before this patch, trusted and encrypted keys are builtin, so verifying
> > > kernel modules with security.evm containing an EVM hmac would succeed. 
> > > Afterwards it would fail, as there's a dependency on the trusted key to
> > > verify the integrity of the trusted key module.
> > 
> > But building with =m was a valid configuration which is the original
> > reason for me submitting the patch. So perhaps this should not be
> > allowed to be a module then?
> 
> My mistake.  Trusted and encrypted key types have always been defined
> as tristate.  Only when EVM selects encrypted keys, and by extension
> trusted keys, are they builtin.

So how do we go about this patch? Building the TPM support as module has
broken actually using the trusted backend. This patch fixes that while
still allowing it to be a builtin. If there is some configuration there
a module isn't acceptable I am sure that is handled within Kconfig?


Andi

^ permalink raw reply	[flat|nested] 12+ messages in thread

* Re: [PATCH v3] KEYS: trusted: Fix trusted key backends when building as module
  2021-10-02 21:47               ` Andreas Rammhold
@ 2021-10-11 10:19                 ` Ahmad Fatoum
  0 siblings, 0 replies; 12+ messages in thread
From: Ahmad Fatoum @ 2021-10-11 10:19 UTC (permalink / raw)
  To: Andreas Rammhold, Mimi Zohar, David Howells, Jarkko Sakkinen,
	James Bottomley
  Cc: James Morris, Serge E. Hallyn, Sumit Garg, linux-integrity,
	keyrings, linux-security-module, linux-kernel

Hello Mimi, David, Jarkko and James,

On 02.10.21 23:47, Andreas Rammhold wrote:
>> My mistake.  Trusted and encrypted key types have always been defined
>> as tristate.  Only when EVM selects encrypted keys, and by extension
>> trusted keys, are they builtin.
> 
> So how do we go about this patch? Building the TPM support as module has
> broken actually using the trusted backend. This patch fixes that while
> still allowing it to be a builtin. If there is some configuration there
> a module isn't acceptable I am sure that is handled within Kconfig?
Can anyone of you four pick this up? Andreas' regression fix has
had Jarkko's Reviewed-by for close to two months and a half now.

Thanks,
Ahmad

-- 
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^ permalink raw reply	[flat|nested] 12+ messages in thread

end of thread, other threads:[~2021-10-11 10:19 UTC | newest]

Thread overview: 12+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-07-30  1:28 [PATCH v3] KEYS: trusted: Fix trusted key backends when building as module Andreas Rammhold
2021-07-30  4:54 ` Sumit Garg
2021-07-30  6:14 ` Ahmad Fatoum
2021-09-13  7:47 ` Ahmad Fatoum
2021-09-27  8:51   ` Andreas Rammhold
2021-09-27 11:27     ` Mimi Zohar
2021-09-27 20:08       ` Andreas Rammhold
2021-09-27 20:33         ` Mimi Zohar
2021-09-27 20:55           ` Andreas Rammhold
2021-09-27 21:31             ` Mimi Zohar
2021-10-02 21:47               ` Andreas Rammhold
2021-10-11 10:19                 ` Ahmad Fatoum

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