[PATCH] ima: add a new CONFIG for loading arch-specific policies

Nayna Jain
2020-02-26T19:10:23Z

Every time a new architecture defines the IMA architecture specific
functions - arch_ima_get_secureboot() and arch_ima_get_policy(), the IMA
include file needs to be updated. To avoid this "noise", this patch
defines a new IMA Kconfig IMA_SECURE_AND_OR_TRUSTED_BOOT option, allowing
the different architectures to select it.

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Nayna Jain <nayna@linux.ibm.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Philipp Rudo <prudo@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
---
arch/powerpc/Kconfig | 2 +-
arch/s390/Kconfig | 1 +
arch/x86/Kconfig | 1 +
include/linux/ima.h | 3 +--
security/integrity/ima/Kconfig | 9 +++++++++
5 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 497b7d0b2d7e..b8ce1b995633 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -246,6 +246,7 @@ config PPC
select SYSCTL_EXCEPTION_TRACE
select THREAD_INFO_IN_TASK
select VIRT_TO_BUS if !PPC64
+ select IMA_SECURE_AND_OR_TRUSTED_BOOT if PPC_SECURE_BOOT
#
# Please keep this list sorted alphabetically.
#
@@ -978,7 +979,6 @@ config PPC_SECURE_BOOT
prompt "Enable secure boot support"
bool
depends on PPC_POWERNV
- depends on IMA_ARCH_POLICY
help
Systems with firmware secure boot enabled need to define security
policies to extend secure boot to the OS. This config allows a user
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index 8abe77536d9d..90ff3633ade6 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -195,6 +195,7 @@ config S390
select ARCH_HAS_FORCE_DMA_UNENCRYPTED
select SWIOTLB
select GENERIC_ALLOCATOR
+ select IMA_SECURE_AND_OR_TRUSTED_BOOT

config SCHED_OMIT_FRAME_POINTER
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index beea77046f9b..cafa66313fe2 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -230,6 +230,7 @@ config X86
select VIRT_TO_BUS
select X86_FEATURE_NAMES if PROC_FS
select PROC_PID_ARCH_STATUS if PROC_FS
+ select IMA_SECURE_AND_OR_TRUSTED_BOOT if EFI

config INSTRUCTION_DECODER
def_bool y
diff --git a/include/linux/ima.h b/include/linux/ima.h
index 1659217e9b60..aefe758f4466 100644
--- a/include/linux/ima.h
+++ b/include/linux/ima.h
@@ -30,8 +30,7 @@ extern void ima_kexec_cmdline(const void *buf, int size);
extern void ima_add_kexec_buffer(struct kimage *image);
#endif

-#if (defined(CONFIG_X86) && defined(CONFIG_EFI)) || defined(CONFIG_S390) \
- || defined(CONFIG_PPC_SECURE_BOOT)
+#ifdef CONFIG_IMA_SECURE_AND_OR_TRUSTED_BOOT
extern bool arch_ima_get_secureboot(void);
extern const char * const *arch_get_ima_policy(void);
#else
diff --git a/security/integrity/ima/Kconfig b/security/integrity/ima/Kconfig
index 3f3ee4e2eb0d..d17972aa413a 100644
--- a/security/integrity/ima/Kconfig
+++ b/security/integrity/ima/Kconfig
@@ -327,3 +327,12 @@ config IMA_QUEUE_EARLY_BOOT_KEYS
depends on IMA_MEASURE_ASYMMETRIC_KEYS
depends on SYSTEM_TRUSTED_KEYRING
default y
+
+config IMA_SECURE_AND_OR_TRUSTED_BOOT
+ bool
+ depends on IMA
+ depends on IMA_ARCH_POLICY
+ default n
+ help
+ This option is selected by architectures to enable secure and/or
+ trusted boot based on IMA runtime policies.
--
2.18.1