After being vouched for by a system keyring, only allow keys into the .ima and .evm keyrings that have the digitalSignature usage field set. Link: https://lore.kernel.org/all/41dffdaeb7eb7840f7e38bc691fbda836635c9f9.camel@xxxxxxxxxxxxx Suggested-by: Mimi Zohar <zohar@xxxxxxxxxxxxx> Signed-off-by: Eric Snowberg <eric.snowberg@xxxxxxxxxx> --- security/integrity/digsig.c | 4 ++-- security/integrity/evm/Kconfig | 3 ++- security/integrity/ima/Kconfig | 3 ++- 3 files changed, 6 insertions(+), 4 deletions(-) diff --git a/security/integrity/digsig.c b/security/integrity/digsig.c index 6f31ffe23c48..d0704b1597d4 100644 --- a/security/integrity/digsig.c +++ b/security/integrity/digsig.c @@ -34,9 +34,9 @@ static const char * const keyring_name[INTEGRITY_KEYRING_MAX] = { }; #ifdef CONFIG_IMA_KEYRINGS_PERMIT_SIGNED_BY_BUILTIN_OR_SECONDARY -#define restrict_link_to_ima restrict_link_by_builtin_and_secondary_trusted +#define restrict_link_to_ima restrict_link_by_digsig_builtin_and_secondary #else -#define restrict_link_to_ima restrict_link_by_builtin_trusted +#define restrict_link_to_ima restrict_link_by_digsig_builtin #endif static struct key *integrity_keyring_from_id(const unsigned int id) diff --git a/security/integrity/evm/Kconfig b/security/integrity/evm/Kconfig index a6e19d23e700..fba9ee359bc9 100644 --- a/security/integrity/evm/Kconfig +++ b/security/integrity/evm/Kconfig @@ -64,7 +64,8 @@ config EVM_LOAD_X509 This option enables X509 certificate loading from the kernel onto the '.evm' trusted keyring. A public key can be used to - verify EVM integrity starting from the 'init' process. + verify EVM integrity starting from the 'init' process. The + key must have digitalSignature usage set. config EVM_X509_PATH string "EVM X509 certificate path" diff --git a/security/integrity/ima/Kconfig b/security/integrity/ima/Kconfig index 60a511c6b583..684425936c53 100644 --- a/security/integrity/ima/Kconfig +++ b/security/integrity/ima/Kconfig @@ -270,7 +270,8 @@ config IMA_KEYRINGS_PERMIT_SIGNED_BY_BUILTIN_OR_SECONDARY help Keys may be added to the IMA or IMA blacklist keyrings, if the key is validly signed by a CA cert in the system built-in or - secondary trusted keyrings. + secondary trusted keyrings. The key must also have the + digitalSignature usage set. Intermediate keys between those the kernel has compiled in and the IMA keys to be added may be added to the system secondary keyring, -- 2.27.0
