[PATCH v4 04/12] integrity: restrict INTEGRITY_KEYRING_MOK to restrict_link_by_ca

From: Eric Snowberg
Date: Wed Aug 18 2021 - 20:22:44 EST


Set the restriction check for INTEGRITY_KEYRING_MOK keys to
restrict_link_by_ca. This will only allow CA keys into the mok
keyring.

Signed-off-by: Eric Snowberg <eric.snowberg@xxxxxxxxxx>
---
v1: Initial version
v2: Added !IS_ENABLED(CONFIG_INTEGRITY_TRUSTED_KEYRING check so mok
keyring gets created even when it isn't enabled
v3: Rename restrict_link_by_system_trusted_or_ca to restrict_link_by_ca
v4: removed unnecessary restriction->check set
---
security/integrity/digsig.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/security/integrity/digsig.c b/security/integrity/digsig.c
index 5cad38e6f56a..1f410242752c 100644
--- a/security/integrity/digsig.c
+++ b/security/integrity/digsig.c
@@ -132,14 +132,18 @@ int __init integrity_init_keyring(const unsigned int id)
goto out;
}

- if (!IS_ENABLED(CONFIG_INTEGRITY_TRUSTED_KEYRING))
+ if (!IS_ENABLED(CONFIG_INTEGRITY_TRUSTED_KEYRING) && id != INTEGRITY_KEYRING_MOK)
return 0;

restriction = kzalloc(sizeof(struct key_restriction), GFP_KERNEL);
if (!restriction)
return -ENOMEM;

- restriction->check = restrict_link_to_ima;
+ if (id == INTEGRITY_KEYRING_MOK)
+ restriction->check = restrict_link_by_ca;
+ else
+ restriction->check = restrict_link_to_ima;
+
if (id != INTEGRITY_KEYRING_MOK)
perm |= KEY_USR_WRITE;

--
2.18.4