[PATCH v8 07/17] integrity: restrict INTEGRITY_KEYRING_MACHINE to restrict_link_by_ca

From: Eric Snowberg
Date: Tue Nov 23 2021 - 23:42:54 EST


Set the restriction check for INTEGRITY_KEYRING_MACHINE keys to
restrict_link_by_ca. This will only allow CA keys into the machine
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
v5: Rename to machine keyring
v6: split line over 80 char (suggested by Mimi)
v8: Unmodified from v6
---
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 910fe29a5037..e7dfc55a7c55 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_MACHINE)
return 0;

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

- restriction->check = restrict_link_to_ima;
+ if (id == INTEGRITY_KEYRING_MACHINE)
+ restriction->check = restrict_link_by_ca;
+ else
+ restriction->check = restrict_link_to_ima;

/*
* No additional keys shall be allowed to load into the machine
--
2.18.4