The machine keyring is setup during init. No additional keys should be allowed to be added afterwards. Leave the permission as read only. Signed-off-by: Eric Snowberg <eric.snowberg@xxxxxxxxxx> --- v2: Initial version v4: Unmodified from v2 v5: Rename to machine keyring v6: Add additional comment (suggested by Jarkko) --- security/integrity/digsig.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/security/integrity/digsig.c b/security/integrity/digsig.c index 8c315be8ad99..910fe29a5037 100644 --- a/security/integrity/digsig.c +++ b/security/integrity/digsig.c @@ -140,7 +140,13 @@ int __init integrity_init_keyring(const unsigned int id) return -ENOMEM; restriction->check = restrict_link_to_ima; - perm |= KEY_USR_WRITE; + + /* + * No additional keys shall be allowed to load into the machine + * keyring following init + */ + if (id != INTEGRITY_KEYRING_MACHINE) + perm |= KEY_USR_WRITE; out: return __integrity_init_keyring(id, perm, restriction); -- 2.18.4
