From d3600bcf9d64d88dc1d189a754dcfab960ce751f Mon Sep 17 00:00:00 2001 From: Mimi Zohar Date: Tue, 10 Nov 2015 08:34:46 -0500 Subject: KEYS: prevent keys from being removed from specified keyrings Userspace should not be allowed to remove keys from certain keyrings (eg. blacklist), though the keys themselves can expire. This patch defines a new key flag named KEY_FLAG_KEEP to prevent userspace from being able to unlink, revoke, invalidate or timed out a key on a keyring. When this flag is set on the keyring, all keys subsequently added are flagged. In addition, when this flag is set, the keyring itself can not be cleared. Signed-off-by: Mimi Zohar Cc: David Howells --- security/keys/key.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'security/keys/key.c') diff --git a/security/keys/key.c b/security/keys/key.c index ab7997ded725..09ef276c4bdc 100644 --- a/security/keys/key.c +++ b/security/keys/key.c @@ -429,8 +429,12 @@ static int __key_instantiate_and_link(struct key *key, awaken = 1; /* and link it into the destination keyring */ - if (keyring) + if (keyring) { + if (test_bit(KEY_FLAG_KEEP, &keyring->flags)) + set_bit(KEY_FLAG_KEEP, &key->flags); + __key_link(key, _edit); + } /* disable the authorisation key */ if (authkey) -- cgit v1.2.3