From 700920eb5ba4de5417b446c9a8bb008df2b973e0 Mon Sep 17 00:00:00 2001 From: David Howells Date: Wed, 18 Jan 2012 15:31:45 +0000 Subject: KEYS: Allow special keyrings to be cleared The kernel contains some special internal keyrings, for instance the DNS resolver keyring : 2a93faf1 I----- 1 perm 1f030000 0 0 keyring .dns_resolver: empty It would occasionally be useful to allow the contents of such keyrings to be flushed by root (cache invalidation). Allow a flag to be set on a keyring to mark that someone possessing the sysadmin capability can clear the keyring, even without normal write access to the keyring. Set this flag on the special keyrings created by the DNS resolver, the NFS identity mapper and the CIFS identity mapper. Signed-off-by: David Howells Acked-by: Jeff Layton Acked-by: Steve Dickson Signed-off-by: James Morris --- fs/cifs/cifsacl.c | 1 + fs/nfs/idmap.c | 1 + 2 files changed, 2 insertions(+) (limited to 'fs') diff --git a/fs/cifs/cifsacl.c b/fs/cifs/cifsacl.c index 72ddf23ef6f..854749d21bb 100644 --- a/fs/cifs/cifsacl.c +++ b/fs/cifs/cifsacl.c @@ -556,6 +556,7 @@ init_cifs_idmap(void) /* instruct request_key() to use this special keyring as a cache for * the results it looks up */ + set_bit(KEY_FLAG_ROOT_CAN_CLEAR, &keyring->flags); cred->thread_keyring = keyring; cred->jit_keyring = KEY_REQKEY_DEFL_THREAD_KEYRING; root_cred = cred; diff --git a/fs/nfs/idmap.c b/fs/nfs/idmap.c index 2c05f1991e1..a1bbf7780df 100644 --- a/fs/nfs/idmap.c +++ b/fs/nfs/idmap.c @@ -198,6 +198,7 @@ int nfs_idmap_init(void) if (ret < 0) goto failed_put_key; + set_bit(KEY_FLAG_ROOT_CAN_CLEAR, &keyring->flags); cred->thread_keyring = keyring; cred->jit_keyring = KEY_REQKEY_DEFL_THREAD_KEYRING; id_resolver_cache = cred; -- cgit v1.2.3