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authorLinus Torvalds <torvalds@linux-foundation.org>2019-07-08 19:56:57 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2019-07-08 19:56:57 -0700
commit0f75ef6a9cff49ff612f7ce0578bced9d0b38325 (patch)
treebdd2a6b7f35695b1d7ab1209efbb40187501fe7d /fs/nfs
parentc84ca912b07901be528e5184fd254fca1dddf2ac (diff)
parent7a1ade847596dadc94b37e49f8c03f167fd71748 (diff)
Merge tag 'keys-acl-20190703' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs
Pull keyring ACL support from David Howells: "This changes the permissions model used by keys and keyrings to be based on an internal ACL by the following means: - Replace the permissions mask internally with an ACL that contains a list of ACEs, each with a specific subject with a permissions mask. Potted default ACLs are available for new keys and keyrings. ACE subjects can be macroised to indicate the UID and GID specified on the key (which remain). Future commits will be able to add additional subject types, such as specific UIDs or domain tags/namespaces. Also split a number of permissions to give finer control. Examples include splitting the revocation permit from the change-attributes permit, thereby allowing someone to be granted permission to revoke a key without allowing them to change the owner; also the ability to join a keyring is split from the ability to link to it, thereby stopping a process accessing a keyring by joining it and thus acquiring use of possessor permits. - Provide a keyctl to allow the granting or denial of one or more permits to a specific subject. Direct access to the ACL is not granted, and the ACL cannot be viewed" * tag 'keys-acl-20190703' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs: keys: Provide KEYCTL_GRANT_PERMISSION keys: Replace uid/gid/perm permissions checking with an ACL
Diffstat (limited to 'fs/nfs')
-rw-r--r--fs/nfs/nfs4idmap.c30
1 files changed, 24 insertions, 6 deletions
diff --git a/fs/nfs/nfs4idmap.c b/fs/nfs/nfs4idmap.c
index 1e7296395d71..69679f4f2e6c 100644
--- a/fs/nfs/nfs4idmap.c
+++ b/fs/nfs/nfs4idmap.c
@@ -72,6 +72,25 @@ struct idmap {
const struct cred *cred;
};
+static struct key_acl nfs_idmap_key_acl = {
+ .usage = REFCOUNT_INIT(1),
+ .nr_ace = 2,
+ .possessor_viewable = true,
+ .aces = {
+ KEY_POSSESSOR_ACE(KEY_ACE_VIEW | KEY_ACE_SEARCH | KEY_ACE_READ),
+ KEY_OWNER_ACE(KEY_ACE_VIEW),
+ }
+};
+
+static struct key_acl nfs_idmap_keyring_acl = {
+ .usage = REFCOUNT_INIT(1),
+ .nr_ace = 2,
+ .aces = {
+ KEY_POSSESSOR_ACE(KEY_ACE_SEARCH | KEY_ACE_WRITE),
+ KEY_OWNER_ACE(KEY_ACE_VIEW | KEY_ACE_READ),
+ }
+};
+
static struct user_namespace *idmap_userns(const struct idmap *idmap)
{
if (idmap && idmap->cred)
@@ -208,8 +227,7 @@ int nfs_idmap_init(void)
keyring = keyring_alloc(".id_resolver",
GLOBAL_ROOT_UID, GLOBAL_ROOT_GID, cred,
- (KEY_POS_ALL & ~KEY_POS_SETATTR) |
- KEY_USR_VIEW | KEY_USR_READ,
+ &nfs_idmap_keyring_acl,
KEY_ALLOC_NOT_IN_QUOTA, NULL, NULL);
if (IS_ERR(keyring)) {
ret = PTR_ERR(keyring);
@@ -287,11 +305,13 @@ static struct key *nfs_idmap_request_key(const char *name, size_t namelen,
return ERR_PTR(ret);
if (!idmap->cred || idmap->cred->user_ns == &init_user_ns)
- rkey = request_key(&key_type_id_resolver, desc, "");
+ rkey = request_key(&key_type_id_resolver, desc, "",
+ &nfs_idmap_key_acl);
if (IS_ERR(rkey)) {
mutex_lock(&idmap->idmap_mutex);
rkey = request_key_with_auxdata(&key_type_id_resolver_legacy,
- desc, NULL, "", 0, idmap);
+ desc, NULL, "", 0, idmap,
+ &nfs_idmap_key_acl);
mutex_unlock(&idmap->idmap_mutex);
}
if (!IS_ERR(rkey))
@@ -320,8 +340,6 @@ static ssize_t nfs_idmap_get_key(const char *name, size_t namelen,
}
rcu_read_lock();
- rkey->perm |= KEY_USR_VIEW;
-
ret = key_validate(rkey);
if (ret < 0)
goto out_up;