userns: Convert security/keys to the new userns infrastructure

- Replace key_user ->user_ns equality checks with kuid_has_mapping checks.
- Use from_kuid to generate key descriptions
- Use kuid_t and kgid_t and the associated helpers instead of uid_t and gid_t
- Avoid potential problems with file descriptor passing by displaying
  keys in the user namespace of the opener of key status proc files.

Cc: linux-security-module@vger.kernel.org
Cc: keyrings@linux-nfs.org
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/security/keys/keyring.c b/security/keys/keyring.c
index 81e7852d281d..a5f5c4b6edc5 100644
--- a/security/keys/keyring.c
+++ b/security/keys/keyring.c
@@ -256,7 +256,7 @@ error:
 /*
  * Allocate a keyring and link into the destination keyring.
  */
-struct key *keyring_alloc(const char *description, uid_t uid, gid_t gid,
+struct key *keyring_alloc(const char *description, kuid_t uid, kgid_t gid,
                           const struct cred *cred, unsigned long flags,
                           struct key *dest)
 {
@@ -612,7 +612,7 @@ struct key *find_keyring_by_name(const char *name, bool skip_perm_check)
                                     &keyring_name_hash[bucket],
                                     type_data.link
                                     ) {
-                        if (keyring->user->user_ns != current_user_ns())
+                        if (!kuid_has_mapping(current_user_ns(), keyring->user->uid))
                                 continue;
 
                         if (test_bit(KEY_FLAG_REVOKED, &keyring->flags))