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, 8 insertions, 7 deletions

diff --git a/security/keys/process_keys.c b/security/keys/process_keys.c
index 54339cfd673..a58f712605d 100644
--- a/security/keys/process_keys.c
+++ b/security/keys/process_keys.c
@@ -34,8 +34,7 @@ struct key_user root_key_user = {
 	.lock		= __SPIN_LOCK_UNLOCKED(root_key_user.lock),
 	.nkeys		= ATOMIC_INIT(2),
 	.nikeys		= ATOMIC_INIT(2),
-	.uid		= 0,
-	.user_ns	= &init_user_ns,
+	.uid		= GLOBAL_ROOT_UID,
 };
 
 /*
@@ -48,11 +47,13 @@ int install_user_keyrings(void)
 	struct key *uid_keyring, *session_keyring;
 	char buf[20];
 	int ret;
+	uid_t uid;
 
 	cred = current_cred();
 	user = cred->user;
+	uid = from_kuid(cred->user_ns, user->uid);
 
-	kenter("%p{%u}", user, user->uid);
+	kenter("%p{%u}", user, uid);
 
 	if (user->uid_keyring) {
 		kleave(" = 0 [exist]");
@@ -67,11 +68,11 @@ int install_user_keyrings(void)
 		 * - there may be one in existence already as it may have been
 		 *   pinned by a session, but the user_struct pointing to it
 		 *   may have been destroyed by setuid */
-		sprintf(buf, "_uid.%u", user->uid);
+		sprintf(buf, "_uid.%u", uid);
 
 		uid_keyring = find_keyring_by_name(buf, true);
 		if (IS_ERR(uid_keyring)) {
-			uid_keyring = keyring_alloc(buf, user->uid, (gid_t) -1,
+			uid_keyring = keyring_alloc(buf, user->uid, INVALID_GID,
 						    cred, KEY_ALLOC_IN_QUOTA,
 						    NULL);
 			if (IS_ERR(uid_keyring)) {
@@ -82,12 +83,12 @@ int install_user_keyrings(void)
 
 		/* get a default session keyring (which might also exist
 		 * already) */
-		sprintf(buf, "_uid_ses.%u", user->uid);
+		sprintf(buf, "_uid_ses.%u", uid);
 
 		session_keyring = find_keyring_by_name(buf, true);
 		if (IS_ERR(session_keyring)) {
 			session_keyring =
-				keyring_alloc(buf, user->uid, (gid_t) -1,
+				keyring_alloc(buf, user->uid, INVALID_GID,
 					      cred, KEY_ALLOC_IN_QUOTA, NULL);
 			if (IS_ERR(session_keyring)) {
 				ret = PTR_ERR(session_keyring);