Merge branch 'keys-fixes' into keys-next

Signed-off-by: David Howells <[email protected]>

crypto/asymmetric_keys/Kconfig

@@ -22,7 +22,6 @@ config ASYMMETRIC_PUBLIC_KEY_SUBTYPE
 
 config PUBLIC_KEY_ALGO_RSA
 	tristate "RSA public-key algorithm"
-	select MPILIB_EXTRA
 	select MPILIB
 	help
 	  This option enables support for the RSA algorithm (PKCS#1, RFC3447).

fs/nfs/idmap.c

@@ -284,6 +284,8 @@ static struct key *nfs_idmap_request_key(const char *name, size_t namelen,
 						desc, "", 0, idmap);
 		mutex_unlock(&idmap->idmap_mutex);
 	}
+	if (!IS_ERR(rkey))
+		set_bit(KEY_FLAG_ROOT_CAN_INVAL, &rkey->flags);
 
 	kfree(desc);
 	return rkey;

include/linux/key.h

@@ -171,6 +171,7 @@ struct key {
 #define KEY_FLAG_TRUSTED	8	/* set if key is trusted */
 #define KEY_FLAG_TRUSTED_ONLY	9	/* set if keyring only accepts links to trusted keys */
 #define KEY_FLAG_BUILTIN	10	/* set if key is builtin */
+#define KEY_FLAG_ROOT_CAN_INVAL	11	/* set if key can be invalidated by root without permission */
 
 	/* the key type and key description string
 	 * - the desc is used to match a key against search criteria

lib/Kconfig

@@ -451,7 +451,8 @@ config MPILIB
 
 config SIGNATURE
 	tristate
-	depends on KEYS && CRYPTO
+	depends on KEYS
+	select CRYPTO
 	select CRYPTO_SHA1
 	select MPILIB
 	help

net/dns_resolver/dns_query.c

@@ -129,6 +129,7 @@ int dns_query(const char *type, const char *name, size_t namelen,
 	}
 
 	down_read(&rkey->sem);
+	set_bit(KEY_FLAG_ROOT_CAN_INVAL, &rkey->flags);
 	rkey->perm |= KEY_USR_VIEW;
 
 	ret = key_validate(rkey);

security/keys/keyctl.c

@@ -406,12 +406,25 @@ long keyctl_invalidate_key(key_serial_t id)
 	key_ref = lookup_user_key(id, 0, KEY_NEED_SEARCH);
 	if (IS_ERR(key_ref)) {
 		ret = PTR_ERR(key_ref);
+
+		/* Root is permitted to invalidate certain special keys */
+		if (capable(CAP_SYS_ADMIN)) {
+			key_ref = lookup_user_key(id, 0, 0);
+			if (IS_ERR(key_ref))
+				goto error;
+			if (test_bit(KEY_FLAG_ROOT_CAN_INVAL,
+				     &key_ref_to_ptr(key_ref)->flags))
+				goto invalidate;
+			goto error_put;
+		}
+
 		goto error;
 	}
 
+invalidate:
 	key_invalidate(key_ref_to_ptr(key_ref));
 	ret = 0;
-
+error_put:
 	key_ref_put(key_ref);
 error:
 	kleave(" = %ld", ret);