Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security

Pull security subsystem updates from James Morris:
 "Highlights:

  IMA:
   - provide ">" and "<" operators for fowner/uid/euid rules

  KEYS:
   - add a system blacklist keyring

   - add KEYCTL_RESTRICT_KEYRING, exposes keyring link restriction
     functionality to userland via keyctl()

  LSM:
   - harden LSM API with __ro_after_init

   - add prlmit security hook, implement for SELinux

   - revive security_task_alloc hook

  TPM:
   - implement contextual TPM command 'spaces'"

* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (98 commits)
  tpm: Fix reference count to main device
  tpm_tis: convert to using locality callbacks
  tpm: fix handling of the TPM 2.0 event logs
  tpm_crb: remove a cruft constant
  keys: select CONFIG_CRYPTO when selecting DH / KDF
  apparmor: Make path_max parameter readonly
  apparmor: fix parameters so that the permission test is bypassed at boot
  apparmor: fix invalid reference to index variable of iterator line 836
  apparmor: use SHASH_DESC_ON_STACK
  security/apparmor/lsm.c: set debug messages
  apparmor: fix boolreturn.cocci warnings
  Smack: Use GFP_KERNEL for smk_netlbl_mls().
  smack: fix double free in smack_parse_opts_str()
  KEYS: add SP800-56A KDF support for DH
  KEYS: Keyring asymmetric key restrict method with chaining
  KEYS: Restrict asymmetric key linkage using a specific keychain
  KEYS: Add a lookup_restriction function for the asymmetric key type
  KEYS: Add KEYCTL_RESTRICT_KEYRING
  KEYS: Consistent ordering for __key_link_begin and restrict check
  KEYS: Add an optional lookup_restriction hook to key_type
  ...

security/keys/keyctl.c

@@ -1584,6 +1584,59 @@ long keyctl_session_to_parent(void)
 	return ret;
 }
 
+/*
+ * Apply a restriction to a given keyring.
+ *
+ * The caller must have Setattr permission to change keyring restrictions.
+ *
+ * The requested type name may be a NULL pointer to reject all attempts
+ * to link to the keyring. If _type is non-NULL, _restriction can be
+ * NULL or a pointer to a string describing the restriction. If _type is
+ * NULL, _restriction must also be NULL.
+ *
+ * Returns 0 if successful.
+ */
+long keyctl_restrict_keyring(key_serial_t id, const char __user *_type,
+			     const char __user *_restriction)
+{
+	key_ref_t key_ref;
+	bool link_reject = !_type;
+	char type[32];
+	char *restriction = NULL;
+	long ret;
+
+	key_ref = lookup_user_key(id, 0, KEY_NEED_SETATTR);
+	if (IS_ERR(key_ref))
+		return PTR_ERR(key_ref);
+
+	if (_type) {
+		ret = key_get_type_from_user(type, _type, sizeof(type));
+		if (ret < 0)
+			goto error;
+	}
+
+	if (_restriction) {
+		if (!_type) {
+			ret = -EINVAL;
+			goto error;
+		}
+
+		restriction = strndup_user(_restriction, PAGE_SIZE);
+		if (IS_ERR(restriction)) {
+			ret = PTR_ERR(restriction);
+			goto error;
+		}
+	}
+
+	ret = keyring_restrict(key_ref, link_reject ? NULL : type, restriction);
+	kfree(restriction);
+
+error:
+	key_ref_put(key_ref);
+
+	return ret;
+}
+
 /*
  * The key control system call
  */
@@ -1693,7 +1746,12 @@ SYSCALL_DEFINE5(keyctl, int, option, unsigned long, arg2, unsigned long, arg3,
 	case KEYCTL_DH_COMPUTE:
 		return keyctl_dh_compute((struct keyctl_dh_params __user *) arg2,
 					 (char __user *) arg3, (size_t) arg4,
-					 (void __user *) arg5);
+					 (struct keyctl_kdf_params __user *) arg5);
+
+	case KEYCTL_RESTRICT_KEYRING:
+		return keyctl_restrict_keyring((key_serial_t) arg2,
+					       (const char __user *) arg3,
+					       (const char __user *) arg4);
 
 	default:
 		return -EOPNOTSUPP;