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
  ...

1 files changed, 12 insertions, 1 deletions

diff --git a/security/keys/gc.c b/security/keys/gc.c
index 9cb4fe4478a1..595becc6d0d2 100644
--- a/security/keys/gc.c
+++ b/security/keys/gc.c
@@ -220,7 +220,7 @@ continue_scanning:
 		key = rb_entry(cursor, struct key, serial_node);
 		cursor = rb_next(cursor);
 
-		if (atomic_read(&key->usage) == 0)
+		if (refcount_read(&key->usage) == 0)
 			goto found_unreferenced_key;
 
 		if (unlikely(gc_state & KEY_GC_REAPING_DEAD_1)) {
@@ -229,6 +229,9 @@ continue_scanning:
 				set_bit(KEY_FLAG_DEAD, &key->flags);
 				key->perm = 0;
 				goto skip_dead_key;
+			} else if (key->type == &key_type_keyring &&
+				   key->restrict_link) {
+				goto found_restricted_keyring;
 			}
 		}
 
@@ -334,6 +337,14 @@ found_unreferenced_key:
 	gc_state |= KEY_GC_REAP_AGAIN;
 	goto maybe_resched;
 
+	/* We found a restricted keyring and need to update the restriction if
+	 * it is associated with the dead key type.
+	 */
+found_restricted_keyring:
+	spin_unlock(&key_serial_lock);
+	keyring_restriction_gc(key, key_gc_dead_keytype);
+	goto maybe_resched;
+
 	/* We found a keyring and we need to check the payload for links to
 	 * dead or expired keys.  We don't flag another reap immediately as we
 	 * have to wait for the old payload to be destroyed by RCU before we