Pull key subsystem fixes from James Morris:
 "Here are a bunch of fixes for Linux keyrings, including:

   - Fix up the refcount handling now that key structs use the
     refcount_t type and the refcount_t ops don't allow a 0->1
     transition.

   - Fix a potential NULL deref after error in x509_cert_parse().

   - Don't put data for the crypto algorithms to use on the stack.

   - Fix the handling of a null payload being passed to add_key().

   - Fix incorrect cleanup an uninitialised key_preparsed_payload in
     key_update().

   - Explicit sanitisation of potentially secure data before freeing.

   - Fixes for the Diffie-Helman code"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (23 commits)
  KEYS: fix refcount_inc() on zero
  KEYS: Convert KEYCTL_DH_COMPUTE to use the crypto KPP API
  crypto : asymmetric_keys : verify_pefile:zero memory content before freeing
  KEYS: DH: add __user annotations to keyctl_kdf_params
  KEYS: DH: ensure the KDF counter is properly aligned
  KEYS: DH: don't feed uninitialized "otherinfo" into KDF
  KEYS: DH: forbid using digest_null as the KDF hash
  KEYS: sanitize key structs before freeing
  KEYS: trusted: sanitize all key material
  KEYS: encrypted: sanitize all key material
  KEYS: user_defined: sanitize key payloads
  KEYS: sanitize add_key() and keyctl() key payloads
  KEYS: fix freeing uninitialized memory in key_update()
  KEYS: fix dereferencing NULL payload with nonzero length
  KEYS: encrypted: use constant-time HMAC comparison
  KEYS: encrypted: fix race causing incorrect HMAC calculations
  KEYS: encrypted: fix buffer overread in valid_master_desc()
  KEYS: encrypted: avoid encrypting/decrypting stack buffers
  KEYS: put keyring if install_session_keyring_to_cred() fails
  KEYS: Delete an error message for a failed memory allocation in get_derived_key()
  ...