Code that uses AES-CMAC might need to zeroize their local aes_cmac_key
and/or aes_cmac_ctx structures after use to avoid leaking sensitive
material on the stack.

The first patch introduces an aes_cmac_zeroize_key() and an
aes_cmac_zeroize_ctx() helper function that can be used with __cleanup()
to automatically clear the key and context when they go out of scope.

Patches 2 - 3 add the __cleanup markers to spots in the code that
missed to clean up the structures so far.

The final two patches are just cosmetics and change some memzero_explicit()
calls to use the __cleanup() way instead.

Thomas Huth (6):
  crypto: Provide wrapper functions for zeroizing aes_cmac_key and
    aes_cmac_ctx
  smb: clear the aes_cmac_key and aes_cmac_ctx when done
  net/tcp-ao: clear the aes_cmac_key when done
  Bluetooth: SMP: clear the aes_cmac_key when done
  lib/crypto: aes: Use _cleanup() for aes_cmac_key instead of
    memzero_explicit()
  mac80211: fils_aead: Use _cleanup for aes_cmac_key instead of
    memzero_explicit

 fs/smb/client/smb2transport.c |  4 ++--
 fs/smb/server/auth.c          |  2 +-
 include/crypto/aes-cbc-macs.h | 26 ++++++++++++++++++++++++++
 lib/crypto/aes.c              |  3 +--
 net/bluetooth/smp.c           |  2 +-
 net/ipv4/tcp_ao.c             |  2 +-
 net/mac80211/fils_aead.c      |  3 +--
 7 files changed, 33 insertions(+), 9 deletions(-)

-- 
2.55.0