tls: separate no-async decryption request handling from async

commit 41532b78 upstream.

If we're not doing async, the handling is much simpler. There's no
reference counting, we just need to wait for the completion to wake us
up and return its result.

We should preferably also use a separate crypto_wait. I'm not seeing a
UAF as I did in the past, I think aec79619 ("tls: fix race between
async notify and socket close") took care of it.

This will make the next fix easier.

Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Link: https://lore.kernel.org/r/47bde5f649707610eaef9f0d679519966fc31061.1709132643.git.sd@queasysnail.net


Signed-off-by: Jakub Kicinski <kuba@kernel.org>
[ William: The original patch did not apply cleanly due to deletions of
  non-existent lines in 6.1.y. The UAF the author stopped seeing can still
  be reproduced on systems without AVX in conjunction with cryptd.
  Also removed an extraneous statement after a return statement that is
  adjacent to diff. ]
Link: https://lore.kernel.org/netdev/he2K1yz_u7bZ-CnYcTSQ4OxuLuHZXN6xZRgp6_ICSWnq8J5FpI_uD1i_1lTSf7WMrYb5ThiX1OR2GTOB2IltgT49Koy7Hhutr4du4KtLvyk=@willsroot.io/


Signed-off-by: William Liu <will@willsroot.io>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>