ksmbd: fix deadlock in ksmbd_find_crypto_ctx()

ksmbd: fix deadlock in ksmbd_find_crypto_ctx()

BugLink: https://bugs.launchpad.net/bugs/2025067
commit 7b4323373d844954bb76e0e9f39c4e5fc785fa7b upstream.

Deadlock is triggered by sending multiple concurrent session setup
requests. It should be reused after releasing when getting ctx for crypto.
Multiple consecutive ctx uses cause deadlock while waiting for releasing
due to the limited number of ctx.

Cc: stable@vger.kernel.org
Reported-by: zdi-disclosures@trendmicro.com # ZDI-CAN-20591
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>