ksmbd: fix deadlock in ksmbd_find_crypto_ctx()

mainline inclusion
from mainline-v6.4-rc1
commit 7b432337
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/I74FIN
CVE: CVE-2023-32253

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=7b4323373d844954bb76e0e9f39c4e5fc785fa7b



--------------------------------

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: ZhaoLong Wang <wangzhaolong1@huawei.com>
(cherry picked from commit 5c18a2ed)