ksmbd: limit pdu length size according to connection status

mainline inclusion
from mainline-v6.3-rc1
commit 62c487b5
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I7CETC
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=62c487b53a7ff31e322cf2874d3796b8202c54a5



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Stream protocol length will never be larger than 16KB until session setup.
After session setup, the size of requests will not be larger than
16KB + SMB2 MAX WRITE size. This patch limits these invalidly oversized
requests and closes the connection immediately.

Fixes: 0626e664 ("cifsd: add server handler for central processing and tranport layers")
Cc: stable@vger.kernel.org
Reported-by: zdi-disclosures@trendmicro.com # ZDI-CAN-18259
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: ZhaoLong Wang <wangzhaolong1@huawei.com>

Conflicts:
    fs/ksmbd/smb2pdu.h