ksmbd: add buffer validation in session setup

mainline inclusion
from mainline-5.15-rc7
commit 0d994cd4
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I60T7G
CVE: NA

Reference: https://git.kernel.org/torvalds/linux/c/0d994cd482ee



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Make sure the security buffer's length/offset are valid with regards to
the packet length.

Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Marios Makassikis <mmakassikis@freebox.fr>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Jason Yan <yanaijie@huawei.com>
Signed-off-by: Zhong Jinghua <zhongjinghua@huawei.com>