ksmbd: add buffer validation for SMB2_CREATE_CONTEXT

mainline inclusion
from mainline-5.15-rc4
commit 8f77150c
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I60T7G
CVE: NA

Reference: https://git.kernel.org/torvalds/linux/c/8f77150c15f8



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Add buffer validation for SMB2_CREATE_CONTEXT.

Cc: Ronnie Sahlberg <ronniesahlberg@gmail.com>
Reviewed-by: Ralph Boehme <slow@samba.org>
Signed-off-by: Hyunchul Lee <hyc.lee@gmail.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Jason Yan <yanaijie@huawei.com>
Signed-off-by: Zhong Jinghua <zhongjinghua@huawei.com>