ksmbd: validate owner of durable handle on reconnect

In the Linux kernel, the following vulnerability has been resolved:

ksmbd: validate owner of durable handle on reconnect

Currently, ksmbd does not verify if the user attempting to reconnect

to a durable handle is the same user who originally opened the file.

This allows any authenticated user to hijack an orphaned durable handle

by predicting or brute-forcing the persistent ID.

According to MS-SMB2, the server MUST verify that the SecurityContext

of the reconnect request matches the SecurityContext associated with

the existing open.

Add a durable_owner structure to ksmbd_file to store the original opener's

UID, GID, and account name. and catpure the owner information when a file

handle becomes orphaned. and implementing ksmbd_vfs_compare_durable_owner()

to validate the identity of the requester during SMB2_CREATE (DHnC).