CVE-2025-38191

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

ksmbd: fix null pointer dereference in destroy_previous_session

If client set ->PreviousSessionId on kerberos session setup stage,
NULL pointer dereference error will happen. Since sess->user is not
set yet, It can pass the user argument as NULL to destroy_previous_session.
sess->user will be set in ksmbd_krb5_authenticate(). So this patch move
calling destroy_previous_session() after ksmbd_krb5_authenticate().

More information : https://git.kernel.org/stable/c/076f1adefb9837977af7ed233883842ddc446644