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().

This vulnerability does not affect supported Red Hat Enterprise Linux releases because the in-kernel SMB server (ksmbd) is not enabled or provided in Red Hat kernel builds. Red Hat relies on user-space Samba to deliver SMB and CIFS file-sharing services. Systems running upstream kernels with ksmbd enabled could experience a denial of service if an unauthenticated client initiates Kerberos session termination before identity validation completes.