ksmbd: restore Kerberos logins with released ksmbd-tools

Commit a47634cd729b ("ksmbd: expire SMB sessions when Kerberos tickets
expire") added a __u64 session_expiry field to struct
ksmbd_spnego_authen_response, growing it from 156 to 168 bytes.
ipc_validate_msg() requires the response to have exactly that size, so
the 156-byte response of every released ksmbd-tools, up to 3.5.7, is
dropped and Kerberos session setup fails with STATUS_LOGON_FAILURE.
The other way round, kernels without that commit, including the stable
trees, drop the 168-byte response of current ksmbd-tools master, and
ksmbd-tools has no way to tell which layout a kernel expects.

Pass the expiry in the reserved area of the embedded struct
ksmbd_login_response instead. ksmbd-tools releases with that area
(3.4.4 and later) allocate the response zeroed and never write to it,
so they send an expiry of 0, which ksmbd already treats as no expiry.
The response is 156 bytes again, so it works with those releases, and
every kernel also accepts a response that sets the expiry. Use two
__u32 halves, as the reserved area is only 4-byte aligned.

Fixes: a47634cd729b ("ksmbd: expire SMB sessions when Kerberos tickets expire")
Cc: stable@vger.kernel.org
Closes: https://lore.kernel.org/all/CAO+rqLhpPvY0NLrAnZjFXz0gOXnA6zsXxK8xCgtA42XUkSsAeg@mail.gmail.com/
Assisted-by: LLM
Signed-off-by: Michail Andreas Michalopoulos <mike.michalo@gmail.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>

0 files changed, 0 insertions, 0 deletions