fs/cifs: correctly to anonymous authentication via NTLMSSP
authorStefan Metzmacher <metze@samba.org>
Tue, 3 May 2016 08:52:30 +0000 (10:52 +0200)
committerSteve French <smfrench@gmail.com>
Tue, 17 May 2016 19:09:33 +0000 (14:09 -0500)
commitcfda35d98298131bf38fbad3ce4cd5ecb3cf18db
tree02e8c5bfae387525a063ebae2d51e7745862f21d
parent11e31647c9263185cfd990db656dbb7f06697faf
fs/cifs: correctly to anonymous authentication via NTLMSSP

See [MS-NLMP] 3.2.5.1.2 Server Receives an AUTHENTICATE_MESSAGE from the Client:

   ...
   Set NullSession to FALSE
   If (AUTHENTICATE_MESSAGE.UserNameLen == 0 AND
      AUTHENTICATE_MESSAGE.NtChallengeResponse.Length == 0 AND
      (AUTHENTICATE_MESSAGE.LmChallengeResponse == Z(1)
       OR
       AUTHENTICATE_MESSAGE.LmChallengeResponse.Length == 0))
       -- Special case: client requested anonymous authentication
       Set NullSession to TRUE
   ...

Only server which map unknown users to guest will allow
access using a non-null NTChallengeResponse.

For Samba it's the "map to guest = bad user" option.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=11913

CC: Stable <stable@vger.kernel.org>
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
fs/cifs/sess.c