fs/cifs: correctly to anonymous authentication for the NTLM(v1) authentication

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

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

diff --git a/fs/cifs/sess.c b/fs/cifs/sess.c
index b9e2cc1437ef753dd37e051dcf5e3b769205a893..5d5d11ea0251fe8e663233a186c3b809dde70cda 100644 (file)
--- a/fs/cifs/sess.c
+++ b/fs/cifs/sess.c
@@ -781,26 +781,31 @@ sess_auth_ntlm(struct sess_data *sess_data)
        capabilities = cifs_ssetup_hdr(ses, pSMB);
 
        pSMB->req_no_secext.Capabilities = cpu_to_le32(capabilities);
-       pSMB->req_no_secext.CaseInsensitivePasswordLength =
-                       cpu_to_le16(CIFS_AUTH_RESP_SIZE);
-       pSMB->req_no_secext.CaseSensitivePasswordLength =
-                       cpu_to_le16(CIFS_AUTH_RESP_SIZE);
+       if (ses->user_name != NULL) {
+               pSMB->req_no_secext.CaseInsensitivePasswordLength =
+                               cpu_to_le16(CIFS_AUTH_RESP_SIZE);
+               pSMB->req_no_secext.CaseSensitivePasswordLength =
+                               cpu_to_le16(CIFS_AUTH_RESP_SIZE);
 
-       /* calculate ntlm response and session key */
-       rc = setup_ntlm_response(ses, sess_data->nls_cp);
-       if (rc) {
-               cifs_dbg(VFS, "Error %d during NTLM authentication\n",
-                                rc);
-               goto out;
-       }
+               /* calculate ntlm response and session key */
+               rc = setup_ntlm_response(ses, sess_data->nls_cp);
+               if (rc) {
+                       cifs_dbg(VFS, "Error %d during NTLM authentication\n",
+                                        rc);
+                       goto out;
+               }
 
-       /* copy ntlm response */
-       memcpy(bcc_ptr, ses->auth_key.response + CIFS_SESS_KEY_SIZE,
-                       CIFS_AUTH_RESP_SIZE);
-       bcc_ptr += CIFS_AUTH_RESP_SIZE;
-       memcpy(bcc_ptr, ses->auth_key.response + CIFS_SESS_KEY_SIZE,
-                       CIFS_AUTH_RESP_SIZE);
-       bcc_ptr += CIFS_AUTH_RESP_SIZE;
+               /* copy ntlm response */
+               memcpy(bcc_ptr, ses->auth_key.response + CIFS_SESS_KEY_SIZE,
+                               CIFS_AUTH_RESP_SIZE);
+               bcc_ptr += CIFS_AUTH_RESP_SIZE;
+               memcpy(bcc_ptr, ses->auth_key.response + CIFS_SESS_KEY_SIZE,
+                               CIFS_AUTH_RESP_SIZE);
+               bcc_ptr += CIFS_AUTH_RESP_SIZE;
+       } else {
+               pSMB->req_no_secext.CaseInsensitivePasswordLength = 0;
+               pSMB->req_no_secext.CaseSensitivePasswordLength = 0;
+       }
 
        if (ses->capabilities & CAP_UNICODE) {
                /* unicode strings must be word aligned */