[PATCH 3.2 27/94] fs/cifs: correctly to anonymous authentication for the NTLM(v1) authentication

From: Ben Hutchings
Date: Sun Aug 14 2016 - 07:01:04 EST


3.2.82-rc1 review patch. If anyone has any objections, please let me know.

------------------

From: Stefan Metzmacher <metze@xxxxxxxxx>

commit 777f69b8d26bf35ade4a76b08f203c11e048365d upstream.

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@xxxxxxxxx>
Signed-off-by: Steve French <smfrench@xxxxxxxxx>
[bwh: Backported to 3.2:
- Adjust context, indentation
- Keep using cERROR()]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
--- a/fs/cifs/sess.c
+++ b/fs/cifs/sess.c
@@ -686,25 +686,31 @@ ssetup_ntlmssp_authenticate:
#endif
} else if (type == NTLM) {
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, nls_cp);
- if (rc) {
- cERROR(1, "Error %d during NTLM authentication", rc);
- goto ssetup_exit;
- }
+ /* calculate ntlm response and session key */
+ rc = setup_ntlm_response(ses, nls_cp);
+ if (rc) {
+ cERROR(1, "Error %d during NTLM authentication",
+ rc);
+ goto ssetup_exit;
+ }

- /* 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 */