[PATCH 4.6 012/100] fs/cifs: correctly to anonymous authentication for the NTLM(v1) authentication

Greg Kroah-Hartman
2016-05-30T21:00:50Z

From: Stefan Metzmacher <metze@samba.org>

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@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
fs/cifs/sess.c | 41 +++++++++++++++++++++++------------------
1 file changed, 23 insertions(+), 18 deletions(-)

--- a/fs/cifs/sess.c
+++ b/fs/cifs/sess.c
@@ -781,26 +781,31 @@ sess_auth_ntlm(struct sess_data *sess_da
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 */