[PATCH 4.4 17/86] fs/cifs: correctly to anonymous authentication for the NTLM(v2) authentication

Greg Kroah-Hartman
2016-05-30T20:50:20Z

From: Stefan Metzmacher <metze@samba.org>

commit 1a967d6c9b39c226be1b45f13acd4d8a5ab3dc44 upstream.

Only server which map unknown users to guest will allow
access using a non-null NTLMv2_Response.

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 | 32 ++++++++++++++++++--------------
1 file changed, 18 insertions(+), 14 deletions(-)

--- a/fs/cifs/sess.c
+++ b/fs/cifs/sess.c
@@ -895,22 +895,26 @@ sess_auth_ntlmv2(struct sess_data *sess_
/* LM2 password would be here if we supported it */
pSMB->req_no_secext.CaseInsensitivePasswordLength = 0;

- /* calculate nlmv2 response and session key */
- rc = setup_ntlmv2_rsp(ses, sess_data->nls_cp);
- if (rc) {
- cifs_dbg(VFS, "Error %d during NTLMv2 authentication\n", rc);
- goto out;
- }
+ if (ses->user_name != NULL) {
+ /* calculate nlmv2 response and session key */
+ rc = setup_ntlmv2_rsp(ses, sess_data->nls_cp);
+ if (rc) {
+ cifs_dbg(VFS, "Error %d during NTLMv2 authentication\n", rc);
+ goto out;
+ }

- memcpy(bcc_ptr, ses->auth_key.response + CIFS_SESS_KEY_SIZE,
- ses->auth_key.len - CIFS_SESS_KEY_SIZE);
- bcc_ptr += ses->auth_key.len - CIFS_SESS_KEY_SIZE;
+ memcpy(bcc_ptr, ses->auth_key.response + CIFS_SESS_KEY_SIZE,
+ ses->auth_key.len - CIFS_SESS_KEY_SIZE);
+ bcc_ptr += ses->auth_key.len - CIFS_SESS_KEY_SIZE;

- /* set case sensitive password length after tilen may get
- * assigned, tilen is 0 otherwise.
- */
- pSMB->req_no_secext.CaseSensitivePasswordLength =
- cpu_to_le16(ses->auth_key.len - CIFS_SESS_KEY_SIZE);
+ /* set case sensitive password length after tilen may get
+ * assigned, tilen is 0 otherwise.
+ */
+ pSMB->req_no_secext.CaseSensitivePasswordLength =
+ cpu_to_le16(ses->auth_key.len - CIFS_SESS_KEY_SIZE);
+ } else {
+ pSMB->req_no_secext.CaseSensitivePasswordLength = 0;
+ }

if (ses->capabilities & CAP_UNICODE) {
if (sess_data->iov[0].iov_len % 2) {