[4.2.y-ckt stable] Patch "fs/cifs: correctly to anonymous authentication for the NTLM(v1) authentication" has been added to the 4.2.y-ckt tree

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

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

to the linux-4.2.y-queue branch of the 4.2.y-ckt extended stable tree 
which can be found at:

    https://git.launchpad.net/~canonical-kernel/linux/+git/linux-stable-ckt/log/?h=linux-4.2.y-queue

This patch is scheduled to be released in version 4.2.8-ckt12.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 4.2.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

---8<------------------------------------------------------------

>From 89052364653bd4063f0bc5d23d114f5abb81326a Mon Sep 17 00:00:00 2001
From: Stefan Metzmacher <metze at samba.org>
Date: Tue, 3 May 2016 10:52:30 +0200
Subject: fs/cifs: correctly to anonymous authentication for the NTLM(v1)
 authentication

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 at samba.org>
Signed-off-by: Steve French <smfrench at gmail.com>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 fs/cifs/sess.c | 41 +++++++++++++++++++++++------------------
 1 file changed, 23 insertions(+), 18 deletions(-)

diff --git a/fs/cifs/sess.c b/fs/cifs/sess.c
index 91dbaca..a58b100 100644
--- 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 */
--
2.7.4