linux-kernel - [PATCH 4.4 01/41] cifs: release auth

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20171003114220.034862397@linuxfoundation.org>
Date:   Tue,  3 Oct 2017 14:21:02 +0200
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Shu Wang <shuwang@...hat.com>,
        Steve French <smfrench@...il.com>,
        Ronnie Sahlberg <lsahlber@...hat.com>
Subject: [PATCH 4.4 01/41] cifs: release auth_key.response for reconnect.

4.4-stable review patch.  If anyone has any objections, please let me know.

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

From: Shu Wang <shuwang@...hat.com>

commit f5c4ba816315d3b813af16f5571f86c8d4e897bd upstream.

There is a race that cause cifs reconnect in cifs_mount,
- cifs_mount
  - cifs_get_tcp_session
    - [ start thread cifs_demultiplex_thread
      - cifs_read_from_socket: -ECONNABORTED
        - DELAY_WORK smb2_reconnect_server ]
  - cifs_setup_session
  - [ smb2_reconnect_server ]

auth_key.response was allocated in cifs_setup_session, and
will release when the session destoried. So when session re-
connect, auth_key.response should be check and released.

Tested with my system:
CIFS VFS: Free previous auth_key.response = ffff8800320bbf80

A simple auth_key.response allocation call trace:
- cifs_setup_session
- SMB2_sess_setup
- SMB2_sess_auth_rawntlmssp_authenticate
- build_ntlmssp_auth_blob
- setup_ntlmv2_rsp

Signed-off-by: Shu Wang <shuwang@...hat.com>
Signed-off-by: Steve French <smfrench@...il.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@...hat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>

---
 fs/cifs/connect.c |    8 ++++++++
 1 file changed, 8 insertions(+)

--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -4060,6 +4060,14 @@ cifs_setup_session(const unsigned int xi
 	cifs_dbg(FYI, "Security Mode: 0x%x Capabilities: 0x%x TimeAdjust: %d\n",
 		 server->sec_mode, server->capabilities, server->timeAdj);
 
+	if (ses->auth_key.response) {
+		cifs_dbg(VFS, "Free previous auth_key.response = %p\n",
+			 ses->auth_key.response);
+		kfree(ses->auth_key.response);
+		ses->auth_key.response = NULL;
+		ses->auth_key.len = 0;
+	}
+
 	if (server->ops->sess_setup)
 		rc = server->ops->sess_setup(xid, ses, nls_info);