linux/net/netlabel/netlabel_user.c
Miloslav Trmac 522ed7767e Audit: add TTY input auditing
Add TTY input auditing, used to audit system administrator's actions.  This is
required by various security standards such as DCID 6/3 and PCI to provide
non-repudiation of administrator's actions and to allow a review of past
actions if the administrator seems to overstep their duties or if the system
becomes misconfigured for unknown reasons.  These requirements do not make it
necessary to audit TTY output as well.

Compared to an user-space keylogger, this approach records TTY input using the
audit subsystem, correlated with other audit events, and it is completely
transparent to the user-space application (e.g.  the console ioctls still
work).

TTY input auditing works on a higher level than auditing all system calls
within the session, which would produce an overwhelming amount of mostly
useless audit events.

Add an "audit_tty" attribute, inherited across fork ().  Data read from TTYs
by process with the attribute is sent to the audit subsystem by the kernel.
The audit netlink interface is extended to allow modifying the audit_tty
attribute, and to allow sending explanatory audit events from user-space (for
example, a shell might send an event containing the final command, after the
interactive command-line editing and history expansion is performed, which
might be difficult to decipher from the TTY input alone).

Because the "audit_tty" attribute is inherited across fork (), it would be set
e.g.  for sshd restarted within an audited session.  To prevent this, the
audit_tty attribute is cleared when a process with no open TTY file
descriptors (e.g.  after daemon startup) opens a TTY.

See https://www.redhat.com/archives/linux-audit/2007-June/msg00000.html for a
more detailed rationale document for an older version of this patch.

[akpm@linux-foundation.org: build fix]
Signed-off-by: Miloslav Trmac <mitr@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Paul Fulghum <paulkf@microgate.com>
Cc: Casey Schaufler <casey@schaufler-ca.com>
Cc: Steve Grubb <sgrubb@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16 09:05:47 -07:00

121 lines
3.1 KiB
C

/*
* NetLabel NETLINK Interface
*
* This file defines the NETLINK interface for the NetLabel system. The
* NetLabel system manages static and dynamic label mappings for network
* protocols such as CIPSO and RIPSO.
*
* Author: Paul Moore <paul.moore@hp.com>
*
*/
/*
* (c) Copyright Hewlett-Packard Development Company, L.P., 2006
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
* the GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/
#include <linux/init.h>
#include <linux/types.h>
#include <linux/list.h>
#include <linux/socket.h>
#include <linux/audit.h>
#include <linux/tty.h>
#include <linux/security.h>
#include <net/sock.h>
#include <net/netlink.h>
#include <net/genetlink.h>
#include <net/netlabel.h>
#include <asm/bug.h>
#include "netlabel_mgmt.h"
#include "netlabel_unlabeled.h"
#include "netlabel_cipso_v4.h"
#include "netlabel_user.h"
/*
* NetLabel NETLINK Setup Functions
*/
/**
* netlbl_netlink_init - Initialize the NETLINK communication channel
*
* Description:
* Call out to the NetLabel components so they can register their families and
* commands with the Generic NETLINK mechanism. Returns zero on success and
* non-zero on failure.
*
*/
int netlbl_netlink_init(void)
{
int ret_val;
ret_val = netlbl_mgmt_genl_init();
if (ret_val != 0)
return ret_val;
ret_val = netlbl_cipsov4_genl_init();
if (ret_val != 0)
return ret_val;
ret_val = netlbl_unlabel_genl_init();
if (ret_val != 0)
return ret_val;
return 0;
}
/*
* NetLabel Audit Functions
*/
/**
* netlbl_audit_start_common - Start an audit message
* @type: audit message type
* @audit_info: NetLabel audit information
*
* Description:
* Start an audit message using the type specified in @type and fill the audit
* message with some fields common to all NetLabel audit messages. Returns
* a pointer to the audit buffer on success, NULL on failure.
*
*/
struct audit_buffer *netlbl_audit_start_common(int type,
struct netlbl_audit *audit_info)
{
struct audit_context *audit_ctx = current->audit_context;
struct audit_buffer *audit_buf;
char *secctx;
u32 secctx_len;
if (audit_enabled == 0)
return NULL;
audit_buf = audit_log_start(audit_ctx, GFP_ATOMIC, type);
if (audit_buf == NULL)
return NULL;
audit_log_format(audit_buf, "netlabel: auid=%u", audit_info->loginuid);
if (audit_info->secid != 0 &&
security_secid_to_secctx(audit_info->secid,
&secctx,
&secctx_len) == 0)
audit_log_format(audit_buf, " subj=%s", secctx);
return audit_buf;
}