From mboxrd@z Thu Jan 1 00:00:00 1970 From: Steve Grubb Subject: [PATCH 2/2] audit: log binding and unbinding to netlink multicast socket Date: Thu, 23 Jul 2015 16:45:19 -0400 Message-ID: <8611875.W95Jo5o7mj@x2> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-audit-bounces@redhat.com Errors-To: linux-audit-bounces@redhat.com To: linux-audit@redhat.com List-Id: linux-audit@redhat.com Log information about programs connecting and disconnecting to the audit netlink multicast socket. This is needed so that during investigations a security officer can tell who or what had access to the audit trail. This helps to meet the FAU_SAR.2 requirement for Common Criteria. Signed-off-by: Steve Grubb --- include/uapi/linux/audit.h | 1 + kernel/audit.c | 30 ++++++++++++++++++++++++++++-- 2 files changed, 29 insertions(+), 2 deletions(-) diff --git a/include/uapi/linux/audit.h b/include/uapi/linux/audit.h index d3475e1..bb4555a 100644 --- a/include/uapi/linux/audit.h +++ b/include/uapi/linux/audit.h @@ -110,6 +110,7 @@ #define AUDIT_SECCOMP 1326 /* Secure Computing event */ #define AUDIT_PROCTITLE 1327 /* Proctitle emit event */ #define AUDIT_FEATURE_CHANGE 1328 /* audit log listing feature changes */ +#define AUDIT_EVENT_LISTENER 1329 /* task joined multicast read socket */ #define AUDIT_AVC 1400 /* SE Linux avc denial or grant */ #define AUDIT_SELINUX_ERR 1401 /* Internal SE Linux Errors */ diff --git a/kernel/audit.c b/kernel/audit.c index 29fb38b..3253f1b 100644 --- a/kernel/audit.c +++ b/kernel/audit.c @@ -1135,13 +1135,36 @@ void audit_log_task_simple(struct audit_buffer *ab, struct task_struct *tsk) } EXPORT_SYMBOL(audit_log_task_simple); +static void audit_log_bind(int group, const char *op, int err) +{ + struct audit_buffer *ab; + + ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_EVENT_LISTENER); + if (!ab) + return; + + audit_log_task_simple(ab, current); + audit_log_format(ab, " nlnk-grp=%d", group); + audit_log_format(ab, " op=%s", op); + audit_log_format(ab, " res=%d", !err); + audit_log_end(ab); +} + /* Run custom bind function on netlink socket group connect or bind requests. */ static int audit_bind(struct net *net, int group) { + int err = 0; + if (!capable(CAP_AUDIT_READ)) - return -EPERM; + err = -EPERM; + audit_log_bind(group, "connect", err); - return 0; + return err; +} + +static void audit_unbind(struct net *net, int group) +{ + audit_log_bind(group, "disconnect", 0); } static int __net_init audit_net_init(struct net *net) @@ -1151,6 +1176,7 @@ static int __net_init audit_net_init(struct net *net) .bind = audit_bind, .flags = NL_CFG_F_NONROOT_RECV, .groups = AUDIT_NLGRP_MAX, + .unbind = audit_unbind, }; struct audit_net *aunet = net_generic(net, audit_net_id); -- 2.4.3