[PATCH ghau90 v2] sig_info: use standard template for log messages

Richard Guy Briggs rgb at redhat.com
Wed May 15 19:02:31 UTC 2019


On 2019-05-15 14:39, Steve Grubb wrote:
> On Friday, May 10, 2019 12:21:57 PM EDT Richard Guy Briggs wrote:
> > Records that are triggered by an AUDIT_SIGNAL_INFO message including
> > AUDIT_DAEMON_CONFIG (HUP), AUDIT_DAEMON_ROTATE (USR1),
> > AUDIT_DAEMON_RESUME (USR2) and AUDIT_DAEMON_END (TERM) have inconsistent
> > reporting of signal info and swinging field "state".
> > 
> > They also assume that an empty security context implies there is no
> > other useful information in the AUDIT_SIGNAL_INFO message so don't use
> > the information that is there.
> > 
> > Normalize AUDIT_DAEMON_CONFIG to use the value "reconfigure" and add the
> > "state" field where missing.
> > 
> > Use audit_sig_info values when available, not making assumptions about
> > their availability when the security context is absent.
> > 
> > See: https://github.com/linux-audit/audit-userspace/issues/90
> 
> This was applied with some fixes. I don't know why ':' was introduced in one 
> event. But we've been trying to get rid of non-meaningful text.

The ":" is there to normalize that record with all the others.  They all
have a format of eg.:
	type=CWD msg=audit(1557843567.201:126068): cwd="/"

The colon was missing after the (date:serial) before the list of fields.

> Also, there were 2 places where a success result was switched to a
> fail.  These were fixed back.

I do prefer you would point out which ones in-line below and let me
submit a new patch to fix them...

> -Steve
> 
> > Signed-off-by: Richard Guy Briggs <rgb at redhat.com>
> > ---
> > Changelog:
> > v2:
> > - omit subj= if selinux unavailable
> > - add missing colon to daemon_config
> > 
> >  docs/audit_request_signal_info.3 |  2 +-
> >  lib/libaudit.c                   | 12 +++++++++
> >  lib/libaudit.h                   |  1 +
> >  src/auditd-event.c               |  2 +-
> >  src/auditd-reconfig.c            |  9 +++----
> >  src/auditd.c                     | 56
> > ++++++++++++++-------------------------- 6 files changed, 38
> > insertions(+), 44 deletions(-)
> > 
> > diff --git a/docs/audit_request_signal_info.3
> > b/docs/audit_request_signal_info.3 index 873deb58bef3..b68d7bbefeed 100644
> > --- a/docs/audit_request_signal_info.3
> > +++ b/docs/audit_request_signal_info.3
> > @@ -8,7 +8,7 @@ int audit_request_signal_info(int fd);
> > 
> >  .SH "DESCRIPTION"
> > 
> > -audit_request_signal_info requests that the kernel send information about
> > the sender of a signal to the audit daemon. The sinal info structure is as
> > follows: +audit_request_signal_info requests that the kernel send
> > information about the sender of a signal to the audit daemon. The signal
> > info structure is as follows:
> > 
> >  .nf
> >  struct audit_sig_info {
> > diff --git a/lib/libaudit.c b/lib/libaudit.c
> > index 2af017a0e520..e695791f9243 100644
> > --- a/lib/libaudit.c
> > +++ b/lib/libaudit.c
> > @@ -674,6 +674,18 @@ int audit_request_signal_info(int fd)
> >  	return rc;
> >  }
> > 
> > +char *audit_format_signal_info(char *buf, int len, char *op, struct
> > audit_reply *rep, char *res) +{
> > +	if (rep->len == 24)
> > +		snprintf(buf, len, "op=%s auid=%u pid=%d res=%s", op,
> > +		 	rep->signal_info->uid, rep->signal_info->pid, res);
> > +	else
> > +		snprintf(buf, len, "op=%s auid=%u pid=%d subj=%s res=%s",
> > +		 	op, rep->signal_info->uid, rep->signal_info->pid,
> > +		 	rep->signal_info->ctx, res);
> > +	return buf;
> > +}
> > +
> >  int audit_update_watch_perms(struct audit_rule_data *rule, int perms)
> >  {
> >  	unsigned int i, done=0;
> > diff --git a/lib/libaudit.h b/lib/libaudit.h
> > index 77e4142beea2..36ea8bc04e8a 100644
> > --- a/lib/libaudit.h
> > +++ b/lib/libaudit.h
> > @@ -573,6 +573,7 @@ extern int  audit_setloginuid(uid_t uid);
> >  extern uint32_t audit_get_session(void);
> >  extern int  audit_detect_machine(void);
> >  extern int audit_determine_machine(const char *arch);
> > +extern char *audit_format_signal_info(char *buf, int len, char *op, struct
> > audit_reply *rep, char *res);
> > 
> >  /* Translation functions */
> >  extern int        audit_name_to_field(const char *field);
> > diff --git a/src/auditd-event.c b/src/auditd-event.c
> > index ef2828d8df94..2970aba44456 100644
> > --- a/src/auditd-event.c
> > +++ b/src/auditd-event.c
> > @@ -1572,7 +1572,7 @@ static void reconfigure(struct auditd_event *e)
> > 
> >  	e->reply.type = AUDIT_DAEMON_CONFIG;
> >  	e->reply.len = snprintf(e->reply.msg.data, 
> MAX_AUDIT_MESSAGE_LENGTH-2,
> > -	"%s op=reconfigure state=changed auid=%u pid=%d subj=%s res=success",
> > +	"%s : op=reconfigure state=changed auid=%u pid=%d subj=%s res=success",
> >  		date, uid, pid, ctx );
> >  	e->reply.message = e->reply.msg.data;
> >  	free((char *)ctx);
> > diff --git a/src/auditd-reconfig.c b/src/auditd-reconfig.c
> > index a03e29aa57ab..f5b00e6d1dc7 100644
> > --- a/src/auditd-reconfig.c
> > +++ b/src/auditd-reconfig.c
> > @@ -115,12 +115,9 @@ static void *config_thread_main(void *arg)
> >  	} else {
> >  		// need to send a failed event message
> >  		char txt[MAX_AUDIT_MESSAGE_LENGTH];
> > -		snprintf(txt, sizeof(txt),
> > -	    "op=reconfigure state=no-change auid=%u pid=%d subj=%s 
> res=failed",
> > -			e->reply.signal_info->uid,
> > -			e->reply.signal_info->pid,
> > -			(e->reply.len > 24) ?
> > -				e->reply.signal_info->ctx : "?");
> > +		audit_format_signal_info(txt, sizeof(txt),
> > +					 "reconfigure state=no-change",
> > +				         &e->reply, "failed");
> >  		// FIXME: need to figure out sending this
> >  		//send_audit_event(AUDIT_DAEMON_CONFIG, txt);
> >  		free_config(&new_config);
> > diff --git a/src/auditd.c b/src/auditd.c
> > index c04a1c9ce93f..63404b25fbc5 100644
> > --- a/src/auditd.c
> > +++ b/src/auditd.c
> > @@ -131,7 +131,7 @@ static void hup_handler( struct ev_loop *loop, struct
> > ev_signal *sig, int revent rc = audit_request_signal_info(fd);
> >  	if (rc < 0)
> >  		send_audit_event(AUDIT_DAEMON_CONFIG,
> > -	  "op=hup-info state=request-siginfo auid=-1 pid=-1 subj=? 
> res=failed");
> > +	  "op=reconfigure state=no-change auid=-1 pid=-1 subj=? res=failed");
> >  	else
> >  		hup_info_requested = 1;
> >  }
> > @@ -147,7 +147,7 @@ static void user1_handler(struct ev_loop *loop, struct
> > ev_signal *sig, rc = audit_request_signal_info(fd);
> >  	if (rc < 0)
> >  		send_audit_event(AUDIT_DAEMON_ROTATE,
> > -			 "op=usr1-info auid=-1 pid=-1 subj=? res=failed");
> > +			 "op=rotate-logs auid=-1 pid=-1 subj=? res=failed");
> >  	else
> >  		usr1_info_requested = 1;
> >  }
> > @@ -163,7 +163,7 @@ static void user2_handler( struct ev_loop *loop, struct
> > ev_signal *sig, int reve if (rc < 0) {
> >  		resume_logging();
> >  		send_audit_event(AUDIT_DAEMON_RESUME,
> > -			 "op=resume-logging auid=-1 pid=-1 subj=? 
> res=success");
> > +			 "op=resume-logging auid=-1 pid=-1 subj=? res=failed");
> >  	} else
> >  		usr2_info_requested = 1;
> >  }
> > @@ -515,45 +515,33 @@ static void netlink_handler(struct ev_loop *loop,
> > struct ev_io *io, break;
> >  		case AUDIT_SIGNAL_INFO:
> >  			if (hup_info_requested) {
> > +				char hup[MAX_AUDIT_MESSAGE_LENGTH];
> >  				audit_msg(LOG_DEBUG,
> >  				    "HUP detected, starting config manager");
> >  				reconfig_ev = cur_event;
> >  				if (start_config_manager(cur_event)) {
> > -					send_audit_event(
> > -						AUDIT_DAEMON_CONFIG,
> > -				  "op=reconfigure state=no-change "
> > -				  "auid=-1 pid=-1 subj=? res=failed");
> > +					audit_format_signal_info(hup, sizeof(hup),
> > +								 "reconfigure 
> state=no-change",
> > +								 &cur_event->reply,
> > +								 "failed");
> > +					send_audit_event(AUDIT_DAEMON_CONFIG, 
> hup);
> >  				}
> >  				cur_event = NULL;
> >  				hup_info_requested = 0;
> >  			} else if (usr1_info_requested) {
> >  				char usr1[MAX_AUDIT_MESSAGE_LENGTH];
> > -				if (cur_event->reply.len == 24) {
> > -					snprintf(usr1, sizeof(usr1),
> > -					"op=rotate-logs auid=-1 pid=-1 subj=?");
> > -				} else {
> > -					snprintf(usr1, sizeof(usr1),
> > -				 "op=rotate-logs auid=%u pid=%d subj=%s",
> > -					 cur_event->reply.signal_info->uid,
> > -					 cur_event->reply.signal_info->pid,
> > -					 cur_event->reply.signal_info->ctx);
> > -				}
> > +				audit_format_signal_info(usr1, sizeof(usr1),
> > +							 "rotate-logs",
> > +							 &cur_event->reply,
> > +							 "success");
> >  				send_audit_event(AUDIT_DAEMON_ROTATE, usr1);
> >  				usr1_info_requested = 0;
> >  			} else if (usr2_info_requested) {
> >  				char usr2[MAX_AUDIT_MESSAGE_LENGTH];
> > -				if (cur_event->reply.len == 24) {
> > -					snprintf(usr2, sizeof(usr2),
> > -						"op=resume-logging auid=-1 "
> > -						"pid=-1 subj=? res=success");
> > -				} else {
> > -					snprintf(usr2, sizeof(usr2),
> > -						"op=resume-logging "
> > -					"auid=%u pid=%d subj=%s res=success",
> > -					 cur_event->reply.signal_info->uid,
> > -					 cur_event->reply.signal_info->pid,
> > -					 cur_event->reply.signal_info->ctx);
> > -				}
> > +				audit_format_signal_info(usr2, sizeof(usr2),
> > +							 "resume-logging",
> > +							 &cur_event->reply,
> > +							 "success");
> >  				resume_logging();
> >  				libdisp_resume();
> >  				send_audit_event(AUDIT_DAEMON_RESUME, usr2);
> > @@ -993,18 +981,14 @@ int main(int argc, char *argv[])
> >  		rc = get_reply(fd, &trep, rc);
> >  		if (rc > 0) {
> >  			char txt[MAX_AUDIT_MESSAGE_LENGTH];
> > -			snprintf(txt, sizeof(txt),
> > -				"op=terminate auid=%u "
> > -				"pid=%d subj=%s res=success",
> > -				 trep.signal_info->uid,
> > -				 trep.signal_info->pid,
> > -				 trep.signal_info->ctx);
> > +			audit_format_signal_info(txt, sizeof(txt), "terminate",
> > +						 &trep, "success");
> >  			send_audit_event(AUDIT_DAEMON_END, txt);
> >  		}
> >  	}
> >  	if (rc <= 0)
> >  		send_audit_event(AUDIT_DAEMON_END,
> > -			"op=terminate auid=-1 pid=-1 subj=? res=success");
> > +			"op=terminate auid=-1 pid=-1 subj=? res=failed");
> >  	free(cur_event);
> > 
> >  	// Tear down IO watchers Part 2
> 
> 
> 
> 

- RGB

--
Richard Guy Briggs <rgb at redhat.com>
Sr. S/W Engineer, Kernel Security, Base Operating Systems
Remote, Ottawa, Red Hat Canada
IRC: rgb, SunRaycer
Voice: +1.647.777.2635, Internal: (81) 32635




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