need rules help

LC Bruzenak lenny at magitekltd.com
Sat Aug 8 17:59:53 UTC 2009


On Sat, 2009-08-08 at 11:34 -0400, Steve Grubb wrote:
> On Thursday 06 August 2009 05:17:36 pm LC Bruzenak wrote:
> > So it appears that the "never" rule is not firing...right?
> 
> No, its actually something else
> 
> 
> > I'm not sure if the rule applies to only the info in the "type=syscall"
> > line. Really I want to compare against the specific scontext/tcontext
> > pair in the "type=AVC" line.
> 
> The issue is that SE Linux AVCs travel a different path. When an AVC denial 
> occurs and there is not a dontaudit associated with it, it sends the event 
> straight to the netlink queue. To suppress an AVC, you would need to make a 
> change to SE Linux policy. The SE Linux folks wanted to make sure there was no 
> way to suppress an AVC without explicitly stating so in policy.
> 
> -Steve

Bummer. But thanks for the explanation; that makes sense...sort of.
Does the "exclude" rule then work for msgtype=AVC (as the manpage says)?
If so, seems like a broad stroke is allowed whereas detailed exclusion
isn't. 

I realize this may be out of your hands, but it might have implications
for event aggregation as this feature matures. At the event generation
level, this might be desired behavior whereas the collecting machine
might not want this detail. 

At some point, would it be possible to instantiate filters at either the
sending side (audisp-remote) or the receiving side (auditd) to narrow
the event collection?


For SElinux then, the "never" flag seems to me almost useless. The vast
majority of events I see (YMMV) are either those I explicitly specify in
the rules, or else AVCs; e.g.:

[root at audit ~]# aureport -ts today -e -i --summary

Event Summary Report
======================
total  type
======================
23851  AVC
121  SYSCALL
60  CRED_DISP
60  USER_END
59  CRED_ACQ
59  USER_ACCT
59  LOGIN
59  USER_START
18  TRUSTED_APP
2  USER_ROLE_CHANGE
1  DAEMON_RESUME
1  CRED_REFR
1  USER_LOGIN
1  USER_AUTH

Thx,
LCB.

-- 
LC (Lenny) Bruzenak
lenny at magitekltd.com




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