What is the bug

Eric Paris eparis at redhat.com
Mon Jan 20 20:25:57 UTC 2014


What's the bugzilla?

On Sat, 2014-01-18 at 08:53 -0500, Steve Grubb wrote:
> Hello,
> 
> On Sat, 18 Jan 2014 20:02:37 +1100
> Burn Alting <burn at swtf.dyndns.org> wrote:
> > Consider the following raw audit event ...
> > 
> >         node=fedora20.swtf.dyndns.org type=CONFIG_CHANGE
> >         msg=audit(1390028319.573:20803): auid=4294967295
> > ses=4294967295 subj=system_u:system_r:auditctl_t:s0 op="remove rule"
> >         key="time-change" list=4 res=1
> > 
> > When the auparse library parses this event event, it does not
> > correctly parse the 'op' value and so both auparse_get_field_str() and
> > auparse_interpret_field() both return '"remove' rather than 'remove
> > rule'.
> 
> Correct. I have pointed this out for years and no one has wanted to fix
> it. The hex-encoding should only be used on fields that a user can
> influence, like file names. Since op= is always filled in by actual
> audit code - which is trusted, it should never _need_ encoding.
> Anywhere there is an op= and the field has blanks in it, it should be
> reformatted to have a dash between the words rather than a space. So,
> you would have remove-rule in your example. Untrusted string should
> never be used for this.
> 
> > Now, I seem to recollect an earlier e-mail that would suggest the bug
> > is in kernel/auditfilter.c:audit_receive_filter() as it calls
> > audit_log_rule_change() with the string "add rule" or "remove rule".
> > One assumes we need to perhaps either
> > a. replace the space with a hyphen in these arguments, or
> > b. in kernel/auditfilter.c:audit_log_rule_change() replace the call
> > 	audit_log_string(ab, action);
> > with
> > 	audit_log_untrustedstring(ab, action); 
> > 
> > If this is the case, then is there any appetite to have these bugs
> > fixed on the next update to the kernel audit code?
> 
> Yes please. I have been wanting this fixed for years. Grep all the auit
> code for this. I seem to recall problems in the ipsec and IMA code.
> 
> Thanks!
> 
> -Steve
> 
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