What is the bug

Burn Alting burn at swtf.dyndns.org
Mon Jan 20 21:05:03 UTC 2014


Eric,

I haven't listed one yet, but I will in the next day or two. I will
identify every string and file involved before doing so. I would only
ask, what kernel version should I use as my reference?

Rgds

On Mon, 2014-01-20 at 15:25 -0500, Eric Paris wrote:
> 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
> > 
> > --
> > Linux-audit mailing list
> > Linux-audit at redhat.com
> > https://www.redhat.com/mailman/listinfo/linux-audit
> 
> 





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