kern/165939: [ipw] security bug: incomplete firewall rules loaded if tables are used in ipfw.conf

[Ian Smith]

On Sat, 14 Jul 2012 18:59:54 +0100, Chris Rees wrote:
 > On 14 Jul 2012 18:49, "Ian Smith" <smithi at nimnet.asn.au> wrote:
 > >
 > > On Sat, 14 Jul 2012, crees at freebsd.org wrote:
 > >  > http://www.freebsd.org/cgi/query-pr.cgi?pr=165939
[..]
 > >  > Description
 > >  > If user has tables used in /etc/ipfw.conf for example:
 > >  >
 > >  > table 1 add 64.6.108.239
 > >  >
 > >  > then firewall restart:
 > >  >
 > >  > /etc/rc.d/ipfw start
 > >  >
 > >  > fails with:
 > >  > Line 8: setsockopt(IP_FW_TABLE_ADD): File exists
 > >  > Firewall rules loaded.
 > >  >
 > >  > and incomplete ruleset is loaded. This is serious security problem.

I've likely said more than enough while awaiting team response, but does 
this still fail if in /etc/rc.conf you set either (should come to the 
same for your custom firewall_type=/etc/ipfw.conf via rc.firewall) of:

firewall_quiet="YES"
firewall_flags="-q"

Just that ipfw(8) reckons, noting the last sentence:

    -q	     Be quiet when executing the add, nat, zero, resetlog or flush
	     commands; (implies -f).  This is useful when updating rulesets by
	     executing multiple ipfw commands in a script (e.g.,
	     `sh /etc/rc.firewall'), or by processing a file with many ipfw
	     rules across a remote login session.  It also stops a table add
	     or delete from failing if the entry already exists or is not
	     present.

ie, with -q on table add commands, you shouldn't need to flush tables.

cheers, Ian