lkml.org 
[lkml]   [1998]   [Nov]   [24]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: Oops in 2.1.129
On Tue, Nov 24, 1998 at 12:33:52PM +1130, Paul Rusty Russell wrote:
> In message <19981119212856.A447@osiris.ml.org> you write:
> > 2.1.129 get a Null Pointer Dereference followed by an oops, followed by a
> > panic when I enable ip_forwarding under 2.1.129 with masquarading ipchains
> > rules present.
> >
> > My IP chains rules:
> >
> > ipchains -P forward DENY
> > ipchains -A forward -j MASQ -s 10.0.16.0/24 -d 0.0.0.0/0
> >
> > Then I enable forwarding:
> >
> > echo "1" >/proc/sys/net/ipv4/ip_forward
> >
> > Then it goes boom (keyed in from my notes):
>
> Sorry for the delay; you should probably have sent this to the IP
> Firewalling maintainer as well; linux-kernel has too much noise about
> elevating chickens in assembler.

Whoops... Sorry.

It's been a while since I've followed the devel kernel stuff. The only
address I remembered was the Linux kernel mailing list.

>
> > >From my /System.map around the value of EIP:
> >
> > c016eba0 t find_special
> > c016ecd0 t cleanup
> > c016ed40 t ip_fw_check
> > c016f2d0 t zero_fw_chain
>
> This trace is currupted: cleanup() is a leafnode. It's almost
> certainly the masq code barfing on a fragment. While that *shouldn't*
> happen, it doesn't surprise me since few people do this.

yes.. I noticed this later and looked up all the return addresses in the
call trace. Here's a better look:

Address closest to EIP and the addresses in the call trace (in order):
c016ecd0 t cleanup (EIP)
c016ed40 t ip_fw_check
c0170304 T ipfw_forward_check
c0149a6c T call_fw_firewall
c015819c T ip_forward
c0157538 T ip_rcv
c014c3f8 T net_bh
c0119570 T get_ioport_list
c010a560 T do_IRQ
c0108cec T ret_from_intr
c0107b7c T sys_rt_sigsuspend

And you're entirely right. It's barfing in ip_fw_check.

Unfortunately, it still barfs even with always defragment turned on. Unless
my kernel configuration is borked, there's still something that needs
fixing.

--
Brian Ristuccia
brianr@osiris.ml.org
bristucc@baynetworks.com
bristucc@cs.uml.edu

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.rutgers.edu
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-03-22 13:45    [from the cache]
©2003-2014 Jasper Spaans. Advertise on this site