netfilter oops (Was: Re: Linux 2.4.18-pre2)

netfilter oops (Was: Re: Linux 2.4.18-pre2)

[CaT]

On Mon, Jan 07, 2002 at 09:38:17PM -0200, Marcelo Tosatti wrote:
> Here goes pre2.
> 
> 
> pre2: 
*snip*

As I was off the net for 2 weeks I wanted to wait for the next pre
release before reporting this bug (incase I missed something and someone
solved it anyways). Anyhow I'm assuming it still applies to pre2 as
there has been no mention of netfilter changes in the changelog, so...

With 18-pre1, 17-rc2 and 17-preX (can't remember now. It's been a week
or so :/) I can get the kernel to consistantly crash after a few minutes
by compiling it with ipchains compatability and using masqueraded net
connections. If I connect to the getway in quetion without hitting the
masq rules I'm fine. I can also use the net from the gateway, but if I
try to use the net from a box behind it and that box gets masqueraded I
get a kernel lockup and an oops after a minute or so of use. Unfortunately
the oops doesn't actually get recorded anywhere and all I can remember
from it is that it was dieing in 'Swapper task' (or something similar).

I did a bit more experimentation and removed all the netfilter changes
done since 2.4.16 and I no longer got oopses so one of the changes after
2.4.16 broke things.

Unfortunately, I am no longer near said gateway. I -can- try and
duplicate this as soon as I get a version of linux compiling on a debian
woody system.

If you have any questions/requests/whatnots then please yell. If I
succeed in duplicateing this and get a recorded oops I'll send that in
also.

Thanks.

-- 
SOCCER PLAYER IN GENITAL-BITING SCANDAL  ---  "It was something between
friends that I thought would have no importance until this morning when
I got up and saw all  the commotion in the news,"  Gallardo told a news
conference. "It stunned me."
Reyes told Marca that he had "felt a slight pinch."

Re: netfilter oops (Was: Re: Linux 2.4.18-pre2)

[Marcelo Tosatti]

On Tue, 8 Jan 2002, CaT wrote:

> On Mon, Jan 07, 2002 at 09:38:17PM -0200, Marcelo Tosatti wrote:
> > Here goes pre2.
> > 
> > 
> > pre2: 
> *snip*
> 
> As I was off the net for 2 weeks I wanted to wait for the next pre
> release before reporting this bug (incase I missed something and someone
> solved it anyways). Anyhow I'm assuming it still applies to pre2 as
> there has been no mention of netfilter changes in the changelog, so...
> 
> With 18-pre1, 17-rc2 and 17-preX (can't remember now. It's been a week
> or so :/) I can get the kernel to consistantly crash after a few minutes
> by compiling it with ipchains compatability and using masqueraded net
> connections. If I connect to the getway in quetion without hitting the
> masq rules I'm fine. I can also use the net from the gateway, but if I
> try to use the net from a box behind it and that box gets masqueraded I
> get a kernel lockup and an oops after a minute or so of use. Unfortunately
> the oops doesn't actually get recorded anywhere and all I can remember
> from it is that it was dieing in 'Swapper task' (or something similar).
> 
> I did a bit more experimentation and removed all the netfilter changes
> done since 2.4.16 and I no longer got oopses so one of the changes after
> 2.4.16 broke things.
> 
> Unfortunately, I am no longer near said gateway. I -can- try and
> duplicate this as soon as I get a version of linux compiling on a debian
> woody system.
> 
> If you have any questions/requests/whatnots then please yell. If I
> succeed in duplicateing this and get a recorded oops I'll send that in
> also.

Please use a serial console to get the oops or write it down in paper.

Thanks

Re: netfilter oops (Was: Re: Linux 2.4.18-pre2)

[CaT]

On Tue, Jan 08, 2002 at 12:04:59PM -0200, Marcelo Tosatti wrote:
> Please use a serial console to get the oops or write it down in paper.

I don't have a null-modem cable so this is a no no as yet. When I
narrow it down and it's need it I'll see if I can scribble it or
score a null-modem cable.

-- 
SOCCER PLAYER IN GENITAL-BITING SCANDAL  ---  "It was something between
friends that I thought would have no importance until this morning when
I got up and saw all  the commotion in the news,"  Gallardo told a news
conference. "It stunned me."
Reyes told Marca that he had "felt a slight pinch."

Re: netfilter oops (Was: Re: Linux 2.4.18-pre2)

[CaT]

This bounced from lk (due to a malformed address)... apologies for the
resend if you get it twice...  Just wanted to remove a bit of chaos from
the thread. ;)

On Tue, Jan 08, 2002 at 04:12:30PM +1100, Rusty Russell wrote:
> > With 18-pre1, 17-rc2 and 17-preX (can't remember now. It's been a week
> > or so :/) I can get the kernel to consistantly crash after a few minutes
> > by compiling it with ipchains compatability and using masqueraded net
> > connections.
> 
> Hi,

Hey.

I haven't forgotten about this little bug. :))

> 	There are three changes which could effect you here.  I can't see
> anything wrong with any of them, but if you could try reverting them one
> at a time, and tell me which causes the problem, that'd narrow it down:

Just did a test and it's not masquerading that's causing it. I'll need
to convert my filesystems to ext3 first because the crashes are not
going to be healthy for this box (or me... 45gig HD involved on a
pentium-200) and I'll experiment some more. It may be redirection
that's doing it.

Once I narrow down what is actually causing it I'll back out the patches
you sent, one by one, until it stops crashing.

-- 
SOCCER PLAYER IN GENITAL-BITING SCANDAL  ---  "It was something between
friends that I thought would have no importance until this morning when
I got up and saw all  the commotion in the news,"  Gallardo told a news
conference. "It stunned me."
Reyes told Marca that he had "felt a slight pinch."

Re: netfilter oops (Was: Re: Linux 2.4.18-pre2)

[CaT]

On Sat, Jan 12, 2002 at 10:04:38PM +1100, CaT wrote:
> Just did a test and it's not masquerading that's causing it. I'll need
> to convert my filesystems to ext3 first because the crashes are not
> going to be healthy for this box (or me... 45gig HD involved on a
> pentium-200) and I'll experiment some more. It may be redirection
> that's doing it.

Ka-ching! Being able to use a fwded net connection without masq was the 
needed clue. I looked at the patches and found this one:

diff -urN -I \$.*\$ --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal
linux-2.4.16/net/ipv4/netfilter/ip_fw_compat_redir.c
linux-2.4.17/net/ipv4/netfilter/ip_fw_compat_redir.c
--- linux-2.4.16/net/ipv4/netfilter/ip_fw_compat_redir.c        Sat Aug 5 06:07:24 2000
+++ linux-2.4.17/net/ipv4/netfilter/ip_fw_compat_redir.c        Thu Dec 27 12:46:11 2001
@@ -206,6 +206,8 @@
                        }
                        list_prepend(&redirs, redir);
                        init_timer(&redir->destroyme);
+                       redir->destroyme.expires = jiffies + 75*HZ;
+                       add_timer(&redir->destroyme);
                }
                /* In case mangling has changed, rewrite this part. */
                redir->core = ((struct redir_core)

As it appeared to deal directly with compatability redirection I removed
this one first and recompiled the kernel. Before, a minute or so of
browsing via a redirected connection (to squid) would make the box go
boom. I've just browsed for 15 minutes to different sites and the box
has not gone down.

Now, if you need the oops then holler and I'll see what I can do about
getting it to you. Writing it down would be a pain so I may opt for the
null-modem cable which may take a week or so for me to get at though.

-- 
SOCCER PLAYER IN GENITAL-BITING SCANDAL  ---  "It was something between
friends that I thought would have no importance until this morning when
I got up and saw all  the commotion in the news,"  Gallardo told a news
conference. "It stunned me."
Reyes told Marca that he had "felt a slight pinch."

Re: netfilter oops (Was: Re: Linux 2.4.18-pre2)

[Willy Tarreau]

> Writing it down would be a pain so I may opt for the
> null-modem cable which may take a week or so for me to
> get at though.

You'd better download my kmsgdump patch which will let you save
all your kernel messages (including oops) to a floppy disk.
Please read the doc in Documentation/kmsgdump.txt to get more info.

http://www-miaif.lip6.fr/willy/linux-patches//kmsgdump/0.4.3/kmsgdump-0.4.3-2.4.16pre1.patch

Regards,
Willy

Re: netfilter oops (Was: Re: Linux 2.4.18-pre2)

[CaT]

On Sat, Jan 12, 2002 at 04:40:07PM +0100, Willy Tarreau wrote:
> > Writing it down would be a pain so I may opt for the
> > null-modem cable which may take a week or so for me to
> > get at though.
> 
> You'd better download my kmsgdump patch which will let you save
> all your kernel messages (including oops) to a floppy disk.
> Please read the doc in Documentation/kmsgdump.txt to get more info.
> 
> http://www-miaif.lip6.fr/willy/linux-patches//kmsgdump/0.4.3/kmsgdump-0.4.3-2.4.16pre1.patch

Well... my floppy drive died and I have no printer. *sigh*

I'll see if Rusty REALLY needs the oops and if so I'll hunt down
another way to get at it.

Thanks though.

-- 
SOCCER PLAYER IN GENITAL-BITING SCANDAL  ---  "It was something between
friends that I thought would have no importance until this morning when
I got up and saw all  the commotion in the news,"  Gallardo told a news
conference. "It stunned me."
Reyes told Marca that he had "felt a slight pinch."