lkml.org 
[lkml]   [2014]   [Mar]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] netfilter: nf_conntrack: reserve two bytes for nf_ct_ext->len
Andrey Vagin <avagin@openvz.org> wrote:
> "len" contains sizeof(nf_ct_ext) and size of extensions. In a worst
> case it can contain all extensions. Bellow you can find sizes for all
> types of extensions. Their sum is definitely bigger than 256.
>
> nf_ct_ext_types[0]->len = 24
> nf_ct_ext_types[1]->len = 32
> nf_ct_ext_types[2]->len = 24
> nf_ct_ext_types[3]->len = 32
> nf_ct_ext_types[4]->len = 152

Guess its the timer in the ecache extension (with LOCKDEP on probably).

I'll submit a patch to get rid of that shortly.

I think your patch is fine because the 'no timer
in ecache extension' change is quite large, needs review/stress testing
etc and is inapropriate for stable tree anyway.

> I have seen "len" up to 280 and my host has crashes w/o this patch.

ecache is 24 bytes without that timer, should be < 256 in total for
all extensions.

I think BUILD_BUG_ON test would be nice.


\
 
 \ /
  Last update: 2014-03-27 17:41    [W:0.047 / U:0.548 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site