From 223b02d923ecd7c84cf9780bb3686f455d279279 Mon Sep 17 00:00:00 2001 From: Andrey Vagin Date: Fri, 28 Mar 2014 13:54:32 +0400 Subject: [PATCH] netfilter: nf_conntrack: reserve two bytes for nf_ct_ext->len "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 nf_ct_ext_types[5]->len = 2 nf_ct_ext_types[6]->len = 16 nf_ct_ext_types[7]->len = 8 I have seen "len" up to 280 and my host has crashes w/o this patch. The right way to fix this problem is reducing the size of the ecache extension (4) and Florian is going to do this, but these changes will be quite large to be appropriate for a stable tree. Fixes: 5b423f6a40a0 (netfilter: nf_conntrack: fix racy timer handling with reliable) Cc: Pablo Neira Ayuso Cc: Patrick McHardy Cc: Jozsef Kadlecsik Cc: "David S. Miller" Signed-off-by: Andrey Vagin Signed-off-by: Pablo Neira Ayuso --- include/net/netfilter/nf_conntrack_extend.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/include/net/netfilter/nf_conntrack_extend.h b/include/net/netfilter/nf_conntrack_extend.h index 956b175523ffa..55d15049ab2fd 100644 --- a/include/net/netfilter/nf_conntrack_extend.h +++ b/include/net/netfilter/nf_conntrack_extend.h @@ -47,8 +47,8 @@ enum nf_ct_ext_id { /* Extensions: optional stuff which isn't permanently in struct. */ struct nf_ct_ext { struct rcu_head rcu; - u8 offset[NF_CT_EXT_NUM]; - u8 len; + u16 offset[NF_CT_EXT_NUM]; + u16 len; char data[0]; };