From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrey Vagin Subject: [PATCH] netfilter: nf_conntrack: reserve two bytes for nf_ct_ext->len Date: Thu, 27 Mar 2014 19:32:34 +0400 Message-ID: <1395934354-13226-1-git-send-email-avagin@openvz.org> Cc: netfilter-devel@vger.kernel.org, netfilter@vger.kernel.org, coreteam@netfilter.org, netdev@vger.kernel.org, vvs@parallels.com, Andrey Vagin , Pablo Neira Ayuso , Patrick McHardy , Jozsef Kadlecsik , "David S. Miller" To: linux-kernel@vger.kernel.org Return-path: Sender: netfilter-owner@vger.kernel.org List-Id: netfilter-devel.vger.kernel.org "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. Cc: Pablo Neira Ayuso Cc: Patrick McHardy Cc: Jozsef Kadlecsik Cc: "David S. Miller" Signed-off-by: Andrey Vagin --- include/net/netfilter/nf_conntrack_extend.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/net/netfilter/nf_conntrack_extend.h b/include/net/netfilter/nf_conntrack_extend.h index 956b175..36fd6bf 100644 --- a/include/net/netfilter/nf_conntrack_extend.h +++ b/include/net/netfilter/nf_conntrack_extend.h @@ -48,7 +48,7 @@ enum nf_ct_ext_id { struct nf_ct_ext { struct rcu_head rcu; u8 offset[NF_CT_EXT_NUM]; - u8 len; + u16 len; char data[0]; }; -- 1.8.5.3