From: Andrey Vagin Date: Fri, 28 Mar 2014 09:54:32 +0000 (+0400) Subject: netfilter: nf_conntrack: reserve two bytes for nf_ct_ext->len X-Git-Tag: v3.2.69~46 X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?p=pandora-kernel.git;a=commitdiff_plain;h=33eedfe8ecbaabcdc38be63901cb2b79e3190fda netfilter: nf_conntrack: reserve two bytes for nf_ct_ext->len commit 223b02d923ecd7c84cf9780bb3686f455d279279 upstream. "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 Signed-off-by: Ben Hutchings --- diff --git a/include/net/netfilter/nf_conntrack_extend.h b/include/net/netfilter/nf_conntrack_extend.h index 2dcf31703acb..d9180742ebb7 100644 --- a/include/net/netfilter/nf_conntrack_extend.h +++ b/include/net/netfilter/nf_conntrack_extend.h @@ -33,8 +33,8 @@ 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]; };