path: root/net/bridge
diff options
authorPablo Neira Ayuso <pablo@netfilter.org>2015-05-14 14:57:23 +0200
committerPablo Neira Ayuso <pablo@netfilter.org>2015-05-15 20:14:07 +0200
commit55917a21d0cc012bb6073bb05bb768fd51d8e237 (patch)
treee484cdbbe6bac4e5b4921117635356a1dfc1bc6d /net/bridge
parent12b7ed29bdea2d6dde58f304321d4e8ca453f13c (diff)
netfilter: x_tables: add context to know if extension runs from nft_compat
Currently, we have four xtables extensions that cannot be used from the xt over nft compat layer. The problem is that they need real access to the full blown xt_entry to validate that the rule comes with the right dependencies. This check was introduced to overcome the lack of sufficient userspace dependency validation in iptables. To resolve this problem, this patch introduces a new field to the xt_tgchk_param structure that tell us if the extension is run from nft_compat context. The three affected extensions are: 1) CLUSTERIP, this target has been superseded by xt_cluster. So just bail out by returning -EINVAL. 2) TCPMSS. Relax the checking when used from nft_compat. If used with the wrong configuration, it will corrupt !syn packets by adding TCP MSS option. 3) ebt_stp. Relax the check to make sure it uses the reserved destination MAC address for STP. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Tested-by: Arturo Borrero Gonzalez <arturo.borrero.glez@gmail.com>
Diffstat (limited to 'net/bridge')
1 files changed, 4 insertions, 2 deletions
diff --git a/net/bridge/netfilter/ebt_stp.c b/net/bridge/netfilter/ebt_stp.c
index 071d87214dde..0c40570069ba 100644
--- a/net/bridge/netfilter/ebt_stp.c
+++ b/net/bridge/netfilter/ebt_stp.c
@@ -164,8 +164,10 @@ static int ebt_stp_mt_check(const struct xt_mtchk_param *par)
!(info->bitmask & EBT_STP_MASK))
return -EINVAL;
/* Make sure the match only receives stp frames */
- if (!ether_addr_equal(e->destmac, bridge_ula) ||
- !ether_addr_equal(e->destmsk, msk) || !(e->bitmask & EBT_DESTMAC))
+ if (!par->nft_compat &&
+ (!ether_addr_equal(e->destmac, bridge_ula) ||
+ !ether_addr_equal(e->destmsk, msk) ||
+ !(e->bitmask & EBT_DESTMAC)))
return -EINVAL;
return 0;

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