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From: Pablo Neira Ayuso <>
Subject: [PATCH 1/5] netfilter: bridge: Drops IPv6 packets if IPv6 module is not loaded
Date: Wed,  4 Sep 2019 21:36:42 +0200
Message-ID: <> (raw)
In-Reply-To: <>

From: Leonardo Bras <>

A kernel panic can happen if a host has disabled IPv6 on boot and have to
process guest packets (coming from a bridge) using it's ip6tables.

IPv6 packets need to be dropped if the IPv6 module is not loaded, and the
host ip6tables will be used.

Signed-off-by: Leonardo Bras <>
Acked-by: Florian Westphal <>
Signed-off-by: Pablo Neira Ayuso <>
 net/bridge/br_netfilter_hooks.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/net/bridge/br_netfilter_hooks.c b/net/bridge/br_netfilter_hooks.c
index d3f9592f4ff8..af7800103e51 100644
--- a/net/bridge/br_netfilter_hooks.c
+++ b/net/bridge/br_netfilter_hooks.c
@@ -496,6 +496,10 @@ static unsigned int br_nf_pre_routing(void *priv,
 		if (!brnet->call_ip6tables &&
 		    !br_opt_get(br, BROPT_NF_CALL_IP6TABLES))
 			return NF_ACCEPT;
+		if (!ipv6_mod_enabled()) {
+			pr_warn_once("Module ipv6 is disabled, so call_ip6tables is not supported.");
+			return NF_DROP;
+		}
 		return br_nf_pre_routing_ipv6(priv, skb, state);

  reply index

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-09-04 19:36 [PATCH 0/5] Netfilter fixes for net Pablo Neira Ayuso
2019-09-04 19:36 ` Pablo Neira Ayuso [this message]
2019-09-04 19:36 ` [PATCH 2/5] netfilter: nft_socket: fix erroneous socket assignment Pablo Neira Ayuso
2019-09-04 19:36 ` [PATCH 3/5] netfilter: nft_fib_netdev: Terminate rule eval if protocol=IPv6 and ipv6 module is disabled Pablo Neira Ayuso
2019-09-04 19:36 ` [PATCH 4/5] netfilter: ctnetlink: honor IPS_OFFLOAD flag Pablo Neira Ayuso
2019-09-04 19:36 ` [PATCH 5/5] netfilter: nf_flow_table: set default timeout after successful insertion Pablo Neira Ayuso
2019-09-04 22:04 ` [PATCH 0/5] Netfilter fixes for net David Miller

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