Re: Netfilter: BUG: unable to handle kernel paging request, RIP: physdev_mt+0xd6/0x160
flat view
From: Florian Westphal <fw@strlen.de>
Date: 2015-09-13 18:06:24
Subsystem:
ethernet bridge, netfilter, networking [general], the rest · Maintainers:
Nikolay Aleksandrov, Ido Schimmel, Pablo Neira Ayuso, Florian Westphal, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
Sander Eikelenboom [off-list ref] wrote:
Using a linux-4.3-rc1 kernel i encountered the splat below:
Thanks for reporting this bug.
[ 290.200642] BUG: unable to handle kernel paging request at 000000000484195d [ 290.211702] IP: [<ffffffff819bc3e6>] physdev_mt+0xd6/0x160
[..]
[ 290.444088] [<ffffffff81a4e6c0>] ipt_do_table+0x210/0x390 [ 290.461951] [<ffffffff81a510ae>] iptable_filter_hook+0x2e/0x70 [ 290.470756] [<ffffffff8199279c>] nf_iterate+0x4c/0x80 [ 290.479587] [<ffffffff81992834>] nf_hook_slow+0x64/0xc0 [ 290.488341] [<ffffffff81a06779>] ip_forward+0x369/0x3c0 [ 290.496927] [<ffffffff81a06380>] ? ip_frag_mem+0x40/0x40 [ 290.505365] [<ffffffff81a04961>] ip_rcv_finish+0x101/0x330 [ 290.513480] [<ffffffff81a05001>] ip_rcv+0x291/0x390 [ 290.521562] [<ffffffff81a04860>] ?
Aye, ip forwarding of bridged packets with call-iptables=1 is broken. Please, could you try this patch? It fixes this bug for me.
diff --git a/net/bridge/br_netfilter_hooks.c b/net/bridge/br_netfilter_hooks.c
--- a/net/bridge/br_netfilter_hooks.c
+++ b/net/bridge/br_netfilter_hooks.c@@ -355,6 +355,7 @@ static int br_nf_pre_routing_finish(struct sock *sk, struct sk_buff *skb) struct iphdr *iph = ip_hdr(skb); struct nf_bridge_info *nf_bridge = nf_bridge_info_get(skb); struct rtable *rt; + bool daddr_changed; int err; nf_bridge->frag_max_size = IPCB(skb)->frag_max_size;
@@ -363,8 +364,15 @@ static int br_nf_pre_routing_finish(struct sock *sk, struct sk_buff *skb) skb->pkt_type = PACKET_OTHERHOST; nf_bridge->pkt_otherhost = false; } + + /* set physoutdev to NULL, its set by the bridge forward hook but + * frame might be routed instead of bridged. + */ + daddr_changed = br_nf_ipv4_daddr_was_changed(skb, nf_bridge); + nf_bridge->physoutdev = NULL; nf_bridge->in_prerouting = 0; - if (br_nf_ipv4_daddr_was_changed(skb, nf_bridge)) { + + if (daddr_changed) { if ((err = ip_route_input(skb, iph->daddr, iph->saddr, iph->tos, dev))) { struct in_device *in_dev = __in_dev_get_rcu(dev);
diff --git a/net/bridge/br_netfilter_ipv6.c b/net/bridge/br_netfilter_ipv6.c
index 77383bf..772222b 100644
--- a/net/bridge/br_netfilter_ipv6.c
+++ b/net/bridge/br_netfilter_ipv6.c@@ -167,6 +167,7 @@ static int br_nf_pre_routing_finish_ipv6(struct sock *sk, struct sk_buff *skb) struct rtable *rt; struct net_device *dev = skb->dev; const struct nf_ipv6_ops *v6ops = nf_get_ipv6_ops(); + bool daddr_changed; nf_bridge->frag_max_size = IP6CB(skb)->frag_max_size;
@@ -174,8 +175,12 @@ static int br_nf_pre_routing_finish_ipv6(struct sock *sk, struct sk_buff *skb) skb->pkt_type = PACKET_OTHERHOST; nf_bridge->pkt_otherhost = false; } + + daddr_changed = br_nf_ipv6_daddr_was_changed(skb, nf_bridge); + nf_bridge->physoutdev = NULL; nf_bridge->in_prerouting = 0; - if (br_nf_ipv6_daddr_was_changed(skb, nf_bridge)) { + + if (daddr_changed) { skb_dst_drop(skb); v6ops->route_input(skb);