For historical reasons, when bridge device is in promisc mode, packets
that are directed to the taps follow bridge input hook path. This patch
adds a workaround to reset conntrack for these packets.
Jianbo Liu reports warning splats in their test infrastructure where
cloned packets reach the br_netfilter input hook to confirm the
conntrack object.
Scratch one bit from BR_INPUT_SKB_CB to annotate that this packet has
reached the input hook because it is passed up to the bridge device to
reach the taps.
[ 57.571874] WARNING: CPU: 1 PID: 0 at net/bridge/br_netfilter_hooks.c:616 br_nf_local_in+0x157/0x180 [br_netfilter]
[ 57.572749] Modules linked in: xt_MASQUERADE nf_conntrack_netlink nfnetlink iptable_nat xt_addrtype xt_conntrack nf_nat br_netfilter rpcsec_gss_krb5 auth_rpcgss oid_registry overlay rpcrdma rdma_ucm ib_iser libiscsi scsi_transport_isc si ib_umad rdma_cm ib_ipoib iw_cm ib_cm mlx5_ib ib_uverbs ib_core mlx5ctl mlx5_core
[ 57.575158] CPU: 1 PID: 0 Comm: swapper/1 Not tainted 6.8.0+ #19
[ 57.575700] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS
rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
[ 57.576662] RIP: 0010:br_nf_local_in+0x157/0x180 [br_netfilter]
[ 57.577195] Code: fe ff ff 41 bd 04 00 00 00 be 04 00 00 00 e9 4a ff ff ff be 04 00 00 00 48 89 ef e8 f3 a9 3c e1 66 83 ad b4 00 00 00 04 eb 91 <0f> 0b e9 f1 fe ff ff 0f 0b e9 df fe ff ff 48 89 df e8 b3 53 47 e1
[ 57.578722] RSP: 0018:
ffff88885f845a08 EFLAGS:
00010202
[ 57.579207] RAX:
0000000000000002 RBX:
ffff88812dfe8000 RCX:
0000000000000000
[ 57.579830] RDX:
ffff88885f845a60 RSI:
ffff8881022dc300 RDI:
0000000000000000
[ 57.580454] RBP:
ffff88885f845a60 R08:
0000000000000001 R09:
0000000000000003
[ 57.581076] R10:
00000000ffff1300 R11:
0000000000000002 R12:
0000000000000000
[ 57.581695] R13:
ffff8881047ffe00 R14:
ffff888108dbee00 R15:
ffff88814519b800
[ 57.582313] FS:
0000000000000000(0000) GS:
ffff88885f840000(0000) knlGS:
0000000000000000
[ 57.583040] CS: 0010 DS: 0000 ES: 0000 CR0:
0000000080050033
[ 57.583564] CR2:
000000c4206aa000 CR3:
0000000103847001 CR4:
0000000000370eb0
[ 57.584194] DR0:
0000000000000000 DR1:
0000000000000000 DR2:
0000000000000000
[ 57.584820] DR3:
0000000000000000 DR6:
00000000fffe0ff0 DR7:
0000000000000400
[ 57.585440] Call Trace:
[ 57.585721] <IRQ>
[ 57.585976] ? __warn+0x7d/0x130
[ 57.586323] ? br_nf_local_in+0x157/0x180 [br_netfilter]
[ 57.586811] ? report_bug+0xf1/0x1c0
[ 57.587177] ? handle_bug+0x3f/0x70
[ 57.587539] ? exc_invalid_op+0x13/0x60
[ 57.587929] ? asm_exc_invalid_op+0x16/0x20
[ 57.588336] ? br_nf_local_in+0x157/0x180 [br_netfilter]
[ 57.588825] nf_hook_slow+0x3d/0xd0
[ 57.589188] ? br_handle_vlan+0x4b/0x110
[ 57.589579] br_pass_frame_up+0xfc/0x150
[ 57.589970] ? br_port_flags_change+0x40/0x40
[ 57.590396] br_handle_frame_finish+0x346/0x5e0
[ 57.590837] ? ipt_do_table+0x32e/0x430
[ 57.591221] ? br_handle_local_finish+0x20/0x20
[ 57.591656] br_nf_hook_thresh+0x4b/0xf0 [br_netfilter]
[ 57.592286] ? br_handle_local_finish+0x20/0x20
[ 57.592802] br_nf_pre_routing_finish+0x178/0x480 [br_netfilter]
[ 57.593348] ? br_handle_local_finish+0x20/0x20
[ 57.593782] ? nf_nat_ipv4_pre_routing+0x25/0x60 [nf_nat]
[ 57.594279] br_nf_pre_routing+0x24c/0x550 [br_netfilter]
[ 57.594780] ? br_nf_hook_thresh+0xf0/0xf0 [br_netfilter]
[ 57.595280] br_handle_frame+0x1f3/0x3d0
[ 57.595676] ? br_handle_local_finish+0x20/0x20
[ 57.596118] ? br_handle_frame_finish+0x5e0/0x5e0
[ 57.596566] __netif_receive_skb_core+0x25b/0xfc0
[ 57.597017] ? __napi_build_skb+0x37/0x40
[ 57.597418] __netif_receive_skb_list_core+0xfb/0x220
Fixes:
62e7151ae3eb ("netfilter: bridge: confirm multicast packets before passing them up the stack")
Reported-by: Jianbo Liu <jianbol@nvidia.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
return netif_receive_skb(skb);
}
-static int br_pass_frame_up(struct sk_buff *skb)
+static int br_pass_frame_up(struct sk_buff *skb, bool promisc)
{
struct net_device *indev, *brdev = BR_INPUT_SKB_CB(skb)->brdev;
struct net_bridge *br = netdev_priv(brdev);
br_multicast_count(br, NULL, skb, br_multicast_igmp_type(skb),
BR_MCAST_DIR_TX);
+ BR_INPUT_SKB_CB(skb)->promisc = promisc;
+
return NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_IN,
dev_net(indev), NULL, skb, indev, NULL,
br_netif_receive_skb);
struct net_bridge_mcast *brmctx;
struct net_bridge_vlan *vlan;
struct net_bridge *br;
+ bool promisc;
u16 vid = 0;
u8 state;
if (p->flags & BR_LEARNING)
br_fdb_update(br, p, eth_hdr(skb)->h_source, vid, 0);
- local_rcv = !!(br->dev->flags & IFF_PROMISC);
+ promisc = !!(br->dev->flags & IFF_PROMISC);
+ local_rcv = promisc;
+
if (is_multicast_ether_addr(eth_hdr(skb)->h_dest)) {
/* by definition the broadcast is also a multicast address */
if (is_broadcast_ether_addr(eth_hdr(skb)->h_dest)) {
unsigned long now = jiffies;
if (test_bit(BR_FDB_LOCAL, &dst->flags))
- return br_pass_frame_up(skb);
+ return br_pass_frame_up(skb, false);
if (now != dst->used)
dst->used = now;
}
if (local_rcv)
- return br_pass_frame_up(skb);
+ return br_pass_frame_up(skb, promisc);
out:
return 0;
goto forward;
}
+ BR_INPUT_SKB_CB(skb)->promisc = false;
+
/* The else clause should be hit when nf_hook():
* - returns < 0 (drop/error)
* - returns = 0 (stolen/nf_queue)
struct sk_buff *skb,
const struct nf_hook_state *state)
{
+ bool promisc = BR_INPUT_SKB_CB(skb)->promisc;
struct nf_conntrack *nfct = skb_nfct(skb);
const struct nf_ct_hook *ct_hook;
struct nf_conn *ct;
int ret;
+ if (promisc) {
+ nf_reset_ct(skb);
+ return NF_ACCEPT;
+ }
+
if (!nfct || skb->pkt_type == PACKET_HOST)
return NF_ACCEPT;
#endif
u8 proxyarp_replied:1;
u8 src_port_isolated:1;
+ u8 promisc:1;
#ifdef CONFIG_BRIDGE_VLAN_FILTERING
u8 vlan_filtered:1;
#endif
static unsigned int nf_ct_bridge_in(void *priv, struct sk_buff *skb,
const struct nf_hook_state *state)
{
- enum ip_conntrack_info ctinfo;
+ bool promisc = BR_INPUT_SKB_CB(skb)->promisc;
+ struct nf_conntrack *nfct = skb_nfct(skb);
struct nf_conn *ct;
- if (skb->pkt_type == PACKET_HOST)
+ if (promisc) {
+ nf_reset_ct(skb);
+ return NF_ACCEPT;
+ }
+
+ if (!nfct || skb->pkt_type == PACKET_HOST)
return NF_ACCEPT;
/* nf_conntrack_confirm() cannot handle concurrent clones,
* this happens for broad/multicast frames with e.g. macvlan on top
* of the bridge device.
*/
- ct = nf_ct_get(skb, &ctinfo);
- if (!ct || nf_ct_is_confirmed(ct) || nf_ct_is_template(ct))
+ ct = container_of(nfct, struct nf_conn, ct_general);
+ if (nf_ct_is_confirmed(ct) || nf_ct_is_template(ct))
return NF_ACCEPT;
/* let inet prerouting call conntrack again */