On 18/03/2020 00:39, Pablo Neira Ayuso wrote:
> From: wenxu <wenxu@xxxxxxxxx>
>
> This patch support both ipv4 and ipv6 tunnel_id, tunnel_src and
> tunnel_dst match for flowtable offload
>
> Signed-off-by: wenxu <wenxu@xxxxxxxxx>
> Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
<snip>
> static int nf_flow_rule_match(struct nf_flow_match *match,
> - const struct flow_offload_tuple *tuple)
> + const struct flow_offload_tuple *tuple,
> + struct dst_entry *other_dst)
> {
> struct nf_flow_key *mask = &match->mask;
> struct nf_flow_key *key = &match->key;
> + struct ip_tunnel_info *tun_info;
>
> NF_FLOW_DISSECTOR(match, FLOW_DISSECTOR_KEY_META, meta);
> NF_FLOW_DISSECTOR(match, FLOW_DISSECTOR_KEY_CONTROL, control);
> @@ -42,6 +92,11 @@ static int nf_flow_rule_match(struct nf_flow_match *match,
> NF_FLOW_DISSECTOR(match, FLOW_DISSECTOR_KEY_TCP, tcp);
> NF_FLOW_DISSECTOR(match, FLOW_DISSECTOR_KEY_PORTS, tp);
>
> + if (other_dst->lwtstate) {
I'm hitting a NULL dereference here, in a non-tunnel-related conntrack offload test:
tc qdisc add dev rh0vr0 ingress
tc qdisc add dev rh0 ingress
tc filter add dev rh0 parent ffff: protocol arp flower action mirred egress redirect dev rh0vr0
tc filter add dev rh0 parent ffff: protocol ip flower ip_proto icmp action mirred egress redirect dev rh0vr0
tc filter add dev rh0 parent ffff: chain 0 flower ct_state -trk action ct zone 1 pipe action goto chain 1
tc filter add dev rh0 parent ffff: chain 1 flower ct_state +trk+new action ct zone 1 commit pipe action mirred egress redirect dev rh0vr0
tc filter add dev rh0 parent ffff: chain 1 flower ct_state +trk+est skip_hw action mirred egress redirect dev rh0vr0
tc filter add dev rh0vr0 parent ffff: protocol arp flower action mirred egress redirect dev rh0
tc filter add dev rh0vr0 parent ffff: protocol ip flower ip_proto icmp action mirred egress redirect dev rh0
tc filter add dev rh0vr0 parent ffff: chain 0 flower ct_state -trk action ct zone 1 pipe action goto chain 1
tc filter add dev rh0vr0 parent ffff: chain 1 flower ct_state +trk+est skip_hw action mirred egress redirect dev rh0
{Open a TCP connection with 'nc'...}
[ 113.864770] BUG: kernel NULL pointer dereference, address: 0000000000000050
[ 113.867223] #PF: supervisor read access in kernel mode
[ 113.868859] #PF: error_code(0x0000) - not-present page
[ 113.870495] PGD 8000000119f82067 P4D 8000000119f82067 PUD 16ea1c067 PMD 0
[ 113.872565] Oops: 0000 [#1] SMP PTI
[ 113.873781] CPU: 0 PID: 269 Comm: kworker/0:4 Tainted: G OE 5.6.0-rc5+ #47
[ 113.876337] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.12.0-33-g43f5df79-dirty-20190916_042048-n551jm 04/01/2014
[ 113.879839] Workqueue: events flow_offload_work_handler [nf_flow_table]
[ 113.881835] RIP: 0010:nf_flow_offload_rule_alloc.isra.21+0xc4/0x3c0 [nf_flow_table]
[ 113.884287] Code: 48 89 50 10 44 89 e8 48 89 7b 04 83 f0 01 bf 64 00 00 00 66 89 4b 36 48 98 66 89 73 2c 66 89 7b 0c 48 c1 e0 06 49 8b 44 04 38 <48> 8b 48 50 48 85 c9 0f 84 c4 00 00 00 f6 41 79 01 0f 84 ba 00 00
[ 113.889680] RSP: 0018:ffffa7a8c012fdb0 EFLAGS: 00010202
[ 113.891336] RAX: 0000000000000000 RBX: ffff9bd02ea16800 RCX: 0000000000000000
[ 113.893466] RDX: ffff9bd02ea16840 RSI: 0000000000000060 RDI: 0000000000000064
[ 113.895596] RBP: ffffa7a8c012fde0 R08: 0000000000031180 R09: ffff9bd02e884000
[ 113.897729] R10: ffffa7a8c012fe00 R11: fefefefefefefeff R12: ffff9bd02ee51840
[ 113.899854] R13: 0000000000000000 R14: 0000000000000000 R15: ffff9bcfd9f96e40
[ 113.901982] FS: 0000000000000000(0000) GS:ffff9bd032c00000(0000) knlGS:0000000000000000
[ 113.904534] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 113.908800] CR2: 0000000000000050 CR3: 000000016ef7e000 CR4: 0000000000000ef0
[ 113.910931] Call Trace:
[ 113.911896] ? flow_offload_work_handler+0x1e9/0x2e0 [nf_flow_table]
[ 113.913841] ? __switch_to_asm+0x34/0x70
[ 113.915167] flow_offload_work_handler+0x1e9/0x2e0 [nf_flow_table]
[ 113.917063] ? __switch_to_asm+0x34/0x70
[ 113.918392] ? __switch_to_asm+0x40/0x70
[ 113.919717] ? __switch_to+0x7a/0x3b0
[ 113.920975] ? __switch_to_asm+0x34/0x70
[ 113.922300] process_one_work+0x197/0x390
[ 113.923650] worker_thread+0x30/0x390
[ 113.924912] ? process_one_work+0x390/0x390
[ 113.926299] kthread+0x113/0x130
[ 113.927453] ? kthread_park+0x90/0x90
[ 113.928710] ret_from_fork+0x35/0x40
>From matching up the Code: line, it appears that %rax is other_dst;
the faulting instruction is "mov 0x50(%rax),%rcx".
IOW other_dst == NULL.
-ed
> + tun_info = lwt_tun_info(other_dst->lwtstate);
> + nf_flow_rule_lwt_match(match, tun_info);
> + }
> +
> key->meta.ingress_ifindex = tuple->iifidx;
> mask->meta.ingress_ifindex = 0xffffffff;
>
> @@ -480,6 +535,7 @@ nf_flow_offload_rule_alloc(struct net *net,
> const struct flow_offload *flow = offload->flow;
> const struct flow_offload_tuple *tuple;
> struct nf_flow_rule *flow_rule;
> + struct dst_entry *other_dst;
> int err = -ENOMEM;
>
> flow_rule = kzalloc(sizeof(*flow_rule), GFP_KERNEL);
> @@ -495,7 +551,8 @@ nf_flow_offload_rule_alloc(struct net *net,
> flow_rule->rule->match.key = &flow_rule->match.key;
>
> tuple = &flow->tuplehash[dir].tuple;
> - err = nf_flow_rule_match(&flow_rule->match, tuple);
> + other_dst = flow->tuplehash[!dir].tuple.dst_cache;
> + err = nf_flow_rule_match(&flow_rule->match, tuple, other_dst);
> if (err < 0)
> goto err_flow_match;
>
