| From f6b56c835d60a45418b624a306dfe1d23190c858 Mon Sep 17 00:00:00 2001 |
| From: Sasha Levin <sashal@kernel.org> |
| Date: Tue, 26 May 2020 14:27:51 +0200 |
| Subject: macvlan: Skip loopback packets in RX handler |
| |
| From: Alexander Sverdlin <alexander.sverdlin@nokia.com> |
| |
| [ Upstream commit 81f3dc9349ce0bf7b8447f147f45e70f0a5b36a6 ] |
| |
| Ignore loopback-originatig packets soon enough and don't try to process L2 |
| header where it doesn't exist. The very similar br_handle_frame() in bridge |
| code performs exactly the same check. |
| |
| This is an example of such ICMPv6 packet: |
| |
| skb len=96 headroom=40 headlen=96 tailroom=56 |
| mac=(40,0) net=(40,40) trans=80 |
| shinfo(txflags=0 nr_frags=0 gso(size=0 type=0 segs=0)) |
| csum(0xae2e9a2f ip_summed=1 complete_sw=0 valid=0 level=0) |
| hash(0xc97ebd88 sw=1 l4=1) proto=0x86dd pkttype=5 iif=24 |
| dev name=etha01.212 feat=0x0x0000000040005000 |
| skb headroom: 00000000: 00 7c 86 52 84 88 ff ff 00 00 00 00 00 00 08 00 |
| skb headroom: 00000010: 45 00 00 9e 5d 5c 40 00 40 11 33 33 00 00 00 01 |
| skb headroom: 00000020: 02 40 43 80 00 00 86 dd |
| skb linear: 00000000: 60 09 88 bd 00 38 3a ff fe 80 00 00 00 00 00 00 |
| skb linear: 00000010: 00 40 43 ff fe 80 00 00 ff 02 00 00 00 00 00 00 |
| skb linear: 00000020: 00 00 00 00 00 00 00 01 86 00 61 00 40 00 00 2d |
| skb linear: 00000030: 00 00 00 00 00 00 00 00 03 04 40 e0 00 00 01 2c |
| skb linear: 00000040: 00 00 00 78 00 00 00 00 fd 5f 42 68 23 87 a8 81 |
| skb linear: 00000050: 00 00 00 00 00 00 00 00 01 01 02 40 43 80 00 00 |
| skb tailroom: 00000000: ... |
| skb tailroom: 00000010: ... |
| skb tailroom: 00000020: ... |
| skb tailroom: 00000030: ... |
| |
| Call Trace, how it happens exactly: |
| ... |
| macvlan_handle_frame+0x321/0x425 [macvlan] |
| ? macvlan_forward_source+0x110/0x110 [macvlan] |
| __netif_receive_skb_core+0x545/0xda0 |
| ? enqueue_task_fair+0xe5/0x8e0 |
| ? __netif_receive_skb_one_core+0x36/0x70 |
| __netif_receive_skb_one_core+0x36/0x70 |
| process_backlog+0x97/0x140 |
| net_rx_action+0x1eb/0x350 |
| ? __hrtimer_run_queues+0x136/0x2e0 |
| __do_softirq+0xe3/0x383 |
| do_softirq_own_stack+0x2a/0x40 |
| </IRQ> |
| do_softirq.part.4+0x4e/0x50 |
| netif_rx_ni+0x60/0xd0 |
| dev_loopback_xmit+0x83/0xf0 |
| ip6_finish_output2+0x575/0x590 [ipv6] |
| ? ip6_cork_release.isra.1+0x64/0x90 [ipv6] |
| ? __ip6_make_skb+0x38d/0x680 [ipv6] |
| ? ip6_output+0x6c/0x140 [ipv6] |
| ip6_output+0x6c/0x140 [ipv6] |
| ip6_send_skb+0x1e/0x60 [ipv6] |
| rawv6_sendmsg+0xc4b/0xe10 [ipv6] |
| ? proc_put_long+0xd0/0xd0 |
| ? rw_copy_check_uvector+0x4e/0x110 |
| ? sock_sendmsg+0x36/0x40 |
| sock_sendmsg+0x36/0x40 |
| ___sys_sendmsg+0x2b6/0x2d0 |
| ? proc_dointvec+0x23/0x30 |
| ? addrconf_sysctl_forward+0x8d/0x250 [ipv6] |
| ? dev_forward_change+0x130/0x130 [ipv6] |
| ? _raw_spin_unlock+0x12/0x30 |
| ? proc_sys_call_handler.isra.14+0x9f/0x110 |
| ? __call_rcu+0x213/0x510 |
| ? get_max_files+0x10/0x10 |
| ? trace_hardirqs_on+0x2c/0xe0 |
| ? __sys_sendmsg+0x63/0xa0 |
| __sys_sendmsg+0x63/0xa0 |
| do_syscall_64+0x6c/0x1e0 |
| entry_SYSCALL_64_after_hwframe+0x49/0xbe |
| |
| Signed-off-by: Alexander Sverdlin <alexander.sverdlin@nokia.com> |
| Signed-off-by: David S. Miller <davem@davemloft.net> |
| Signed-off-by: Sasha Levin <sashal@kernel.org> |
| --- |
| drivers/net/macvlan.c | 4 ++++ |
| 1 file changed, 4 insertions(+) |
| |
| diff --git a/drivers/net/macvlan.c b/drivers/net/macvlan.c |
| index 225bfc808112..349123592af0 100644 |
| --- a/drivers/net/macvlan.c |
| +++ b/drivers/net/macvlan.c |
| @@ -451,6 +451,10 @@ static rx_handler_result_t macvlan_handle_frame(struct sk_buff **pskb) |
| int ret; |
| rx_handler_result_t handle_res; |
| |
| + /* Packets from dev_loopback_xmit() do not have L2 header, bail out */ |
| + if (unlikely(skb->pkt_type == PACKET_LOOPBACK)) |
| + return RX_HANDLER_PASS; |
| + |
| port = macvlan_port_get_rcu(skb->dev); |
| if (is_multicast_ether_addr(eth->h_dest)) { |
| unsigned int hash; |
| -- |
| 2.25.1 |
| |
