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 4f582ce929f2..9dda2dc6b5e7 100644 --- a/drivers/net/macvlan.c +++ b/drivers/net/macvlan.c @@ -421,6 +421,10 @@ 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;