| Message ID | CAJZOPZL9h0q3iiN7Q2jJWW+uEs0EpNaWqVMqQMyL+-5QGxGWPg@mail.gmail.com |
|---|---|
| State | RFC, archived |
| Delegated to: | David Miller |
| Headers | show |
From: Or Gerlitz <or.gerlitz@gmail.com> Date: Sun, 23 Mar 2014 16:43:52 +0200 > On Sun, Mar 23, 2014 at 11:27 AM, Mike Rapoport > <mike.rapoport@ravellosystems.com> wrote: > >> I believe I've groked what's going on in vxlan_udp_encap_recv and >> vxlan_rcv. There are actually two unrelated problems: >> >> 1) When the vxlan is configured with IPv4 group it crashes when it >> starts to receive IPv6 IGMP packets encapsulated into IPv4 vxlan >> packets. This happens because when ipv6_rcv handles the inner packet, >> the skb->dst still refernces outer IPv4 info. The very old vxlan code >> had skb_dst_drop call in vxlan_udp_encap_recv, which was removed when >> vxlan was refactored to use iptunnel_pull_header (commit >> 7ce04758279514ca1d8ebfe322508a4a430fe2c8: "vxlan: Restructure vxlan >> receive"). The iptunnel_pull_header called skb_dst_drop until recent >> commit 10ddceb22bab11dab10ba645c7df2e4a8e7a5db5 ("ip_tunnel:multicast >> process cause panic due to skb->_skb_refdst NULL pointer"). >> The simplest fix, I think, would be to restore call to skb_dst_drop in >> vxlan_udp_encap_recv. > > Yep, following Mike's suggestion, adding the below call allows things to work, > where trying vxlan without OVS, e.g using > > $ ip link add vxlan42 type vxlan id 42 group 239.0.0.42 ttl 10 dev ethN > > $ ifconfig vxlan42 192.168.42.54/24 up > > over the net tree with 3.14-rc6 and beyond crashes instantly on node A > when node B is > taken up and starts sending, so commit 10ddceb22b indeed introduced a > regression. It turns out we are going to partially revert that commit and iptunnel_pull_header() will start doing the skb_dst_drop() again. See: http://patchwork.ozlabs.org/patch/332956/ for details. Will that fix this bug too? Thanks. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c index a7eb3f2..22d7484 100644 --- a/drivers/net/vxlan.c +++ b/drivers/net/vxlan.c @@ -1150,6 +1150,8 @@ static int vxlan_udp_encap_recv(struct sock *sk, struct sk_buff *skb) if (iptunnel_pull_header(skb, VXLAN_HLEN, htons(ETH_P_TEB))) goto drop; + skb_dst_drop(skb); + port = inet_sk(sk)->inet_sport;