[PATCH 3.17 010/141] vxlan: Do not reuse sockets for a different address family

Greg Kroah-Hartman
2014-11-19T22:42:28Z

From: Marcelo Leitner <mleitner@redhat.com>

[ Upstream commit 19ca9fc1445b76b60d34148f7ff837b055f5dcf3 ]

Currently, we only match against local port number in order to reuse
socket. But if this new vxlan wants an IPv6 socket and a IPv4 one bound
to that port, vxlan will reuse an IPv4 socket as IPv6 and a panic will
follow. The following steps reproduce it:

# ip link add vxlan6 type vxlan id 42 group 229.10.10.10 \
srcport 5000 6000 dev eth0
# ip link add vxlan7 type vxlan id 43 group ff0e::110 \
srcport 5000 6000 dev eth0
# ip link set vxlan6 up
# ip link set vxlan7 up
<panic>

[ 4.187481] BUG: unable to handle kernel NULL pointer dereference at 0000000000000058
...
[ 4.188076] Call Trace:
[ 4.188085] [<ffffffff81667c4a>] ? ipv6_sock_mc_join+0x3a/0x630
[ 4.188098] [<ffffffffa05a6ad6>] vxlan_igmp_join+0x66/0xd0 [vxlan]
[ 4.188113] [<ffffffff810a3430>] process_one_work+0x220/0x710
[ 4.188125] [<ffffffff810a33c4>] ? process_one_work+0x1b4/0x710
[ 4.188138] [<ffffffff810a3a3b>] worker_thread+0x11b/0x3a0
[ 4.188149] [<ffffffff810a3920>] ? process_one_work+0x710/0x710

So address family must also match in order to reuse a socket.

Reported-by: Jean-Tsung Hsiao <jhsiao@redhat.com>
Signed-off-by: Marcelo Ricardo Leitner <mleitner@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/net/vxlan.c | 29 +++++++++++++++++++----------
1 file changed, 19 insertions(+), 10 deletions(-)

--- a/drivers/net/vxlan.c
+++ b/drivers/net/vxlan.c
@@ -274,13 +274,15 @@ static inline struct vxlan_rdst *first_r
return list_first_entry(&fdb->remotes, struct vxlan_rdst, list);
}

-/* Find VXLAN socket based on network namespace and UDP port */
-static struct vxlan_sock *vxlan_find_sock(struct net *net, __be16 port)
+/* Find VXLAN socket based on network namespace, address family and UDP port */
+static struct vxlan_sock *vxlan_find_sock(struct net *net,
+ sa_family_t family, __be16 port)
{
struct vxlan_sock *vs;

hlist_for_each_entry_rcu(vs, vs_head(net, port), hlist) {
- if (inet_sk(vs->sock->sk)->inet_sport == port)
+ if (inet_sk(vs->sock->sk)->inet_sport == port &&
+ inet_sk(vs->sock->sk)->sk.sk_family == family)
return vs;
}
return NULL;
@@ -299,11 +301,12 @@ static struct vxlan_dev *vxlan_vs_find_v
}

/* Look up VNI in a per net namespace table */
-static struct vxlan_dev *vxlan_find_vni(struct net *net, u32 id, __be16 port)
+static struct vxlan_dev *vxlan_find_vni(struct net *net, u32 id,
+ sa_family_t family, __be16 port)
{
struct vxlan_sock *vs;

- vs = vxlan_find_sock(net, port);
+ vs = vxlan_find_sock(net, family, port);
if (!vs)
return NULL;

@@ -1822,7 +1825,8 @@ static void vxlan_xmit_one(struct sk_buf
struct vxlan_dev *dst_vxlan;

ip_rt_put(rt);
- dst_vxlan = vxlan_find_vni(vxlan->net, vni, dst_port);
+ dst_vxlan = vxlan_find_vni(vxlan->net, vni,
+ dst->sa.sa_family, dst_port);
if (!dst_vxlan)
goto tx_error;
vxlan_encap_bypass(skb, vxlan, dst_vxlan);
@@ -1876,7 +1880,8 @@ static void vxlan_xmit_one(struct sk_buf
struct vxlan_dev *dst_vxlan;

dst_release(ndst);
- dst_vxlan = vxlan_find_vni(vxlan->net, vni, dst_port);
+ dst_vxlan = vxlan_find_vni(vxlan->net, vni,
+ dst->sa.sa_family, dst_port);
if (!dst_vxlan)
goto tx_error;
vxlan_encap_bypass(skb, vxlan, dst_vxlan);
@@ -2036,13 +2041,15 @@ static int vxlan_init(struct net_device
struct vxlan_dev *vxlan = netdev_priv(dev);
struct vxlan_net *vn = net_generic(vxlan->net, vxlan_net_id);
struct vxlan_sock *vs;
+ bool ipv6 = vxlan->flags & VXLAN_F_IPV6;

dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
if (!dev->tstats)
return -ENOMEM;

spin_lock(&vn->sock_lock);
- vs = vxlan_find_sock(vxlan->net, vxlan->dst_port);
+ vs = vxlan_find_sock(vxlan->net, ipv6 ? AF_INET6 : AF_INET,
+ vxlan->dst_port);
if (vs) {
/* If we have a socket with same port already, reuse it */
atomic_inc(&vs->refcnt);
@@ -2441,6 +2448,7 @@ struct vxlan_sock *vxlan_sock_add(struct
{
struct vxlan_net *vn = net_generic(net, vxlan_net_id);
struct vxlan_sock *vs;
+ bool ipv6 = flags & VXLAN_F_IPV6;

vs = vxlan_socket_create(net, port, rcv, data, flags);
if (!IS_ERR(vs))
@@ -2450,7 +2458,7 @@ struct vxlan_sock *vxlan_sock_add(struct
return vs;

spin_lock(&vn->sock_lock);
- vs = vxlan_find_sock(net, port);
+ vs = vxlan_find_sock(net, ipv6 ? AF_INET6 : AF_INET, port);
if (vs) {
if (vs->rcv == rcv)
atomic_inc(&vs->refcnt);
@@ -2609,7 +2617,8 @@ static int vxlan_newlink(struct net *net
nla_get_u8(data[IFLA_VXLAN_UDP_ZERO_CSUM6_RX]))
vxlan->flags |= VXLAN_F_UDP_ZERO_CSUM6_RX;

- if (vxlan_find_vni(net, vni, vxlan->dst_port)) {
+ if (vxlan_find_vni(net, vni, use_ipv6 ? AF_INET6 : AF_INET,
+ vxlan->dst_port)) {
pr_info("duplicate VNI %u\n", vni);
return -EEXIST;
}