3.14-stable review patch. If anyone has any objections, please let me know.
------------------
From: Marcelo Leitner <mleitner@xxxxxxxxxx>
[ 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@xxxxxxxxxx>
Signed-off-by: Marcelo Ricardo Leitner <mleitner@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/net/vxlan.c | 28 ++++++++++++++++++----------
1 file changed, 18 insertions(+), 10 deletions(-)
--- a/drivers/net/vxlan.c
+++ b/drivers/net/vxlan.c
@@ -279,13 +279,15 @@ 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;
@@ -304,11 +306,12 @@ 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;
@@ -1872,7 +1875,8 @@ static void vxlan_xmit_one(struct sk_buf
struct vxlan_dev *dst_vxlan;
ip_rt_put(rt);
- dst_vxlan = vxlan_find_vni(dev_net(dev), vni, dst_port);
+ dst_vxlan = vxlan_find_vni(dev_net(dev), vni,
+ dst->sa.sa_family, dst_port);
if (!dst_vxlan)
goto tx_error;
vxlan_encap_bypass(skb, vxlan, dst_vxlan);
@@ -1925,7 +1929,8 @@ static void vxlan_xmit_one(struct sk_buf
struct vxlan_dev *dst_vxlan;
dst_release(ndst);
- dst_vxlan = vxlan_find_vni(dev_net(dev), vni, dst_port);
+ dst_vxlan = vxlan_find_vni(dev_net(dev), vni,
+ dst->sa.sa_family, dst_port);
if (!dst_vxlan)
goto tx_error;
vxlan_encap_bypass(skb, vxlan, dst_vxlan);
@@ -2083,6 +2088,7 @@ static int vxlan_init(struct net_device
{
struct vxlan_dev *vxlan = netdev_priv(dev);
struct vxlan_net *vn = net_generic(dev_net(dev), vxlan_net_id);
+ bool ipv6 = vxlan->flags & VXLAN_F_IPV6;
struct vxlan_sock *vs;
int i;
@@ -2098,7 +2104,8 @@ static int vxlan_init(struct net_device
spin_lock(&vn->sock_lock);
- vs = vxlan_find_sock(dev_net(dev), vxlan->dst_port);
+ vs = vxlan_find_sock(dev_net(dev), 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);
@@ -2566,7 +2573,7 @@ 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);
@@ -2712,7 +2719,8 @@ static int vxlan_newlink(struct net *net
if (data[IFLA_VXLAN_PORT])
vxlan->dst_port = nla_get_be16(data[IFLA_VXLAN_PORT]);
- 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;
}
--
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