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geneve: avoid using stale geneve socket.

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This patch is similar to earlier vxlan patch.
Geneve device close operation frees geneve socket. This
operation can race with geneve-xmit function which
dereferences geneve socket. Following patch uses RCU
mechanism to avoid this situation.

Signed-off-by: Pravin B Shelar <pshelar@ovn.org>
Acked-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
pravin shelar 2016-10-28 09:59:16 -07:00 committed by David S. Miller
parent c6fcc4fc5f
commit fceb9c3e38
1 changed files with 34 additions and 11 deletions
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45
drivers/net/geneve.c
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@ -58,9 +58,9 @@ struct geneve_dev {
struct hlist_node hlist; /* vni hash table */
struct net *net; /* netns for packet i/o */
struct net_device *dev; /* netdev for geneve tunnel */
struct geneve_sock *sock4; /* IPv4 socket used for geneve tunnel */
struct geneve_sock __rcu *sock4; /* IPv4 socket used for geneve tunnel */
#if IS_ENABLED(CONFIG_IPV6)
struct geneve_sock *sock6; /* IPv6 socket used for geneve tunnel */
struct geneve_sock __rcu *sock6; /* IPv6 socket used for geneve tunnel */
#endif
u8 vni[3]; /* virtual network ID for tunnel */
u8 ttl; /* TTL override */
@ -543,9 +543,19 @@ static void __geneve_sock_release(struct geneve_sock *gs)
static void geneve_sock_release(struct geneve_dev *geneve)
{
__geneve_sock_release(geneve->sock4);
struct geneve_sock *gs4 = rtnl_dereference(geneve->sock4);
#if IS_ENABLED(CONFIG_IPV6)
__geneve_sock_release(geneve->sock6);
struct geneve_sock *gs6 = rtnl_dereference(geneve->sock6);
rcu_assign_pointer(geneve->sock6, NULL);
#endif
rcu_assign_pointer(geneve->sock4, NULL);
synchronize_net();
__geneve_sock_release(gs4);
#if IS_ENABLED(CONFIG_IPV6)
__geneve_sock_release(gs6);
#endif
}
@ -586,10 +596,10 @@ out:
gs->flags = geneve->flags;
#if IS_ENABLED(CONFIG_IPV6)
if (ipv6)
geneve->sock6 = gs;
rcu_assign_pointer(geneve->sock6, gs);
else
#endif
geneve->sock4 = gs;
rcu_assign_pointer(geneve->sock4, gs);
hash = geneve_net_vni_hash(geneve->vni);
hlist_add_head_rcu(&geneve->hlist, &gs->vni_list[hash]);
@ -603,9 +613,7 @@ static int geneve_open(struct net_device *dev)
bool metadata = geneve->collect_md;
int ret = 0;
geneve->sock4 = NULL;
#if IS_ENABLED(CONFIG_IPV6)
geneve->sock6 = NULL;
if (ipv6 || metadata)
ret = geneve_sock_add(geneve, true);
#endif
@ -720,6 +728,9 @@ static struct rtable *geneve_get_v4_rt(struct sk_buff *skb,
struct rtable *rt = NULL;
__u8 tos;
if (!rcu_dereference(geneve->sock4))
return ERR_PTR(-EIO);
memset(fl4, 0, sizeof(*fl4));
fl4->flowi4_mark = skb->mark;
fl4->flowi4_proto = IPPROTO_UDP;
@ -772,11 +783,15 @@ static struct dst_entry *geneve_get_v6_dst(struct sk_buff *skb,
{
bool use_cache = ip_tunnel_dst_cache_usable(skb, info);
struct geneve_dev *geneve = netdev_priv(dev);
struct geneve_sock *gs6 = geneve->sock6;
struct dst_entry *dst = NULL;
struct dst_cache *dst_cache;
struct geneve_sock *gs6;
__u8 prio;
gs6 = rcu_dereference(geneve->sock6);
if (!gs6)
return ERR_PTR(-EIO);
memset(fl6, 0, sizeof(*fl6));
fl6->flowi6_mark = skb->mark;
fl6->flowi6_proto = IPPROTO_UDP;
@ -842,7 +857,7 @@ static netdev_tx_t geneve_xmit_skb(struct sk_buff *skb, struct net_device *dev,
struct ip_tunnel_info *info)
{
struct geneve_dev *geneve = netdev_priv(dev);
struct geneve_sock *gs4 = geneve->sock4;
struct geneve_sock *gs4;
struct rtable *rt = NULL;
const struct iphdr *iip; /* interior IP header */
int err = -EINVAL;
@ -853,6 +868,10 @@ static netdev_tx_t geneve_xmit_skb(struct sk_buff *skb, struct net_device *dev,
bool xnet = !net_eq(geneve->net, dev_net(geneve->dev));
u32 flags = geneve->flags;
gs4 = rcu_dereference(geneve->sock4);
if (!gs4)
goto tx_error;
if (geneve->collect_md) {
if (unlikely(!info || !(info->mode & IP_TUNNEL_INFO_TX))) {
netdev_dbg(dev, "no tunnel metadata\n");
@ -932,9 +951,9 @@ static netdev_tx_t geneve6_xmit_skb(struct sk_buff *skb, struct net_device *dev,
struct ip_tunnel_info *info)
{
struct geneve_dev *geneve = netdev_priv(dev);
struct geneve_sock *gs6 = geneve->sock6;
struct dst_entry *dst = NULL;
const struct iphdr *iip; /* interior IP header */
struct geneve_sock *gs6;
int err = -EINVAL;
struct flowi6 fl6;
__u8 prio, ttl;
@ -943,6 +962,10 @@ static netdev_tx_t geneve6_xmit_skb(struct sk_buff *skb, struct net_device *dev,
bool xnet = !net_eq(geneve->net, dev_net(geneve->dev));
u32 flags = geneve->flags;
gs6 = rcu_dereference(geneve->sock6);
if (!gs6)
goto tx_error;
if (geneve->collect_md) {
if (unlikely(!info || !(info->mode & IP_TUNNEL_INFO_TX))) {
netdev_dbg(dev, "no tunnel metadata\n");