[PATCH 4.11 19/88] geneve: fix hlist corruption

From: Greg Kroah-Hartman
Date: Wed Jul 19 2017 - 06:09:49 EST


4.11-stable review patch. If anyone has any objections, please let me know.

------------------

From: Jiri Benc <jbenc@xxxxxxxxxx>


[ Upstream commit 4b4c21fad6ae6bd58ff1566f23b0f4f70fdc9a30 ]

It's not a good idea to add the same hlist_node to two different hash lists.
This leads to various hard to debug memory corruptions.

Fixes: 8ed66f0e8235 ("geneve: implement support for IPv6-based tunnels")
Cc: John W. Linville <linville@xxxxxxxxxxxxx>
Signed-off-by: Jiri Benc <jbenc@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/net/geneve.c | 48 ++++++++++++++++++++++++++++++++----------------
1 file changed, 32 insertions(+), 16 deletions(-)

--- a/drivers/net/geneve.c
+++ b/drivers/net/geneve.c
@@ -45,9 +45,17 @@ struct geneve_net {

static unsigned int geneve_net_id;

+struct geneve_dev_node {
+ struct hlist_node hlist;
+ struct geneve_dev *geneve;
+};
+
/* Pseudo network device */
struct geneve_dev {
- struct hlist_node hlist; /* vni hash table */
+ struct geneve_dev_node hlist4; /* vni hash table for IPv4 socket */
+#if IS_ENABLED(CONFIG_IPV6)
+ struct geneve_dev_node hlist6; /* vni hash table for IPv6 socket */
+#endif
struct net *net; /* netns for packet i/o */
struct net_device *dev; /* netdev for geneve tunnel */
struct ip_tunnel_info info;
@@ -123,16 +131,16 @@ static struct geneve_dev *geneve_lookup(
__be32 addr, u8 vni[])
{
struct hlist_head *vni_list_head;
- struct geneve_dev *geneve;
+ struct geneve_dev_node *node;
__u32 hash;

/* Find the device for this VNI */
hash = geneve_net_vni_hash(vni);
vni_list_head = &gs->vni_list[hash];
- hlist_for_each_entry_rcu(geneve, vni_list_head, hlist) {
- if (eq_tun_id_and_vni((u8 *)&geneve->info.key.tun_id, vni) &&
- addr == geneve->info.key.u.ipv4.dst)
- return geneve;
+ hlist_for_each_entry_rcu(node, vni_list_head, hlist) {
+ if (eq_tun_id_and_vni((u8 *)&node->geneve->info.key.tun_id, vni) &&
+ addr == node->geneve->info.key.u.ipv4.dst)
+ return node->geneve;
}
return NULL;
}
@@ -142,16 +150,16 @@ static struct geneve_dev *geneve6_lookup
struct in6_addr addr6, u8 vni[])
{
struct hlist_head *vni_list_head;
- struct geneve_dev *geneve;
+ struct geneve_dev_node *node;
__u32 hash;

/* Find the device for this VNI */
hash = geneve_net_vni_hash(vni);
vni_list_head = &gs->vni_list[hash];
- hlist_for_each_entry_rcu(geneve, vni_list_head, hlist) {
- if (eq_tun_id_and_vni((u8 *)&geneve->info.key.tun_id, vni) &&
- ipv6_addr_equal(&addr6, &geneve->info.key.u.ipv6.dst))
- return geneve;
+ hlist_for_each_entry_rcu(node, vni_list_head, hlist) {
+ if (eq_tun_id_and_vni((u8 *)&node->geneve->info.key.tun_id, vni) &&
+ ipv6_addr_equal(&addr6, &node->geneve->info.key.u.ipv6.dst))
+ return node->geneve;
}
return NULL;
}
@@ -579,6 +587,7 @@ static int geneve_sock_add(struct geneve
{
struct net *net = geneve->net;
struct geneve_net *gn = net_generic(net, geneve_net_id);
+ struct geneve_dev_node *node;
struct geneve_sock *gs;
__u8 vni[3];
__u32 hash;
@@ -597,15 +606,20 @@ static int geneve_sock_add(struct geneve
out:
gs->collect_md = geneve->collect_md;
#if IS_ENABLED(CONFIG_IPV6)
- if (ipv6)
+ if (ipv6) {
rcu_assign_pointer(geneve->sock6, gs);
- else
+ node = &geneve->hlist6;
+ } else
#endif
+ {
rcu_assign_pointer(geneve->sock4, gs);
+ node = &geneve->hlist4;
+ }
+ node->geneve = geneve;

tunnel_id_to_vni(geneve->info.key.tun_id, vni);
hash = geneve_net_vni_hash(vni);
- hlist_add_head_rcu(&geneve->hlist, &gs->vni_list[hash]);
+ hlist_add_head_rcu(&node->hlist, &gs->vni_list[hash]);
return 0;
}

@@ -632,8 +646,10 @@ static int geneve_stop(struct net_device
{
struct geneve_dev *geneve = netdev_priv(dev);

- if (!hlist_unhashed(&geneve->hlist))
- hlist_del_rcu(&geneve->hlist);
+ hlist_del_init_rcu(&geneve->hlist4.hlist);
+#if IS_ENABLED(CONFIG_IPV6)
+ hlist_del_init_rcu(&geneve->hlist6.hlist);
+#endif
geneve_sock_release(geneve);
return 0;
}