[PATCH 4.4 06/29] net: l2tp: Make l2tp_ip6 namespace aware

From: Greg Kroah-Hartman
Date: Sat Apr 11 2020 - 08:10:55 EST


From: Shmulik Ladkani <shmulik.ladkani@xxxxxxxxx>

commit 0e6b5259824e97a0f7e7b450421ff12865d3b0e2 upstream.

l2tp_ip6 tunnel and session lookups were still using init_net, although
the l2tp core infrastructure already supports lookups keyed by 'net'.

As a result, l2tp_ip6_recv discarded packets for tunnels/sessions
created in namespaces other than the init_net.

Fix, by using dev_net(skb->dev) or sock_net(sk) where appropriate.

Signed-off-by: Shmulik Ladkani <shmulik.ladkani@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Will Deacon <will@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/l2tp/l2tp_ip6.c | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)

--- a/net/l2tp/l2tp_ip6.c
+++ b/net/l2tp/l2tp_ip6.c
@@ -127,6 +127,7 @@ static inline struct sock *l2tp_ip6_bind
*/
static int l2tp_ip6_recv(struct sk_buff *skb)
{
+ struct net *net = dev_net(skb->dev);
struct sock *sk;
u32 session_id;
u32 tunnel_id;
@@ -153,7 +154,7 @@ static int l2tp_ip6_recv(struct sk_buff
}

/* Ok, this is a data packet. Lookup the session. */
- session = l2tp_session_find(&init_net, NULL, session_id);
+ session = l2tp_session_find(net, NULL, session_id);
if (session == NULL)
goto discard;

@@ -190,7 +191,7 @@ pass_up:
goto discard;

tunnel_id = ntohl(*(__be32 *) &skb->data[4]);
- tunnel = l2tp_tunnel_find(&init_net, tunnel_id);
+ tunnel = l2tp_tunnel_find(net, tunnel_id);
if (tunnel) {
sk = tunnel->sock;
sock_hold(sk);
@@ -198,7 +199,7 @@ pass_up:
struct ipv6hdr *iph = ipv6_hdr(skb);

read_lock_bh(&l2tp_ip6_lock);
- sk = __l2tp_ip6_bind_lookup(&init_net, &iph->daddr,
+ sk = __l2tp_ip6_bind_lookup(net, &iph->daddr,
0, tunnel_id);
if (!sk) {
read_unlock_bh(&l2tp_ip6_lock);
@@ -267,6 +268,7 @@ static int l2tp_ip6_bind(struct sock *sk
struct inet_sock *inet = inet_sk(sk);
struct ipv6_pinfo *np = inet6_sk(sk);
struct sockaddr_l2tpip6 *addr = (struct sockaddr_l2tpip6 *) uaddr;
+ struct net *net = sock_net(sk);
__be32 v4addr = 0;
int addr_type;
int err;
@@ -288,7 +290,7 @@ static int l2tp_ip6_bind(struct sock *sk

err = -EADDRINUSE;
read_lock_bh(&l2tp_ip6_lock);
- if (__l2tp_ip6_bind_lookup(&init_net, &addr->l2tp_addr,
+ if (__l2tp_ip6_bind_lookup(net, &addr->l2tp_addr,
sk->sk_bound_dev_if, addr->l2tp_conn_id))
goto out_in_use;
read_unlock_bh(&l2tp_ip6_lock);
@@ -461,7 +463,7 @@ static int l2tp_ip6_backlog_recv(struct
return 0;

drop:
- IP_INC_STATS(&init_net, IPSTATS_MIB_INDISCARDS);
+ IP_INC_STATS(sock_net(sk), IPSTATS_MIB_INDISCARDS);
kfree_skb(skb);
return -1;
}