Merge tag 'net-6.1-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

Pull networking fixes from Paolo Abeni:
 "Including fixes from bpf.

  Current release - regressions:

   - tls: fix memory leak in tls_enc_skb() and tls_sw_fallback_init()

  Previous releases - regressions:

   - bridge: fix memory leaks when changing VLAN protocol

   - dsa: make dsa_master_ioctl() see through port_hwtstamp_get() shims

   - dsa: don't leak tagger-owned storage on switch driver unbind

   - eth: mlxsw: avoid warnings when not offloaded FDB entry with IPv6
     is removed

   - eth: stmmac: ensure tx function is not running in
     stmmac_xdp_release()

   - eth: hns3: fix return value check bug of rx copybreak

  Previous releases - always broken:

   - kcm: close race conditions on sk_receive_queue

   - bpf: fix alignment problem in bpf_prog_test_run_skb()

   - bpf: fix writing offset in case of fault in
     strncpy_from_kernel_nofault

   - eth: macvlan: use built-in RCU list checking

   - eth: marvell: add sleep time after enabling the loopback bit

   - eth: octeon_ep: fix potential memory leak in octep_device_setup()

  Misc:

   - tcp: configurable source port perturb table size

   - bpf: Convert BPF_DISPATCHER to use static_call() (not ftrace)"

* tag 'net-6.1-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (51 commits)
  net: use struct_group to copy ip/ipv6 header addresses
  net: usb: smsc95xx: fix external PHY reset
  net: usb: qmi_wwan: add Telit 0x103a composition
  netdevsim: Fix memory leak of nsim_dev->fa_cookie
  tcp: configurable source port perturb table size
  l2tp: Serialize access to sk_user_data with sk_callback_lock
  net: thunderbolt: Fix error handling in tbnet_init()
  net: microchip: sparx5: Fix potential null-ptr-deref in sparx_stats_init() and sparx5_start()
  net: lan966x: Fix potential null-ptr-deref in lan966x_stats_init()
  net: dsa: don't leak tagger-owned storage on switch driver unbind
  net/x25: Fix skb leak in x25_lapb_receive_frame()
  net: ag71xx: call phylink_disconnect_phy if ag71xx_hw_enable() fail in ag71xx_open()
  bridge: switchdev: Fix memory leaks when changing VLAN protocol
  net: hns3: fix setting incorrect phy link ksettings for firmware in resetting process
  net: hns3: fix return value check bug of rx copybreak
  net: hns3: fix incorrect hw rss hash type of rx packet
  net: phy: marvell: add sleep time after enabling the loopback bit
  net: ena: Fix error handling in ena_init()
  kcm: close race conditions on sk_receive_queue
  net: ionic: Fix error handling in ionic_init_module()
  ...

1 files changed, 13 insertions, 6 deletions

diff --git a/net/l2tp/l2tp_core.c b/net/l2tp/l2tp_core.c
index 7499c51b1850..754fdda8a5f5 100644
--- a/net/l2tp/l2tp_core.c
+++ b/net/l2tp/l2tp_core.c
@@ -1150,8 +1150,10 @@ static void l2tp_tunnel_destruct(struct sock *sk)
 	}
 
 	/* Remove hooks into tunnel socket */
+	write_lock_bh(&sk->sk_callback_lock);
 	sk->sk_destruct = tunnel->old_sk_destruct;
 	sk->sk_user_data = NULL;
+	write_unlock_bh(&sk->sk_callback_lock);
 
 	/* Call the original destructor */
 	if (sk->sk_destruct)
@@ -1469,16 +1471,18 @@ int l2tp_tunnel_register(struct l2tp_tunnel *tunnel, struct net *net,
 		sock = sockfd_lookup(tunnel->fd, &ret);
 		if (!sock)
 			goto err;
-
-		ret = l2tp_validate_socket(sock->sk, net, tunnel->encap);
-		if (ret < 0)
-			goto err_sock;
 	}
 
+	sk = sock->sk;
+	write_lock(&sk->sk_callback_lock);
+
+	ret = l2tp_validate_socket(sk, net, tunnel->encap);
+	if (ret < 0)
+		goto err_sock;
+
 	tunnel->l2tp_net = net;
 	pn = l2tp_pernet(net);
 
-	sk = sock->sk;
 	sock_hold(sk);
 	tunnel->sock = sk;
 
@@ -1504,7 +1508,7 @@ int l2tp_tunnel_register(struct l2tp_tunnel *tunnel, struct net *net,
 
 		setup_udp_tunnel_sock(net, sock, &udp_cfg);
 	} else {
-		sk->sk_user_data = tunnel;
+		rcu_assign_sk_user_data(sk, tunnel);
 	}
 
 	tunnel->old_sk_destruct = sk->sk_destruct;
@@ -1518,6 +1522,7 @@ int l2tp_tunnel_register(struct l2tp_tunnel *tunnel, struct net *net,
 	if (tunnel->fd >= 0)
 		sockfd_put(sock);
 
+	write_unlock(&sk->sk_callback_lock);
 	return 0;
 
 err_sock:
@@ -1525,6 +1530,8 @@ err_sock:
 		sock_release(sock);
 	else
 		sockfd_put(sock);
+
+	write_unlock(&sk->sk_callback_lock);
 err:
 	return ret;
 }