Merge tag 'net-6.0-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

Pull networking fixes from Paolo Abeni:
 "Including fixes from bluetooth, bpf and wireless.

  Current release - regressions:

   - bpf:
      - fix wrong last sg check in sk_msg_recvmsg()
      - fix kernel BUG in purge_effective_progs()

   - mac80211:
      - fix possible leak in ieee80211_tx_control_port()
      - potential NULL dereference in ieee80211_tx_control_port()

  Current release - new code bugs:

   - nfp: fix the access to management firmware hanging

  Previous releases - regressions:

   - ip: fix triggering of 'icmp redirect'

   - sched: tbf: don't call qdisc_put() while holding tree lock

   - bpf: fix corrupted packets for XDP_SHARED_UMEM

   - bluetooth: hci_sync: fix suspend performance regression

   - micrel: fix probe failure

  Previous releases - always broken:

   - tcp: make global challenge ack rate limitation per net-ns and
     default disabled

   - tg3: fix potential hang-up on system reboot

   - mac802154: fix reception for no-daddr packets

  Misc:

   - r8152: add PID for the lenovo onelink+ dock"

* tag 'net-6.0-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (56 commits)
  net/smc: Remove redundant refcount increase
  Revert "sch_cake: Return __NET_XMIT_STOLEN when consuming enqueued skb"
  tcp: make global challenge ack rate limitation per net-ns and default disabled
  tcp: annotate data-race around challenge_timestamp
  net: dsa: hellcreek: Print warning only once
  ip: fix triggering of 'icmp redirect'
  sch_cake: Return __NET_XMIT_STOLEN when consuming enqueued skb
  selftests: net: sort .gitignore file
  Documentation: networking: correct possessive "its"
  kcm: fix strp_init() order and cleanup
  mlxbf_gige: compute MDIO period based on i1clk
  ethernet: rocker: fix sleep in atomic context bug in neigh_timer_handler
  net: lan966x: improve error handle in lan966x_fdma_rx_get_frame()
  nfp: fix the access to management firmware hanging
  net: phy: micrel: Make the GPIO to be non-exclusive
  net: virtio_net: fix notification coalescing comments
  net/sched: fix netdevice reference leaks in attach_default_qdiscs()
  net: sched: tbf: don't call qdisc_put() while holding tree lock
  net: Use u64_stats_fetch_begin_irq() for stats fetch.
  net: dsa: xrs700x: Use irqsave variant for u64 stats update
  ...

1 files changed, 11 insertions, 10 deletions

diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index ab5f0ea166f1..b85a9f755da4 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -3614,12 +3614,9 @@ bool tcp_oow_rate_limited(struct net *net, const struct sk_buff *skb,
 /* RFC 5961 7 [ACK Throttling] */
 static void tcp_send_challenge_ack(struct sock *sk)
 {
-	/* unprotected vars, we dont care of overwrites */
-	static u32 challenge_timestamp;
-	static unsigned int challenge_count;
 	struct tcp_sock *tp = tcp_sk(sk);
 	struct net *net = sock_net(sk);
-	u32 count, now;
+	u32 count, now, ack_limit;
 
 	/* First check our per-socket dupack rate limit. */
 	if (__tcp_oow_rate_limited(net,
@@ -3627,18 +3624,22 @@ static void tcp_send_challenge_ack(struct sock *sk)
 				   &tp->last_oow_ack_time))
 		return;
 
+	ack_limit = READ_ONCE(net->ipv4.sysctl_tcp_challenge_ack_limit);
+	if (ack_limit == INT_MAX)
+		goto send_ack;
+
 	/* Then check host-wide RFC 5961 rate limit. */
 	now = jiffies / HZ;
-	if (now != challenge_timestamp) {
-		u32 ack_limit = READ_ONCE(net->ipv4.sysctl_tcp_challenge_ack_limit);
+	if (now != READ_ONCE(net->ipv4.tcp_challenge_timestamp)) {
 		u32 half = (ack_limit + 1) >> 1;
 
-		challenge_timestamp = now;
-		WRITE_ONCE(challenge_count, half + prandom_u32_max(ack_limit));
+		WRITE_ONCE(net->ipv4.tcp_challenge_timestamp, now);
+		WRITE_ONCE(net->ipv4.tcp_challenge_count, half + prandom_u32_max(ack_limit));
 	}
-	count = READ_ONCE(challenge_count);
+	count = READ_ONCE(net->ipv4.tcp_challenge_count);
 	if (count > 0) {
-		WRITE_ONCE(challenge_count, count - 1);
+		WRITE_ONCE(net->ipv4.tcp_challenge_count, count - 1);
+send_ack:
 		NET_INC_STATS(net, LINUX_MIB_TCPCHALLENGEACK);
 		tcp_send_ack(sk);
 	}