Merge tag 'net-6.0-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

Pull networking fixes from Paolo Abeni:
 "Including fixes from rxrpc, netfilter, wireless and bluetooth
  subtrees.

  Current release - regressions:

   - skb: export skb drop reaons to user by TRACE_DEFINE_ENUM

   - bluetooth: fix regression preventing ACL packet transmission

  Current release - new code bugs:

   - dsa: microchip: fix kernel oops on ksz8 switches

   - dsa: qca8k: fix NULL pointer dereference for
     of_device_get_match_data

  Previous releases - regressions:

   - netfilter: clean up hook list when offload flags check fails

   - wifi: mt76: fix crash in chip reset fail

   - rxrpc: fix ICMP/ICMP6 error handling

   - ice: fix DMA mappings leak

   - i40e: fix kernel crash during module removal

  Previous releases - always broken:

   - ipv6: sr: fix out-of-bounds read when setting HMAC data.

   - tcp: TX zerocopy should not sense pfmemalloc status

   - sch_sfb: don't assume the skb is still around after
     enqueueing to child

   - netfilter: drop dst references before setting

   - wifi: wilc1000: fix DMA on stack objects

   - rxrpc: fix an insufficiently large sglist in
     rxkad_verify_packet_2()

   - fec: use a spinlock to guard `fep->ptp_clk_on`

  Misc:

   - usb: qmi_wwan: add Quectel RM520N"

* tag 'net-6.0-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (50 commits)
  sch_sfb: Also store skb len before calling child enqueue
  net: phy: lan87xx: change interrupt src of link_up to comm_ready
  net/smc: Fix possible access to freed memory in link clear
  net: ethernet: mtk_eth_soc: check max allowed hash in mtk_ppe_check_skb
  net: skb: export skb drop reaons to user by TRACE_DEFINE_ENUM
  net: ethernet: mtk_eth_soc: fix typo in __mtk_foe_entry_clear
  net: dsa: felix: access QSYS_TAG_CONFIG under tas_lock in vsc9959_sched_speed_set
  net: dsa: felix: disable cut-through forwarding for frames oversized for tc-taprio
  net: dsa: felix: tc-taprio intervals smaller than MTU should send at least one packet
  net: usb: qmi_wwan: add Quectel RM520N
  net: dsa: qca8k: fix NULL pointer dereference for of_device_get_match_data
  tcp: fix early ETIMEDOUT after spurious non-SACK RTO
  stmmac: intel: Simplify intel_eth_pci_remove()
  net: mvpp2: debugfs: fix memory leak when using debugfs_lookup()
  ipv6: sr: fix out-of-bounds read when setting HMAC data.
  bonding: accept unsolicited NA message
  bonding: add all node mcast address when slave up
  bonding: use unspecified address if no available link local address
  wifi: use struct_group to copy addresses
  wifi: mac80211_hwsim: check length for virtio packets
  ...

1 files changed, 18 insertions, 7 deletions

diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index b85a9f755da4..bc2ea12221f9 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -2513,6 +2513,21 @@ static inline bool tcp_may_undo(const struct tcp_sock *tp)
 	return tp->undo_marker && (!tp->undo_retrans || tcp_packet_delayed(tp));
 }
 
+static bool tcp_is_non_sack_preventing_reopen(struct sock *sk)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+
+	if (tp->snd_una == tp->high_seq && tcp_is_reno(tp)) {
+		/* Hold old state until something *above* high_seq
+		 * is ACKed. For Reno it is MUST to prevent false
+		 * fast retransmits (RFC2582). SACK TCP is safe. */
+		if (!tcp_any_retrans_done(sk))
+			tp->retrans_stamp = 0;
+		return true;
+	}
+	return false;
+}
+
 /* People celebrate: "We love our President!" */
 static bool tcp_try_undo_recovery(struct sock *sk)
 {
@@ -2535,14 +2550,8 @@ static bool tcp_try_undo_recovery(struct sock *sk)
 	} else if (tp->rack.reo_wnd_persist) {
 		tp->rack.reo_wnd_persist--;
 	}
-	if (tp->snd_una == tp->high_seq && tcp_is_reno(tp)) {
-		/* Hold old state until something *above* high_seq
-		 * is ACKed. For Reno it is MUST to prevent false
-		 * fast retransmits (RFC2582). SACK TCP is safe. */
-		if (!tcp_any_retrans_done(sk))
-			tp->retrans_stamp = 0;
+	if (tcp_is_non_sack_preventing_reopen(sk))
 		return true;
-	}
 	tcp_set_ca_state(sk, TCP_CA_Open);
 	tp->is_sack_reneg = 0;
 	return false;
@@ -2578,6 +2587,8 @@ static bool tcp_try_undo_loss(struct sock *sk, bool frto_undo)
 			NET_INC_STATS(sock_net(sk),
 					LINUX_MIB_TCPSPURIOUSRTOS);
 		inet_csk(sk)->icsk_retransmits = 0;
+		if (tcp_is_non_sack_preventing_reopen(sk))
+			return true;
 		if (frto_undo || tcp_is_sack(tp)) {
 			tcp_set_ca_state(sk, TCP_CA_Open);
 			tp->is_sack_reneg = 0;