Merge tag 'net-6.16-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netHEADmaster

Pull networking fixes from Jakub Kicinski:
 "Including fixes from Bluetooth, CAN, WiFi and Netfilter.

  More code here than I would have liked. That said, better now than
  next week. Nothing particularly scary stands out. The improvement to
  the OpenVPN input validation is a bit large but better get them in
  before the code makes it to a final release. Some of the changes we
  got from sub-trees could have been split better between the fix and
  -next refactoring, IMHO, that has been communicated.

  We have one known regression in a TI AM65 board not getting link. The
  investigation is going a bit slow, a number of people are on vacation.
  We'll try to wrap it up, but don't think it should hold up the
  release.

  Current release - fix to a fix:

   - Bluetooth: L2CAP: fix attempting to adjust outgoing MTU, it broke
     some headphones and speakers

  Current release - regressions:

   - wifi: ath12k: fix packets received in WBM error ring with REO LUT
     enabled, fix Rx performance regression

   - wifi: iwlwifi:
       - fix crash due to a botched indexing conversion
       - mask reserved bits in chan_state_active_bitmap, avoid FW assert()

  Current release - new code bugs:

   - nf_conntrack: fix crash due to removal of uninitialised entry

   - eth: airoha: fix potential UaF in airoha_npu_get()

  Previous releases - regressions:

   - net: fix segmentation after TCP/UDP fraglist GRO

   - af_packet: fix the SO_SNDTIMEO constraint not taking effect and a
     potential soft lockup waiting for a completion

   - rpl: fix UaF in rpl_do_srh_inline() for sneaky skb geometry

   - virtio-net: fix recursive rtnl_lock() during probe()

   - eth: stmmac: populate entire system_counterval_t in get_time_fn()

   - eth: libwx: fix a number of crashes in the driver Rx path

   - hv_netvsc: prevent IPv6 addrconf after IFF_SLAVE lost that meaning

  Previous releases - always broken:

   - mptcp: fix races in handling connection fallback to pure TCP

   - rxrpc: assorted error handling and race fixes

   - sched: another batch of "security" fixes for qdiscs (QFQ, HTB)

   - tls: always refresh the queue when reading sock, avoid UaF

   - phy: don't register LEDs for genphy, avoid deadlock

   - Bluetooth: btintel: check if controller is ISO capable on
     btintel_classify_pkt_type(), work around FW returning incorrect
     capabilities

  Misc:

   - make OpenVPN Netlink input checking more strict before it makes it
     to a final release

   - wifi: cfg80211: remove scan request n_channels __counted_by, it's
     only yielding false positives"

* tag 'net-6.16-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (66 commits)
  rxrpc: Fix to use conn aborts for conn-wide failures
  rxrpc: Fix transmission of an abort in response to an abort
  rxrpc: Fix notification vs call-release vs recvmsg
  rxrpc: Fix recv-recv race of completed call
  rxrpc: Fix irq-disabled in local_bh_enable()
  selftests/tc-testing: Test htb_dequeue_tree with deactivation and row emptying
  net/sched: Return NULL when htb_lookup_leaf encounters an empty rbtree
  net: bridge: Do not offload IGMP/MLD messages
  selftests: Add test cases for vlan_filter modification during runtime
  net: vlan: fix VLAN 0 refcount imbalance of toggling filtering during runtime
  tls: always refresh the queue when reading sock
  virtio-net: fix recursived rtnl_lock() during probe()
  net/mlx5: Update the list of the PCI supported devices
  hv_netvsc: Set VF priv_flags to IFF_NO_ADDRCONF before open to prevent IPv6 addrconf
  phonet/pep: Move call to pn_skb_get_dst_sockaddr() earlier in pep_sock_accept()
  Bluetooth: L2CAP: Fix attempting to adjust outgoing MTU
  netfilter: nf_conntrack: fix crash due to removal of uninitialised entry
  net: fix segmentation after TCP/UDP fraglist GRO
  ipv6: mcast: Delay put pmc->idev in mld_del_delrec()
  net: airoha: fix potential use-after-free in airoha_npu_get()
  ...

1 files changed, 22 insertions, 7 deletions

diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index 3dd11dd3ba16e..6ec245fd2778e 100644
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -346,10 +346,16 @@ struct mptcp_sock {
 		u64	rtt_us; /* last maximum rtt of subflows */
 	} rcvq_space;
 	u8		scaling_ratio;
+	bool		allow_subflows;
 
 	u32		subflow_id;
 	u32		setsockopt_seq;
 	char		ca_name[TCP_CA_NAME_MAX];
+
+	spinlock_t	fallback_lock;	/* protects fallback,
+					 * allow_infinite_fallback and
+					 * allow_join
+					 */
 };
 
 #define mptcp_data_lock(sk) spin_lock_bh(&(sk)->sk_lock.slock)
@@ -1216,15 +1222,22 @@ static inline bool mptcp_check_fallback(const struct sock *sk)
 	return __mptcp_check_fallback(msk);
 }
 
-static inline void __mptcp_do_fallback(struct mptcp_sock *msk)
+static inline bool __mptcp_try_fallback(struct mptcp_sock *msk)
 {
 	if (__mptcp_check_fallback(msk)) {
 		pr_debug("TCP fallback already done (msk=%p)\n", msk);
-		return;
+		return true;
 	}
-	if (WARN_ON_ONCE(!READ_ONCE(msk->allow_infinite_fallback)))
-		return;
+	spin_lock_bh(&msk->fallback_lock);
+	if (!msk->allow_infinite_fallback) {
+		spin_unlock_bh(&msk->fallback_lock);
+		return false;
+	}
+
+	msk->allow_subflows = false;
 	set_bit(MPTCP_FALLBACK_DONE, &msk->flags);
+	spin_unlock_bh(&msk->fallback_lock);
+	return true;
 }
 
 static inline bool __mptcp_has_initial_subflow(const struct mptcp_sock *msk)
@@ -1236,14 +1249,15 @@ static inline bool __mptcp_has_initial_subflow(const struct mptcp_sock *msk)
 			TCPF_SYN_RECV | TCPF_LISTEN));
 }
 
-static inline void mptcp_do_fallback(struct sock *ssk)
+static inline bool mptcp_try_fallback(struct sock *ssk)
 {
 	struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);
 	struct sock *sk = subflow->conn;
 	struct mptcp_sock *msk;
 
 	msk = mptcp_sk(sk);
-	__mptcp_do_fallback(msk);
+	if (!__mptcp_try_fallback(msk))
+		return false;
 	if (READ_ONCE(msk->snd_data_fin_enable) && !(ssk->sk_shutdown & SEND_SHUTDOWN)) {
 		gfp_t saved_allocation = ssk->sk_allocation;
 
@@ -1255,6 +1269,7 @@ static inline void mptcp_do_fallback(struct sock *ssk)
 		tcp_shutdown(ssk, SEND_SHUTDOWN);
 		ssk->sk_allocation = saved_allocation;
 	}
+	return true;
 }
 
 #define pr_fallback(a) pr_debug("%s:fallback to TCP (msk=%p)\n", __func__, a)
@@ -1264,7 +1279,7 @@ static inline void mptcp_subflow_early_fallback(struct mptcp_sock *msk,
 {
 	pr_fallback(msk);
 	subflow->request_mptcp = 0;
-	__mptcp_do_fallback(msk);
+	WARN_ON_ONCE(!__mptcp_try_fallback(msk));
 }
 
 static inline bool mptcp_check_infinite_map(struct sk_buff *skb)