Merge tag 'net-6.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

Pull networking fixes from Jakub Kicinski:
 "Including fixes from bluetooth and netfilter.

  Current release - regressions:

   - dsa: sja1105: fix reception from VLAN-unaware bridges

   - Revert "net: stmmac: set PP_FLAG_DMA_SYNC_DEV only if XDP is
     enabled"

   - eth: fec: don't save PTP state if PTP is unsupported

  Current release - new code bugs:

   - smc: fix lack of icsk_syn_mss with IPPROTO_SMC, prevent null-deref

   - eth: airoha: update Tx CPU DMA ring idx at the end of xmit loop

   - phy: aquantia: AQR115c fix up PMA capabilities

  Previous releases - regressions:

   - tcp: 3 fixes for retrans_stamp and undo logic

  Previous releases - always broken:

   - net: do not delay dst_entries_add() in dst_release()

   - netfilter: restrict xtables extensions to families that are safe,
     syzbot found a way to combine ebtables with extensions that are
     never used by userspace tools

   - sctp: ensure sk_state is set to CLOSED if hashing fails in
     sctp_listen_start

   - mptcp: handle consistently DSS corruption, and prevent corruption
     due to large pmtu xmit"

* tag 'net-6.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (87 commits)
  MAINTAINERS: Add headers and mailing list to UDP section
  MAINTAINERS: consistently exclude wireless files from NETWORKING [GENERAL]
  slip: make slhc_remember() more robust against malicious packets
  net/smc: fix lacks of icsk_syn_mss with IPPROTO_SMC
  ppp: fix ppp_async_encode() illegal access
  docs: netdev: document guidance on cleanup patches
  phonet: Handle error of rtnl_register_module().
  mpls: Handle error of rtnl_register_module().
  mctp: Handle error of rtnl_register_module().
  bridge: Handle error of rtnl_register_module().
  vxlan: Handle error of rtnl_register_module().
  rtnetlink: Add bulk registration helpers for rtnetlink message handlers.
  net: do not delay dst_entries_add() in dst_release()
  mptcp: pm: do not remove closing subflows
  mptcp: fallback when MPTCP opts are dropped after 1st data
  tcp: fix mptcp DSS corruption due to large pmtu xmit
  mptcp: handle consistently DSS corruption
  net: netconsole: fix wrong warning
  net: dsa: refuse cross-chip mirroring operations
  net: fec: don't save PTP state if PTP is unsupported
  ...

1 files changed, 21 insertions, 3 deletions

diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index c2317919fc14..6d0e201c3eb2 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -620,6 +620,18 @@ static bool mptcp_check_data_fin(struct sock *sk)
 	return ret;
 }
 
+static void mptcp_dss_corruption(struct mptcp_sock *msk, struct sock *ssk)
+{
+	if (READ_ONCE(msk->allow_infinite_fallback)) {
+		MPTCP_INC_STATS(sock_net(ssk),
+				MPTCP_MIB_DSSCORRUPTIONFALLBACK);
+		mptcp_do_fallback(ssk);
+	} else {
+		MPTCP_INC_STATS(sock_net(ssk), MPTCP_MIB_DSSCORRUPTIONRESET);
+		mptcp_subflow_reset(ssk);
+	}
+}
+
 static bool __mptcp_move_skbs_from_subflow(struct mptcp_sock *msk,
 					   struct sock *ssk,
 					   unsigned int *bytes)
@@ -692,10 +704,16 @@ static bool __mptcp_move_skbs_from_subflow(struct mptcp_sock *msk,
 				moved += len;
 			seq += len;
 
-			if (WARN_ON_ONCE(map_remaining < len))
-				break;
+			if (unlikely(map_remaining < len)) {
+				DEBUG_NET_WARN_ON_ONCE(1);
+				mptcp_dss_corruption(msk, ssk);
+			}
 		} else {
-			WARN_ON_ONCE(!fin);
+			if (unlikely(!fin)) {
+				DEBUG_NET_WARN_ON_ONCE(1);
+				mptcp_dss_corruption(msk, ssk);
+			}
+
 			sk_eat_skb(ssk, skb);
 			done = true;
 		}