[PATCH net 0/6] mptcp: fixes for 6.4

[Matthieu Baerts]

Patch 1 correctly handles disconnect() failures that can happen in some
specific cases: now the socket state is set as unconnected as expected.
That fixes an issue introduced in v6.2.

Patch 2 fixes a divide by zero bug in mptcp_recvmsg() with a fix similar
to a recent one from Eric Dumazet for TCP introducing sk_wait_pending
flag. It should address an issue present in MPTCP from almost the
beginning, from v5.9.

Patch 3 fixes a possible list corruption on passive MPJ even if the race
seems very unlikely, better be safe than sorry. The possible issue is
present from v5.17.

Patch 4 consolidates fallback and non fallback state machines to avoid
leaking some MPTCP sockets. The fix is likely needed for versions from
v5.11.

Patch 5 drops code that is no longer used after the introduction of
patch 4/6. This is not really a fix but this patch can probably land in
the -net tree as well not to leave unused code.

Patch 6 ensures listeners are unhashed before updating their sk status
to avoid possible deadlocks when diag info are going to be retrieved
with a lock. Even if it should not be visible with the way we are
currently getting diag info, the issue is present from v5.17.

Signed-off-by: Matthieu Baerts <matthieu.baerts@xxxxxxxxxxxx>
---
Paolo Abeni (6):
      mptcp: handle correctly disconnect() failures
      mptcp: fix possible divide by zero in recvmsg()
      mptcp: fix possible list corruption on passive MPJ
      mptcp: consolidate fallback and non fallback state machine
      mptcp: drop legacy code around RX EOF
      mptcp: ensure listener is unhashed before updating the sk status

 net/mptcp/pm_netlink.c |   1 +
 net/mptcp/protocol.c   | 160 ++++++++++++++++++++-----------------------------
 net/mptcp/protocol.h   |   5 +-
 net/mptcp/subflow.c    |  17 +++---
 4 files changed, 76 insertions(+), 107 deletions(-)
---
base-commit: 9a43827e876c9a071826cc81783aa2222b020f1d
change-id: 20230620-upstream-net-20230620-misc-fixes-for-v6-4-55ef43802324

Best regards,
-- 
Matthieu Baerts <matthieu.baerts@xxxxxxxxxxxx>