[PATCH mptcp-net v2 0/4] mptcp: fix duplicate subflow creation

[Paolo Abeni <pabeni@redhat.com>]

As reported by Mat, the in kernel PM can, in some edge scenarios,
unexpectedly create multiple subflows with the same local and remote
address.

The real fix is implemented by patch 4/4 with some more accurate check
at subflow creation time.

Patches 1-3 are roughly optional pre-requisities, added to avoid
introducing more data-races with the actual fix. Patch 1/4 is a bit
debatable, as it changes the existing ULP API, but I could not find a
better solution and there is some similar prior art:
commit 0df48c26d841 ("tcp: add tcpi_bytes_acked to tcp_info")

This address feedback from Mat on v1, see the patches changelog for 
the details (no changes in patch 1/4).

Paolo Abeni (4):
  mptcp: fix lockless access in subflow ULP diag
  mptcp: fix data races on local_id
  mptcp: fix data races on remote_id
  mptcp: fix duplicate subflow creation

 include/net/tcp.h        |  2 +-
 net/mptcp/diag.c         |  8 +++++--
 net/mptcp/pm_netlink.c   | 45 +++++++++++++++++++++-------------------
 net/mptcp/pm_userspace.c |  2 +-
 net/mptcp/protocol.c     |  2 +-
 net/mptcp/protocol.h     | 15 +++++++++++---
 net/mptcp/subflow.c      | 15 +++++++-------
 net/tls/tls_main.c       |  2 +-
 8 files changed, 54 insertions(+), 37 deletions(-)

-- 
2.43.0