commit bdd70eb689 upstream.
Such field is there to avoid acquiring the data lock in a few spots,
but it adds complexity to the already non trivial locking schema.
All the relevant call sites (mptcp-level re-injection, set socket
options), are slow-path, drop such field in favor of 'cb_flags', adding
the relevant locking.
This patch could be seen as an improvement, instead of a fix. But it
simplifies the next patch. The 'Fixes' tag has been added to help having
this series backported to stable.
Fixes: e9d09baca6 ("mptcp: avoid atomic bit manipulation when possible")
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit b6c620dc43 upstream.
When the MPTCP PM detects that a subflow is stale, all the packet
scheduler must re-inject all the mptcp-level unacked data. To avoid
acquiring unneeded locks, it first try to check if any unacked data
is present at all in the RTX queue, but such check is currently
broken, as it uses TCP-specific helper on an MPTCP socket.
Funnily enough fuzzers and static checkers are happy, as the accessed
memory still belongs to the mptcp_sock struct, and even from a
functional perspective the recovery completed successfully, as
the short-cut test always failed.
A recent unrelated TCP change - commit d5fed5addb ("tcp: reorganize
tcp_sock fast path variables") - exposed the issue, as the tcp field
reorganization makes the mptcp code always skip the re-inection.
Fix the issue dropping the bogus call: we are on a slow path, the early
optimization proved once again to be evil.
Fixes: 1e1d9d6f11 ("mptcp: handle pending data on closed subflow")
Cc: stable@vger.kernel.org
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/468
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://lore.kernel.org/r/20240131-upstream-net-20240131-mptcp-ci-issues-v1-1-4c1c11e571ff@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 14c56686a6 upstream.
When closing the first subflow, the MPTCP protocol unconditionally
calls tcp_disconnect(), which in turn generates a reset if the subflow
is established.
That is unexpected and different from what MPTCP does with MPJ
subflows, where resets are generated only on FASTCLOSE and other edge
scenarios.
We can't reuse for the first subflow the same code in place for MPJ
subflows, as MPTCP clean them up completely via a tcp_close() call,
while must keep the first subflow socket alive for later re-usage, due
to implementation constraints.
This patch adds a new helper __mptcp_subflow_disconnect() that
encapsulates, a logic similar to tcp_close, issuing a reset only when
the MPTCP_CF_FASTCLOSE flag is set, and performing a clean shutdown
otherwise.
Fixes: c2b2ae3925 ("mptcp: handle correctly disconnect() failures")
Cc: stable@vger.kernel.org
Reviewed-by: Matthieu Baerts <matttbe@kernel.org>
Co-developed-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Geliang Tang <geliang.tang@suse.com>
Signed-off-by: Mat Martineau <martineau@kernel.org>
Link: https://lore.kernel.org/r/20231018-send-net-20231018-v1-4-17ecb002e41d@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Matthieu Baerts <matttbe@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 419ce133ab ]
As reported by Tom, .NET and applications build on top of it rely
on connect(AF_UNSPEC) to async cancel pending I/O operations on TCP
socket.
The blamed commit below caused a regression, as such cancellation
can now fail.
As suggested by Eric, this change addresses the problem explicitly
causing blocking I/O operation to terminate immediately (with an error)
when a concurrent disconnect() is executed.
Instead of tracking the number of threads blocked on a given socket,
track the number of disconnect() issued on such socket. If such counter
changes after a blocking operation releasing and re-acquiring the socket
lock, error out the current operation.
Fixes: 4faeee0cf8 ("tcp: deny tcp_disconnect() when threads are waiting")
Reported-by: Tom Deseyn <tdeseyn@redhat.com>
Closes: https://bugzilla.redhat.com/show_bug.cgi?id=1886305
Suggested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/f3b95e47e3dbed840960548aebaa8d954372db41.1697008693.git.pabeni@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit a5efdbcece ]
The delegated action infrastructure is prone to the following
race: different CPUs can try to schedule different delegated
actions on the same subflow at the same time.
Each of them will check different bits via mptcp_subflow_delegate(),
and will try to schedule the action on the related per-cpu napi
instance.
Depending on the timing, both can observe an empty delegated list
node, causing the same entry to be added simultaneously on two different
lists.
The root cause is that the delegated actions infra does not provide
a single synchronization point. Address the issue reserving an additional
bit to mark the subflow as scheduled for delegation. Acquiring such bit
guarantee the caller to own the delegated list node, and being able to
safely schedule the subflow.
Clear such bit only when the subflow scheduling is completed, ensuring
proper barrier in place.
Additionally swap the meaning of the delegated_action bitmask, to allow
the usage of the existing helper to set multiple bit at once.
Fixes: bcd9773431 ("mptcp: use delegate action to schedule 3rd ack retrans")
Cc: stable@vger.kernel.org
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <martineau@kernel.org>
Link: https://lore.kernel.org/r/20231004-send-net-20231004-v1-1-28de4ac663ae@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 9f1a98813b ]
On incoming TCP reset, subflow closing could happen before error
propagation. That in turn could cause the socket error being ignored,
and a missing socket state transition, as reported by Daire-Byrne.
Address the issues explicitly checking for subflow socket error at
close time. To avoid code duplication, factor-out of __mptcp_error_report()
a new helper implementing the relevant bits.
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/429
Fixes: 15cc104533 ("mptcp: deliver ssk errors to msk")
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit d5fbeff1ab ]
This will simplify the next patch ("mptcp: process pending subflow error
on close").
No functional change intended.
Cc: stable@vger.kernel.org # v5.12+
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 9ae8e5ad99 ]
mptcp_poll() reads sk->sk_err without socket lock held/owned.
Add READ_ONCE() and WRITE_ONCE() to avoid load/store tearing.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Stable-dep-of: d5fbeff1ab ("mptcp: move __mptcp_error_report in protocol.c")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 27e5ccc2d5 ]
According to RFC 8684 section 3.3:
A connection is not closed unless [...] or an implementation-specific
connection-level send timeout.
Currently the MPTCP protocol does not implement such timeout, and
connection timing-out at the TCP-level never move to close state.
Introduces a catch-up condition at subflow close time to move the
MPTCP socket to close, too.
That additionally allows removing similar existing inside the worker.
Finally, allow some additional timeout for plain ESTABLISHED mptcp
sockets, as the protocol allows creating new subflows even at that
point and making the connection functional again.
This issue is actually present since the beginning, but it is basically
impossible to solve without a long chain of functional pre-requisites
topped by commit bbd49d114d ("mptcp: consolidate transition to
TCP_CLOSE in mptcp_do_fastclose()"). When backporting this current
patch, please also backport this other commit as well.
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/430
Fixes: e16163b6e2 ("mptcp: refactor shutdown and close")
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit f6909dc1c1 ]
The msk socket uses to different timeout to track close related
events and retransmissions. The existing helpers do not indicate
clearly which timer they actually touch, making the related code
quite confusing.
Change the existing helpers name to avoid such confusion. No
functional change intended.
This patch is linked to the next one ("mptcp: fix dangling connection
hang-up"). The two patches are supposed to be backported together.
Cc: stable@vger.kernel.org # v5.11+
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Stable-dep-of: 27e5ccc2d5 ("mptcp: fix dangling connection hang-up")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 9531e4a83f ]
msk->rmem_fwd_alloc can be read locklessly.
Add mptcp_rmem_fwd_alloc_add(), similar to sk_forward_alloc_add(),
and appropriate READ_ONCE()/WRITE_ONCE() annotations.
Fixes: 6511882cdd ("mptcp: allocate fwd memory separately on the rx and tx path")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 5e6300e7b3 ]
Every time sk->sk_forward_alloc is read locklessly,
add a READ_ONCE().
Add sk_forward_alloc_add() helper to centralize updates,
to reduce number of WRITE_ONCE().
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 17ebf8a4c3 upstream.
Coccicheck reports the error below:
net/mptcp/protocol.c:3330:15-28: ERROR: test of a variable/field address
Since the address of msk->cb_flags is used in __test_and_clear_bit, the
address should not be NULL. The judgment for if (unlikely(msk->cb_flags))
will always be true, we should check the real value of msk->cb_flags here.
Fixes: 65a569b03c ("mptcp: optimize release_cb for the common case")
Signed-off-by: Xiang Yang <xiangyang3@huawei.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Link: https://lore.kernel.org/r/20230803072438.1847500-1-xiangyang3@huawei.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit ff18f9ef30 upstream.
Since the blamed commit, the MPTCP protocol unconditionally sends
TCP resets on all the subflows on disconnect().
That fits full-blown MPTCP sockets - to implement the fastclose
mechanism - but causes unexpected corruption of the data stream,
caught as sporadic self-tests failures.
Fixes: d21f834855 ("mptcp: use fastclose on more edge scenarios")
Cc: stable@vger.kernel.org
Tested-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/419
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Link: https://lore.kernel.org/r/20230803-upstream-net-20230803-misc-fixes-6-5-v1-3-6671b1ab11cc@tessares.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 3fffa15bfe upstream.
While tacking care of the mptcp-level listener I unintentionally
moved the subflow level unhash after the subflow listener backlog
cleanup.
That could cause some nasty race and makes the code harder to read.
Address the issue restoring the proper order of operations.
Fixes: 57fc0f1cea ("mptcp: ensure listener is unhashed before updating the sk status")
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 0226436acf ]
Since the blamed commit, closing the first subflow resets the first
subflow socket state to SS_UNCONNECTED.
The current mptcp listen implementation relies only on such
state to prevent touching not-fully-disconnected sockets.
Incoming mptcp fastclose (or paired endpoint removal) unconditionally
closes the first subflow.
All the above allows an incoming fastclose followed by a listen() call
to successfully race with a blocking recvmsg(), potentially causing the
latter to hit a divide by zero bug in cleanup_rbuf/__tcp_select_window().
Address the issue explicitly checking the msk socket state in
mptcp_listen(). An alternative solution would be moving the first
subflow socket state update into mptcp_disconnect(), but in the long
term the first subflow socket should be removed: better avoid relaying
on it for internal consistency check.
Fixes: b29fcfb54c ("mptcp: full disconnect implementation")
Cc: stable@vger.kernel.org
Reported-by: Christoph Paasch <cpaasch@apple.com>
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/414
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit cfdcfeed64 ]
'sock->sk' is used frequently in mptcp_listen(). Therefore, we can
introduce the 'sk' and replace 'sock->sk' with it.
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Menglong Dong <imagedong@tencent.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Stable-dep-of: 0226436acf ("mptcp: do not rely on implicit state check in mptcp_listen()")
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 57fc0f1cea upstream.
The MPTCP protocol access the listener subflow in a lockless
manner in a couple of places (poll, diag). That works only if
the msk itself leaves the listener status only after that the
subflow itself has been closed/disconnected. Otherwise we risk
deadlock in diag, as reported by Christoph.
Address the issue ensuring that the first subflow (the listener
one) is always disconnected before updating the msk socket status.
Reported-by: Christoph Paasch <cpaasch@apple.com>
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/407
Fixes: b29fcfb54c ("mptcp: full disconnect implementation")
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 81c1d02901 upstream.
An orphaned msk releases the used resources via the worker,
when the latter first see the msk in CLOSED status.
If the msk status transitions to TCP_CLOSE in the release callback
invoked by the worker's final release_sock(), such instance of the
workqueue will not take any action.
Additionally the MPTCP code prevents scheduling the worker once the
socket reaches the CLOSE status: such msk resources will be leaked.
The only code path that can trigger the above scenario is the
__mptcp_check_send_data_fin() in fallback mode.
Address the issue removing the special handling of fallback socket
in __mptcp_check_send_data_fin(), consolidating the state machine
for fallback and non fallback socket.
Since non-fallback sockets do not send and do not receive data_fin,
the mptcp code can update the msk internal status to match the next
step in the SM every time data fin (ack) should be generated or
received.
As a consequence we can remove a bunch of checks for fallback from
the fastpath.
Fixes: 6e628cd3a8 ("mptcp: use mptcp release_cb for delayed tasks")
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 56a666c48b upstream.
At passive MPJ time, if the msk socket lock is held by the user,
the new subflow is appended to the msk->join_list under the msk
data lock.
In mptcp_release_cb()/__mptcp_flush_join_list(), the subflows in
that list are moved from the join_list into the conn_list under the
msk socket lock.
Append and removal could race, possibly corrupting such list.
Address the issue splicing the join list into a temporary one while
still under the msk data lock.
Found by code inspection, the race itself should be almost impossible
to trigger in practice.
Fixes: 3e5014909b ("mptcp: cleanup MPJ subflow list handling")
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit c2b2ae3925 upstream.
Currently the mptcp code has assumes that disconnect() can fail only
at mptcp_sendmsg_fastopen() time - to avoid a deadlock scenario - and
don't even bother returning an error code.
Soon mptcp_disconnect() will handle more error conditions: let's track
them explicitly.
As a bonus, explicitly annotate TCP-level disconnect as not failing:
the mptcp code never blocks for event on the subflows.
Fixes: 7d803344fd ("mptcp: fix deadlock in fastopen error path")
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Tested-by: Christoph Paasch <cpaasch@apple.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 55b47ca7d8 upstream.
Active subflow are inserted into the connection list at creation time.
When the MPJ handshake completes successfully, a new subflow creation
netlink event is generated correctly, but the current code wrongly
avoid initializing a couple of subflow data.
The above will cause misbehavior on a few exceptional events: unneeded
mptcp-level retransmission on msk-level sequence wrap-around and infinite
mapping fallback even when a MPJ socket is present.
Address the issue factoring out the needed initialization in a new helper
and invoking the latter from __mptcp_finish_join() time for passive
subflow and from mptcp_finish_join() for active ones.
Fixes: 0530020a7c ("mptcp: track and update contiguous data status")
Cc: stable@vger.kernel.org
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 786fc12457 upstream.
Ondrej reported a functional issue WRT timeout handling on connect
with a nice reproducer.
The problem is that the current mptcp connect waits for both the
MPTCP socket level timeout, and the first subflow socket timeout.
The latter is not influenced/touched by the exposed setsockopt().
Overall the above makes the SO_SNDTIMEO a no-op on connect.
Since mptcp_connect is invoked via inet_stream_connect and the
latter properly handle the MPTCP level timeout, we can address the
issue making the nested subflow level connect always unblocking.
This also allow simplifying a bit the code, dropping an ugly hack
to handle the fastopen and custom proto_ops connect.
The issues predates the blamed commit below, but the current resolution
requires the infrastructure introduced there.
Fixes: 54f1944ed6 ("mptcp: factor out mptcp_connect()")
Reported-by: Ondrej Mosnacek <omosnace@redhat.com>
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/399
Cc: stable@vger.kernel.org
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 6b9831bfd9 ]
Christoph reported the mptcp variant of a recently addressed plain
TCP issue. Similar to commit e14cadfd80 ("tcp: add annotations around
sk->sk_shutdown accesses") add READ/WRITE ONCE annotations to silence
KCSAN reports around lockless sk_shutdown access.
Fixes: 71ba088ce0 ("mptcp: cleanup accept and poll")
Reported-by: Christoph Paasch <cpaasch@apple.com>
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/401
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 1b1b43ee7a ]
The first subflow socket is accessed outside the msk socket lock
by mptcp_subflow_fail(), we need to annotate each write access
with WRITE_ONCE, but a few spots still lacks it.
Fixes: 76a13b3157 ("mptcp: invoke MP_FAIL response when needed")
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 7e8b88ec35 ]
When the msk socket is cloned at MPC handshake time, a few
fields are initialized in a racy way outside mptcp_sk_clone()
and the msk socket lock.
The above is due historical reasons: before commit a88d0092b2
("mptcp: simplify subflow_syn_recv_sock()") as the first subflow socket
carrying all the needed date was not available yet at msk creation
time
We can now refactor the code moving the missing initialization bit
under the socket lock, removing the init race and avoiding some
code duplication.
This will also simplify the next patch, as all msk->first write
access are now under the msk socket lock.
Fixes: 0397c6d85f ("mptcp: keep unaccepted MPC subflow into join list")
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 5b825727d0 ]
The MPTCP can access the first subflow socket in a few spots
outside the socket lock scope. That is actually safe, as MPTCP
will delete the socket itself only after the msk sock close().
Still the such accesses causes a few KCSAN splats, as reported
by Christoph. Silence the harmless warning adding a few annotation
around the relevant accesses.
Fixes: 71ba088ce0 ("mptcp: cleanup accept and poll")
Reported-by: Christoph Paasch <cpaasch@apple.com>
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/402
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 6176123169 ]
In a few spots, the mptcp code invokes the __mptcp_nmpc_socket() helper
multiple times under the same socket lock scope. Additionally, in such
places, the socket status ensures that there is no MP capable handshake
running.
Under the above condition we can replace the later __mptcp_nmpc_socket()
helper invocation with direct access to the msk->subflow pointer and
better document such access is not supposed to fail with WARN().
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Stable-dep-of: 5b825727d0 ("mptcp: add annotations around msk->subflow accesses")
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit b5fc29233d upstream.
After commit d38afeec26 ("tcp/udp: Call inet6_destroy_sock()
in IPv6 sk->sk_destruct()."), we call inet6_destroy_sock() in
sk->sk_destruct() by setting inet6_sock_destruct() to it to make
sure we do not leak inet6-specific resources.
Now we can remove unnecessary inet6_destroy_sock() calls in
sk->sk_prot->destroy().
DCCP and SCTP have their own sk->sk_destruct() function, so we
change them separately in the following patches.
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ziyang Xuan <william.xuanziyang@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 0a3f4f1f9c ]
Backports notes: one simple conflict in net/mptcp/protocol.c with:
commit f8c9dfbd87 ("mptcp: add pm listener events")
Where one commit removes code in __mptcp_close_ssk() while the other
one adds one line at the same place. We can simply remove the whole
condition because this extra instruction is not present in v6.1.
As reported by Christoph after having refactored the passive
socket initialization, the mptcp listener shutdown path is prone
to an UaF issue.
BUG: KASAN: use-after-free in _raw_spin_lock_bh+0x73/0xe0
Write of size 4 at addr ffff88810cb23098 by task syz-executor731/1266
CPU: 1 PID: 1266 Comm: syz-executor731 Not tainted 6.2.0-rc59af4eaa31c1f6c00c8f1e448ed99a45c66340dd5 #6
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl+0x6e/0x91
print_report+0x16a/0x46f
kasan_report+0xad/0x130
kasan_check_range+0x14a/0x1a0
_raw_spin_lock_bh+0x73/0xe0
subflow_error_report+0x6d/0x110
sk_error_report+0x3b/0x190
tcp_disconnect+0x138c/0x1aa0
inet_child_forget+0x6f/0x2e0
inet_csk_listen_stop+0x209/0x1060
__mptcp_close_ssk+0x52d/0x610
mptcp_destroy_common+0x165/0x640
mptcp_destroy+0x13/0x80
__mptcp_destroy_sock+0xe7/0x270
__mptcp_close+0x70e/0x9b0
mptcp_close+0x2b/0x150
inet_release+0xe9/0x1f0
__sock_release+0xd2/0x280
sock_close+0x15/0x20
__fput+0x252/0xa20
task_work_run+0x169/0x250
exit_to_user_mode_prepare+0x113/0x120
syscall_exit_to_user_mode+0x1d/0x40
do_syscall_64+0x48/0x90
entry_SYSCALL_64_after_hwframe+0x72/0xdc
The msk grace period can legitly expire in between the last
reference count dropped in mptcp_subflow_queue_clean() and
the later eventual access in inet_csk_listen_stop()
After the previous patch we don't need anymore special-casing
msk listener socket cleanup: the mptcp worker will process each
of the unaccepted msk sockets.
Just drop the now unnecessary code.
Please note this commit depends on the two parent ones:
mptcp: refactor passive socket initialization
mptcp: use the workqueue to destroy unaccepted sockets
Fixes: 6aeed90450 ("mptcp: fix race on unaccepted mptcp sockets")
Cc: stable@vger.kernel.org
Reported-and-tested-by: Christoph Paasch <cpaasch@apple.com>
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/346
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit b6985b9b82 ]
Backports notes: one simple conflict in net/mptcp/protocol.c with:
commit a5ef058dc4 ("net: introduce and use custom sockopt socket flag")
Where the two commits add a new line for different actions in the same
context in mptcp_stream_accept().
Christoph reported a UaF at token lookup time after having
refactored the passive socket initialization part:
BUG: KASAN: use-after-free in __token_bucket_busy+0x253/0x260
Read of size 4 at addr ffff88810698d5b0 by task syz-executor653/3198
CPU: 1 PID: 3198 Comm: syz-executor653 Not tainted 6.2.0-rc59af4eaa31c1f6c00c8f1e448ed99a45c66340dd5 #6
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl+0x6e/0x91
print_report+0x16a/0x46f
kasan_report+0xad/0x130
__token_bucket_busy+0x253/0x260
mptcp_token_new_connect+0x13d/0x490
mptcp_connect+0x4ed/0x860
__inet_stream_connect+0x80e/0xd90
tcp_sendmsg_fastopen+0x3ce/0x710
mptcp_sendmsg+0xff1/0x1a20
inet_sendmsg+0x11d/0x140
__sys_sendto+0x405/0x490
__x64_sys_sendto+0xdc/0x1b0
do_syscall_64+0x3b/0x90
entry_SYSCALL_64_after_hwframe+0x72/0xdc
We need to properly clean-up all the paired MPTCP-level
resources and be sure to release the msk last, even when
the unaccepted subflow is destroyed by the TCP internals
via inet_child_forget().
We can re-use the existing MPTCP_WORK_CLOSE_SUBFLOW infra,
explicitly checking that for the critical scenario: the
closed subflow is the MPC one, the msk is not accepted and
eventually going through full cleanup.
With such change, __mptcp_destroy_sock() is always called
on msk sockets, even on accepted ones. We don't need anymore
to transiently drop one sk reference at msk clone time.
Please note this commit depends on the parent one:
mptcp: refactor passive socket initialization
Fixes: 58b0991962 ("mptcp: create msk early")
Cc: stable@vger.kernel.org
Reported-and-tested-by: Christoph Paasch <cpaasch@apple.com>
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/347
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 3a236aef28 ]
After commit 30e51b923e ("mptcp: fix unreleased socket in accept queue")
unaccepted msk sockets go throu complete shutdown, we don't need anymore
to delay inserting the first subflow into the subflow lists.
The reference counting deserve some extra care, as __mptcp_close() is
unaware of the request socket linkage to the first subflow.
Please note that this is more a refactoring than a fix but because this
modification is needed to include other corrections, see the following
commits. Then a Fixes tag has been added here to help the stable team.
Fixes: 30e51b923e ("mptcp: fix unreleased socket in accept queue")
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Tested-by: Christoph Paasch <cpaasch@apple.com>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit d4e85922e3 upstream.
If the peer closes all the existing subflows for a given
mptcp socket and later the application closes it, the current
implementation let it survive until the timewait timeout expires.
While the above is allowed by the protocol specification it
consumes resources for almost no reason and additionally
causes sporadic self-tests failures.
Let's move the mptcp socket to the TCP_CLOSE state when there are
no alive subflows at close time, so that the allocated resources
will be freed immediately.
Fixes: e16163b6e2 ("mptcp: refactor shutdown and close")
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 6bc1fe7dd7 upstream.
Let the caller specify the to-be-created subflow family.
For a given MPTCP socket created with the AF_INET6 family, the current
userspace PM can already ask the kernel to create subflows in v4 and v6.
If "plain" IPv4 addresses are passed to the kernel, they are
automatically mapped in v6 addresses "by accident". This can be
problematic because the userspace will need to pass different addresses,
now the v4-mapped-v6 addresses to destroy this new subflow.
On the other hand, if the MPTCP socket has been created with the AF_INET
family, the command to create a subflow in v6 will be accepted but the
result will not be the one as expected as new subflow will be created in
IPv4 using part of the v6 addresses passed to the kernel: not creating
the expected subflow then.
No functional change intended for the in-kernel PM where an explicit
enforcement is currently in place. This arbitrary enforcement will be
leveraged by other patches in a future version.
Fixes: 702c2f646d ("mptcp: netlink: allow userspace-driven subflow establishment")
Cc: stable@vger.kernel.org
Co-developed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit fec3adfd75 ]
MattB reported a lockdep splat in the mptcp listener code cleanup:
WARNING: possible circular locking dependency detected
packetdrill/14278 is trying to acquire lock:
ffff888017d868f0 ((work_completion)(&msk->work)){+.+.}-{0:0}, at: __flush_work (kernel/workqueue.c:3069)
but task is already holding lock:
ffff888017d84130 (sk_lock-AF_INET){+.+.}-{0:0}, at: mptcp_close (net/mptcp/protocol.c:2973)
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (sk_lock-AF_INET){+.+.}-{0:0}:
__lock_acquire (kernel/locking/lockdep.c:5055)
lock_acquire (kernel/locking/lockdep.c:466)
lock_sock_nested (net/core/sock.c:3463)
mptcp_worker (net/mptcp/protocol.c:2614)
process_one_work (kernel/workqueue.c:2294)
worker_thread (include/linux/list.h:292)
kthread (kernel/kthread.c:376)
ret_from_fork (arch/x86/entry/entry_64.S:312)
-> #0 ((work_completion)(&msk->work)){+.+.}-{0:0}:
check_prev_add (kernel/locking/lockdep.c:3098)
validate_chain (kernel/locking/lockdep.c:3217)
__lock_acquire (kernel/locking/lockdep.c:5055)
lock_acquire (kernel/locking/lockdep.c:466)
__flush_work (kernel/workqueue.c:3070)
__cancel_work_timer (kernel/workqueue.c:3160)
mptcp_cancel_work (net/mptcp/protocol.c:2758)
mptcp_subflow_queue_clean (net/mptcp/subflow.c:1817)
__mptcp_close_ssk (net/mptcp/protocol.c:2363)
mptcp_destroy_common (net/mptcp/protocol.c:3170)
mptcp_destroy (include/net/sock.h:1495)
__mptcp_destroy_sock (net/mptcp/protocol.c:2886)
__mptcp_close (net/mptcp/protocol.c:2959)
mptcp_close (net/mptcp/protocol.c:2974)
inet_release (net/ipv4/af_inet.c:432)
__sock_release (net/socket.c:651)
sock_close (net/socket.c:1367)
__fput (fs/file_table.c:320)
task_work_run (kernel/task_work.c:181 (discriminator 1))
exit_to_user_mode_prepare (include/linux/resume_user_mode.h:49)
syscall_exit_to_user_mode (kernel/entry/common.c:130)
do_syscall_64 (arch/x86/entry/common.c:87)
entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:120)
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(sk_lock-AF_INET);
lock((work_completion)(&msk->work));
lock(sk_lock-AF_INET);
lock((work_completion)(&msk->work));
*** DEADLOCK ***
The report is actually a false positive, since the only existing lock
nesting is the msk socket lock acquired by the mptcp work.
cancel_work_sync() is invoked without the relevant socket lock being
held, but under a different (the msk listener) socket lock.
We could silence the splat adding a per workqueue dynamic lockdep key,
but that looks overkill. Instead just tell lockdep the msk socket lock
is not held around cancel_work_sync().
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/322
Fixes: 30e51b923e ("mptcp: fix unreleased socket in accept queue")
Reported-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 7d803344fd ]
MatM reported a deadlock at fastopening time:
INFO: task syz-executor.0:11454 blocked for more than 143 seconds.
Tainted: G S 6.1.0-rc5-03226-gdb0157db5153 #1
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.0 state:D stack:25104 pid:11454 ppid:424 flags:0x00004006
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5191 [inline]
__schedule+0x5c2/0x1550 kernel/sched/core.c:6503
schedule+0xe8/0x1c0 kernel/sched/core.c:6579
__lock_sock+0x142/0x260 net/core/sock.c:2896
lock_sock_nested+0xdb/0x100 net/core/sock.c:3466
__mptcp_close_ssk+0x1a3/0x790 net/mptcp/protocol.c:2328
mptcp_destroy_common+0x16a/0x650 net/mptcp/protocol.c:3171
mptcp_disconnect+0xb8/0x450 net/mptcp/protocol.c:3019
__inet_stream_connect+0x897/0xa40 net/ipv4/af_inet.c:720
tcp_sendmsg_fastopen+0x3dd/0x740 net/ipv4/tcp.c:1200
mptcp_sendmsg_fastopen net/mptcp/protocol.c:1682 [inline]
mptcp_sendmsg+0x128a/0x1a50 net/mptcp/protocol.c:1721
inet6_sendmsg+0x11f/0x150 net/ipv6/af_inet6.c:663
sock_sendmsg_nosec net/socket.c:714 [inline]
sock_sendmsg+0xf7/0x190 net/socket.c:734
____sys_sendmsg+0x336/0x970 net/socket.c:2476
___sys_sendmsg+0x122/0x1c0 net/socket.c:2530
__sys_sendmmsg+0x18d/0x460 net/socket.c:2616
__do_sys_sendmmsg net/socket.c:2645 [inline]
__se_sys_sendmmsg net/socket.c:2642 [inline]
__x64_sys_sendmmsg+0x9d/0x110 net/socket.c:2642
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x38/0x90 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f5920a75e7d
RSP: 002b:00007f59201e8028 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 00007f5920bb4f80 RCX: 00007f5920a75e7d
RDX: 0000000000000001 RSI: 0000000020002940 RDI: 0000000000000005
RBP: 00007f5920ae7593 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000020004050 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007f5920bb4f80 R15: 00007f59201c8000
</TASK>
In the error path, tcp_sendmsg_fastopen() ends-up calling
mptcp_disconnect(), and the latter tries to close each
subflow, acquiring the socket lock on each of them.
At fastopen time, we have a single subflow, and such subflow
socket lock is already held by the called, causing the deadlock.
We already track the 'fastopen in progress' status inside the msk
socket. Use it to address the issue, making mptcp_disconnect() a
no op when invoked from the fastopen (error) path and doing the
relevant cleanup after releasing the subflow socket lock.
While at the above, rename the fastopen status bit to something
more meaningful.
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/321
Fixes: fa9e57468a ("mptcp: fix abba deadlock on fastopen")
Reported-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
All of the subflows of a msk will be orphaned in mptcp_close(), which
means the subflows are in DEAD state. After then, DATA_FIN will be sent,
and the other side will response with a DATA_ACK for this DATA_FIN.
However, if the other side still has pending data, the data that received
on these subflows will not be passed to the msk, as they are DEAD and
subflow_data_ready() will not be called in tcp_data_ready(). Therefore,
these data can't be acked, and they will be retransmitted again and again,
until timeout.
Fix this by setting ssk->sk_socket and ssk->sk_wq to 'NULL', instead of
orphaning the subflows in __mptcp_close(), as Paolo suggested.
Fixes: e16163b6e2 ("mptcp: refactor shutdown and close")
Reviewed-by: Biao Jiang <benbjiang@tencent.com>
Reviewed-by: Mengen Sun <mengensun@tencent.com>
Signed-off-by: Menglong Dong <imagedong@tencent.com>
Reviewed-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Our CI reported lockdep splat in the fastopen code:
======================================================
WARNING: possible circular locking dependency detected
6.0.0.mptcp_f5e8bfe9878d+ #1558 Not tainted
------------------------------------------------------
packetdrill/1071 is trying to acquire lock:
ffff8881bd198140 (sk_lock-AF_INET){+.+.}-{0:0}, at: inet_wait_for_connect+0x19c/0x310
but task is already holding lock:
ffff8881b8346540 (k-sk_lock-AF_INET){+.+.}-{0:0}, at: mptcp_sendmsg+0xfdf/0x1740
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (k-sk_lock-AF_INET){+.+.}-{0:0}:
__lock_acquire+0xb6d/0x1860
lock_acquire+0x1d8/0x620
lock_sock_nested+0x37/0xd0
inet_stream_connect+0x3f/0xa0
mptcp_connect+0x411/0x800
__inet_stream_connect+0x3ab/0x800
mptcp_stream_connect+0xac/0x110
__sys_connect+0x101/0x130
__x64_sys_connect+0x6e/0xb0
do_syscall_64+0x59/0x90
entry_SYSCALL_64_after_hwframe+0x63/0xcd
-> #0 (sk_lock-AF_INET){+.+.}-{0:0}:
check_prev_add+0x15e/0x2110
validate_chain+0xace/0xdf0
__lock_acquire+0xb6d/0x1860
lock_acquire+0x1d8/0x620
lock_sock_nested+0x37/0xd0
inet_wait_for_connect+0x19c/0x310
__inet_stream_connect+0x26c/0x800
tcp_sendmsg_fastopen+0x341/0x650
mptcp_sendmsg+0x109d/0x1740
sock_sendmsg+0xe1/0x120
__sys_sendto+0x1c7/0x2a0
__x64_sys_sendto+0xdc/0x1b0
do_syscall_64+0x59/0x90
entry_SYSCALL_64_after_hwframe+0x63/0xcd
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(k-sk_lock-AF_INET);
lock(sk_lock-AF_INET);
lock(k-sk_lock-AF_INET);
lock(sk_lock-AF_INET);
*** DEADLOCK ***
1 lock held by packetdrill/1071:
#0: ffff8881b8346540 (k-sk_lock-AF_INET){+.+.}-{0:0}, at: mptcp_sendmsg+0xfdf/0x1740
======================================================
The problem is caused by the blocking inet_wait_for_connect() releasing
and re-acquiring the msk socket lock while the subflow socket lock is
still held and the MPTCP socket requires that the msk socket lock must
be acquired before the subflow socket lock.
Address the issue always invoking tcp_sendmsg_fastopen() in an
unblocking manner, and later eventually complete the blocking
__inet_stream_connect() as needed.
Fixes: d98a82a6af ("mptcp: handle defer connect in mptcp_sendmsg")
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The current MPTCP connect implementation duplicates a bit of inet
code and does not use nor provide a struct proto->connect callback,
which in turn will not fit the upcoming fastopen implementation.
Refactor such implementation to use the common helper, moving the
MPTCP-specific bits into mptcp_connect(). Additionally, avoid an
indirect call to the subflow connect callback.
Note that the fastopen call-path invokes mptcp_connect() while already
holding the subflow socket lock. Explicitly keep track of such path
via a new MPTCP-level flag and handle the locking accordingly.
Additionally, track the connect flags in a new msk field to allow
propagating them to the subflow inet_stream_connect call.
Fixes: d98a82a6af ("mptcp: handle defer connect in mptcp_sendmsg")
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The mptcp_pm_nl_get_local_id() code assumes that the msk local address
is available at that point. For passive sockets, we initialize such
address at accept() time.
Depending on the running configuration and the user-space timing, a
passive MPJ subflow can join the msk socket before accept() completes.
In such case, the PM assigns a wrong local id to the MPJ subflow
and later PM netlink operations will end-up touching the wrong/unexpected
subflow.
All the above causes sporadic self-tests failures, especially when
the host is heavy loaded.
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/308
Fixes: 01cacb00b3 ("mptcp: add netlink-based PM")
Fixes: d045b9eb95 ("mptcp: introduce implicit endpoints")
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The MPTCP data path is quite complex and hard to understend even
without some foggy comments referring to modified code and/or
completely misleading from the beginning.
Update a few of them to more accurately describing the current
status.
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Daire reported a user-space application hang-up when the
peer is forcibly closed before the data transfer completion.
The relevant application expects the peer to either
do an application-level clean shutdown or a transport-level
connection reset.
We can accommodate a such user by extending the fastclose
usage: at fd close time, if the msk socket has some unread
data, and at FIN_WAIT timeout.
Note that at MPTCP close time we must ensure that the TCP
subflows will reset: set the linger socket option to a suitable
value.
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When an mptcp socket is closed due to an incoming FASTCLOSE
option, so specific sk_err is set and later syscall will
fail usually with EPIPE.
Align the current fastclose error handling with TCP reset,
properly setting the socket error according to the current
msk state and propagating such error.
Additionally sendmsg() is currently not handling properly
the sk_err, always returning EPIPE.
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Paolo Abeni