Commit Graph

573 Commits

Author SHA1 Message Date
Paolo Abeni
59701b1870 mptcp: minor move_skbs_to_msk() cleanup
Such function is called only by __mptcp_data_ready(), which in turn
is always invoked when msk is not owned by the user: we can drop the
redundant, related check.

Additionally mptcp needs to propagate the socket error only for
current subflow.

Reviewed-by: Geliang Tang <geliang@kernel.org>
Tested-by: Geliang Tang <geliang@kernel.org>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250927-net-next-mptcp-rcv-path-imp-v1-7-5da266aa9c1a@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-29 18:23:36 -07:00
Paolo Abeni
68c7af988b mptcp: factor out a basic skb coalesce helper
The upcoming patch will introduced backlog processing for MPTCP
socket, and we want to leverage coalescing in such data path.

Factor out the relevant bits not touching memory accounting to
deal with such use-case.

Co-developed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Geliang Tang <geliang@kernel.org>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250927-net-next-mptcp-rcv-path-imp-v1-6-5da266aa9c1a@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-29 18:23:35 -07:00
Paolo Abeni
c4ebc4ee4e mptcp: remove unneeded mptcp_move_skb()
Since commit b7535cfed2 ("mptcp: drop legacy code around RX EOF"),
sk_shutdown can't change during the main recvmsg loop, we can drop
the related race breaker.

Reviewed-by: Geliang Tang <geliang@kernel.org>
Tested-by: Geliang Tang <geliang@kernel.org>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250927-net-next-mptcp-rcv-path-imp-v1-5-5da266aa9c1a@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-29 18:23:35 -07:00
Paolo Abeni
9a0afe0db4 mptcp: introduce the mptcp_init_skb helper
Factor out all the skb initialization step in a new helper and
use it. Note that this change moves the MPTCP CB initialization
earlier: we can do such step as soon as the skb leaves the
subflow socket receive queues.

Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Geliang Tang <geliang@kernel.org>
Tested-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250927-net-next-mptcp-rcv-path-imp-v1-4-5da266aa9c1a@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-29 18:23:35 -07:00
Paolo Abeni
e118cdc34d mptcp: rcvbuf auto-tuning improvement
Apply to the MPTCP auto-tuning the same improvements introduced for the
TCP protocol by the merge commit 2da35e4b4d ("Merge branch
'tcp-receive-side-improvements'").

The main difference is that TCP subflow and the main MPTCP socket need
to account separately for OoO: MPTCP does not care for TCP-level OoO
and vice versa, as a consequence do not reflect MPTCP-level rcvbuf
increase due to OoO packets at the subflow level.

This refeactor additionally allow dropping the msk receive buffer update
at receive time, as the latter only intended to cope with subflow receive
buffer increase due to OoO packets.

Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/487
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/559
Reviewed-by: Geliang Tang <geliang@kernel.org>
Tested-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250927-net-next-mptcp-rcv-path-imp-v1-3-5da266aa9c1a@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-29 18:23:35 -07:00
Paolo Abeni
9aa59323f2 mptcp: leverage skb deferral free
Usage of the skb deferral API is straight-forward; with multiple
subflows actives this allow moving part of the received application
load into multiple CPUs.

Also fix a typo in the related comment.

Reviewed-by: Geliang Tang <geliang@kernel.org>
Tested-by: Geliang Tang <geliang@kernel.org>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250927-net-next-mptcp-rcv-path-imp-v1-1-5da266aa9c1a@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-29 18:23:34 -07:00
Matthieu Baerts (NGI0)
1be5b82c45 mptcp: remove unused returned value of check_data_fin
When working on a fix modifying mptcp_check_data_fin(), I noticed the
returned value was no longer used.

It looks like it was used for 3 days, between commit 7ed90803a2
("mptcp: send explicit ack on delayed ack_seq incr") and commit
ea4ca586b1 ("mptcp: refine MPTCP-level ack scheduling").

This returned value can be safely removed.

Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250919-net-next-mptcp-server-side-flag-v1-6-a97a5d561a8b@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-22 11:51:25 -07:00
Jakub Kicinski
f2cdc4c22b Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR (net-6.17-rc7).

No conflicts.

Adjacent changes:

drivers/net/ethernet/mellanox/mlx5/core/en/fs.h
  9536fbe10c ("net/mlx5e: Add PSP steering in local NIC RX")
  7601a0a462 ("net/mlx5e: Add a miss level for ipsec crypto offload")

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-18 11:26:06 -07:00
Matthieu Baerts (NGI0)
f755be0b1f mptcp: propagate shutdown to subflows when possible
When the MPTCP DATA FIN have been ACKed, there is no more MPTCP related
metadata to exchange, and all subflows can be safely shutdown.

Before this patch, the subflows were actually terminated at 'close()'
time. That's certainly fine most of the time, but not when the userspace
'shutdown()' a connection, without close()ing it. When doing so, the
subflows were staying in LAST_ACK state on one side -- and consequently
in FIN_WAIT2 on the other side -- until the 'close()' of the MPTCP
socket.

Now, when the DATA FIN have been ACKed, all subflows are shutdown. A
consequence of this is that the TCP 'FIN' flag can be set earlier now,
but the end result is the same. This affects the packetdrill tests
looking at the end of the MPTCP connections, but for a good reason.

Note that tcp_shutdown() will check the subflow state, so no need to do
that again before calling it.

Fixes: 3721b9b646 ("mptcp: Track received DATA_FIN sequence number and add related helpers")
Cc: stable@vger.kernel.org
Fixes: 16a9a9da17 ("mptcp: Add helper to process acks of DATA_FIN")
Reviewed-by: Mat Martineau <martineau@kernel.org>
Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250912-net-mptcp-fix-sft-connect-v1-1-d40e77cbbf02@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-15 18:10:36 -07:00
Jakub Kicinski
5ef04a7b06 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR (net-6.17-rc5).

No conflicts.

Adjacent changes:

include/net/sock.h
  c51613fa27 ("net: add sk->sk_drop_counters")
  5d6b58c932 ("net: lockless sock_i_ino()")

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-04 13:33:00 -07:00
Eric Dumazet
5d6b58c932 net: lockless sock_i_ino()
Followup of commit c51da3f7a1 ("net: remove sock_i_uid()")

A recent syzbot report was the trigger for this change.

Over the years, we had many problems caused by the
read_lock[_bh](&sk->sk_callback_lock) in sock_i_uid().

We could fix smc_diag_dump_proto() or make a more radical move:

Instead of waiting for new syzbot reports, cache the socket
inode number in sk->sk_ino, so that we no longer
need to acquire sk->sk_callback_lock in sock_i_ino().

This makes socket dumps faster (one less cache line miss,
and two atomic ops avoided).

Prior art:

commit 25a9c8a443 ("netlink: Add __sock_i_ino() for __netlink_diag_dump().")
commit 4f9bf2a2f5 ("tcp: Don't acquire inet_listen_hashbucket::lock with disabled BH.")
commit efc3dbc374 ("rds: Make rds_sock_lock BH rather than IRQ safe.")

Fixes: d2d6422f8b ("x86: Allow to enable PREEMPT_RT.")
Reported-by: syzbot+50603c05bbdf4dfdaffa@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/netdev/68b73804.050a0220.3db4df.01d8.GAE@google.com/T/#u
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://patch.msgid.link/20250902183603.740428-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-03 16:08:24 -07:00
Christoph Paasch
3bd4f98a4e mptcp: record subflows in RPS table
Accelerated Receive Flow Steering (aRFS) relies on sockets recording
their RX flow hash into the rps_sock_flow_table so that incoming packets
are steered to the CPU where the application runs.

With MPTCP, the application interacts with the parent MPTCP socket while
data is carried over per-subflow TCP sockets. Without recording these
subflows, aRFS cannot steer interrupts and RX processing for the flows
to the desired CPU.

Record all subflows in the RPS table by calling sock_rps_record_flow()
for each subflow at the start of mptcp_sendmsg(), mptcp_recvmsg() and
mptcp_stream_accept(), by using the new helper
mptcp_rps_record_subflows().

It does not by itself improve throughput, but ensures that IRQ and RX
processing are directed to the right CPU, which is a
prerequisite for effective aRFS.

Signed-off-by: Christoph Paasch <cpaasch@openai.com>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250902-net-next-mptcp-misc-feat-6-18-v2-4-fa02bb3188b1@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-03 15:08:20 -07:00
Eric Dumazet
cb4d5a6eb6 net: add sk_drops_skbadd() helper
Existing sk_drops_add() helper is renamed to sk_drops_skbadd().

Add sk_drops_add() and convert sk_drops_inc() to use it.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20250826125031.1578842-3-edumazet@google.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-08-28 13:14:50 +02:00
Eric Dumazet
e6f178be3c tcp: annotate data-races around icsk->icsk_retransmits
icsk->icsk_retransmits is read locklessly from inet_sk_diag_fill(),
tcp_get_timestamping_opt_stats, get_tcp4_sock() and get_tcp6_sock().

Add corresponding READ_ONCE()/WRITE_ONCE() annotations.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Neal Cardwell <ncardwell@google.com>
Link: https://patch.msgid.link/20250822091727.835869-2-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-08-25 16:20:59 -07:00
Paolo Abeni
829fec0244 mptcp: remove pr_fallback()
We can now track fully the fallback status of a given connection via the
relevant mibs, the mentioned helper is redundant. Remove it completely.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250723-net-next-mptcp-track-fallbacks-v1-2-a83cce08f2d5@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-07-25 11:29:04 -07:00
Paolo Abeni
c65c2e3bae mptcp: track fallbacks accurately via mibs
Add the mibs required to cover the few possible fallback causes still
lacking suck info.

Move the relevant mib increment into the fallback helper, so that no
eventual future fallback operation will miss a paired mib increment.

Additionally track failed fallback via its own mib, such mib is
incremented only when a fallback mandated by the protocol fails - due to
racing subflow creation.

While at the above, rename an existing helper to reduce long lines
problems all along.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250723-net-next-mptcp-track-fallbacks-v1-1-a83cce08f2d5@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-07-25 11:29:04 -07:00
moyuanhao
154e56a77d mptcp: fix typo in a comment
This patch fixes the follow spelling mistake in a comment:

  greter -> greater

Signed-off-by: moyuanhao <moyuanhao3676@163.com>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250719-net-next-mptcp-tcp_maxseg-v2-4-8c910fbc5307@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-07-21 17:48:33 -07:00
Jakub Kicinski
af2d6148d2 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR (net-6.16-rc7).

Conflicts:

Documentation/netlink/specs/ovpn.yaml
  880d43ca9a ("netlink: specs: clean up spaces in brackets")
  af52020fc5 ("ovpn: reject unexpected netlink attributes")

drivers/net/phy/phy_device.c
  a44312d58e ("net: phy: Don't register LEDs for genphy")
  f0f2b992d8 ("net: phy: Don't register LEDs for genphy")
https://lore.kernel.org/20250710114926.7ec3a64f@kernel.org

drivers/net/wireless/intel/iwlwifi/fw/regulatory.c
drivers/net/wireless/intel/iwlwifi/mld/regulatory.c
  5fde0fcbd7 ("wifi: iwlwifi: mask reserved bits in chan_state_active_bitmap")
  ea045a0de3 ("wifi: iwlwifi: add support for accepting raw DSM tables by firmware")

net/ipv6/mcast.c
  ae3264a25a ("ipv6: mcast: Delay put pmc->idev in mld_del_delrec()")
  a8594c956c ("ipv6: mcast: Avoid a duplicate pointer check in mld_del_delrec()")
https://lore.kernel.org/8cc52891-3653-4b03-a45e-05464fe495cf@kernel.org

No adjacent changes.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-07-17 11:00:33 -07:00
Paolo Abeni
da9b2fc7b7 mptcp: reset fallback status gracefully at disconnect() time
mptcp_disconnect() clears the fallback bit unconditionally, without
touching the associated flags.

The bit clear is safe, as no fallback operation can race with that --
all subflow are already in TCP_CLOSE status thanks to the previous
FASTCLOSE -- but we need to consistently reset all the fallback related
status.

Also acquire the relevant lock, to avoid fouling static analyzers.

Fixes: b29fcfb54c ("mptcp: full disconnect implementation")
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250714-net-mptcp-fallback-races-v1-3-391aff963322@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-07-15 17:31:25 -07:00
Paolo Abeni
def5b7b264 mptcp: plug races between subflow fail and subflow creation
We have races similar to the one addressed by the previous patch between
subflow failing and additional subflow creation. They are just harder to
trigger.

The solution is similar. Use a separate flag to track the condition
'socket state prevent any additional subflow creation' protected by the
fallback lock.

The socket fallback makes such flag true, and also receiving or sending
an MP_FAIL option.

The field 'allow_infinite_fallback' is now always touched under the
relevant lock, we can drop the ONCE annotation on write.

Fixes: 478d770008 ("mptcp: send out MP_FAIL when data checksum fails")
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250714-net-mptcp-fallback-races-v1-2-391aff963322@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-07-15 17:31:25 -07:00
Paolo Abeni
f8a1d9b18c mptcp: make fallback action and fallback decision atomic
Syzkaller reported the following splat:

  WARNING: CPU: 1 PID: 7704 at net/mptcp/protocol.h:1223 __mptcp_do_fallback net/mptcp/protocol.h:1223 [inline]
  WARNING: CPU: 1 PID: 7704 at net/mptcp/protocol.h:1223 mptcp_do_fallback net/mptcp/protocol.h:1244 [inline]
  WARNING: CPU: 1 PID: 7704 at net/mptcp/protocol.h:1223 check_fully_established net/mptcp/options.c:982 [inline]
  WARNING: CPU: 1 PID: 7704 at net/mptcp/protocol.h:1223 mptcp_incoming_options+0x21a8/0x2510 net/mptcp/options.c:1153
  Modules linked in:
  CPU: 1 UID: 0 PID: 7704 Comm: syz.3.1419 Not tainted 6.16.0-rc3-gbd5ce2324dba #20 PREEMPT(voluntary)
  Hardware name: QEMU Ubuntu 24.04 PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
  RIP: 0010:__mptcp_do_fallback net/mptcp/protocol.h:1223 [inline]
  RIP: 0010:mptcp_do_fallback net/mptcp/protocol.h:1244 [inline]
  RIP: 0010:check_fully_established net/mptcp/options.c:982 [inline]
  RIP: 0010:mptcp_incoming_options+0x21a8/0x2510 net/mptcp/options.c:1153
  Code: 24 18 e8 bb 2a 00 fd e9 1b df ff ff e8 b1 21 0f 00 e8 ec 5f c4 fc 44 0f b7 ac 24 b0 00 00 00 e9 54 f1 ff ff e8 d9 5f c4 fc 90 <0f> 0b 90 e9 b8 f4 ff ff e8 8b 2a 00 fd e9 8d e6 ff ff e8 81 2a 00
  RSP: 0018:ffff8880a3f08448 EFLAGS: 00010246
  RAX: 0000000000000000 RBX: ffff8880180a8000 RCX: ffffffff84afcf45
  RDX: ffff888090223700 RSI: ffffffff84afdaa7 RDI: 0000000000000001
  RBP: ffff888017955780 R08: 0000000000000001 R09: 0000000000000000
  R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
  R13: ffff8880180a8910 R14: ffff8880a3e9d058 R15: 0000000000000000
  FS:  00005555791b8500(0000) GS:ffff88811c495000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 000000110c2800b7 CR3: 0000000058e44000 CR4: 0000000000350ef0
  Call Trace:
   <IRQ>
   tcp_reset+0x26f/0x2b0 net/ipv4/tcp_input.c:4432
   tcp_validate_incoming+0x1057/0x1b60 net/ipv4/tcp_input.c:5975
   tcp_rcv_established+0x5b5/0x21f0 net/ipv4/tcp_input.c:6166
   tcp_v4_do_rcv+0x5dc/0xa70 net/ipv4/tcp_ipv4.c:1925
   tcp_v4_rcv+0x3473/0x44a0 net/ipv4/tcp_ipv4.c:2363
   ip_protocol_deliver_rcu+0xba/0x480 net/ipv4/ip_input.c:205
   ip_local_deliver_finish+0x2f1/0x500 net/ipv4/ip_input.c:233
   NF_HOOK include/linux/netfilter.h:317 [inline]
   NF_HOOK include/linux/netfilter.h:311 [inline]
   ip_local_deliver+0x1be/0x560 net/ipv4/ip_input.c:254
   dst_input include/net/dst.h:469 [inline]
   ip_rcv_finish net/ipv4/ip_input.c:447 [inline]
   NF_HOOK include/linux/netfilter.h:317 [inline]
   NF_HOOK include/linux/netfilter.h:311 [inline]
   ip_rcv+0x514/0x810 net/ipv4/ip_input.c:567
   __netif_receive_skb_one_core+0x197/0x1e0 net/core/dev.c:5975
   __netif_receive_skb+0x1f/0x120 net/core/dev.c:6088
   process_backlog+0x301/0x1360 net/core/dev.c:6440
   __napi_poll.constprop.0+0xba/0x550 net/core/dev.c:7453
   napi_poll net/core/dev.c:7517 [inline]
   net_rx_action+0xb44/0x1010 net/core/dev.c:7644
   handle_softirqs+0x1d0/0x770 kernel/softirq.c:579
   do_softirq+0x3f/0x90 kernel/softirq.c:480
   </IRQ>
   <TASK>
   __local_bh_enable_ip+0xed/0x110 kernel/softirq.c:407
   local_bh_enable include/linux/bottom_half.h:33 [inline]
   inet_csk_listen_stop+0x2c5/0x1070 net/ipv4/inet_connection_sock.c:1524
   mptcp_check_listen_stop.part.0+0x1cc/0x220 net/mptcp/protocol.c:2985
   mptcp_check_listen_stop net/mptcp/mib.h:118 [inline]
   __mptcp_close+0x9b9/0xbd0 net/mptcp/protocol.c:3000
   mptcp_close+0x2f/0x140 net/mptcp/protocol.c:3066
   inet_release+0xed/0x200 net/ipv4/af_inet.c:435
   inet6_release+0x4f/0x70 net/ipv6/af_inet6.c:487
   __sock_release+0xb3/0x270 net/socket.c:649
   sock_close+0x1c/0x30 net/socket.c:1439
   __fput+0x402/0xb70 fs/file_table.c:465
   task_work_run+0x150/0x240 kernel/task_work.c:227
   resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
   exit_to_user_mode_loop+0xd4/0xe0 kernel/entry/common.c:114
   exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline]
   syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline]
   syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline]
   do_syscall_64+0x245/0x360 arch/x86/entry/syscall_64.c:100
   entry_SYSCALL_64_after_hwframe+0x77/0x7f
  RIP: 0033:0x7fc92f8a36ad
  Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48
  RSP: 002b:00007ffcf52802d8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
  RAX: 0000000000000000 RBX: 00007ffcf52803a8 RCX: 00007fc92f8a36ad
  RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
  RBP: 00007fc92fae7ba0 R08: 0000000000000001 R09: 0000002800000000
  R10: 00007fc92f700000 R11: 0000000000000246 R12: 00007fc92fae5fac
  R13: 00007fc92fae5fa0 R14: 0000000000026d00 R15: 0000000000026c51
   </TASK>
  irq event stamp: 4068
  hardirqs last  enabled at (4076): [<ffffffff81544816>] __up_console_sem+0x76/0x80 kernel/printk/printk.c:344
  hardirqs last disabled at (4085): [<ffffffff815447fb>] __up_console_sem+0x5b/0x80 kernel/printk/printk.c:342
  softirqs last  enabled at (3096): [<ffffffff840e1be0>] local_bh_enable include/linux/bottom_half.h:33 [inline]
  softirqs last  enabled at (3096): [<ffffffff840e1be0>] inet_csk_listen_stop+0x2c0/0x1070 net/ipv4/inet_connection_sock.c:1524
  softirqs last disabled at (3097): [<ffffffff813b6b9f>] do_softirq+0x3f/0x90 kernel/softirq.c:480

Since we need to track the 'fallback is possible' condition and the
fallback status separately, there are a few possible races open between
the check and the actual fallback action.

Add a spinlock to protect the fallback related information and use it
close all the possible related races. While at it also remove the
too-early clearing of allow_infinite_fallback in __mptcp_subflow_connect():
the field will be correctly cleared by subflow_finish_connect() if/when
the connection will complete successfully.

If fallback is not possible, as per RFC, reset the current subflow.

Since the fallback operation can now fail and return value should be
checked, rename the helper accordingly.

Fixes: 0530020a7c ("mptcp: track and update contiguous data status")
Cc: stable@vger.kernel.org
Reported-by: Matthieu Baerts <matttbe@kernel.org>
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/570
Reported-by: syzbot+5cf807c20386d699b524@syzkaller.appspotmail.com
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/555
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250714-net-mptcp-fallback-races-v1-1-391aff963322@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-07-15 17:31:25 -07:00
Eric Dumazet
8308133741 tcp: move tcp_memory_allocated into net_aligned_data
____cacheline_aligned_in_smp attribute only makes sure to align
a field to a cache line. It does not prevent the linker to use
the remaining of the cache line for other variables, causing
potential false sharing.

Move tcp_memory_allocated into a dedicated cache line.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20250630093540.3052835-4-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-07-02 14:22:02 -07:00
Eric Dumazet
e84a4927a4 net: annotate races around sk->sk_uid
sk->sk_uid can be read while another thread changes its
value in sockfs_setattr().

Add sk_uid(const struct sock *sk) helper to factorize the needed
READ_ONCE() annotations, and add corresponding WRITE_ONCE()
where needed.

Fixes: 86741ec254 ("net: core: Add a UID field to struct sock.")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Lorenzo Colitti <lorenzo@google.com>
Reviewed-by: Maciej Żenczykowski <maze@google.com>
Link: https://patch.msgid.link/20250620133001.4090592-2-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-06-23 17:04:03 -07:00
Ingo Molnar
41cb08555c treewide, timers: Rename from_timer() to timer_container_of()
Move this API to the canonical timer_*() namespace.

[ tglx: Redone against pre rc1 ]

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/aB2X0jCKQO56WdMt@gmail.com
2025-06-08 09:07:37 +02:00
Sebastian Andrzej Siewior
82d9e6b9a0 mptcp: Use nested-BH locking for hmac_storage
mptcp_delegated_actions is a per-CPU variable and relies on disabled BH for its
locking. Without per-CPU locking in local_bh_disable() on PREEMPT_RT this data
structure requires explicit locking.

Add a local_lock_t to the data structure and use local_lock_nested_bh() for
locking. This change adds only lockdep coverage and does not alter the
functional behaviour for !PREEMPT_RT.

Cc: Matthieu Baerts <matttbe@kernel.org>
Cc: Mat Martineau <martineau@kernel.org>
Cc: Geliang Tang <geliang@kernel.org>
Cc: mptcp@lists.linux.dev
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://patch.msgid.link/20250512092736.229935-13-bigeasy@linutronix.de
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-05-15 15:23:31 +02:00
Pedro Falcato
a2f6476ed1 mptcp: Align mptcp_inet6_sk with other protocols
Ever since commit f5f80e32de ("ipv6: remove hard coded limitation on
ipv6_pinfo") that protocols stopped using the old "obj_size -
sizeof(struct ipv6_pinfo)" way of grabbing ipv6_pinfo, that severely
restricted struct layout and caused fun, hard to see issues.

However, mptcp_inet6_sk wasn't fixed (unlike tcp_inet6_sk). Do so.
The non-cloned sockets already do the right thing using
ipv6_pinfo_offset + the generic IPv6 code.

Signed-off-by: Pedro Falcato <pfalcato@suse.de>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250430154541.1038561-1-pfalcato@suse.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-05-02 18:28:21 -07:00
Matthieu Baerts (NGI0)
4ce7fb8de5 mptcp: add MPJoinRejected MIB counter
This counter is useful to understand why some paths are rejected, and
not created as expected.

It is incremented when receiving a connection request, if the PM didn't
allow the creation of new subflows.

Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250413-net-next-mptcp-sched-mib-sft-misc-v2-5-0f83a4350150@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-04-15 08:21:47 -07:00
Eric Dumazet
f1e30061e8 tcp/dccp: remove icsk->icsk_ack.timeout
icsk->icsk_ack.timeout can be replaced by icsk->csk_delack_timer.expires

This saves 8 bytes in TCP/DCCP sockets and helps for better cache locality.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20250324203607.703850-3-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-03-25 10:34:33 -07:00
Eric Dumazet
a7c428ee8f tcp/dccp: remove icsk->icsk_timeout
icsk->icsk_timeout can be replaced by icsk->icsk_retransmit_timer.expires

This saves 8 bytes in TCP/DCCP sockets and helps for better cache locality.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20250324203607.703850-2-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-03-25 10:34:33 -07:00
Matthieu Baerts (NGI0)
a17336b2b2 mptcp: pm: avoid calling PM specific code from core
When destroying an MPTCP socket, some userspace PM specific code was
called from mptcp_destroy_common() in protocol.c. That feels wrong, and
it is the only case.

Instead, the core now calls mptcp_pm_destroy() from pm.c which is now in
charge of cleaning the announced addresses list, and ask the different
PMs to do extra cleaning if needed, e.g. the userspace PM, if used, will
clean the local addresses list.

While at it, the userspace PM specific helper has been prefixed with
'mptcp_userspace_pm_' like the other ones.

No behavioural changes intended.

Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250307-net-next-mptcp-pm-reorg-v1-9-abef20ada03b@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-03-10 13:35:49 -07:00
Matthieu Baerts (NGI0)
551a9ad787 mptcp: pm: remove '_nl' from mptcp_pm_nl_work
Currently, in-kernel PM specific helpers are prefixed with
'mptcp_pm_nl_'. But here 'mptcp_pm_nl_work' is not specific to this PM:
it is called from the core to call helpers, some of them needed by both
the in-kernel and userspace PMs.

To avoid confusions, the '_nl' bit has been removed from the name.

Also used 'worker' instead of 'work', similar to protocol.c's worker.

No behavioural changes intended.

Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250307-net-next-mptcp-pm-reorg-v1-4-abef20ada03b@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-03-10 13:35:49 -07:00
Geliang Tang
483cec55c1 net: use sock_kmemdup for ip_options
Instead of using sock_kmalloc() to allocate an ip_options and then
immediately duplicate another ip_options to the newly allocated one in
ipv6_dup_options(), mptcp_copy_ip_options() and sctp_v4_copy_ip_options(),
the newly added sock_kmemdup() helper can be used to simplify the code.

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Acked-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/91ae749d66600ec6fb679e0e518fda6acb5c3e6f.1740735165.git.tanggeliang@kylinos.cn
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-03-03 17:16:34 -08:00
Paolo Abeni
e0ca4057e0 mptcp: micro-optimize __mptcp_move_skb()
After the RX path refactor the mentioned function is expected to run
frequently, let's optimize it a bit.

Scan for ready subflow from the last processed one, and stop after
traversing the list once or reaching the msk memory limit - instead of
looking for dubious per-subflow conditions.
Also re-order the memory limit checks, to avoid duplicate tests.

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://patch.msgid.link/20250218-net-next-mptcp-rx-path-refactor-v1-7-4a47d90d7998@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-02-19 19:05:29 -08:00
Paolo Abeni
51fe9cb921 mptcp: dismiss __mptcp_rmem()
After the RX path refactor, it become a wrapper for sk_rmem_alloc
access, with a slightly misleading name. Just drop it.

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://patch.msgid.link/20250218-net-next-mptcp-rx-path-refactor-v1-6-4a47d90d7998@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-02-19 19:05:28 -08:00
Paolo Abeni
6639498ed8 mptcp: cleanup mem accounting
After the previous patch, updating sk_forward_memory is cheap and
we can drop a lot of complexity from the MPTCP memory accounting,
removing the custom fwd mem allocations for rmem.

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://patch.msgid.link/20250218-net-next-mptcp-rx-path-refactor-v1-4-4a47d90d7998@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-02-19 19:05:28 -08:00
Paolo Abeni
bc68b0efa1 mptcp: move the whole rx path under msk socket lock protection
After commit c2e6048fa1 ("mptcp: fix race in release_cb") we can
move the whole MPTCP rx path under the socket lock leveraging the
release_cb.

We can drop a bunch of spin_lock pairs in the receive functions, use
a single receive queue and invoke __mptcp_move_skbs only when subflows
ask for it.

This will allow more cleanup in the next patch.

Some changes are worth specific mention:

The msk rcvbuf update now always happens under both the msk and the
subflow socket lock: we can drop a bunch of ONCE annotation and
consolidate the checks.

When the skbs move is delayed at msk release callback time, even the
msk rcvbuf update is delayed; additionally take care of such action in
__mptcp_move_skbs().

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://patch.msgid.link/20250218-net-next-mptcp-rx-path-refactor-v1-3-4a47d90d7998@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-02-19 19:05:28 -08:00
Paolo Abeni
f03afb3aeb mptcp: drop __mptcp_fastopen_gen_msk_ackseq()
When we will move the whole RX path under the msk socket lock, updating
the already queued skb for passive fastopen socket at 3rd ack time will
be extremely painful and race prone

The map_seq for already enqueued skbs is used only to allow correct
coalescing with later data; preventing collapsing to the first skb of
a fastopen connect we can completely remove the
__mptcp_fastopen_gen_msk_ackseq() helper.

Before dropping this helper, a new item had to be added to the
mptcp_skb_cb structure. Because this item will be frequently tested in
the fast path -- almost on every packet -- and because there is free
space there, a single byte is used instead of a bitfield. This micro
optimisation slightly reduces the number of CPU operations to do the
associated check.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250218-net-next-mptcp-rx-path-refactor-v1-2-4a47d90d7998@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-02-19 19:05:28 -08:00
Paolo Abeni
619af16b3b mptcp: handle fastopen disconnect correctly
Syzbot was able to trigger a data stream corruption:

  WARNING: CPU: 0 PID: 9846 at net/mptcp/protocol.c:1024 __mptcp_clean_una+0xddb/0xff0 net/mptcp/protocol.c:1024
  Modules linked in:
  CPU: 0 UID: 0 PID: 9846 Comm: syz-executor351 Not tainted 6.13.0-rc2-syzkaller-00059-g00a5acdbf398 #0
  Hardware name: Google Compute Engine/Google Compute Engine, BIOS Google 11/25/2024
  RIP: 0010:__mptcp_clean_una+0xddb/0xff0 net/mptcp/protocol.c:1024
  Code: fa ff ff 48 8b 4c 24 18 80 e1 07 fe c1 38 c1 0f 8c 8e fa ff ff 48 8b 7c 24 18 e8 e0 db 54 f6 e9 7f fa ff ff e8 e6 80 ee f5 90 <0f> 0b 90 4c 8b 6c 24 40 4d 89 f4 e9 04 f5 ff ff 44 89 f1 80 e1 07
  RSP: 0018:ffffc9000c0cf400 EFLAGS: 00010293
  RAX: ffffffff8bb0dd5a RBX: ffff888033f5d230 RCX: ffff888059ce8000
  RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
  RBP: ffffc9000c0cf518 R08: ffffffff8bb0d1dd R09: 1ffff110170c8928
  R10: dffffc0000000000 R11: ffffed10170c8929 R12: 0000000000000000
  R13: ffff888033f5d220 R14: dffffc0000000000 R15: ffff8880592b8000
  FS:  00007f6e866496c0(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 00007f6e86f491a0 CR3: 00000000310e6000 CR4: 00000000003526f0
  DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
  Call Trace:
   <TASK>
   __mptcp_clean_una_wakeup+0x7f/0x2d0 net/mptcp/protocol.c:1074
   mptcp_release_cb+0x7cb/0xb30 net/mptcp/protocol.c:3493
   release_sock+0x1aa/0x1f0 net/core/sock.c:3640
   inet_wait_for_connect net/ipv4/af_inet.c:609 [inline]
   __inet_stream_connect+0x8bd/0xf30 net/ipv4/af_inet.c:703
   mptcp_sendmsg_fastopen+0x2a2/0x530 net/mptcp/protocol.c:1755
   mptcp_sendmsg+0x1884/0x1b10 net/mptcp/protocol.c:1830
   sock_sendmsg_nosec net/socket.c:711 [inline]
   __sock_sendmsg+0x1a6/0x270 net/socket.c:726
   ____sys_sendmsg+0x52a/0x7e0 net/socket.c:2583
   ___sys_sendmsg net/socket.c:2637 [inline]
   __sys_sendmsg+0x269/0x350 net/socket.c:2669
   do_syscall_x64 arch/x86/entry/common.c:52 [inline]
   do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
   entry_SYSCALL_64_after_hwframe+0x77/0x7f
  RIP: 0033:0x7f6e86ebfe69
  Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 b1 1f 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48
  RSP: 002b:00007f6e86649168 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
  RAX: ffffffffffffffda RBX: 00007f6e86f491b8 RCX: 00007f6e86ebfe69
  RDX: 0000000030004001 RSI: 0000000020000080 RDI: 0000000000000003
  RBP: 00007f6e86f491b0 R08: 00007f6e866496c0 R09: 0000000000000000
  R10: 0000000000000000 R11: 0000000000000246 R12: 00007f6e86f491bc
  R13: 000000000000006e R14: 00007ffe445d9420 R15: 00007ffe445d9508
   </TASK>

The root cause is the bad handling of disconnect() generated internally
by the MPTCP protocol in case of connect FASTOPEN errors.

Address the issue increasing the socket disconnect counter even on such
a case, to allow other threads waiting on the same socket lock to
properly error out.

Fixes: c2b2ae3925 ("mptcp: handle correctly disconnect() failures")
Cc: stable@vger.kernel.org
Reported-by: syzbot+ebc0b8ae5d3590b2c074@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/67605870.050a0220.37aaf.0137.GAE@google.com
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/537
Tested-by: syzbot+ebc0b8ae5d3590b2c074@syzkaller.appspotmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250123-net-mptcp-syzbot-issues-v1-3-af73258a726f@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-01-27 15:07:02 -08:00
Jakub Kicinski
f835bdae71 net: remove init_dummy_netdev()
init_dummy_netdev() can initialize statically declared or embedded
net_devices. Such netdevs did not come from alloc_netdev_mqs().
After recent work by Breno, there are the only two cases where
we have do that.

Switch those cases to alloc_netdev_mqs() and delete init_dummy_netdev().
Dealing with static netdevs is not worth the maintenance burden.

Reviewed-by: Alexander Lobakin <aleksander.lobakin@intel.com>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Reviewed-by: Joe Damato <jdamato@fastly.com>
Link: https://patch.msgid.link/20250113003456.3904110-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-01-13 19:06:51 -08:00
Paolo Abeni
56b824eb49 mptcp: prevent excessive coalescing on receive
Currently the skb size after coalescing is only limited by the skb
layout (the skb must not carry frag_list). A single coalesced skb
covering several MSS can potentially fill completely the receive
buffer. In such a case, the snd win will zero until the receive buffer
will be empty again, affecting tput badly.

Fixes: 8268ed4c9d ("mptcp: introduce and use mptcp_try_coalesce()")
Cc: stable@vger.kernel.org # please delay 2 weeks after 6.13-final release
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://patch.msgid.link/20241230-net-mptcp-rbuf-fixes-v1-3-8608af434ceb@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-01-02 18:44:03 -08:00
Paolo Abeni
551844f26d mptcp: don't always assume copied data in mptcp_cleanup_rbuf()
Under some corner cases the MPTCP protocol can end-up invoking
mptcp_cleanup_rbuf() when no data has been copied, but such helper
assumes the opposite condition.

Explicitly drop such assumption and performs the costly call only
when strictly needed - before releasing the msk socket lock.

Fixes: fd8976790a ("mptcp: be careful on MPTCP-level ack.")
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>
Link: https://patch.msgid.link/20241230-net-mptcp-rbuf-fixes-v1-2-8608af434ceb@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-01-02 18:44:03 -08:00
Paolo Abeni
449e6912a2 mptcp: fix recvbuffer adjust on sleeping rcvmsg
If the recvmsg() blocks after receiving some data - i.e. due to
SO_RCVLOWAT - the MPTCP code will attempt multiple times to
adjust the receive buffer size, wrongly accounting every time the
cumulative of received data - instead of accounting only for the
delta.

Address the issue moving mptcp_rcv_space_adjust just after the
data reception and passing it only the just received bytes.

This also removes an unneeded difference between the TCP and MPTCP
RX code path implementation.

Fixes: 5813022985 ("mptcp: error out earlier on disconnect")
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>
Link: https://patch.msgid.link/20241230-net-mptcp-rbuf-fixes-v1-1-8608af434ceb@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-01-02 18:44:03 -08:00
Jakub Kicinski
a79993b5fc Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR (net-6.12-rc8).

Conflicts:

tools/testing/selftests/net/.gitignore
  252e01e682 ("selftests: net: add netlink-dumps to .gitignore")
  be43a6b238 ("selftests: ncdevmem: Move ncdevmem under drivers/net/hw")
https://lore.kernel.org/all/20241113122359.1b95180a@canb.auug.org.au/

drivers/net/phy/phylink.c
  671154f174 ("net: phylink: ensure PHY momentary link-fails are handled")
  7530ea26c8 ("net: phylink: remove "using_mac_select_pcs"")

Adjacent changes:

drivers/net/ethernet/stmicro/stmmac/dwmac-intel-plat.c
  5b366eae71 ("stmmac: dwmac-intel-plat: fix call balance of tx_clk handling routines")
  e96321fad3 ("net: ethernet: Switch back to struct platform_driver::remove()")

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-11-14 11:29:15 -08:00
Dmitry Kandybka
b169e76eba mptcp: fix possible integer overflow in mptcp_reset_tout_timer
In 'mptcp_reset_tout_timer', promote 'probe_timestamp' to unsigned long
to avoid possible integer overflow. Compile tested only.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Signed-off-by: Dmitry Kandybka <d.kandybka@gmail.com>
Link: https://patch.msgid.link/20241107103657.1560536-1-d.kandybka@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-11-12 18:11:23 -08:00
Paolo Abeni
ce7356ae35 mptcp: cope racing subflow creation in mptcp_rcv_space_adjust
Additional active subflows - i.e. created by the in kernel path
manager - are included into the subflow list before starting the
3whs.

A racing recvmsg() spooling data received on an already established
subflow would unconditionally call tcp_cleanup_rbuf() on all the
current subflows, potentially hitting a divide by zero error on
the newly created ones.

Explicitly check that the subflow is in a suitable state before
invoking tcp_cleanup_rbuf().

Fixes: c76c695656 ("mptcp: call tcp_cleanup_rbuf on subflows")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/02374660836e1b52afc91966b7535c8c5f7bafb0.1731060874.git.pabeni@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-11-11 19:06:34 -08:00
Paolo Abeni
5813022985 mptcp: error out earlier on disconnect
Eric reported a division by zero splat in the MPTCP protocol:

Oops: divide error: 0000 [#1] PREEMPT SMP KASAN PTI
CPU: 1 UID: 0 PID: 6094 Comm: syz-executor317 Not tainted
6.12.0-rc5-syzkaller-00291-g05b92660cdfe #0
Hardware name: Google Google Compute Engine/Google Compute Engine,
BIOS Google 09/13/2024
RIP: 0010:__tcp_select_window+0x5b4/0x1310 net/ipv4/tcp_output.c:3163
Code: f6 44 01 e3 89 df e8 9b 75 09 f8 44 39 f3 0f 8d 11 ff ff ff e8
0d 74 09 f8 45 89 f4 e9 04 ff ff ff e8 00 74 09 f8 44 89 f0 99 <f7> 7c
24 14 41 29 d6 45 89 f4 e9 ec fe ff ff e8 e8 73 09 f8 48 89
RSP: 0018:ffffc900041f7930 EFLAGS: 00010293
RAX: 0000000000017e67 RBX: 0000000000017e67 RCX: ffffffff8983314b
RDX: 0000000000000000 RSI: ffffffff898331b0 RDI: 0000000000000004
RBP: 00000000005d6000 R08: 0000000000000004 R09: 0000000000017e67
R10: 0000000000003e80 R11: 0000000000000000 R12: 0000000000003e80
R13: ffff888031d9b440 R14: 0000000000017e67 R15: 00000000002eb000
FS: 00007feb5d7f16c0(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007feb5d8adbb8 CR3: 0000000074e4c000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
__tcp_cleanup_rbuf+0x3e7/0x4b0 net/ipv4/tcp.c:1493
mptcp_rcv_space_adjust net/mptcp/protocol.c:2085 [inline]
mptcp_recvmsg+0x2156/0x2600 net/mptcp/protocol.c:2289
inet_recvmsg+0x469/0x6a0 net/ipv4/af_inet.c:885
sock_recvmsg_nosec net/socket.c:1051 [inline]
sock_recvmsg+0x1b2/0x250 net/socket.c:1073
__sys_recvfrom+0x1a5/0x2e0 net/socket.c:2265
__do_sys_recvfrom net/socket.c:2283 [inline]
__se_sys_recvfrom net/socket.c:2279 [inline]
__x64_sys_recvfrom+0xe0/0x1c0 net/socket.c:2279
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7feb5d857559
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 51 18 00 00 90 48 89 f8 48
89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d
01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007feb5d7f1208 EFLAGS: 00000246 ORIG_RAX: 000000000000002d
RAX: ffffffffffffffda RBX: 00007feb5d8e1318 RCX: 00007feb5d857559
RDX: 000000800000000e RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00007feb5d8e1310 R08: 0000000000000000 R09: ffffffff81000000
R10: 0000000000000100 R11: 0000000000000246 R12: 00007feb5d8e131c
R13: 00007feb5d8ae074 R14: 000000800000000e R15: 00000000fffffdef

and provided a nice reproducer.

The root cause is the current bad handling of racing disconnect.
After the blamed commit below, sk_wait_data() can return (with
error) with the underlying socket disconnected and a zero rcv_mss.

Catch the error and return without performing any additional
operations on the current socket.

Reported-by: Eric Dumazet <edumazet@google.com>
Fixes: 419ce133ab ("tcp: allow again tcp_disconnect() when threads are waiting")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/8c82ecf71662ecbc47bf390f9905de70884c9f2d.1731060874.git.pabeni@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-11-11 19:06:34 -08:00
Jakub Kicinski
5b1c965956 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR (net-6.12-rc6).

Conflicts:

drivers/net/wireless/intel/iwlwifi/mvm/mld-mac80211.c
  cbe84e9ad5 ("wifi: iwlwifi: mvm: really send iwl_txpower_constraints_cmd")
  188a1bf894 ("wifi: mac80211: re-order assigning channel in activate links")
https://lore.kernel.org/all/20241028123621.7bbb131b@canb.auug.org.au/

net/mac80211/cfg.c
  c4382d5ca1 ("wifi: mac80211: update the right link for tx power")
  8dd0498983 ("wifi: mac80211: Fix setting txpower with emulate_chanctx")

drivers/net/ethernet/intel/ice/ice_ptp_hw.h
  6e58c33106 ("ice: fix crash on probe for DPLL enabled E810 LOM")
  e4291b64e1 ("ice: Align E810T GPIO to other products")
  ebb2693f8f ("ice: Read SDP section from NVM for pin definitions")
  ac532f4f42 ("ice: Cleanup unused declarations")
https://lore.kernel.org/all/20241030120524.1ee1af18@canb.auug.org.au/

No adjacent changes.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-10-31 18:10:07 -07:00
Geliang Tang
5add80bfdc mptcp: implement mptcp_pm_connection_closed
The MPTCP path manager event handler mptcp_pm_connection_closed
interface has been added in the commit 1b1c7a0ef7 ("mptcp: Add path
manager interface") but it was an empty function from then on.

With such name, it sounds good to invoke mptcp_event with the
MPTCP_EVENT_CLOSED event type from it. It also removes a bit of
duplicated code.

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20241021-net-next-mptcp-misc-6-13-v1-3-1ef02746504a@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-10-28 15:55:45 -07:00
Gang Yan
581c8cbfa9 mptcp: annotate data-races around subflow->fully_established
We introduce the same handling for potential data races with the
'fully_established' flag in subflow as previously done for
msk->fully_established.

Additionally, we make a crucial change: convert the subflow's
'fully_established' from 'bit_field' to 'bool' type. This is
necessary because methods for avoiding data races don't work well
with 'bit_field'. Specifically, the 'READ_ONCE' needs to know
the size of the variable being accessed, which is not supported in
'bit_field'. Also, 'test_bit' expect the address of 'bit_field'.

Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/516
Signed-off-by: Gang Yan <yangang@kylinos.cn>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20241021-net-next-mptcp-misc-6-13-v1-2-1ef02746504a@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-10-28 15:55:45 -07:00
Matthieu Baerts (NGI0)
3deb12c788 mptcp: init: protect sched with rcu_read_lock
Enabling CONFIG_PROVE_RCU_LIST with its dependence CONFIG_RCU_EXPERT
creates this splat when an MPTCP socket is created:

  =============================
  WARNING: suspicious RCU usage
  6.12.0-rc2+ #11 Not tainted
  -----------------------------
  net/mptcp/sched.c:44 RCU-list traversed in non-reader section!!

  other info that might help us debug this:

  rcu_scheduler_active = 2, debug_locks = 1
  no locks held by mptcp_connect/176.

  stack backtrace:
  CPU: 0 UID: 0 PID: 176 Comm: mptcp_connect Not tainted 6.12.0-rc2+ #11
  Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
  Call Trace:
   <TASK>
   dump_stack_lvl (lib/dump_stack.c:123)
   lockdep_rcu_suspicious (kernel/locking/lockdep.c:6822)
   mptcp_sched_find (net/mptcp/sched.c:44 (discriminator 7))
   mptcp_init_sock (net/mptcp/protocol.c:2867 (discriminator 1))
   ? sock_init_data_uid (arch/x86/include/asm/atomic.h:28)
   inet_create.part.0.constprop.0 (net/ipv4/af_inet.c:386)
   ? __sock_create (include/linux/rcupdate.h:347 (discriminator 1))
   __sock_create (net/socket.c:1576)
   __sys_socket (net/socket.c:1671)
   ? __pfx___sys_socket (net/socket.c:1712)
   ? do_user_addr_fault (arch/x86/mm/fault.c:1419 (discriminator 1))
   __x64_sys_socket (net/socket.c:1728)
   do_syscall_64 (arch/x86/entry/common.c:52 (discriminator 1))
   entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)

That's because when the socket is initialised, rcu_read_lock() is not
used despite the explicit comment written above the declaration of
mptcp_sched_find() in sched.c. Adding the missing lock/unlock avoids the
warning.

Fixes: 1730b2b2c5 ("mptcp: add sched in mptcp_sock")
Cc: stable@vger.kernel.org
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/523
Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20241021-net-mptcp-sched-lock-v1-1-637759cf061c@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-10-28 15:50:54 -07:00