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837 commits

Author SHA1 Message Date
Eric Dumazet
fdf3df297f mptcp: refine opt_mp_capable determination
[ Upstream commit 724b00c129 ]

OPTIONS_MPTCP_MPC is a combination of three flags.

It would be better to be strict about testing what
flag is expected, at least for code readability.

mptcp_parse_option() already makes the distinction.

- subflow_check_req() should use OPTION_MPTCP_MPC_SYN.

- mptcp_subflow_init_cookie_req() should use OPTION_MPTCP_MPC_ACK.

- subflow_finish_connect() should use OPTION_MPTCP_MPC_SYNACK

- subflow_syn_recv_sock should use OPTION_MPTCP_MPC_ACK

Suggested-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <martineau@kernel.org>
Fixes: 74c7dfbee3 ("mptcp: consolidate in_opt sub-options fields in a bitmask")
Link: https://lore.kernel.org/r/20240111194917.4044654-6-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-01-25 15:27:49 -08:00
Eric Dumazet
c0749c8770 mptcp: use OPTION_MPTCP_MPJ_SYN in subflow_check_req()
[ Upstream commit 66ff70df1a ]

syzbot reported that subflow_check_req() was using uninitialized data in
subflow_check_req() [1]

This is because mp_opt.token is only set when OPTION_MPTCP_MPJ_SYN is also set.

While we are are it, fix mptcp_subflow_init_cookie_req()
to test for OPTION_MPTCP_MPJ_ACK.

[1]

BUG: KMSAN: uninit-value in subflow_token_join_request net/mptcp/subflow.c:91 [inline]
 BUG: KMSAN: uninit-value in subflow_check_req+0x1028/0x15d0 net/mptcp/subflow.c:209
  subflow_token_join_request net/mptcp/subflow.c:91 [inline]
  subflow_check_req+0x1028/0x15d0 net/mptcp/subflow.c:209
  subflow_v6_route_req+0x269/0x410 net/mptcp/subflow.c:367
  tcp_conn_request+0x153a/0x4240 net/ipv4/tcp_input.c:7164
 subflow_v6_conn_request+0x3ee/0x510
  tcp_rcv_state_process+0x2e1/0x4ac0 net/ipv4/tcp_input.c:6659
  tcp_v6_do_rcv+0x11bf/0x1fe0 net/ipv6/tcp_ipv6.c:1669
  tcp_v6_rcv+0x480b/0x4fb0 net/ipv6/tcp_ipv6.c:1900
  ip6_protocol_deliver_rcu+0xda6/0x2a60 net/ipv6/ip6_input.c:438
  ip6_input_finish net/ipv6/ip6_input.c:483 [inline]
  NF_HOOK include/linux/netfilter.h:314 [inline]
  ip6_input+0x15d/0x430 net/ipv6/ip6_input.c:492
  dst_input include/net/dst.h:461 [inline]
  ip6_rcv_finish+0x5db/0x870 net/ipv6/ip6_input.c:79
  NF_HOOK include/linux/netfilter.h:314 [inline]
  ipv6_rcv+0xda/0x390 net/ipv6/ip6_input.c:310
  __netif_receive_skb_one_core net/core/dev.c:5532 [inline]
  __netif_receive_skb+0x1a6/0x5a0 net/core/dev.c:5646
  netif_receive_skb_internal net/core/dev.c:5732 [inline]
  netif_receive_skb+0x58/0x660 net/core/dev.c:5791
  tun_rx_batched+0x3ee/0x980 drivers/net/tun.c:1555
  tun_get_user+0x53af/0x66d0 drivers/net/tun.c:2002
  tun_chr_write_iter+0x3af/0x5d0 drivers/net/tun.c:2048
  call_write_iter include/linux/fs.h:2020 [inline]
  new_sync_write fs/read_write.c:491 [inline]
  vfs_write+0x8ef/0x1490 fs/read_write.c:584
  ksys_write+0x20f/0x4c0 fs/read_write.c:637
  __do_sys_write fs/read_write.c:649 [inline]
  __se_sys_write fs/read_write.c:646 [inline]
  __x64_sys_write+0x93/0xd0 fs/read_write.c:646
  do_syscall_x64 arch/x86/entry/common.c:52 [inline]
  do_syscall_64+0x44/0x110 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

Local variable mp_opt created at:
  subflow_check_req+0x6d/0x15d0 net/mptcp/subflow.c:145
  subflow_v6_route_req+0x269/0x410 net/mptcp/subflow.c:367

CPU: 1 PID: 5924 Comm: syz-executor.3 Not tainted 6.7.0-rc8-syzkaller-00055-g5eff55d725a4 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023

Fixes: f296234c98 ("mptcp: Add handling of incoming MP_JOIN requests")
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Florian Westphal <fw@strlen.de>
Cc: Peter Krystad <peter.krystad@linux.intel.com>
Cc: Matthieu Baerts <matttbe@kernel.org>
Cc: Mat Martineau <martineau@kernel.org>
Cc: Geliang Tang <geliang.tang@linux.dev>
Reviewed-by: Simon Horman <horms@kernel.org>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <martineau@kernel.org>
Link: https://lore.kernel.org/r/20240111194917.4044654-5-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-01-25 15:27:49 -08:00
Eric Dumazet
51e4cb032d mptcp: use OPTION_MPTCP_MPJ_SYNACK in subflow_finish_connect()
[ Upstream commit be1d9d9d38 ]

subflow_finish_connect() uses four fields (backup, join_id, thmac, none)
that may contain garbage unless OPTION_MPTCP_MPJ_SYNACK has been set
in mptcp_parse_option()

Fixes: f296234c98 ("mptcp: Add handling of incoming MP_JOIN requests")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Florian Westphal <fw@strlen.de>
Cc: Peter Krystad <peter.krystad@linux.intel.com>
Cc: Matthieu Baerts <matttbe@kernel.org>
Cc: Mat Martineau <martineau@kernel.org>
Cc: Geliang Tang <geliang.tang@linux.dev>
Reviewed-by: Simon Horman <horms@kernel.org>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <martineau@kernel.org>
Link: https://lore.kernel.org/r/20240111194917.4044654-4-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-01-25 15:27:49 -08:00
Eric Dumazet
081273082d mptcp: strict validation before using mp_opt->hmac
[ Upstream commit c1665273bd ]

mp_opt->hmac contains uninitialized data unless OPTION_MPTCP_MPJ_ACK
was set in mptcp_parse_option().

We must refine the condition before we call subflow_hmac_valid().

Fixes: f296234c98 ("mptcp: Add handling of incoming MP_JOIN requests")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Florian Westphal <fw@strlen.de>
Cc: Peter Krystad <peter.krystad@linux.intel.com>
Cc: Matthieu Baerts <matttbe@kernel.org>
Cc: Mat Martineau <martineau@kernel.org>
Cc: Geliang Tang <geliang.tang@linux.dev>
Reviewed-by: Simon Horman <horms@kernel.org>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <martineau@kernel.org>
Link: https://lore.kernel.org/r/20240111194917.4044654-3-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-01-25 15:27:49 -08:00
Eric Dumazet
67feafe7a3 mptcp: mptcp_parse_option() fix for MPTCPOPT_MP_JOIN
[ Upstream commit 89e23277f9 ]

mptcp_parse_option() currently sets OPTIONS_MPTCP_MPJ, for the three
possible cases handled for MPTCPOPT_MP_JOIN option.

OPTIONS_MPTCP_MPJ is the combination of three flags:
- OPTION_MPTCP_MPJ_SYN
- OPTION_MPTCP_MPJ_SYNACK
- OPTION_MPTCP_MPJ_ACK

This is a problem, because backup, join_id, token, nonce and/or hmac fields
could be left uninitialized in some cases.

Distinguish the three cases, as following patches will need this step.

Fixes: f296234c98 ("mptcp: Add handling of incoming MP_JOIN requests")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Florian Westphal <fw@strlen.de>
Cc: Peter Krystad <peter.krystad@linux.intel.com>
Cc: Matthieu Baerts <matttbe@kernel.org>
Cc: Mat Martineau <martineau@kernel.org>
Cc: Geliang Tang <geliang.tang@linux.dev>
Reviewed-by: Simon Horman <horms@kernel.org>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <martineau@kernel.org>
Link: https://lore.kernel.org/r/20240111194917.4044654-2-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-01-25 15:27:49 -08:00
Edward Adam Davis
91edb0cd1b mptcp: fix uninit-value in mptcp_incoming_options
[ Upstream commit 237ff253f2 ]

Added initialization use_ack to mptcp_parse_option().

Reported-by: syzbot+b834a6b2decad004cfa1@syzkaller.appspotmail.com
Signed-off-by: Edward Adam Davis <eadavis@qq.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-01-20 11:50:03 +01:00
Paolo Abeni
af9a530765 mptcp: prevent tcp diag from closing listener subflows
commit 4c0288299f upstream.

The MPTCP protocol does not expect that any other entity could change
the first subflow status when such socket is listening.
Unfortunately the TCP diag interface allows aborting any TCP socket,
including MPTCP listeners subflows. As reported by syzbot, that trigger
a WARN() and could lead to later bigger trouble.

The MPTCP protocol needs to do some MPTCP-level cleanup actions to
properly shutdown the listener. To keep the fix simple, prevent
entirely the diag interface from stopping such listeners.

We could refine the diag callback in a later, larger patch targeting
net-next.

Fixes: 57fc0f1cea ("mptcp: ensure listener is unhashed before updating the sk status")
Cc: stable@vger.kernel.org
Reported-by: <syzbot+5a01c3a666e726bc8752@syzkaller.appspotmail.com>
Closes: https://lore.kernel.org/netdev/0000000000004f4579060c68431b@google.com/
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts <matttbe@kernel.org>
Link: https://lore.kernel.org/r/20231226-upstream-net-20231226-mptcp-prevent-warn-v1-2-1404dcc431ea@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-10 17:10:20 +01:00
Paolo Abeni
9e9e2107ae mptcp: fix setsockopt(IP_TOS) subflow locking
commit 7679d34f97 upstream.

The MPTCP implementation of the IP_TOS socket option uses the lockless
variant of the TOS manipulation helper and does not hold such lock at
the helper invocation time.

Add the required locking.

Fixes: ffcacff87c ("mptcp: Support for IP_TOS for MPTCP setsockopt()")
Cc: stable@vger.kernel.org
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/457
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts <matttbe@kernel.org>
Link: https://lore.kernel.org/r/20231114-upstream-net-20231113-mptcp-misc-fixes-6-7-rc2-v1-4-7b9cd6a7b7f4@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-11-28 17:07:20 +00:00
Geliang Tang
dba6f08cef mptcp: add validity check for sending RM_ADDR
commit 8df220b292 upstream.

This patch adds the validity check for sending RM_ADDRs for userspace PM
in mptcp_pm_remove_addrs(), only send a RM_ADDR when the address is in the
anno_list or conn_list.

Fixes: 8b1c94da1e ("mptcp: only send RM_ADDR in nl_cmd_remove")
Cc: stable@vger.kernel.org
Signed-off-by: Geliang Tang <geliang.tang@suse.com>
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts <matttbe@kernel.org>
Link: https://lore.kernel.org/r/20231114-upstream-net-20231113-mptcp-misc-fixes-6-7-rc2-v1-3-7b9cd6a7b7f4@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-11-28 17:07:20 +00:00
Paolo Abeni
70ff9b65a7 mptcp: deal with large GSO size
commit 9fce92f050 upstream.

After the blamed commit below, the TCP sockets (and the MPTCP subflows)
can build egress packets larger than 64K. That exceeds the maximum DSS
data size, the length being misrepresent on the wire and the stream being
corrupted, as later observed on the receiver:

  WARNING: CPU: 0 PID: 9696 at net/mptcp/protocol.c:705 __mptcp_move_skbs_from_subflow+0x2604/0x26e0
  CPU: 0 PID: 9696 Comm: syz-executor.7 Not tainted 6.6.0-rc5-gcd8bdf563d46 #45
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-2.el7 04/01/2014
  netlink: 8 bytes leftover after parsing attributes in process `syz-executor.4'.
  RIP: 0010:__mptcp_move_skbs_from_subflow+0x2604/0x26e0 net/mptcp/protocol.c:705
  RSP: 0018:ffffc90000006e80 EFLAGS: 00010246
  RAX: ffffffff83e9f674 RBX: ffff88802f45d870 RCX: ffff888102ad0000
  netlink: 8 bytes leftover after parsing attributes in process `syz-executor.4'.
  RDX: 0000000080000303 RSI: 0000000000013908 RDI: 0000000000003908
  RBP: ffffc90000007110 R08: ffffffff83e9e078 R09: 1ffff1100e548c8a
  R10: dffffc0000000000 R11: ffffed100e548c8b R12: 0000000000013908
  R13: dffffc0000000000 R14: 0000000000003908 R15: 000000000031cf29
  FS:  00007f239c47e700(0000) GS:ffff88811b200000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 00007f239c45cd78 CR3: 000000006a66c006 CR4: 0000000000770ef0
  DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
  PKRU: 55555554
  Call Trace:
   <IRQ>
   mptcp_data_ready+0x263/0xac0 net/mptcp/protocol.c:819
   subflow_data_ready+0x268/0x6d0 net/mptcp/subflow.c:1409
   tcp_data_queue+0x21a1/0x7a60 net/ipv4/tcp_input.c:5151
   tcp_rcv_established+0x950/0x1d90 net/ipv4/tcp_input.c:6098
   tcp_v6_do_rcv+0x554/0x12f0 net/ipv6/tcp_ipv6.c:1483
   tcp_v6_rcv+0x2e26/0x3810 net/ipv6/tcp_ipv6.c:1749
   ip6_protocol_deliver_rcu+0xd6b/0x1ae0 net/ipv6/ip6_input.c:438
   ip6_input+0x1c5/0x470 net/ipv6/ip6_input.c:483
   ipv6_rcv+0xef/0x2c0 include/linux/netfilter.h:304
   __netif_receive_skb+0x1ea/0x6a0 net/core/dev.c:5532
   process_backlog+0x353/0x660 net/core/dev.c:5974
   __napi_poll+0xc6/0x5a0 net/core/dev.c:6536
   net_rx_action+0x6a0/0xfd0 net/core/dev.c:6603
   __do_softirq+0x184/0x524 kernel/softirq.c:553
   do_softirq+0xdd/0x130 kernel/softirq.c:454

Address the issue explicitly bounding the maximum GSO size to what MPTCP
actually allows.

Reported-by: Christoph Paasch <cpaasch@apple.com>
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/450
Fixes: 7c4e983c4f ("net: allow gso_max_size to exceed 65536")
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 <matttbe@kernel.org>
Link: https://lore.kernel.org/r/20231114-upstream-net-20231113-mptcp-misc-fixes-6-7-rc2-v1-1-7b9cd6a7b7f4@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-11-28 17:07:20 +00:00
Geliang Tang
300447c572 mptcp: avoid sending RST when closing the initial subflow
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>
2023-10-25 12:03:16 +02:00
Paolo Abeni
ec9bc89a01 tcp: allow again tcp_disconnect() when threads are waiting
[ 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>
2023-10-25 12:03:12 +02:00
Paolo Abeni
d4ae85b883 mptcp: more conservative check for zero probes
commit 72377ab2d6 upstream.

Christoph reported that the MPTCP protocol can find the subflow-level
write queue unexpectedly not empty while crafting a zero-window probe,
hitting a warning:

------------[ cut here ]------------
WARNING: CPU: 0 PID: 188 at net/mptcp/protocol.c:1312 mptcp_sendmsg_frag+0xc06/0xe70
Modules linked in:
CPU: 0 PID: 188 Comm: kworker/0:2 Not tainted 6.6.0-rc2-g1176aa719d7a #47
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-2.el7 04/01/2014
Workqueue: events mptcp_worker
RIP: 0010:mptcp_sendmsg_frag+0xc06/0xe70 net/mptcp/protocol.c:1312
RAX: 47d0530de347ff6a RBX: 47d0530de347ff6b RCX: ffff8881015d3c00
RDX: ffff8881015d3c00 RSI: 47d0530de347ff6b RDI: 47d0530de347ff6b
RBP: 47d0530de347ff6b R08: ffffffff8243c6a8 R09: ffffffff82042d9c
R10: 0000000000000002 R11: ffffffff82056850 R12: ffff88812a13d580
R13: 0000000000000001 R14: ffff88812b375e50 R15: ffff88812bbf3200
FS:  0000000000000000(0000) GS:ffff88813bc00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000695118 CR3: 0000000115dfc001 CR4: 0000000000170ef0
Call Trace:
 <TASK>
 __subflow_push_pending+0xa4/0x420 net/mptcp/protocol.c:1545
 __mptcp_push_pending+0x128/0x3b0 net/mptcp/protocol.c:1614
 mptcp_release_cb+0x218/0x5b0 net/mptcp/protocol.c:3391
 release_sock+0xf6/0x100 net/core/sock.c:3521
 mptcp_worker+0x6e8/0x8f0 net/mptcp/protocol.c:2746
 process_scheduled_works+0x341/0x690 kernel/workqueue.c:2630
 worker_thread+0x3a7/0x610 kernel/workqueue.c:2784
 kthread+0x143/0x180 kernel/kthread.c:388
 ret_from_fork+0x4d/0x60 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1b/0x30 arch/x86/entry/entry_64.S:304
 </TASK>

The root cause of the issue is that expectations are wrong: e.g. due
to MPTCP-level re-injection we can hit the critical condition.

Explicitly avoid the zero-window probe when the subflow write queue
is not empty and drop the related warnings.

Reported-by: Christoph Paasch <cpaasch@apple.com>
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/444
Fixes: f70cad1085 ("mptcp: stop relying on tcp_tx_skb_cache")
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/20231018-send-net-20231018-v1-3-17ecb002e41d@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-10-25 12:03:04 +02:00
Paolo Abeni
f2060a3a59 mptcp: fix delegated action races
[ 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>
2023-10-19 23:08:49 +02:00
Geliang Tang
454bb54b8f mptcp: userspace pm allow creating id 0 subflow
commit e5ed101a60 upstream.

This patch drops id 0 limitation in mptcp_nl_cmd_sf_create() to allow
creating additional subflows with the local addr ID 0.

There is no reason not to allow additional subflows from this local
address: we should be able to create new subflows from the initial
endpoint. This limitation was breaking fullmesh support from userspace.

Fixes: 702c2f646d ("mptcp: netlink: allow userspace-driven subflow establishment")
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/391
Cc: stable@vger.kernel.org
Suggested-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Geliang Tang <geliang.tang@suse.com>
Signed-off-by: Mat Martineau <martineau@kernel.org>
Link: https://lore.kernel.org/r/20231004-send-net-20231004-v1-2-28de4ac663ae@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-10-10 22:00:38 +02:00
Paolo Abeni
0786516470 mptcp: process pending subflow error on close
[ 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>
2023-10-10 22:00:34 +02:00
Paolo Abeni
fc8917b790 mptcp: move __mptcp_error_report in protocol.c
[ 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>
2023-10-10 22:00:34 +02:00
Eric Dumazet
c1432ece79 mptcp: annotate lockless accesses to sk->sk_err
[ 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>
2023-10-10 22:00:34 +02:00
Paolo Abeni
09b6fdf7a1 mptcp: fix dangling connection hang-up
[ 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>
2023-10-10 22:00:34 +02:00
Paolo Abeni
7544918e48 mptcp: rename timer related helper to less confusing names
[ 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>
2023-10-10 22:00:34 +02:00
Paolo Abeni
5d6613ed2b mptcp: fix bogus receive window shrinkage with multiple subflows
commit 6bec041147 upstream.

In case multiple subflows race to update the mptcp-level receive
window, the subflow losing the race should use the window value
provided by the "winning" subflow to update it's own tcp-level
rcv_wnd.

To such goal, the current code bogusly uses the mptcp-level rcv_wnd
value as observed before the update attempt. On unlucky circumstances
that may lead to TCP-level window shrinkage, and stall the other end.

Address the issue feeding to the rcv wnd update the correct value.

Fixes: f3589be0c4 ("mptcp: never shrink offered window")
Cc: stable@vger.kernel.org
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/427
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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-10-06 14:57:00 +02:00
Eric Dumazet
b7d25ac362 mptcp: annotate data-races around msk->rmem_fwd_alloc
[ 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>
2023-09-19 12:28:01 +02:00
Eric Dumazet
787c582968 net: annotate data-races around sk->sk_forward_alloc
[ 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>
2023-09-19 12:28:01 +02:00
Xiang Yang
b249c510b4 mptcp: fix the incorrect judgment for msk->cb_flags
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>
2023-08-16 18:27:26 +02:00
Paolo Abeni
ded9f5551c mptcp: fix disconnect vs accept race
commit 511b90e392 upstream.

Despite commit 0ad529d9fd ("mptcp: fix possible divide by zero in
recvmsg()"), the mptcp protocol is still prone to a race between
disconnect() (or shutdown) and accept.

The root cause is that the mentioned commit checks the msk-level
flag, but mptcp_stream_accept() does acquire the msk-level lock,
as it can rely directly on the first subflow lock.

As reported by Christoph than can lead to a race where an msk
socket is accepted after that mptcp_subflow_queue_clean() releases
the listener socket lock and just before it takes destructive
actions leading to the following splat:

BUG: kernel NULL pointer dereference, address: 0000000000000012
PGD 5a4ca067 P4D 5a4ca067 PUD 37d4c067 PMD 0
Oops: 0000 [#1] PREEMPT SMP
CPU: 2 PID: 10955 Comm: syz-executor.5 Not tainted 6.5.0-rc1-gdc7b257ee5dd #37
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-2.el7 04/01/2014
RIP: 0010:mptcp_stream_accept+0x1ee/0x2f0 include/net/inet_sock.h:330
Code: 0a 09 00 48 8b 1b 4c 39 e3 74 07 e8 bc 7c 7f fe eb a1 e8 b5 7c 7f fe 4c 8b 6c 24 08 eb 05 e8 a9 7c 7f fe 49 8b 85 d8 09 00 00 <0f> b6 40 12 88 44 24 07 0f b6 6c 24 07 bf 07 00 00 00 89 ee e8 89
RSP: 0018:ffffc90000d07dc0 EFLAGS: 00010293
RAX: 0000000000000000 RBX: ffff888037e8d020 RCX: ffff88803b093300
RDX: 0000000000000000 RSI: ffffffff833822c5 RDI: ffffffff8333896a
RBP: 0000607f82031520 R08: ffff88803b093300 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000003e83 R12: ffff888037e8d020
R13: ffff888037e8c680 R14: ffff888009af7900 R15: ffff888009af6880
FS:  00007fc26d708640(0000) GS:ffff88807dd00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000012 CR3: 0000000066bc5001 CR4: 0000000000370ee0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 do_accept+0x1ae/0x260 net/socket.c:1872
 __sys_accept4+0x9b/0x110 net/socket.c:1913
 __do_sys_accept4 net/socket.c:1954 [inline]
 __se_sys_accept4 net/socket.c:1951 [inline]
 __x64_sys_accept4+0x20/0x30 net/socket.c:1951
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x47/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x6e/0xd8

Address the issue by temporary removing the pending request socket
from the accept queue, so that racing accept() can't touch them.

After depleting the msk - the ssk still exists, as plain TCP sockets,
re-insert them into the accept queue, so that later inet_csk_listen_stop()
will complete the tcp socket disposal.

Fixes: 2a6a870e44 ("mptcp: stops worker on unaccepted sockets at listener close")
Cc: stable@vger.kernel.org
Reported-by: Christoph Paasch <cpaasch@apple.com>
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/423
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-v1-4-6671b1ab11cc@tessares.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-08-16 18:27:21 +02:00
Paolo Abeni
84aa65a525 mptcp: avoid bogus reset on fallback close
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>
2023-08-16 18:27:21 +02:00
Eric Dumazet
b53468041d net: annotate data-races around sk->sk_mark
[ Upstream commit 3c5b4d69c3 ]

sk->sk_mark is often read while another thread could change the value.

Fixes: 4a19ec5800 ("[NET]: Introducing socket mark socket option.")
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>
2023-08-11 12:08:14 +02:00
Paolo Abeni
bd2decac73 mptcp: ensure subflow is unhashed before cleaning the backlog
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>
2023-08-03 10:24:18 +02:00
Paolo Abeni
f5ded0c11d mptcp: do not rely on implicit state check in mptcp_listen()
[ 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>
2023-08-03 10:23:54 +02:00
Menglong Dong
fbe9fa195e mptcp: introduce 'sk' to replace 'sock->sk' in mptcp_listen()
[ 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>
2023-08-03 10:23:54 +02:00
Paolo Abeni
69925a346a mptcp: ensure listener is unhashed before updating the sk status
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>
2023-07-01 13:16:22 +02:00
Paolo Abeni
c2c46a7028 mptcp: consolidate fallback and non fallback state machine
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>
2023-06-28 11:12:24 +02:00
Paolo Abeni
1d31275426 mptcp: fix possible list corruption on passive MPJ
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>
2023-06-28 11:12:24 +02:00
Paolo Abeni
b747e75598 mptcp: fix possible divide by zero in recvmsg()
commit 0ad529d9fd upstream.

Christoph reported a divide by zero bug in mptcp_recvmsg():

divide error: 0000 [#1] PREEMPT SMP
CPU: 1 PID: 19978 Comm: syz-executor.6 Not tainted 6.4.0-rc2-gffcc7899081b #20
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-2.el7 04/01/2014
RIP: 0010:__tcp_select_window+0x30e/0x420 net/ipv4/tcp_output.c:3018
Code: 11 ff 0f b7 cd c1 e9 0c b8 ff ff ff ff d3 e0 89 c1 f7 d1 01 cb 21 c3 eb 17 e8 2e 83 11 ff 31 db eb 0e e8 25 83 11 ff 89 d8 99 <f7> 7c 24 04 29 d3 65 48 8b 04 25 28 00 00 00 48 3b 44 24 10 75 60
RSP: 0018:ffffc90000a07a18 EFLAGS: 00010246
RAX: 000000000000ffd7 RBX: 000000000000ffd7 RCX: 0000000000040000
RDX: 0000000000000000 RSI: 000000000003ffff RDI: 0000000000040000
RBP: 000000000000ffd7 R08: ffffffff820cf297 R09: 0000000000000001
R10: 0000000000000000 R11: ffffffff8103d1a0 R12: 0000000000003f00
R13: 0000000000300000 R14: ffff888101cf3540 R15: 0000000000180000
FS:  00007f9af4c09640(0000) GS:ffff88813bd00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b33824000 CR3: 000000012f241001 CR4: 0000000000170ee0
Call Trace:
 <TASK>
 __tcp_cleanup_rbuf+0x138/0x1d0 net/ipv4/tcp.c:1611
 mptcp_recvmsg+0xcb8/0xdd0 net/mptcp/protocol.c:2034
 inet_recvmsg+0x127/0x1f0 net/ipv4/af_inet.c:861
 ____sys_recvmsg+0x269/0x2b0 net/socket.c:1019
 ___sys_recvmsg+0xe6/0x260 net/socket.c:2764
 do_recvmmsg+0x1a5/0x470 net/socket.c:2858
 __do_sys_recvmmsg net/socket.c:2937 [inline]
 __se_sys_recvmmsg net/socket.c:2953 [inline]
 __x64_sys_recvmmsg+0xa6/0x130 net/socket.c:2953
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x47/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x72/0xdc
RIP: 0033:0x7f9af58fc6a9
Code: 5c c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 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 8b 0d 4f 37 0d 00 f7 d8 64 89 01 48
RSP: 002b:00007f9af4c08cd8 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 00000000006bc050 RCX: 00007f9af58fc6a9
RDX: 0000000000000001 RSI: 0000000020000140 RDI: 0000000000000004
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000f00 R11: 0000000000000246 R12: 00000000006bc05c
R13: fffffffffffffea8 R14: 00000000006bc050 R15: 000000000001fe40
 </TASK>

mptcp_recvmsg is allowed to release the msk socket lock when
blocking, and before re-acquiring it another thread could have
switched the sock to TCP_LISTEN status - with a prior
connect(AF_UNSPEC) - also clearing icsk_ack.rcv_mss.

Address the issue preventing the disconnect if some other process is
concurrently performing a blocking syscall on the same socket, alike
commit 4faeee0cf8 ("tcp: deny tcp_disconnect() when threads are waiting").

Fixes: a6b118febb ("mptcp: add receive buffer auto-tuning")
Cc: stable@vger.kernel.org
Reported-by: Christoph Paasch <cpaasch@apple.com>
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/404
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>
2023-06-28 11:12:24 +02:00
Paolo Abeni
b7bb71dfb5 mptcp: handle correctly disconnect() failures
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>
2023-06-28 11:12:24 +02:00
Geliang Tang
3fa051b18f mptcp: update userspace pm infos
commit 77e4b94a3d upstream.

Increase pm subflows counter on both server side and client side when
userspace pm creates a new subflow, and decrease the counter when it
closes a subflow.

Increase add_addr_signaled counter in mptcp_nl_cmd_announce() when the
address is announced by userspace PM.

This modification is similar to how the in-kernel PM is updating the
counter: when additional subflows are created/removed.

Fixes: 9ab4807c84 ("mptcp: netlink: Add MPTCP_PM_CMD_ANNOUNCE")
Fixes: 702c2f646d ("mptcp: netlink: allow userspace-driven subflow establishment")
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/329
Cc: stable@vger.kernel.org
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Geliang Tang <geliang.tang@suse.com>
Signed-off-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-06-14 11:15:27 +02:00
Geliang Tang
9b7fa33fda mptcp: add address into userspace pm list
commit 24430f8bf5 upstream.

Add the address into userspace_pm_local_addr_list when the subflow is
created. Make sure it can be found in mptcp_nl_cmd_remove(). And delete
it in the new helper mptcp_userspace_pm_delete_local_addr().

By doing this, the "REMOVE" command also works with subflows that have
been created via the "SUB_CREATE" command instead of restricting to
the addresses that have been announced via the "ANNOUNCE" command.

Fixes: d9a4594eda ("mptcp: netlink: Add MPTCP_PM_CMD_REMOVE")
Link: https://github.com/multipath-tcp/mptcp_net-next/issues/379
Cc: stable@vger.kernel.org
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Geliang Tang <geliang.tang@suse.com>
Signed-off-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-06-14 11:15:27 +02:00
Geliang Tang
d80a36ad40 mptcp: only send RM_ADDR in nl_cmd_remove
commit 8b1c94da1e upstream.

The specifications from [1] about the "REMOVE" command say:

    Announce that an address has been lost to the peer

It was then only supposed to send a RM_ADDR and not trying to delete
associated subflows.

A new helper mptcp_pm_remove_addrs() is then introduced to do just
that, compared to mptcp_pm_remove_addrs_and_subflows() also removing
subflows.

To delete a subflow, the userspace daemon can use the "SUB_DESTROY"
command, see mptcp_nl_cmd_sf_destroy().

Fixes: d9a4594eda ("mptcp: netlink: Add MPTCP_PM_CMD_REMOVE")
Link: https://github.com/multipath-tcp/mptcp/blob/mptcp_v0.96/include/uapi/linux/mptcp.h [1]
Cc: stable@vger.kernel.org
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Geliang Tang <geliang.tang@suse.com>
Signed-off-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-06-14 11:15:26 +02:00
Paolo Abeni
9ce0319b05 mptcp: fix active subflow finalization
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>
2023-06-09 10:34:25 +02:00
Paolo Abeni
977a63afd4 mptcp: fix connect timeout handling
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>
2023-06-09 10:34:25 +02:00
Paolo Abeni
e2feb39312 mptcp: add annotations around sk->sk_shutdown accesses
[ 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>
2023-06-09 10:34:06 +02:00
Paolo Abeni
0b9e6d64cd mptcp: fix data race around msk->first access
[ 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>
2023-06-09 10:34:06 +02:00
Paolo Abeni
519f16d96c mptcp: consolidate passive msk socket initialization
[ 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>
2023-06-09 10:34:06 +02:00
Paolo Abeni
fa2cbd1d68 mptcp: simplify subflow_syn_recv_sock()
[ Upstream commit a88d0092b2 ]

Postpone the msk cloning to the child process creation
so that we can avoid a bunch of conditionals.

Link: https://github.com/multipath-tcp/mptcp_net-next/issues/61
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: 7e8b88ec35 ("mptcp: consolidate passive msk socket initialization")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-06-09 10:34:06 +02:00
Paolo Abeni
9872e8c632 mptcp: avoid unneeded address copy
[ Upstream commit 2bb9a37f0e ]

In the syn_recv fallback path, the msk is unused. We can skip
setting the socket address.

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: 7e8b88ec35 ("mptcp: consolidate passive msk socket initialization")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-06-09 10:34:06 +02:00
Paolo Abeni
1b9e3ab669 mptcp: add annotations around msk->subflow accesses
[ 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>
2023-06-09 10:34:05 +02:00
Paolo Abeni
c5ebb5cec9 mptcp: avoid unneeded __mptcp_nmpc_socket() usage
[ 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>
2023-06-09 10:34:05 +02:00
Paolo Abeni
34cec5cd7a mptcp: fix accept vs worker race
commit 63740448a3 upstream.

The mptcp worker and mptcp_accept() can race, as reported by Christoph:

refcount_t: addition on 0; use-after-free.
WARNING: CPU: 1 PID: 14351 at lib/refcount.c:25 refcount_warn_saturate+0x105/0x1b0 lib/refcount.c:25
Modules linked in:
CPU: 1 PID: 14351 Comm: syz-executor.2 Not tainted 6.3.0-rc1-gde5e8fd0123c #11
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-2.el7 04/01/2014
RIP: 0010:refcount_warn_saturate+0x105/0x1b0 lib/refcount.c:25
Code: 02 31 ff 89 de e8 1b f0 a7 ff 84 db 0f 85 6e ff ff ff e8 3e f5 a7 ff 48 c7 c7 d8 c7 34 83 c6 05 6d 2d 0f 02 01 e8 cb 3d 90 ff <0f> 0b e9 4f ff ff ff e8 1f f5 a7 ff 0f b6 1d 54 2d 0f 02 31 ff 89
RSP: 0018:ffffc90000a47bf8 EFLAGS: 00010282
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: ffff88802eae98c0 RSI: ffffffff81097d4f RDI: 0000000000000001
RBP: ffff88802e712180 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: ffff88802eaea148 R12: ffff88802e712100
R13: ffff88802e712a88 R14: ffff888005cb93a8 R15: ffff88802e712a88
FS:  0000000000000000(0000) GS:ffff88803ed00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f277fd89120 CR3: 0000000035486002 CR4: 0000000000370ee0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 __refcount_add include/linux/refcount.h:199 [inline]
 __refcount_inc include/linux/refcount.h:250 [inline]
 refcount_inc include/linux/refcount.h:267 [inline]
 sock_hold include/net/sock.h:775 [inline]
 __mptcp_close+0x4c6/0x4d0 net/mptcp/protocol.c:3051
 mptcp_close+0x24/0xe0 net/mptcp/protocol.c:3072
 inet_release+0x56/0xa0 net/ipv4/af_inet.c:429
 __sock_release+0x51/0xf0 net/socket.c:653
 sock_close+0x18/0x20 net/socket.c:1395
 __fput+0x113/0x430 fs/file_table.c:321
 task_work_run+0x96/0x100 kernel/task_work.c:179
 exit_task_work include/linux/task_work.h:38 [inline]
 do_exit+0x4fc/0x10c0 kernel/exit.c:869
 do_group_exit+0x51/0xf0 kernel/exit.c:1019
 get_signal+0x12b0/0x1390 kernel/signal.c:2859
 arch_do_signal_or_restart+0x25/0x260 arch/x86/kernel/signal.c:306
 exit_to_user_mode_loop kernel/entry/common.c:168 [inline]
 exit_to_user_mode_prepare+0x131/0x1a0 kernel/entry/common.c:203
 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline]
 syscall_exit_to_user_mode+0x19/0x40 kernel/entry/common.c:296
 do_syscall_64+0x46/0x90 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x72/0xdc
RIP: 0033:0x7fec4b4926a9
Code: Unable to access opcode bytes at 0x7fec4b49267f.
RSP: 002b:00007fec49f9dd78 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00000000006bc058 RCX: 00007fec4b4926a9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00000000006bc058
RBP: 00000000006bc050 R08: 00000000007df998 R09: 00000000007df998
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006bc05c
R13: fffffffffffffea8 R14: 000000000000000b R15: 000000000001fe40
 </TASK>

The root cause is that the worker can force fallback to TCP the first
mptcp subflow, actually deleting the unaccepted msk socket.

We can explicitly prevent the race delaying the unaccepted msk deletion
at listener shutdown time. In case the closed subflow is later accepted,
just drop the mptcp context and let the user-space deal with the
paired mptcp socket.

Fixes: b6985b9b82 ("mptcp: use the workqueue to destroy unaccepted sockets")
Cc: stable@vger.kernel.org
Reported-by: Christoph Paasch <cpaasch@apple.com>
Link: https://github.com/multipath-tcp/mptcp_net-next/issues/375
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: David S. Miller <davem@davemloft.net>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-05-01 08:26:27 +09:00
Paolo Abeni
b45d8f5375 mptcp: stops worker on unaccepted sockets at listener close
commit 2a6a870e44 upstream.

This is a partial revert of the blamed commit, with a relevant
change: mptcp_subflow_queue_clean() now just change the msk
socket status and stop the worker, so that the UaF issue addressed
by the blamed commit is not re-introduced.

The above prevents the mptcp worker from running concurrently with
inet_csk_listen_stop(), as such race would trigger a warning, as
reported by Christoph:

RSP: 002b:00007f784fe09cd8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
WARNING: CPU: 0 PID: 25807 at net/ipv4/inet_connection_sock.c:1387 inet_csk_listen_stop+0x664/0x870 net/ipv4/inet_connection_sock.c:1387
RAX: ffffffffffffffda RBX: 00000000006bc050 RCX: 00007f7850afd6a9
RDX: 0000000000000000 RSI: 0000000020000340 RDI: 0000000000000004
Modules linked in:
RBP: 0000000000000002 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006bc05c
R13: fffffffffffffea8 R14: 00000000006bc050 R15: 000000000001fe40

 </TASK>
CPU: 0 PID: 25807 Comm: syz-executor.7 Not tainted 6.2.0-g778e54711659 #7
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-2.el7 04/01/2014
RIP: 0010:inet_csk_listen_stop+0x664/0x870 net/ipv4/inet_connection_sock.c:1387
RAX: 0000000000000000 RBX: ffff888100dfbd40 RCX: 0000000000000000
RDX: ffff8881363aab80 RSI: ffffffff81c494f4 RDI: 0000000000000005
RBP: ffff888126dad080 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: ffff888100dfe040
R13: 0000000000000001 R14: 0000000000000000 R15: ffff888100dfbdd8
FS:  00007f7850a2c800(0000) GS:ffff88813bc00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b32d26000 CR3: 000000012fdd8006 CR4: 0000000000770ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
PKRU: 55555554
Call Trace:
 <TASK>
 __tcp_close+0x5b2/0x620 net/ipv4/tcp.c:2875
 __mptcp_close_ssk+0x145/0x3d0 net/mptcp/protocol.c:2427
 mptcp_destroy_common+0x8a/0x1c0 net/mptcp/protocol.c:3277
 mptcp_destroy+0x41/0x60 net/mptcp/protocol.c:3304
 __mptcp_destroy_sock+0x56/0x140 net/mptcp/protocol.c:2965
 __mptcp_close+0x38f/0x4a0 net/mptcp/protocol.c:3057
 mptcp_close+0x24/0xe0 net/mptcp/protocol.c:3072
 inet_release+0x53/0xa0 net/ipv4/af_inet.c:429
 __sock_release+0x4e/0xf0 net/socket.c:651
 sock_close+0x15/0x20 net/socket.c:1393
 __fput+0xff/0x420 fs/file_table.c:321
 task_work_run+0x8b/0xe0 kernel/task_work.c:179
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:171 [inline]
 exit_to_user_mode_prepare+0x113/0x120 kernel/entry/common.c:203
 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline]
 syscall_exit_to_user_mode+0x1d/0x40 kernel/entry/common.c:296
 do_syscall_64+0x46/0x90 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x72/0xdc
RIP: 0033:0x7f7850af70dc
RAX: 0000000000000000 RBX: 0000000000000004 RCX: 00007f7850af70dc
RDX: 00007f7850a2c800 RSI: 0000000000000002 RDI: 0000000000000003
RBP: 00000000006bd980 R08: 0000000000000000 R09: 00000000000018a0
R10: 00000000316338a4 R11: 0000000000000293 R12: 0000000000211e31
R13: 00000000006bc05c R14: 00007f785062c000 R15: 0000000000211af0

Fixes: 0a3f4f1f9c ("mptcp: fix UaF in listener shutdown")
Cc: stable@vger.kernel.org
Reported-by: Christoph Paasch <cpaasch@apple.com>
Link: https://github.com/multipath-tcp/mptcp_net-next/issues/371
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>
2023-05-01 08:26:27 +09:00
Kuniyuki Iwashima
a8cf114105 inet6: Remove inet6_destroy_sock() in sk->sk_prot->destroy().
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>
2023-04-26 14:28:43 +02:00