Граф коммитов

571 Коммитов

Автор SHA1 Сообщение Дата
Mat Martineau 0c3f34beb4 mptcp: Correctly set DATA_FIN timeout when number of retransmits is large
commit 877d11f033 upstream.

Syzkaller with UBSAN uncovered a scenario where a large number of
DATA_FIN retransmits caused a shift-out-of-bounds in the DATA_FIN
timeout calculation:

================================================================================
UBSAN: shift-out-of-bounds in net/mptcp/protocol.c:470:29
shift exponent 32 is too large for 32-bit type 'unsigned int'
CPU: 1 PID: 13059 Comm: kworker/1:0 Not tainted 5.17.0-rc2-00630-g5fbf21c90c60 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014
Workqueue: events mptcp_worker
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
 ubsan_epilogue+0xb/0x5a lib/ubsan.c:151
 __ubsan_handle_shift_out_of_bounds.cold+0xb2/0x20e lib/ubsan.c:330
 mptcp_set_datafin_timeout net/mptcp/protocol.c:470 [inline]
 __mptcp_retrans.cold+0x72/0x77 net/mptcp/protocol.c:2445
 mptcp_worker+0x58a/0xa70 net/mptcp/protocol.c:2528
 process_one_work+0x9df/0x16d0 kernel/workqueue.c:2307
 worker_thread+0x95/0xe10 kernel/workqueue.c:2454
 kthread+0x2f4/0x3b0 kernel/kthread.c:377
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
================================================================================

This change limits the maximum timeout by limiting the size of the
shift, which keeps all intermediate values in-bounds.

Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/259
Fixes: 6477dd39e6 ("mptcp: Retransmit DATA_FIN")
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-03-08 19:12:48 +01:00
Paolo Abeni f25ae162f4 mptcp: add mibs counter for ignored incoming options
commit f73c119463 upstream.

The MPTCP in kernel path manager has some constraints on incoming
addresses announce processing, so that in edge scenarios it can
end-up dropping (ignoring) some of such announces.

The above is not very limiting in practice since such scenarios are
very uncommon and MPTCP will recover due to ADD_ADDR retransmissions.

This patch adds a few MIB counters to account for such drop events
to allow easier introspection of the critical scenarios.

Fixes: f7efc7771e ("mptcp: drop argument port from mptcp_pm_announce_addr")
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-03-02 11:47:53 +01:00
Paolo Abeni 150d1e06c4 mptcp: fix race in incoming ADD_ADDR option processing
commit 837cf45df1 upstream.

If an MPTCP endpoint received multiple consecutive incoming
ADD_ADDR options, mptcp_pm_add_addr_received() can overwrite
the current remote address value after the PM lock is released
in mptcp_pm_nl_add_addr_received() and before such address
is echoed.

Fix the issue caching the remote address value a little earlier
and always using the cached value after releasing the PM lock.

Fixes: f7efc7771e ("mptcp: drop argument port from mptcp_pm_announce_addr")
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-03-02 11:47:52 +01:00
Kishen Maloor 29b25d5f8f mptcp: netlink: process IPv6 addrs in creating listening sockets
[ Upstream commit 029744cd4b ]

This change updates mptcp_pm_nl_create_listen_socket() to create
listening sockets bound to IPv6 addresses (where IPv6 is supported).

Fixes: 1729cf186d ("mptcp: create the listening socket for new port")
Acked-by: Geliang Tang <geliang.tang@suse.com>
Signed-off-by: Kishen Maloor <kishen.maloor@intel.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-02-16 12:56:31 +01:00
Paolo Abeni 9908c759a1 mptcp: fix msk traversal in mptcp_nl_cmd_set_flags()
commit 8e9eacad7e upstream.

The MPTCP endpoint list is under RCU protection, guarded by the
pernet spinlock. mptcp_nl_cmd_set_flags() traverses the list
without acquiring the spin-lock nor under the RCU critical section.

This change addresses the issue performing the lookup and the endpoint
update under the pernet spinlock.

[The upstream commit had to handle a lookup_by_id variable that is only
 present in 5.17. This version of the patch removes that variable, so
 the __lookup_addr() function only handles the lookup as it is
 implemented in 5.15 and 5.16. It also removes one 'const' keyword to
 prevent a warning due to differing const-ness in the 5.17 version of
 addresses_equal().]

Fixes: 0f9f696a50 ("mptcp: add set_flags command in PM netlink")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-02-08 18:34:06 +01:00
Geliang Tang e1652f70e8 mptcp: fix a DSS option writing error
[ Upstream commit 110b6d1fe9 ]

'ptr += 1;' was omitted in the original code.

If the DSS is the last option -- which is what we have most of the
time -- that's not an issue. But it is if we need to send something else
after like a RM_ADDR or an MP_PRIO.

Fixes: 1bff1e43a3 ("mptcp: optimize out option generation")
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Geliang Tang <geliang.tang@suse.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-01-27 11:03:59 +01:00
Matthieu Baerts 72aba03ba8 mptcp: fix opt size when sending DSS + MP_FAIL
[ Upstream commit 04fac2cae9 ]

When these two options had to be sent -- which is not common -- the DSS
size was not being taken into account in the remaining size.

Additionally in this situation, the reported size was only the one of
the MP_FAIL which can cause issue if at the end, we need to write more
in the TCP options than previously said.

Here we use a dedicated variable for MP_FAIL size to keep the
WARN_ON_ONCE() just after.

Fixes: c25aeb4e09 ("mptcp: MP_FAIL suboption sending")
Acked-and-tested-by: Geliang Tang <geliang.tang@suse.com>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-01-27 11:03:59 +01:00
Paolo Abeni c310df0eab mptcp: fix per socket endpoint accounting
[ Upstream commit f7d6a237d7 ]

Since full-mesh endpoint support, the reception of a single ADD_ADDR
option can cause multiple subflows creation. When such option is
accepted we increment 'add_addr_accepted' by one. When we received
a paired RM_ADDR option, we deleted all the relevant subflows,
decrementing 'add_addr_accepted' by one for each of them.

We have a similar issue for 'local_addr_used'

Fix them moving the pm endpoint accounting outside the subflow
traversal.

Fixes: 1a0d6136c5 ("mptcp: local addresses fullmesh")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-01-27 11:03:58 +01:00
Maxim Galaganov 23311b9275 mptcp: fix deadlock in __mptcp_push_pending()
[ Upstream commit 3d79e3756c ]

__mptcp_push_pending() may call mptcp_flush_join_list() with subflow
socket lock held. If such call hits mptcp_sockopt_sync_all() then
subsequently __mptcp_sockopt_sync() could try to lock the subflow
socket for itself, causing a deadlock.

sysrq: Show Blocked State
task:ss-server       state:D stack:    0 pid:  938 ppid:     1 flags:0x00000000
Call Trace:
 <TASK>
 __schedule+0x2d6/0x10c0
 ? __mod_memcg_state+0x4d/0x70
 ? csum_partial+0xd/0x20
 ? _raw_spin_lock_irqsave+0x26/0x50
 schedule+0x4e/0xc0
 __lock_sock+0x69/0x90
 ? do_wait_intr_irq+0xa0/0xa0
 __lock_sock_fast+0x35/0x50
 mptcp_sockopt_sync_all+0x38/0xc0
 __mptcp_push_pending+0x105/0x200
 mptcp_sendmsg+0x466/0x490
 sock_sendmsg+0x57/0x60
 __sys_sendto+0xf0/0x160
 ? do_wait_intr_irq+0xa0/0xa0
 ? fpregs_restore_userregs+0x12/0xd0
 __x64_sys_sendto+0x20/0x30
 do_syscall_64+0x38/0x90
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f9ba546c2d0
RSP: 002b:00007ffdc3b762d8 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007f9ba56c8060 RCX: 00007f9ba546c2d0
RDX: 000000000000077a RSI: 0000000000e5e180 RDI: 0000000000000234
RBP: 0000000000cc57f0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f9ba56c8060
R13: 0000000000b6ba60 R14: 0000000000cc7840 R15: 41d8685b1d7901b8
 </TASK>

Fix the issue by using __mptcp_flush_join_list() instead of plain
mptcp_flush_join_list() inside __mptcp_push_pending(), as suggested by
Florian. The sockopt sync will be deferred to the workqueue.

Fixes: 1b3e7ede13 ("mptcp: setsockopt: handle SO_KEEPALIVE and SO_PRIORITY")
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/244
Suggested-by: Florian Westphal <fw@strlen.de>
Reviewed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Maxim Galaganov <max@internet.ru>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-12-22 09:32:43 +01:00
Florian Westphal c26ac0ea3a mptcp: clear 'kern' flag from fallback sockets
[ Upstream commit d6692b3b97 ]

The mptcp ULP extension relies on sk->sk_sock_kern being set correctly:
It prevents setsockopt(fd, IPPROTO_TCP, TCP_ULP, "mptcp", 6); from
working for plain tcp sockets (any userspace-exposed socket).

But in case of fallback, accept() can return a plain tcp sk.
In such case, sk is still tagged as 'kernel' and setsockopt will work.

This will crash the kernel, The subflow extension has a NULL ctx->conn
mptcp socket:

BUG: KASAN: null-ptr-deref in subflow_data_ready+0x181/0x2b0
Call Trace:
 tcp_data_ready+0xf8/0x370
 [..]

Fixes: cf7da0d66c ("mptcp: Create SUBFLOW socket for incoming connections")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-12-22 09:32:43 +01:00
Florian Westphal 3de0c86d42 mptcp: remove tcp ulp setsockopt support
[ Upstream commit 404cd9a221 ]

TCP_ULP setsockopt cannot be used for mptcp because its already
used internally to plumb subflow (tcp) sockets to the mptcp layer.

syzbot managed to trigger a crash for mptcp connections that are
in fallback mode:

KASAN: null-ptr-deref in range [0x0000000000000020-0x0000000000000027]
CPU: 1 PID: 1083 Comm: syz-executor.3 Not tainted 5.16.0-rc2-syzkaller #0
RIP: 0010:tls_build_proto net/tls/tls_main.c:776 [inline]
[..]
 __tcp_set_ulp net/ipv4/tcp_ulp.c:139 [inline]
 tcp_set_ulp+0x428/0x4c0 net/ipv4/tcp_ulp.c:160
 do_tcp_setsockopt+0x455/0x37c0 net/ipv4/tcp.c:3391
 mptcp_setsockopt+0x1b47/0x2400 net/mptcp/sockopt.c:638

Remove support for TCP_ULP setsockopt.

Fixes: d9e4c12918 ("mptcp: only admit explicitly supported sockopt")
Reported-by: syzbot+1fd9b69cde42967d1add@syzkaller.appspotmail.com
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-12-22 09:32:43 +01:00
Paolo Abeni 1456a0004c mptcp: never allow the PM to close a listener subflow
[ Upstream commit b0cdc5dbcf ]

Currently, when deleting an endpoint the netlink PM treverses
all the local MPTCP sockets, regardless of their status.

If an MPTCP listener socket is bound to the IP matching the
delete endpoint, the listener TCP socket will be closed.
That is unexpected, the PM should only affect data subflows.

Additionally, syzbot was able to trigger a NULL ptr dereference
due to the above:

general protection fault, probably for non-canonical address 0xdffffc0000000003: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000018-0x000000000000001f]
CPU: 1 PID: 6550 Comm: syz-executor122 Not tainted 5.16.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:__lock_acquire+0xd7d/0x54a0 kernel/locking/lockdep.c:4897
Code: 0f 0e 41 be 01 00 00 00 0f 86 c8 00 00 00 89 05 69 cc 0f 0e e9 bd 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 da 48 c1 ea 03 <80> 3c 02 00 0f 85 f3 2f 00 00 48 81 3b 20 75 17 8f 0f 84 52 f3 ff
RSP: 0018:ffffc90001f2f818 EFLAGS: 00010016
RAX: dffffc0000000000 RBX: 0000000000000018 RCX: 0000000000000000
RDX: 0000000000000003 RSI: 0000000000000000 RDI: 0000000000000001
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000001
R10: 0000000000000000 R11: 000000000000000a R12: 0000000000000000
R13: ffff88801b98d700 R14: 0000000000000000 R15: 0000000000000001
FS:  00007f177cd3d700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f177cd1b268 CR3: 000000001dd55000 CR4: 0000000000350ee0
Call Trace:
 <TASK>
 lock_acquire kernel/locking/lockdep.c:5637 [inline]
 lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5602
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0x39/0x50 kernel/locking/spinlock.c:162
 finish_wait+0xc0/0x270 kernel/sched/wait.c:400
 inet_csk_wait_for_connect net/ipv4/inet_connection_sock.c:464 [inline]
 inet_csk_accept+0x7de/0x9d0 net/ipv4/inet_connection_sock.c:497
 mptcp_accept+0xe5/0x500 net/mptcp/protocol.c:2865
 inet_accept+0xe4/0x7b0 net/ipv4/af_inet.c:739
 mptcp_stream_accept+0x2e7/0x10e0 net/mptcp/protocol.c:3345
 do_accept+0x382/0x510 net/socket.c:1773
 __sys_accept4_file+0x7e/0xe0 net/socket.c:1816
 __sys_accept4+0xb0/0x100 net/socket.c:1846
 __do_sys_accept net/socket.c:1864 [inline]
 __se_sys_accept net/socket.c:1861 [inline]
 __x64_sys_accept+0x71/0xb0 net/socket.c:1861
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f177cd8b8e9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 b1 14 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f177cd3d308 EFLAGS: 00000246 ORIG_RAX: 000000000000002b
RAX: ffffffffffffffda RBX: 00007f177ce13408 RCX: 00007f177cd8b8e9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00007f177ce13400 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f177ce1340c
R13: 00007f177cde1004 R14: 6d705f706374706d R15: 0000000000022000
 </TASK>

Fix the issue explicitly skipping MPTCP socket in TCP_LISTEN
status.

Reported-and-tested-by: syzbot+e4d843bb96a9431e6331@syzkaller.appspotmail.com
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Fixes: 740d798e87 ("mptcp: remove id 0 address")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Link: https://lore.kernel.org/r/ebc7594cdd420d241fb2172ddb8542ba64717657.1639238695.git.pabeni@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-12-22 09:32:41 +01:00
Paolo Abeni 97e5d85030 mptcp: use delegate action to schedule 3rd ack retrans
[ Upstream commit bcd9773431 ]

Scheduling a delack in mptcp_established_options_mp() is
not a good idea: such function is called by tcp_send_ack() and
the pending delayed ack will be cleared shortly after by the
tcp_event_ack_sent() call in __tcp_transmit_skb().

Instead use the mptcp delegated action infrastructure to
schedule the delayed ack after the current bh processing completes.

Additionally moves the schedule_3rdack_retransmission() helper
into protocol.c to avoid making it visible in a different compilation
unit.

Fixes: ec3edaa7ca ("mptcp: Add handling of outgoing MP_JOIN requests")
Reviewed-by: Mat Martineau <mathew.j.martineau>@linux.intel.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-12-01 09:04:49 +01:00
Eric Dumazet 10ef3a1c93 mptcp: fix delack timer
[ Upstream commit ee50e67ba0 ]

To compute the rtx timeout schedule_3rdack_retransmission() does multiple
things in the wrong way: srtt_us is measured in usec/8 and the timeout
itself is an absolute value.

Fixes: ec3edaa7ca ("mptcp: Add handling of outgoing MP_JOIN requests")
Acked-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau>@linux.intel.com>
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>
2021-12-01 09:04:49 +01:00
Florian Westphal c9f95c6783 mptcp: do not shrink snd_nxt when recovering
[ Upstream commit 0d199e4363 ]

When recovering after a link failure, snd_nxt should not be set to a
lower value.  Else, update of snd_nxt is broken because:

  msk->snd_nxt += ret; (where ret is number of bytes sent)

assumes that snd_nxt always moves forward.
After reduction, its possible that snd_nxt update gets out of sync:
dfrag we just sent might have had a data sequence number even past
recovery_snd_nxt.

This change factors the common msk state update to a helper
and updates snd_nxt based on the current dfrag data sequence number.

The conditional is required for the recovery phase where we may
re-transmit old dfrags that are before current snd_nxt.

After this change, snd_nxt only moves forward and covers all in-sequence
data that was transmitted.

recovery_snd_nxt is retained to detect when recovery has completed.

Fixes: 1e1d9d6f11 ("mptcp: handle pending data on closed subflow")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-11-18 19:16:25 +01:00
Davide Caratti f7cc8890f3 mptcp: fix corrupt receiver key in MPC + data + checksum
using packetdrill it's possible to observe that the receiver key contains
random values when clients transmit MP_CAPABLE with data and checksum (as
specified in RFC8684 §3.1). Fix the layout of mptcp_out_options, to avoid
using the skb extension copy when writing the MP_CAPABLE sub-option.

Fixes: d7b2690837 ("mptcp: shrink mptcp_out_options struct")
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/233
Reported-by: Poorva Sonparote <psonparo@redhat.com>
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Link: https://lore.kernel.org/r/20211027203855.264600-1-mathew.j.martineau@linux.intel.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-10-28 08:19:06 -07:00
Paolo Abeni 612f71d732 mptcp: fix possible stall on recvmsg()
recvmsg() can enter an infinite loop if the caller provides the
MSG_WAITALL, the data present in the receive queue is not sufficient to
fulfill the request, and no more data is received by the peer.

When the above happens, mptcp_wait_data() will always return with
no wait, as the MPTCP_DATA_READY flag checked by such function is
set and never cleared in such code path.

Leveraging the above syzbot was able to trigger an RCU stall:

rcu: INFO: rcu_preempt self-detected stall on CPU
rcu:    0-...!: (10499 ticks this GP) idle=0af/1/0x4000000000000000 softirq=10678/10678 fqs=1
        (t=10500 jiffies g=13089 q=109)
rcu: rcu_preempt kthread starved for 10497 jiffies! g13089 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1
rcu:    Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
task:rcu_preempt     state:R  running task     stack:28696 pid:   14 ppid:     2 flags:0x00004000
Call Trace:
 context_switch kernel/sched/core.c:4955 [inline]
 __schedule+0x940/0x26f0 kernel/sched/core.c:6236
 schedule+0xd3/0x270 kernel/sched/core.c:6315
 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1881
 rcu_gp_fqs_loop+0x186/0x810 kernel/rcu/tree.c:1955
 rcu_gp_kthread+0x1de/0x320 kernel/rcu/tree.c:2128
 kthread+0x405/0x4f0 kernel/kthread.c:327
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 8510 Comm: syz-executor827 Not tainted 5.15.0-rc2-next-20210920-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:bytes_is_nonzero mm/kasan/generic.c:84 [inline]
RIP: 0010:memory_is_nonzero mm/kasan/generic.c:102 [inline]
RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:128 [inline]
RIP: 0010:memory_is_poisoned mm/kasan/generic.c:159 [inline]
RIP: 0010:check_region_inline mm/kasan/generic.c:180 [inline]
RIP: 0010:kasan_check_range+0xc8/0x180 mm/kasan/generic.c:189
Code: 38 00 74 ed 48 8d 50 08 eb 09 48 83 c0 01 48 39 d0 74 7a 80 38 00 74 f2 48 89 c2 b8 01 00 00 00 48 85 d2 75 56 5b 5d 41 5c c3 <48> 85 d2 74 5e 48 01 ea eb 09 48 83 c0 01 48 39 d0 74 50 80 38 00
RSP: 0018:ffffc9000cd676c8 EFLAGS: 00000283
RAX: ffffed100e9a110e RBX: ffffed100e9a110f RCX: ffffffff88ea062a
RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffff888074d08870
RBP: ffffed100e9a110e R08: 0000000000000001 R09: ffff888074d08877
R10: ffffed100e9a110e R11: 0000000000000000 R12: ffff888074d08000
R13: ffff888074d08000 R14: ffff888074d08088 R15: ffff888074d08000
FS:  0000555556d8e300(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
S:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020000180 CR3: 0000000068909000 CR4: 00000000001506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 instrument_atomic_read_write include/linux/instrumented.h:101 [inline]
 test_and_clear_bit include/asm-generic/bitops/instrumented-atomic.h:83 [inline]
 mptcp_release_cb+0x14a/0x210 net/mptcp/protocol.c:3016
 release_sock+0xb4/0x1b0 net/core/sock.c:3204
 mptcp_wait_data net/mptcp/protocol.c:1770 [inline]
 mptcp_recvmsg+0xfd1/0x27b0 net/mptcp/protocol.c:2080
 inet6_recvmsg+0x11b/0x5e0 net/ipv6/af_inet6.c:659
 sock_recvmsg_nosec net/socket.c:944 [inline]
 ____sys_recvmsg+0x527/0x600 net/socket.c:2626
 ___sys_recvmsg+0x127/0x200 net/socket.c:2670
 do_recvmmsg+0x24d/0x6d0 net/socket.c:2764
 __sys_recvmmsg net/socket.c:2843 [inline]
 __do_sys_recvmmsg net/socket.c:2866 [inline]
 __se_sys_recvmmsg net/socket.c:2859 [inline]
 __x64_sys_recvmmsg+0x20b/0x260 net/socket.c:2859
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7fc200d2dc39
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 41 15 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 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffc5758e5a8 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007fc200d2dc39
RDX: 0000000000000002 RSI: 00000000200017c0 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000f0b5ff
R10: 0000000000000100 R11: 0000000000000246 R12: 0000000000000003
R13: 00007ffc5758e5d0 R14: 00007ffc5758e5c0 R15: 0000000000000003

Fix the issue by replacing the MPTCP_DATA_READY bit with direct
inspection of the msk receive queue.

Reported-and-tested-by: syzbot+3360da629681aa0d22fe@syzkaller.appspotmail.com
Fixes: 7a6a6cbc3e ("mptcp: recvmsg() can drain data from multiple subflow")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-10-08 14:55:54 +01:00
Paolo Abeni 4905455628 net: introduce and use lock_sock_fast_nested()
Syzkaller reported a false positive deadlock involving
the nl socket lock and the subflow socket lock:

MPTCP: kernel_bind error, err=-98
============================================
WARNING: possible recursive locking detected
5.15.0-rc1-syzkaller #0 Not tainted
--------------------------------------------
syz-executor998/6520 is trying to acquire lock:
ffff8880795718a0 (k-sk_lock-AF_INET){+.+.}-{0:0}, at: mptcp_close+0x267/0x7b0 net/mptcp/protocol.c:2738

but task is already holding lock:
ffff8880787c8c60 (k-sk_lock-AF_INET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1612 [inline]
ffff8880787c8c60 (k-sk_lock-AF_INET){+.+.}-{0:0}, at: mptcp_close+0x23/0x7b0 net/mptcp/protocol.c:2720

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
       ----
  lock(k-sk_lock-AF_INET);
  lock(k-sk_lock-AF_INET);

 *** DEADLOCK ***

 May be due to missing lock nesting notation

3 locks held by syz-executor998/6520:
 #0: ffffffff8d176c50 (cb_lock){++++}-{3:3}, at: genl_rcv+0x15/0x40 net/netlink/genetlink.c:802
 #1: ffffffff8d176d08 (genl_mutex){+.+.}-{3:3}, at: genl_lock net/netlink/genetlink.c:33 [inline]
 #1: ffffffff8d176d08 (genl_mutex){+.+.}-{3:3}, at: genl_rcv_msg+0x3e0/0x580 net/netlink/genetlink.c:790
 #2: ffff8880787c8c60 (k-sk_lock-AF_INET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1612 [inline]
 #2: ffff8880787c8c60 (k-sk_lock-AF_INET){+.+.}-{0:0}, at: mptcp_close+0x23/0x7b0 net/mptcp/protocol.c:2720

stack backtrace:
CPU: 1 PID: 6520 Comm: syz-executor998 Not tainted 5.15.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
 print_deadlock_bug kernel/locking/lockdep.c:2944 [inline]
 check_deadlock kernel/locking/lockdep.c:2987 [inline]
 validate_chain kernel/locking/lockdep.c:3776 [inline]
 __lock_acquire.cold+0x149/0x3ab kernel/locking/lockdep.c:5015
 lock_acquire kernel/locking/lockdep.c:5625 [inline]
 lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5590
 lock_sock_fast+0x36/0x100 net/core/sock.c:3229
 mptcp_close+0x267/0x7b0 net/mptcp/protocol.c:2738
 inet_release+0x12e/0x280 net/ipv4/af_inet.c:431
 __sock_release net/socket.c:649 [inline]
 sock_release+0x87/0x1b0 net/socket.c:677
 mptcp_pm_nl_create_listen_socket+0x238/0x2c0 net/mptcp/pm_netlink.c:900
 mptcp_nl_cmd_add_addr+0x359/0x930 net/mptcp/pm_netlink.c:1170
 genl_family_rcv_msg_doit+0x228/0x320 net/netlink/genetlink.c:731
 genl_family_rcv_msg net/netlink/genetlink.c:775 [inline]
 genl_rcv_msg+0x328/0x580 net/netlink/genetlink.c:792
 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2504
 genl_rcv+0x24/0x40 net/netlink/genetlink.c:803
 netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline]
 netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1340
 netlink_sendmsg+0x86d/0xdb0 net/netlink/af_netlink.c:1929
 sock_sendmsg_nosec net/socket.c:704 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:724
 sock_no_sendpage+0x101/0x150 net/core/sock.c:2980
 kernel_sendpage.part.0+0x1a0/0x340 net/socket.c:3504
 kernel_sendpage net/socket.c:3501 [inline]
 sock_sendpage+0xe5/0x140 net/socket.c:1003
 pipe_to_sendpage+0x2ad/0x380 fs/splice.c:364
 splice_from_pipe_feed fs/splice.c:418 [inline]
 __splice_from_pipe+0x43e/0x8a0 fs/splice.c:562
 splice_from_pipe fs/splice.c:597 [inline]
 generic_splice_sendpage+0xd4/0x140 fs/splice.c:746
 do_splice_from fs/splice.c:767 [inline]
 direct_splice_actor+0x110/0x180 fs/splice.c:936
 splice_direct_to_actor+0x34b/0x8c0 fs/splice.c:891
 do_splice_direct+0x1b3/0x280 fs/splice.c:979
 do_sendfile+0xae9/0x1240 fs/read_write.c:1249
 __do_sys_sendfile64 fs/read_write.c:1314 [inline]
 __se_sys_sendfile64 fs/read_write.c:1300 [inline]
 __x64_sys_sendfile64+0x1cc/0x210 fs/read_write.c:1300
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f215cb69969
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 14 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 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffc96bb3868 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00007f215cbad072 RCX: 00007f215cb69969
RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000005
RBP: 0000000000000000 R08: 00007ffc96bb3a08 R09: 00007ffc96bb3a08
R10: 0000000100000002 R11: 0000000000000246 R12: 00007ffc96bb387c
R13: 431bde82d7b634db R14: 0000000000000000 R15: 0000000000000000

the problem originates from uncorrect lock annotation in the mptcp
code and is only visible since commit 2dcb96bacc ("net: core: Correct
the sock::sk_lock.owned lockdep annotations"), but is present since
the port-based endpoint support initial implementation.

This patch addresses the issue introducing a nested variant of
lock_sock_fast() and using it in the relevant code path.

Fixes: 1729cf186d ("mptcp: create the listening socket for new port")
Fixes: 2dcb96bacc ("net: core: Correct the sock::sk_lock.owned lockdep annotations")
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Reported-and-tested-by: syzbot+1dd53f7a89b299d59eaf@syzkaller.appspotmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-09-30 13:06:47 +01:00
Davide Caratti 3f4a08909e mptcp: allow changing the 'backup' bit when no sockets are open
current Linux refuses to change the 'backup' bit of MPTCP endpoints, i.e.
using MPTCP_PM_CMD_SET_FLAGS, unless it finds (at least) one subflow that
matches the endpoint address. There is no reason for that, so we can just
ignore the return value of mptcp_nl_addr_backup(). In this way, endpoints
can reconfigure their 'backup' flag even if no MPTCP sockets are open (or
more generally, in case the MP_PRIO message is not sent out).

Fixes: 0f9f696a50 ("mptcp: add set_flags command in PM netlink")
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-09-24 10:51:36 +01:00
Florian Westphal ea1300b9df mptcp: don't return sockets in foreign netns
mptcp_token_get_sock() may return a mptcp socket that is in
a different net namespace than the socket that received the token value.

The mptcp syncookie code path had an explicit check for this,
this moves the test into mptcp_token_get_sock() function.

Eventually token.c should be converted to pernet storage, but
such change is not suitable for net tree.

Fixes: 2c5ebd001d ("mptcp: refactor token container")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-09-24 10:51:36 +01:00
Paolo Abeni 977d293e23 mptcp: ensure tx skbs always have the MPTCP ext
Due to signed/unsigned comparison, the expression:

	info->size_goal - skb->len > 0

evaluates to true when the size goal is smaller than the
skb size. That results in lack of tx cache refill, so that
the skb allocated by the core TCP code lacks the required
MPTCP skb extensions.

Due to the above, syzbot is able to trigger the following WARN_ON():

WARNING: CPU: 1 PID: 810 at net/mptcp/protocol.c:1366 mptcp_sendmsg_frag+0x1362/0x1bc0 net/mptcp/protocol.c:1366
Modules linked in:
CPU: 1 PID: 810 Comm: syz-executor.4 Not tainted 5.14.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:mptcp_sendmsg_frag+0x1362/0x1bc0 net/mptcp/protocol.c:1366
Code: ff 4c 8b 74 24 50 48 8b 5c 24 58 e9 0f fb ff ff e8 13 44 8b f8 4c 89 e7 45 31 ed e8 98 57 2e fe e9 81 f4 ff ff e8 fe 43 8b f8 <0f> 0b 41 bd ea ff ff ff e9 6f f4 ff ff 4c 89 e7 e8 b9 8e d2 f8 e9
RSP: 0018:ffffc9000531f6a0 EFLAGS: 00010216
RAX: 000000000000697f RBX: 0000000000000000 RCX: ffffc90012107000
RDX: 0000000000040000 RSI: ffffffff88eac9e2 RDI: 0000000000000003
RBP: ffff888078b15780 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffff88eac017 R11: 0000000000000000 R12: ffff88801de0a280
R13: 0000000000006b58 R14: ffff888066278280 R15: ffff88803c2fe9c0
FS:  00007fd9f866e700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007faebcb2f718 CR3: 00000000267cb000 CR4: 00000000001506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 __mptcp_push_pending+0x1fb/0x6b0 net/mptcp/protocol.c:1547
 mptcp_release_cb+0xfe/0x210 net/mptcp/protocol.c:3003
 release_sock+0xb4/0x1b0 net/core/sock.c:3206
 sk_stream_wait_memory+0x604/0xed0 net/core/stream.c:145
 mptcp_sendmsg+0xc39/0x1bc0 net/mptcp/protocol.c:1749
 inet6_sendmsg+0x99/0xe0 net/ipv6/af_inet6.c:643
 sock_sendmsg_nosec net/socket.c:704 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:724
 sock_write_iter+0x2a0/0x3e0 net/socket.c:1057
 call_write_iter include/linux/fs.h:2163 [inline]
 new_sync_write+0x40b/0x640 fs/read_write.c:507
 vfs_write+0x7cf/0xae0 fs/read_write.c:594
 ksys_write+0x1ee/0x250 fs/read_write.c:647
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x4665f9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fd9f866e188 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 000000000056c038 RCX: 00000000004665f9
RDX: 00000000000e7b78 RSI: 0000000020000000 RDI: 0000000000000003
RBP: 00000000004bfcc4 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056c038
R13: 0000000000a9fb1f R14: 00007fd9f866e300 R15: 0000000000022000

Fix the issue rewriting the relevant expression to avoid
sign-related problems - note: size_goal is always >= 0.

Additionally, ensure that the skb in the tx cache always carries
the relevant extension.

Reported-and-tested-by: syzbot+263a248eec3e875baa7b@syzkaller.appspotmail.com
Fixes: 1094c6fe72 ("mptcp: fix possible divide by zero")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-09-22 14:39:41 +01:00
Mat Martineau 340fa6667a mptcp: Only send extra TCP acks in eligible socket states
Recent changes exposed a bug where specifically-timed requests to the
path manager netlink API could trigger a divide-by-zero in
__tcp_select_window(), as syzkaller does:

divide error: 0000 [#1] SMP KASAN NOPTI
CPU: 0 PID: 9667 Comm: syz-executor.0 Not tainted 5.14.0-rc6+ #3
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014
RIP: 0010:__tcp_select_window+0x509/0xa60 net/ipv4/tcp_output.c:3016
Code: 44 89 ff e8 c9 29 e9 fd 45 39 e7 0f 8d 20 ff ff ff e8 db 28 e9 fd 44 89 e3 e9 13 ff ff ff e8 ce 28 e9 fd 44 89 e0 44 89 e3 99 <f7> 7c 24 04 29 d3 e9 fc fe ff ff e8 b7 28 e9 fd 44 89 f1 48 89 ea
RSP: 0018:ffff888031ccf020 EFLAGS: 00010216
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000040000
RDX: 0000000000000000 RSI: ffff88811532c080 RDI: 0000000000000002
RBP: 0000000000000000 R08: ffffffff835807c2 R09: 0000000000000000
R10: 0000000000000004 R11: ffffed1020b92441 R12: 0000000000000000
R13: 1ffff11006399e08 R14: 0000000000000000 R15: 0000000000000000
FS:  00007fa4c8344700(0000) GS:ffff88811ae00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2f424000 CR3: 000000003e4e2003 CR4: 0000000000770ef0
PKRU: 55555554
Call Trace:
 tcp_select_window net/ipv4/tcp_output.c:264 [inline]
 __tcp_transmit_skb+0xc00/0x37a0 net/ipv4/tcp_output.c:1351
 __tcp_send_ack.part.0+0x3ec/0x760 net/ipv4/tcp_output.c:3972
 __tcp_send_ack net/ipv4/tcp_output.c:3978 [inline]
 tcp_send_ack+0x7d/0xa0 net/ipv4/tcp_output.c:3978
 mptcp_pm_nl_addr_send_ack+0x1ab/0x380 net/mptcp/pm_netlink.c:654
 mptcp_pm_remove_addr+0x161/0x200 net/mptcp/pm.c:58
 mptcp_nl_remove_id_zero_address+0x197/0x460 net/mptcp/pm_netlink.c:1328
 mptcp_nl_cmd_del_addr+0x98b/0xd40 net/mptcp/pm_netlink.c:1359
 genl_family_rcv_msg_doit.isra.0+0x225/0x340 net/netlink/genetlink.c:731
 genl_family_rcv_msg net/netlink/genetlink.c:775 [inline]
 genl_rcv_msg+0x341/0x5b0 net/netlink/genetlink.c:792
 netlink_rcv_skb+0x148/0x430 net/netlink/af_netlink.c:2504
 genl_rcv+0x24/0x40 net/netlink/genetlink.c:803
 netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline]
 netlink_unicast+0x537/0x750 net/netlink/af_netlink.c:1340
 netlink_sendmsg+0x846/0xd80 net/netlink/af_netlink.c:1929
 sock_sendmsg_nosec net/socket.c:704 [inline]
 sock_sendmsg+0x14e/0x190 net/socket.c:724
 ____sys_sendmsg+0x709/0x870 net/socket.c:2403
 ___sys_sendmsg+0xff/0x170 net/socket.c:2457
 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2486
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x38/0x90 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

mptcp_pm_nl_addr_send_ack() was attempting to send a TCP ACK on the
first subflow in the MPTCP socket's connection list without validating
that the subflow was in a suitable connection state. To address this,
always validate subflow state when sending extra ACKs on subflows
for address advertisement or subflow priority change.

Fixes: 84dfe3677a ("mptcp: send out dedicated ADD_ADDR packet")
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/229
Co-developed-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Acked-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-09-03 11:49:30 +01:00
Paolo Abeni 1094c6fe72 mptcp: fix possible divide by zero
Florian noted that if mptcp_alloc_tx_skb() allocation fails
in __mptcp_push_pending(), we can end-up invoking
mptcp_push_release()/tcp_push() with a zero mss, causing
a divide by 0 error.

This change addresses the issue refactoring the skb allocation
code checking if skb collapsing will happen for sure and doing
the skb allocation only after such check. Skb allocation will
now happen only after the call to tcp_send_mss() which
correctly initializes mss_now.

As side bonuses we now fill the skb tx cache only when needed,
and this also clean-up a bit the output path.

v1 -> v2:
 - use lockdep_assert_held_once() - Jakub
 - fix indentation - Jakub

Reported-by: Florian Westphal <fw@strlen.de>
Fixes: 724cfd2ee8 ("mptcp: allocate TX skbs in msk context")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-09-01 10:55:49 -07:00
Wan Jiabing 780aa1209f mptcp: Fix duplicated argument in protocol.h
Fix the following coccicheck warning:
./net/mptcp/protocol.h:36:50-73: duplicated argument to & or |

The OPTION_MPTCP_MPJ_SYNACK here is duplicate.
Here should be OPTION_MPTCP_MPJ_ACK.

Fixes: 74c7dfbee3 ("mptcp: consolidate in_opt sub-options fields in a bitmask")
Signed-off-by: Wan Jiabing <wanjiabing@vivo.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-09-01 12:51:48 +01:00
Paolo Abeni 9758f40e90 mptcp: make the locking tx schema more readable
Florian noted the locking schema used by __mptcp_push_pending()
is hard to follow, let's add some more descriptive comments
and drop an unneeded and confusing check.

Suggested-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-27 09:45:07 +01:00
Paolo Abeni f6c2ef59bc mptcp: optimize the input options processing
Most MPTCP packets carries a single MPTCP subption: the
DSS containing the mapping for the current packet.

Check explicitly for the above, so that is such scenario we
replace most conditional statements with a single likely() one.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-27 09:45:07 +01:00
Paolo Abeni 74c7dfbee3 mptcp: consolidate in_opt sub-options fields in a bitmask
This makes input options processing more consistent with
output ones and will simplify the next patch.

Also avoid clearing the suboption field after processing
it, since it's not needed.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-27 09:45:07 +01:00
Paolo Abeni a086aebae0 mptcp: better binary layout for mptcp_options_received
This change reorder the mptcp_options_received fields
to shrink the structure a bit and to ensure the most
frequently used fields are all in the first cacheline.

Sub-opt specific flags are moved out of the suboptions area,
and we must now explicitly set them when the relevant
suboption is parsed.

There is a notable exception: 'csum_reqd' is used by both DSS
and MPC suboptions, and keeping such field in the suboptions
flag area will simplfy the next patch.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-27 09:45:07 +01:00
Paolo Abeni 8d548ea1dd mptcp: do not set unconditionally csum_reqd on incoming opt
Should be set only if the ingress packets present it, otherwise
we can confuse csum validation.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-27 09:45:07 +01:00
Geliang Tang eb7f33654d mptcp: add the mibs for MP_FAIL
This patch added the mibs for MP_FAIL: MPTCP_MIB_MPFAILTX and
MPTCP_MIB_MPFAILRX.

Signed-off-by: Geliang Tang <geliangtang@xiaomi.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-25 11:02:35 +01:00
Geliang Tang 478d770008 mptcp: send out MP_FAIL when data checksum fails
When a bad checksum is detected, set the send_mp_fail flag to send out
the MP_FAIL option.

Add a new function mptcp_has_another_subflow() to check whether there's
only a single subflow.

When multiple subflows are in use, close the affected subflow with a RST
that includes an MP_FAIL option and discard the data with the bad
checksum.

Set the sk_state of the subsocket to TCP_CLOSE, then the flag
MPTCP_WORK_CLOSE_SUBFLOW will be set in subflow_sched_work_if_closed,
and the subflow will be closed.

When a single subfow is in use, temporarily handled by sending MP_FAIL
with a RST too.

Signed-off-by: Geliang Tang <geliangtang@xiaomi.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-25 11:02:35 +01:00
Geliang Tang 5580d41b75 mptcp: MP_FAIL suboption receiving
This patch added handling for receiving MP_FAIL suboption.

Add a new members mp_fail and fail_seq in struct mptcp_options_received.
When MP_FAIL suboption is received, set mp_fail to 1 and save the sequence
number to fail_seq.

Then invoke mptcp_pm_mp_fail_received to deal with the MP_FAIL suboption.

Signed-off-by: Geliang Tang <geliangtang@xiaomi.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-25 11:02:34 +01:00
Geliang Tang c25aeb4e09 mptcp: MP_FAIL suboption sending
This patch added the MP_FAIL suboption sending support.

Add a new flag named send_mp_fail in struct mptcp_subflow_context. If
this flag is set, send out MP_FAIL suboption.

Add a new member fail_seq in struct mptcp_out_options to save the data
sequence number to put into the MP_FAIL suboption.

An MP_FAIL option could be included in a RST or on the subflow-level
ACK.

Suggested-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Geliang Tang <geliangtang@xiaomi.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-25 11:02:34 +01:00
Paolo Abeni 1bff1e43a3 mptcp: optimize out option generation
Currently we have several protocol constraints on MPTCP options
generation (e.g. MPC and MPJ subopt are mutually exclusive)
and some additional ones required by our implementation
(e.g. almost all ADD_ADDR variant are mutually exclusive with
everything else).

We can leverage the above to optimize the out option generation:
we check DSS/MPC/MPJ presence in a mutually exclusive way,
avoiding many unneeded conditionals in the common cases.

Additionally extend the existing constraints on ADD_ADDR opt on
all subvariants, so that it becomes fully mutually exclusive with
the above and we can skip another conditional statement for the
common case.

This change is also needed by the next patch.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-25 11:02:34 +01:00
Yonglong Li c233ef1390 mptcp: remove MPTCP_ADD_ADDR_IPV6 and MPTCP_ADD_ADDR_PORT
MPTCP_ADD_ADDR_IPV6 and MPTCP_ADD_ADDR_PORT are not necessary, we can get
these info from pm.local or pm.remote.

Drop mptcp_pm_should_add_signal_ipv6 and mptcp_pm_should_add_signal_port
too.

Co-developed-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Yonglong Li <liyonglong@chinatelecom.cn>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-24 09:28:29 +01:00
Yonglong Li f462a44638 mptcp: build ADD_ADDR/echo-ADD_ADDR option according pm.add_signal
According to the MPTCP_ADD_ADDR_SIGNAL or MPTCP_ADD_ADDR_ECHO flag, build
the ADD_ADDR/ADD_ADDR_ECHO option.

In mptcp_pm_add_addr_signal(), use opts->addr to save the announced
ADD_ADDR or ADD_ADDR_ECHO address.

Co-developed-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Co-developed-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Yonglong Li <liyonglong@chinatelecom.cn>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-24 09:28:28 +01:00
Yonglong Li 119c022096 mptcp: fix ADD_ADDR and RM_ADDR maybe flush addr_signal each other
ADD_ADDR shares pm.addr_signal with RM_ADDR, so after RM_ADDR/ADD_ADDR
has done, we should not clean ADD_ADDR/RM_ADDR's addr_signal.

Co-developed-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Yonglong Li <liyonglong@chinatelecom.cn>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-24 09:28:28 +01:00
Yonglong Li 18fc1a922e mptcp: make MPTCP_ADD_ADDR_SIGNAL and MPTCP_ADD_ADDR_ECHO separate
Use MPTCP_ADD_ADDR_SIGNAL only for the action of sending ADD_ADDR, and
use MPTCP_ADD_ADDR_ECHO only for the action of sending ADD_ADDR echo.

Use msk->pm.local to save the announced ADD_ADDR address only, and reuse
msk->pm.remote to save the announced ADD_ADDR_ECHO address.

To prepare for the next patch.

Co-developed-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Yonglong Li <liyonglong@chinatelecom.cn>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-24 09:28:28 +01:00
Yonglong Li 1f5e9e2f5f mptcp: move drop_other_suboptions check under pm lock
This patch moved the drop_other_suboptions check from
mptcp_established_options_add_addr() into mptcp_pm_add_addr_signal(), do
it under the PM lock to avoid the race between this check and
mptcp_pm_add_addr_signal().

For this, added a new parameter for mptcp_pm_add_addr_signal() to get
the drop_other_suboptions value. And drop the other suboptions after the
option length check if drop_other_suboptions is true.

Additionally, always drop the other suboption for TCP pure ack:
that makes both the code simpler and the MPTCP behaviour more
consistent.

Co-developed-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Co-developed-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Yonglong Li <liyonglong@chinatelecom.cn>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-24 09:28:28 +01:00
Jakub Kicinski f444fea789 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
drivers/ptp/Kconfig:
  55c8fca1da ("ptp_pch: Restore dependency on PCI")
  e5f3155267 ("ethernet: fix PTP_1588_CLOCK dependencies")

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-08-19 18:09:18 -07:00
Matthieu Baerts 67b12f792d mptcp: full fully established support after ADD_ADDR
If directly after an MP_CAPABLE 3WHS, the client receives an ADD_ADDR
with HMAC from the server, it is enough to switch to a "fully
established" mode because it has received more MPTCP options.

It was then OK to enable the "fully_established" flag on the MPTCP
socket. Still, best to check if the ADD_ADDR looks valid by looking if
it contains an HMAC (no 'echo' bit). If an ADD_ADDR echo is received
while we are not in "fully established" mode, it is strange and then
we should not switch to this mode now.

But that is not enough. On one hand, the path-manager has be notified
the state has changed. On the other hand, the "fully_established" flag
on the subflow socket should be turned on as well not to re-send the
MP_CAPABLE 3rd ACK content with the next ACK.

Fixes: 84dfe3677a ("mptcp: send out dedicated ADD_ADDR packet")
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-19 12:16:54 +01:00
Paolo Abeni a0eea5f10e mptcp: fix memory leak on address flush
The endpoint cleanup path is prone to a memory leak, as reported
by syzkaller:

 BUG: memory leak
 unreferenced object 0xffff88810680ea00 (size 64):
   comm "syz-executor.6", pid 6191, jiffies 4295756280 (age 24.138s)
   hex dump (first 32 bytes):
     58 75 7d 3c 80 88 ff ff 22 01 00 00 00 00 ad de  Xu}<....".......
     01 00 02 00 00 00 00 00 ac 1e 00 07 00 00 00 00  ................
   backtrace:
     [<0000000072a9f72a>] kmalloc include/linux/slab.h:591 [inline]
     [<0000000072a9f72a>] mptcp_nl_cmd_add_addr+0x287/0x9f0 net/mptcp/pm_netlink.c:1170
     [<00000000f6e931bf>] genl_family_rcv_msg_doit.isra.0+0x225/0x340 net/netlink/genetlink.c:731
     [<00000000f1504a2c>] genl_family_rcv_msg net/netlink/genetlink.c:775 [inline]
     [<00000000f1504a2c>] genl_rcv_msg+0x341/0x5b0 net/netlink/genetlink.c:792
     [<0000000097e76f6a>] netlink_rcv_skb+0x148/0x430 net/netlink/af_netlink.c:2504
     [<00000000ceefa2b8>] genl_rcv+0x24/0x40 net/netlink/genetlink.c:803
     [<000000008ff91aec>] netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline]
     [<000000008ff91aec>] netlink_unicast+0x537/0x750 net/netlink/af_netlink.c:1340
     [<0000000041682c35>] netlink_sendmsg+0x846/0xd80 net/netlink/af_netlink.c:1929
     [<00000000df3aa8e7>] sock_sendmsg_nosec net/socket.c:704 [inline]
     [<00000000df3aa8e7>] sock_sendmsg+0x14e/0x190 net/socket.c:724
     [<000000002154c54c>] ____sys_sendmsg+0x709/0x870 net/socket.c:2403
     [<000000001aab01d7>] ___sys_sendmsg+0xff/0x170 net/socket.c:2457
     [<00000000fa3b1446>] __sys_sendmsg+0xe5/0x1b0 net/socket.c:2486
     [<00000000db2ee9c7>] do_syscall_x64 arch/x86/entry/common.c:50 [inline]
     [<00000000db2ee9c7>] do_syscall_64+0x38/0x90 arch/x86/entry/common.c:80
     [<000000005873517d>] entry_SYSCALL_64_after_hwframe+0x44/0xae

We should not require an allocation to cleanup stuff.

Rework the code a bit so that the additional RCU work is no more needed.

Fixes: 1729cf186d ("mptcp: create the listening socket for new port")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-19 12:16:54 +01:00
Geliang Tang 1a0d6136c5 mptcp: local addresses fullmesh
In mptcp_pm_nl_add_addr_received(), fill a temporary allocate array of
all local address corresponding to the fullmesh endpoint. If such array
is empty, keep the current behavior.

Elsewhere loop on such array and create a subflow for each local address
towards the given remote address

Suggested-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Geliang Tang <geliangtang@xiaomi.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-18 10:10:01 +01:00
Geliang Tang 2843ff6f36 mptcp: remote addresses fullmesh
This patch added and managed a new per endpoint flag, named
MPTCP_PM_ADDR_FLAG_FULLMESH.

In mptcp_pm_create_subflow_or_signal_addr(), if such flag is set, instead
of:
        remote_address((struct sock_common *)sk, &remote);
fill a temporary allocated array of all known remote address. After
releaseing the pm lock loop on such array and create a subflow for each
remote address from the given local.

Note that the we could still use an array even for non 'fullmesh'
endpoint: with a single entry corresponding to the primary MPC subflow
remote address.

Suggested-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Geliang Tang <geliangtang@xiaomi.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-18 10:10:01 +01:00
Geliang Tang ee285257a9 mptcp: drop flags and ifindex arguments
This patch added a new helper mptcp_pm_get_flags_and_ifindex_by_id(),
and used it in __mptcp_subflow_connect() to get the flags and ifindex
values.

Then the two arguments flags and ifindex of __mptcp_subflow_connect()
can be dropped.

Signed-off-by: Geliang Tang <geliangtang@xiaomi.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-18 10:10:01 +01:00
Paolo Abeni 0460ce229f mptcp: backup flag from incoming MPJ ack option
the parsed incoming backup flag is not propagated
to the subflow itself, the client may end-up using it
to send data.

Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/191
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-14 11:37:25 +01:00
Paolo Abeni fc1b4e3b62 mptcp: add mibs for stale subflows processing
This allows monitoring exceptional events like
active backup scenarios.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-14 11:37:25 +01:00
Paolo Abeni ff5a0b421c mptcp: faster active backup recovery
The msk can use backup subflows to transmit in-sequence data
only if there are no other active subflow. On active backup
scenario, the MPTCP connection can do forward progress only
due to MPTCP retransmissions - rtx can pick backup subflows.

This patch introduces a new flag flow MPTCP subflows: if the
underlying TCP connection made no progresses for long time,
and there are other less problematic subflows available, the
given subflow become stale.

Stale subflows are not considered active: if all non backup
subflows become stale, the MPTCP scheduler can pick backup
subflows for plain transmissions.

Stale subflows can return in active state, as soon as any reply
from the peer is observed.

Active backup scenarios can now leverage the available b/w
with no restrinction.

Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/207
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-14 11:37:25 +01:00
Paolo Abeni 6da14d74e2 mptcp: cleanup sysctl data and helpers
Reorder the data in mptcp_pernet to avoid wasting space
with no reasons and constify the access helpers.

No functional changes intended.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-14 11:37:25 +01:00
Paolo Abeni 1e1d9d6f11 mptcp: handle pending data on closed subflow
The PM can close active subflow, e.g. due to ingress RM_ADDR
option. Such subflow could carry data still unacked at the
MPTCP-level, both in the write and the rtx_queue, which has
never reached the other peer.

Currently the mptcp-level retransmission will deliver such data,
but at a very low rate (at most 1 DSM for each MPTCP rtx interval).

We can speed-up the recovery a lot, moving all the unacked in the
tcp write_queue, so that it will be pushed again via other
subflows, at the speed allowed by them.

Also make available the new helper for later patches.

Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/207
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-14 11:37:25 +01:00