Граф коммитов

597 Коммитов

Автор SHA1 Сообщение Дата
Paolo Abeni b46021ab83 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>
2023-07-05 18:25:04 +01:00
Paolo Abeni 42ff95b4bd 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>
2023-07-05 18:25:04 +01:00
Kuniyuki Iwashima b60d534d1e 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 13:51:54 +02:00
Paolo Abeni f0b4a4086c mptcp: stricter state check in mptcp_worker
commit d6a0443733 upstream.

As reported by Christoph, the mptcp protocol can run the
worker when the relevant msk socket is in an unexpected state:

connect()
// incoming reset + fastclose
// the mptcp worker is scheduled
mptcp_disconnect()
// msk is now CLOSED
listen()
mptcp_worker()

Leading to the following splat:

divide error: 0000 [#1] PREEMPT SMP
CPU: 1 PID: 21 Comm: kworker/1:0 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
Workqueue: events mptcp_worker
RIP: 0010:__tcp_select_window+0x22c/0x4b0 net/ipv4/tcp_output.c:3018
RSP: 0018:ffffc900000b3c98 EFLAGS: 00010293
RAX: 000000000000ffd7 RBX: 000000000000ffd7 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff8214ce97 RDI: 0000000000000004
RBP: 000000000000ffd7 R08: 0000000000000004 R09: 0000000000010000
R10: 000000000000ffd7 R11: ffff888005afa148 R12: 000000000000ffd7
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff88803ed00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000405270 CR3: 000000003011e006 CR4: 0000000000370ee0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 tcp_select_window net/ipv4/tcp_output.c:262 [inline]
 __tcp_transmit_skb+0x356/0x1280 net/ipv4/tcp_output.c:1345
 tcp_transmit_skb net/ipv4/tcp_output.c:1417 [inline]
 tcp_send_active_reset+0x13e/0x320 net/ipv4/tcp_output.c:3459
 mptcp_check_fastclose net/mptcp/protocol.c:2530 [inline]
 mptcp_worker+0x6c7/0x800 net/mptcp/protocol.c:2705
 process_one_work+0x3bd/0x950 kernel/workqueue.c:2390
 worker_thread+0x5b/0x610 kernel/workqueue.c:2537
 kthread+0x138/0x170 kernel/kthread.c:376
 ret_from_fork+0x2c/0x50 arch/x86/entry/entry_64.S:308
 </TASK>

This change addresses the issue explicitly checking for bad states
before running the mptcp worker.

Fixes: e16163b6e2 ("mptcp: refactor shutdown and close")
Cc: stable@vger.kernel.org
Reported-by: Christoph Paasch <cpaasch@apple.com>
Link: https://github.com/multipath-tcp/mptcp_net-next/issues/374
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Tested-by: Christoph Paasch <cpaasch@apple.com>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-04-20 12:13:56 +02:00
Paolo Abeni 925e1a510a mptcp: use mptcp_schedule_work instead of open-coding it
commit a5cb752b12 upstream.

Beyond reducing code duplication this also avoids scheduling
the mptcp_worker on a closed socket on some edge scenarios.

The addressed issue is actually older than the blamed commit
below, but this fix needs it as a pre-requisite.

Fixes: ba8f48f7a4 ("mptcp: introduce mptcp_schedule_work")
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>
2023-04-20 12:13:56 +02:00
Paolo Abeni ad7f9c6982 mptcp: fix lockdep false positive in mptcp_pm_nl_create_listen_socket()
commit cee4034a3d upstream.

Christoph reports a lockdep splat in the mptcp_subflow_create_socket()
error path, when such function is invoked by
mptcp_pm_nl_create_listen_socket().

Such code path acquires two separates, nested socket lock, with the
internal lock operation lacking the "nested" annotation. Adding that
in sock_release() for mptcp's sake only could be confusing.

Instead just add a new lockclass to the in-kernel msk socket,
re-initializing the lockdep infra after the socket creation.

Fixes: ad2171009d ("mptcp: fix locking for in-kernel listener creation")
Cc: stable@vger.kernel.org
Reported-by: Christoph Paasch <cpaasch@apple.com>
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/354
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Tested-by: Christoph Paasch <cpaasch@apple.com>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-22 13:31:35 +01:00
Matthieu Baerts f4afee17de mptcp: avoid setting TCP_CLOSE state twice
commit 3ba1452868 upstream.

tcp_set_state() is called from tcp_done() already.

There is then no need to first set the state to TCP_CLOSE, then call
tcp_done().

Fixes: d582484726 ("mptcp: fix fallback for MP_JOIN subflows")
Cc: stable@vger.kernel.org
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/362
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-22 13:31:34 +01:00
Geliang Tang 64473c18d2 mptcp: add ro_after_init for tcp{,v6}_prot_override
commit 822467a48e upstream.

Add __ro_after_init labels for the variables tcp_prot_override and
tcpv6_prot_override, just like other variables adjacent to them, to
indicate that they are initialised from the init hooks and no writes
occur afterwards.

Fixes: b19bc2945b ("mptcp: implement delegated actions")
Cc: stable@vger.kernel.org
Fixes: 51fa7f8ebf ("mptcp: mark ops structures as ro_after_init")
Signed-off-by: Geliang Tang <geliang.tang@suse.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>
2023-03-22 13:31:34 +01:00
Paolo Abeni c1df4bed3d mptcp: fix possible deadlock in subflow_error_report
commit b7a679ba7c upstream.

Christoph reported a possible deadlock while the TCP stack
destroys an unaccepted subflow due to an incoming reset: the
MPTCP socket error path tries to acquire the msk-level socket
lock while TCP still owns the listener socket accept queue
spinlock, and the reverse dependency already exists in the
TCP stack.

Note that the above is actually a lockdep false positive, as
the chain involves two separate sockets. A different per-socket
lockdep key will address the issue, but such a change will be
quite invasive.

Instead, we can simply stop earlier the socket error handling
for orphaned or unaccepted subflows, breaking the critical
lockdep chain. Error handling in such a scenario is a no-op.

Reported-and-tested-by: Christoph Paasch <cpaasch@apple.com>
Fixes: 15cc104533 ("mptcp: deliver ssk errors to msk")
Cc: stable@vger.kernel.org
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/355
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>
2023-03-22 13:31:34 +01:00
Paolo Abeni 3cfc5e84ac mptcp: do not wait for bare sockets' timeout
commit d4e85922e3 upstream.

If the peer closes all the existing subflows for a given
mptcp socket and later the application closes it, the current
implementation let it survive until the timewait timeout expires.

While the above is allowed by the protocol specification it
consumes resources for almost no reason and additionally
causes sporadic self-tests failures.

Let's move the mptcp socket to the TCP_CLOSE state when there are
no alive subflows at close time, so that the allocated resources
will be freed immediately.

Fixes: e16163b6e2 ("mptcp: refactor shutdown and close")
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-02-22 12:57:05 +01:00
Paolo Abeni 2a6853c0ea mptcp: fix locking for in-kernel listener creation
[ Upstream commit ad2171009d ]

For consistency, in mptcp_pm_nl_create_listen_socket(), we need to
call the __mptcp_nmpc_socket() under the msk socket lock.

Note that as a side effect, mptcp_subflow_create_socket() needs a
'nested' lockdep annotation, as it will acquire the subflow (kernel)
socket lock under the in-kernel listener msk socket lock.

The current lack of locking is almost harmless, because the relevant
socket is not exposed to the user space, but in future we will add
more complexity to the mentioned helper, let's play safe.

Fixes: 1729cf186d ("mptcp: create the listening socket for new port")
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: Sasha Levin <sashal@kernel.org>
2023-02-22 12:57:00 +01:00
Paolo Abeni 8d13f2c3e2 mptcp: be careful on subflow status propagation on errors
commit 1249db44a1 upstream.

Currently the subflow error report callback unconditionally
propagates the fallback subflow status to the owning msk.

If the msk is already orphaned, the above prevents the code
from correctly tracking the msk moving to the TCP_CLOSE state
and doing the appropriate cleanup.

All the above causes increasing memory usage over time and
sporadic self-tests failures.

There is a great deal of infrastructure trying to propagate
correctly the fallback subflow status to the owning mptcp socket,
e.g. via mptcp_subflow_eof() and subflow_sched_work_if_closed():
in the error propagation path we need only to cope with unorphaned
sockets.

Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/339
Fixes: 15cc104533 ("mptcp: deliver ssk errors to msk")
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-02-14 19:18:02 +01:00
Matthieu Baerts bd5dc96fea mptcp: use proper req destructor for IPv6
commit d3295fee3c upstream.

Before, only the destructor from TCP request sock in IPv4 was called
even if the subflow was IPv6.

It is important to use the right destructor to avoid memory leaks with
some advanced IPv6 features, e.g. when the request socks contain
specific IPv6 options.

Fixes: 79c0949e9a ("mptcp: Add key generation and token tree")
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
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>
2023-01-12 11:59:19 +01:00
Matthieu Baerts 78bd6ab52c mptcp: dedicated request sock for subflow in v6
commit 34b21d1ddc upstream.

tcp_request_sock_ops structure is specific to IPv4. It should then not
be used with MPTCP subflows on top of IPv6.

For example, it contains the 'family' field, initialised to AF_INET.
This 'family' field is used by TCP FastOpen code to generate the cookie
but also by TCP Metrics, SELinux and SYN Cookies. Using the wrong family
will not lead to crashes but displaying/using/checking wrong things.

Note that 'send_reset' callback from request_sock_ops structure is used
in some error paths. It is then also important to use the correct one
for IPv4 or IPv6.

The slab name can also be different in IPv4 and IPv6, it will be used
when printing some log messages. The slab pointer will anyway be the
same because the object size is the same for both v4 and v6. A
BUILD_BUG_ON() has also been added to make sure this size is the same.

Fixes: cec37a6e41 ("mptcp: Handle MP_CAPABLE options for outgoing connections")
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
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>
2023-01-12 11:59:19 +01:00
Matthieu Baerts a9e89a567f mptcp: remove MPTCP 'ifdef' in TCP SYN cookies
commit 3fff88186f upstream.

To ease the maintenance, it is often recommended to avoid having #ifdef
preprocessor conditions.

Here the section related to CONFIG_MPTCP was quite short but the next
commit needs to add more code around. It is then cleaner to move
specific MPTCP code to functions located in net/mptcp directory.

Now that mptcp_subflow_request_sock_ops structure can be static, it can
also be marked as "read only after init".

Suggested-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
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>
2023-01-12 11:58:52 +01:00
Florian Westphal 13b9fd0dee mptcp: mark ops structures as ro_after_init
commit 51fa7f8ebf upstream.

These structures are initialised from the init hooks, so we can't make
them 'const'.  But no writes occur afterwards, so we can use ro_after_init.

Also, remove bogus EXPORT_SYMBOL, the only access comes from ip
stack, not from kernel modules.

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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-12 11:58:52 +01:00
Yonglong Li af61a8f760 mptcp: Fix crash due to tcp_tsorted_anchor was initialized before release skb
commit 3ef3905aa3 upstream.

Got crash when doing pressure test of mptcp:

===========================================================================
dst_release: dst:ffffa06ce6e5c058 refcnt:-1
kernel tried to execute NX-protected page - exploit attempt? (uid: 0)
BUG: unable to handle kernel paging request at ffffa06ce6e5c058
PGD 190a01067 P4D 190a01067 PUD 43fffb067 PMD 22e403063 PTE 8000000226e5c063
Oops: 0011 [#1] SMP PTI
CPU: 7 PID: 7823 Comm: kworker/7:0 Kdump: loaded Tainted: G            E
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.2.1 04/01/2014
Call Trace:
 ? skb_release_head_state+0x68/0x100
 ? skb_release_all+0xe/0x30
 ? kfree_skb+0x32/0xa0
 ? mptcp_sendmsg_frag+0x57e/0x750
 ? __mptcp_retrans+0x21b/0x3c0
 ? __switch_to_asm+0x35/0x70
 ? mptcp_worker+0x25e/0x320
 ? process_one_work+0x1a7/0x360
 ? worker_thread+0x30/0x390
 ? create_worker+0x1a0/0x1a0
 ? kthread+0x112/0x130
 ? kthread_flush_work_fn+0x10/0x10
 ? ret_from_fork+0x35/0x40
===========================================================================

In __mptcp_alloc_tx_skb skb was allocated and skb->tcp_tsorted_anchor will
be initialized, in under memory pressure situation sk_wmem_schedule will
return false and then kfree_skb. In this case skb->_skb_refdst is not null
because_skb_refdst and tcp_tsorted_anchor are stored in the same mem, and
kfree_skb will try to release dst and cause crash.

Fixes: f70cad1085 ("mptcp: stop relying on tcp_tx_skb_cache")
Reviewed-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>
Link: https://lore.kernel.org/r/20220317220953.426024-1-mathew.j.martineau@linux.intel.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-08-31 17:16:50 +02:00
Kuniyuki Iwashima 70564ad8d1 net: Fix data-races around sysctl_max_skb_frags.
[ Upstream commit 657b991afb ]

While reading sysctl_max_skb_frags, it can be changed concurrently.
Thus, we need to add READ_ONCE() to its readers.

Fixes: 5f74f82ea3 ("net:Add sysctl_max_skb_frags")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-08-31 17:16:44 +02:00
Paolo Abeni 289f2f5826 mptcp: stop relying on tcp_tx_skb_cache
[ Upstream commit f70cad1085 ]

We want to revert the skb TX cache, but MPTCP is currently
using it unconditionally.

Rework the MPTCP tx code, so that tcp_tx_skb_cache is not
needed anymore: do the whole coalescing check, skb allocation
skb initialization/update inside mptcp_sendmsg_frag(), quite
alike the current TCP code.

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>
2022-08-31 17:16:44 +02:00
Kuniyuki Iwashima 618116a273 net: Fix data-races around sysctl_[rw]mem(_offset)?.
[ Upstream commit 0273954595 ]

While reading these sysctl variables, they can be changed concurrently.
Thus, we need to add READ_ONCE() to their readers.

  - .sysctl_rmem
  - .sysctl_rwmem
  - .sysctl_rmem_offset
  - .sysctl_wmem_offset
  - sysctl_tcp_rmem[1, 2]
  - sysctl_tcp_wmem[1, 2]
  - sysctl_decnet_rmem[1]
  - sysctl_decnet_wmem[1]
  - sysctl_tipc_rmem[1]

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-08-03 12:03:51 +02:00
Kuniyuki Iwashima 664a3311e6 tcp: Fix data-races around sysctl_tcp_moderate_rcvbuf.
commit 7804764888 upstream.

While reading sysctl_tcp_moderate_rcvbuf, it can be changed
concurrently.  Thus, we need to add READ_ONCE() to its readers.

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-08-03 12:03:46 +02:00
Paolo Abeni c07f6772a0 mptcp: reset the packet scheduler on PRIO change
[ Upstream commit 0e203c3247 ]

Similar to the previous patch, for priority changes
requested by the local PM.

Reported-and-suggested-by: Davide Caratti <dcaratti@redhat.com>
Fixes: 067065422f ("mptcp: add the outgoing MP_PRIO support")
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>
2022-06-09 10:22:46 +02:00
Mat Martineau d12cd0bf5d mptcp: Do TCP fallback on early DSS checksum failure
commit ae66fb2ba6 upstream.

RFC 8684 section 3.7 describes several opportunities for a MPTCP
connection to "fall back" to regular TCP early in the connection
process, before it has been confirmed that MPTCP options can be
successfully propagated on all SYN, SYN/ACK, and data packets. If a peer
acknowledges the first received data packet with a regular TCP header
(no MPTCP options), fallback is allowed.

If the recipient of that first data packet finds a MPTCP DSS checksum
error, this provides an opportunity to fail gracefully with a TCP
fallback rather than resetting the connection (as might happen if a
checksum failure were detected later).

This commit modifies the checksum failure code to attempt fallback on
the initial subflow of a MPTCP connection, only if it's a failure in the
first data mapping. In cases where the peer initiates the connection,
requests checksums, is the first to send data, and the peer is sending
incorrect checksums (see
https://github.com/multipath-tcp/mptcp_net-next/issues/275), this allows
the connection to proceed as TCP rather than reset.

Fixes: dd8bcd1768 ("mptcp: validate the data checksum")
Acked-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>
[mathew.j.martineau: backport: Resolved bitfield conflict in protocol.h]
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-05-25 14:42:07 +02:00
Paolo Abeni bf6800a394 mptcp: fix checksum byte order
[ Upstream commit ba2c89e0ea ]

The MPTCP code typecasts the checksum value to u16 and
then converts it to big endian while storing the value into
the MPTCP option.

As a result, the wire encoding for little endian host is
wrong, and that causes interoperabilty interoperability
issues with other implementation or host with different endianness.

Address the issue writing in the packet the unmodified __sum16 value.

MPTCP checksum is disabled by default, interoperating with systems
with bad mptcp-level csum encoding should cause fallback to TCP.

Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/275
Fixes: c5b39e26d0 ("mptcp: send out checksum for DSS")
Fixes: 390b95a5fb ("mptcp: receive checksum for DSS")
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>
2022-05-25 09:57:33 +02:00
Geliang Tang f67eeb03fe mptcp: reuse __mptcp_make_csum in validate_data_csum
[ Upstream commit 8401e87f5a ]

This patch reused __mptcp_make_csum() in validate_data_csum() instead of
open-coding.

Signed-off-by: Geliang Tang <geliang.tang@suse.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>
2022-05-25 09:57:33 +02:00
Geliang Tang 6e66d31618 mptcp: change the parameter of __mptcp_make_csum
[ Upstream commit c312ee2191 ]

This patch changed the type of the last parameter of __mptcp_make_csum()
from __sum16 to __wsum. And export this function in protocol.h.

Signed-off-by: Geliang Tang <geliang.tang@suse.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>
2022-05-25 09:57:33 +02:00
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