Currently any MPTCP socket using syn cookies will fallback to
TCP at 3rd ack time. In case of MP_JOIN requests, the RFC mandate
closing the child and sockets, but the existing error paths
do not handle the syncookie scenario correctly.
Address the issue always forcing the child shutdown in case of
MP_JOIN fallback.
Fixes: ae2dd71649 ("mptcp: handle tcp fallback when using syn cookies")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The msk ownership is transferred to the child socket at
3rd ack time, so that we avoid more lookups later. If the
request does not reach the 3rd ack, the MSK reference is
dropped at request sock release time.
As a side effect, fallback is now tracked by a NULL msk
reference instead of zeroed 'mp_join' field. This will
simplify the next patch.
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Use list_first_entry_or_null to simplify the code.
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We have defined MPTCP_PM_ADDR_MAX in pm_netlink.c, so drop this duplicate macro.
Fixes: 1b1c7a0ef7 ("mptcp: Add path manager interface")
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
If a listening MPTCP socket has unaccepted sockets at close
time, the related msks are freed via mptcp_sock_destruct(),
which in turn does not invoke the proto->destroy() method
nor the mptcp_token_destroy() function.
Due to the above, the child msk socket is not removed from
the token container, leading to later UaF.
Address the issue explicitly removing the token even in the
above error path.
Fixes: 79c0949e9a ("mptcp: Add key generation and token tree")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
The msk sk_shutdown flag is set by a workqueue, possibly
introducing some delay in user-space notification. If the last
subflow carries some data with the fin packet, the user space
can wake-up before RCV_SHUTDOWN is set. If it executes unblocking
recvmsg(), it may return with an error instead of eof.
Address the issue explicitly checking for eof in recvmsg(), when
no data is found.
Fixes: 59832e2465 ("mptcp: subflow: check parent mptcp socket on subflow state change")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
In MPTCPOPT_RM_ADDR option parsing, the pointer "ptr" pointed to the
"Subtype" octet, the pointer "ptr+1" pointed to the "Address ID" octet:
+-------+-------+---------------+
|Subtype|(resvd)| Address ID |
+-------+-------+---------------+
| |
ptr ptr+1
We should set mp_opt->rm_id to the value of "ptr+1", not "ptr". This patch
will fix this bug.
Fixes: 3df523ab58 ("mptcp: Add ADD_ADDR handling")
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pull networking updates from David Miller:
1) Allow setting bluetooth L2CAP modes via socket option, from Luiz
Augusto von Dentz.
2) Add GSO partial support to igc, from Sasha Neftin.
3) Several cleanups and improvements to r8169 from Heiner Kallweit.
4) Add IF_OPER_TESTING link state and use it when ethtool triggers a
device self-test. From Andrew Lunn.
5) Start moving away from custom driver versions, use the globally
defined kernel version instead, from Leon Romanovsky.
6) Support GRO vis gro_cells in DSA layer, from Alexander Lobakin.
7) Allow hard IRQ deferral during NAPI, from Eric Dumazet.
8) Add sriov and vf support to hinic, from Luo bin.
9) Support Media Redundancy Protocol (MRP) in the bridging code, from
Horatiu Vultur.
10) Support netmap in the nft_nat code, from Pablo Neira Ayuso.
11) Allow UDPv6 encapsulation of ESP in the ipsec code, from Sabrina
Dubroca. Also add ipv6 support for espintcp.
12) Lots of ReST conversions of the networking documentation, from Mauro
Carvalho Chehab.
13) Support configuration of ethtool rxnfc flows in bcmgenet driver,
from Doug Berger.
14) Allow to dump cgroup id and filter by it in inet_diag code, from
Dmitry Yakunin.
15) Add infrastructure to export netlink attribute policies to
userspace, from Johannes Berg.
16) Several optimizations to sch_fq scheduler, from Eric Dumazet.
17) Fallback to the default qdisc if qdisc init fails because otherwise
a packet scheduler init failure will make a device inoperative. From
Jesper Dangaard Brouer.
18) Several RISCV bpf jit optimizations, from Luke Nelson.
19) Correct the return type of the ->ndo_start_xmit() method in several
drivers, it's netdev_tx_t but many drivers were using
'int'. From Yunjian Wang.
20) Add an ethtool interface for PHY master/slave config, from Oleksij
Rempel.
21) Add BPF iterators, from Yonghang Song.
22) Add cable test infrastructure, including ethool interfaces, from
Andrew Lunn. Marvell PHY driver is the first to support this
facility.
23) Remove zero-length arrays all over, from Gustavo A. R. Silva.
24) Calculate and maintain an explicit frame size in XDP, from Jesper
Dangaard Brouer.
25) Add CAP_BPF, from Alexei Starovoitov.
26) Support terse dumps in the packet scheduler, from Vlad Buslov.
27) Support XDP_TX bulking in dpaa2 driver, from Ioana Ciornei.
28) Add devm_register_netdev(), from Bartosz Golaszewski.
29) Minimize qdisc resets, from Cong Wang.
30) Get rid of kernel_getsockopt and kernel_setsockopt in order to
eliminate set_fs/get_fs calls. From Christoph Hellwig.
* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (2517 commits)
selftests: net: ip_defrag: ignore EPERM
net_failover: fixed rollback in net_failover_open()
Revert "tipc: Fix potential tipc_aead refcnt leak in tipc_crypto_rcv"
Revert "tipc: Fix potential tipc_node refcnt leak in tipc_rcv"
vmxnet3: allow rx flow hash ops only when rss is enabled
hinic: add set_channels ethtool_ops support
selftests/bpf: Add a default $(CXX) value
tools/bpf: Don't use $(COMPILE.c)
bpf, selftests: Use bpf_probe_read_kernel
s390/bpf: Use bcr 0,%0 as tail call nop filler
s390/bpf: Maintain 8-byte stack alignment
selftests/bpf: Fix verifier test
selftests/bpf: Fix sample_cnt shared between two threads
bpf, selftests: Adapt cls_redirect to call csum_level helper
bpf: Add csum_level helper for fixing up csum levels
bpf: Fix up bpf_skb_adjust_room helper's skb csum setting
sfc: add missing annotation for efx_ef10_try_update_nic_stats_vf()
crypto/chtls: IPv6 support for inline TLS
Crypto/chcr: Fixes a coccinile check error
Crypto/chcr: Fixes compilations warnings
...
Pull crypto updates from Herbert Xu:
"API:
- Introduce crypto_shash_tfm_digest() and use it wherever possible.
- Fix use-after-free and race in crypto_spawn_alg.
- Add support for parallel and batch requests to crypto_engine.
Algorithms:
- Update jitter RNG for SP800-90B compliance.
- Always use jitter RNG as seed in drbg.
Drivers:
- Add Arm CryptoCell driver cctrng.
- Add support for SEV-ES to the PSP driver in ccp"
* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (114 commits)
crypto: hisilicon - fix driver compatibility issue with different versions of devices
crypto: engine - do not requeue in case of fatal error
crypto: cavium/nitrox - Fix a typo in a comment
crypto: hisilicon/qm - change debugfs file name from qm_regs to regs
crypto: hisilicon/qm - add DebugFS for xQC and xQE dump
crypto: hisilicon/zip - add debugfs for Hisilicon ZIP
crypto: hisilicon/hpre - add debugfs for Hisilicon HPRE
crypto: hisilicon/sec2 - add debugfs for Hisilicon SEC
crypto: hisilicon/qm - add debugfs to the QM state machine
crypto: hisilicon/qm - add debugfs for QM
crypto: stm32/crc32 - protect from concurrent accesses
crypto: stm32/crc32 - don't sleep in runtime pm
crypto: stm32/crc32 - fix multi-instance
crypto: stm32/crc32 - fix run-time self test issue.
crypto: stm32/crc32 - fix ext4 chksum BUG_ON()
crypto: hisilicon/zip - Use temporary sqe when doing work
crypto: hisilicon - add device error report through abnormal irq
crypto: hisilicon - remove codes of directly report device errors through MSI
crypto: hisilicon - QM memory management optimization
crypto: hisilicon - unify initial value assignment into QM
...
xdp_umem.c had overlapping changes between the 64-bit math fix
for the calculation of npgs and the removal of the zerocopy
memory type which got rid of the chunk_size_nohdr member.
The mlx5 Kconfig conflict is a case where we just take the
net-next copy of the Kconfig entry dependency as it takes on
the ESWITCH dependency by one level of indirection which is
what the 'net' conflicting change is trying to ensure.
Signed-off-by: David S. Miller <davem@davemloft.net>
When token lookup on MP_JOIN 3rd ack fails, the server
socket closes with a reset the incoming child. Such socket
has the 'is_mptcp' flag set, but no msk socket associated
- due to the failed lookup.
While crafting the reset packet mptcp_established_options_mp()
will try to dereference the child's master socket, causing
a NULL ptr dereference.
This change addresses the issue with explicit fallback to
TCP in such error path.
Fixes: 729cd6436f ("mptcp: cope better with MP_JOIN failure")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently we remote the msk from the token container only
via mptcp_close(). The MPTCP master socket can be destroyed
also via other paths (e.g. if not yet accepted, when shutting
down the listener socket). When we hit the latter scenario,
dangling msk references are left into the token container,
leading to memory corruption and/or UaF.
This change addresses the issue by moving the token removal
into the msk destructor.
Fixes: 79c0949e9a ("mptcp: Add key generation and token tree")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
If a MP_JOIN subflow completes the 3whs while another
CPU is closing the master msk, we can hit the
following race:
CPU1 CPU2
close()
mptcp_close
subflow_syn_recv_sock
mptcp_token_get_sock
mptcp_finish_join
inet_sk_state_load
mptcp_token_destroy
inet_sk_state_store(TCP_CLOSE)
__mptcp_flush_join_list()
mptcp_sock_graft
list_add_tail
sk_common_release
sock_orphan()
<socket free>
The MP_JOIN socket will be leaked. Additionally we can hit
UaF for the msk 'struct socket' referenced via the 'conn'
field.
This change try to address the issue introducing some
synchronization between the MP_JOIN 3whs and mptcp_close
via the join_list spinlock. If we detect the msk is closing
the MP_JOIN socket is closed, too.
Fixes: f296234c98 ("mptcp: Add handling of incoming MP_JOIN requests")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently unblocking connect() on MPTCP sockets fails frequently.
If mptcp_stream_connect() is invoked to complete a previously
attempted unblocking connection, it will still try to create
the first subflow via __mptcp_socket_create(). If the 3whs is
completed and the 'can_ack' flag is already set, the latter
will fail with -EINVAL.
This change addresses the issue checking for pending connect and
delegating the completion to the first subflow. Additionally
do msk addresses and sk_state changes only when needed.
Fixes: 2303f994b3 ("mptcp: Associate MPTCP context with TCP socket")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We can try to coalesce skbs we take from the subflows rx queue with the
tail of the mptcp rx queue.
If successful, the skb head can be discarded early.
We can also free the skb extensions, we do not access them after this.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
The MSCC bug fix in 'net' had to be slightly adjusted because the
register accesses are done slightly differently in net-next.
Signed-off-by: David S. Miller <davem@davemloft.net>
There is some ambiguity in the RFC as to whether the ADD_ADDR HMAC is
the rightmost 64 bits of the entire hash or of the leftmost 160 bits
of the hash. The intention, as clarified with the author of the RFC,
is the entire hash.
This change returns the entire hash from
mptcp_crypto_hmac_sha (instead of only the first 160 bits), and moves
any truncation/selection operation on the hash to the caller.
Fixes: 12555a2d97 ("mptcp: use rightmost 64 bits in ADD_ADDR HMAC")
Reviewed-by: Christoph Paasch <cpaasch@apple.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Todd Malsbary <todd.malsbary@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This changes the HMAC used in the ADD_ADDR option from the leftmost 64
bits to the rightmost 64 bits as described in RFC 8684, section 3.4.1.
This issue was discovered while adding support to packetdrill for the
ADD_ADDR v1 option.
Fixes: 3df523ab58 ("mptcp: Add ADD_ADDR handling")
Signed-off-by: Todd Malsbary <todd.malsbary@linux.intel.com>
Acked-by: Christoph Paasch <cpaasch@apple.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
To prepare removing the global routing_ioctl hack start lifting the code
into a newly added ipv6 ->compat_ioctl handler.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
mptcp calls this from the transmit side, from process context.
Allow a sleeping allocation instead of unconditional GFP_ATOMIC.
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
previous patches made sure we only call into this function
when these prerequisites are met, so no need to wait on the
subflow socket anymore.
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/7
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
The mptcp_sendmsg_frag helper contains a loop that will wait on the
subflow sk.
It seems preferrable to only wait in mptcp_sendmsg() when blocking io is
requested. mptcp_sendmsg already has such a wait loop that is used when
no subflow socket is available for transmission.
This is another preparation patch that makes sure we call
mptcp_sendmsg_frag only if the page frag cache has been refilled.
Followup patch will remove the wait loop from mptcp_sendmsg_frag().
The retransmit worker doesn't need to do this refill as it won't
transmit new mptcp-level data.
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
The mptcp_sendmsg_frag helper contains a loop that will wait on the
subflow sk.
It seems preferrable to only wait in mptcp_sendmsg() when blocking io is
requested. mptcp_sendmsg already has such a wait loop that is used when
no subflow socket is available for transmission.
This is a preparation patch that makes sure we call
mptcp_sendmsg_frag only if a skb extension has been allocated.
Moreover, such allocation currently uses GFP_ATOMIC while it
could use sleeping allocation instead.
Followup patches will remove the wait loop from mptcp_sendmsg_frag()
and will allow to do a sleeping allocation for the extension.
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
The transmit loop continues to xmit new data until an error is returned
or all data was transmitted.
For the blocking i/o case, this means that tcp_sendpages() may block on
the subflow until more space becomes available, i.e. we end up sleeping
with the mptcp socket lock held.
Instead we should check if a different subflow is ready to be used.
This restarts the subflow sk lookup when the tx operation succeeded
and the tcp subflow can't accept more data or if tcp_sendpages
indicates -EAGAIN on a blocking mptcp socket.
In that case we also need to set the NOSPACE bit to make sure we get
notified once memory becomes available.
In case all subflows are busy, the existing logic will wait until a
subflow is ready, releasing the mptcp socket lock while doing so.
The mptcp worker already sets DONTWAIT, so no need to make changes there.
v2:
* set NOSPACE bit
* add a comment to clarify that mptcp-sk sndbuf limits need to
be checked as well.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Its not enough to check for available tcp send space.
We also hold on to transmitted data for mptcp-level retransmits.
Right now we will send more and more data if the peer can ack data
at the tcp level fast enough, since that frees up tcp send buffer space.
But we also need to check that data was acked and reclaimed at the mptcp
level.
Therefore add needed check in mptcp_sendmsg, flush tcp data and
wait until more mptcp snd space becomes available if we are over the
limit. Before we wait for more data, also make sure we start the
retransmit timer if we ran out of sndbuf space.
Otherwise there is a very small chance that we wait forever:
* receiver is waiting for data
* sender is blocked because mptcp socket buffer is full
* at tcp level, all data was acked
* mptcp-level snd_una was not updated, because last ack
that acknowledged the last data packet carried an older
MPTCP-ack.
Restarting the retransmit timer avoids this problem: if TCP
subflow is idle, data is retransmitted from the RTX queue.
New data will make the peer send a new, updated MPTCP-Ack.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Paolo noticed that ssk_check_wmem() has same pattern, so add/use
common helper for both places.
Suggested-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
RFC8684 allows to send 32-bit DATA_ACKs as long as the peer is not
sending 64-bit data-sequence numbers. The 64-bit DSN is only there for
extreme scenarios when a very high throughput subflow is combined with a
long-RTT subflow such that the high-throughput subflow wraps around the
32-bit sequence number space within an RTT of the high-RTT subflow.
It is thus a rare scenario and we should try to use the 32-bit DATA_ACK
instead as long as possible. It allows to reduce the TCP-option overhead
by 4 bytes, thus makes space for an additional SACK-block. It also makes
tcpdumps much easier to read when the DSN and DATA_ACK are both either
32 or 64-bit.
Signed-off-by: Christoph Paasch <cpaasch@apple.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Move the bpf verifier trace check into the new switch statement in
HEAD.
Resolve the overlapping changes in hinic, where bug fixes overlap
the addition of VF support.
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently, on MP_JOIN failure we reset the child
socket, but leave the request socket untouched.
tcp_check_req will deal with it according to the
'tcp_abort_on_overflow' sysctl value - by default the
req socket will stay alive.
The above leads to inconsistent behavior on MP JOIN
failure, and bad listener overflow accounting.
This patch addresses the issue leveraging the infrastructure
just introduced to ask the TCP stack to drop the req on
failure.
The child socket is not freed anymore by subflow_syn_recv_sock(),
instead it's moved to a dead state and will be disposed by the
next sock_put done by the TCP stack, so that listener overflow
accounting is not affected by MP JOIN failure.
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Christoph Paasch <cpaasch@apple.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
MP_JOIN subflows must not land into the accept queue.
Currently tcp_check_req() calls an mptcp specific helper
to detect such scenario.
Such helper leverages the subflow context to check for
MP_JOIN subflows. We need to deal also with MP JOIN
failures, even when the subflow context is not available
due allocation failure.
A possible solution would be changing the syn_recv_sock()
signature to allow returning a more descriptive action/
error code and deal with that in tcp_check_req().
Since the above need is MPTCP specific, this patch instead
uses a TCP request socket hole to add a MPTCP specific flag.
Such flag is used by the MPTCP syn_recv_sock() to tell
tcp_check_req() how to deal with the request socket.
This change is a no-op for !MPTCP build, and makes the
MPTCP code simpler. It allows also the next patch to deal
correctly with MP JOIN failure.
v1 -> v2:
- be more conservative on drop_req initialization (Mat)
RFC -> v1:
- move the drop_req bit inside tcp_request_sock (Eric)
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Reviewed-by: Christoph Paasch <cpaasch@apple.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When the other MPTCP-peer uses 32-bit data-sequence numbers, we rely on
map_seq to indicate how to expand to a 64-bit data-sequence number in
expand_seq() when receiving data.
For new subflows, this field is not initialized, thus results in an
"invalid" mapping being discarded.
Fix this by initializing map_seq upon subflow establishment time.
Fixes: f296234c98 ("mptcp: Add handling of incoming MP_JOIN requests")
Signed-off-by: Christoph Paasch <cpaasch@apple.com>
Reviewed-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In preparation for naming the SHA-1 stuff in <linux/cryptohash.h>
properly and moving it to a more appropriate header, fix the HMAC-SHA256
code in mptcp_crypto_hmac_sha() to use SHA256_BLOCK_SIZE instead of
"SHA_MESSAGE_BYTES" which is actually the SHA-1 block size.
(Fortunately these are both 64 bytes, so this wasn't a "real" bug...)
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: mptcp@lists.01.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
When a subflow is created via mptcp_subflow_create_socket(),
a new 'struct socket' is allocated, with a new i_ino value.
When inspecting TCP sockets via the procfs and or the diag
interface, the above ones are not related to the process owning
the MPTCP master socket, even if they are a logical part of it
('ss -p' shows an empty process field)
Additionally, subflows created by the path manager get
the uid/gid from the running workqueue.
Subflows are part of the owning MPTCP master socket, let's
adjust the vfs info to reflect this.
After this patch, 'ss' correctly displays subflows as belonging
to the msk socket creator.
Fixes: 2303f994b3 ("mptcp: Associate MPTCP context with TCP socket")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
tcp_v{4,6}_syn_recv_sock() set 'own_req' only when returning
a not NULL 'child', let's check 'own_req' only if child is
available to avoid an - unharmful - UBSAN splat.
v1 -> v2:
- reference the correct hash
Fixes: 4c8941de78 ("mptcp: avoid flipping mp_capable field in syn_recv_sock()")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When parsing MPC+data packets we set the dss field, so
we must also initialize the data_fin, or we can find stray
value there.
Fixes: 9a19371bf0 ("mptcp: fix data_fin handing in RX path")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The mentioned RX option field is initialized only for DSS
packet, we must access it only if 'dss' is set too, or
the subflow will end-up in a bad status, leading to
RFC violations.
Fixes: d22f4988ff ("mptcp: process MP_CAPABLE data option")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Syzcaller has found a way to trigger the WARN_ON_ONCE condition
in check_fully_established().
The root cause is a legit fallback to TCP scenario, so replace
the WARN with a plain message on a more strict condition.
Fixes: f296234c98 ("mptcp: Add handling of incoming MP_JOIN requests")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently the MPTCP code uses 2 hooks to process syn-ack
packets, mptcp_rcv_synsent() and the sk_rx_dst_set()
callback.
We can drop the first, moving the relevant code into the
latter, reducing the hooking into the TCP code. This is
also needed by the next patch.
v1 -> v2:
- use local tcp sock ptr instead of casting the sk variable
several times - DaveM
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Paolo points out that mptcp_disconnect is bogus:
"lock_sock(sk);
looks suspicious (lock should be already held by the caller)
And call to: tcp_disconnect(sk, flags); too, sk is not a tcp
socket".
->disconnect() gets called from e.g. inet_stream_connect when
one tries to disassociate a connected socket again (to re-connect
without closing the socket first).
MPTCP however uses mptcp_stream_connect, not inet_stream_connect,
for the mptcp-socket connect call.
inet_stream_connect only gets called indirectly, for the tcp socket,
so any ->disconnect() calls end up calling tcp_disconnect for that
tcp subflow sk.
This also explains why syzkaller has not yet reported a problem
here. So for now replace this with a stub that doesn't do anything.
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/14
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently subflow_finish_connect() changes unconditionally
any msk socket status other than TCP_ESTABLISHED.
If an unblocking connect() races with close(), we can end-up
triggering:
IPv4: Attempt to release TCP socket in state 1 00000000e32b8b7e
when the msk socket is disposed.
Be sure to enter the established status only from SYN_SENT.
Fixes: c3c123d16c ("net: mptcp: don't hang in mptcp_sendmsg() after TCP fallback")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In MPTCP, the receive window is shared across all subflows, because it
refers to the mptcp-level sequence space.
MPTCP receivers already place incoming packets on the mptcp socket
receive queue and will charge it to the mptcp socket rcvbuf until
userspace consumes the data.
Update __tcp_select_window to use the occupancy of the parent/mptcp
socket instead of the subflow socket in case the tcp socket is part
of a logical mptcp connection.
This commit doesn't change choice of initial window for passive or active
connections.
While it would be possible to change those as well, this adds complexity
(especially when handling MP_JOIN requests). Furthermore, the MPTCP RFC
specifically says that a MPTCP sender 'MUST NOT use the RCV.WND field
of a TCP segment at the connection level if it does not also carry a DSS
option with a Data ACK field.'
SYN/SYNACK packets do not carry a DSS option with a Data ACK field.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Normal there should be checked for nla_put_in6_addr like other
usage in net.
Detected by CoverityScan, CID# 1461639
Fixes: 01cacb00b3 ("mptcp: add netlink-based PM")
Signed-off-by: Bo YU <tsu.yubo@gmail.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The data fin flag is set only via a DSS option, but
mptcp_incoming_options() copies it unconditionally from the
provided RX options.
Since we do not clear all the mptcp sock RX options in a
socket free/alloc cycle, we can end-up with a stray data_fin
value while parsing e.g. MPC packets.
That would lead to mapping data corruption and will trigger
a few WARN_ON() in the RX path.
Instead of adding a costly memset(), fetch the data_fin flag
only for DSS packets - when we always explicitly initialize
such bit at option parsing time.
Fixes: 648ef4b886 ("mptcp: Implement MPTCP receive path")
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>
We don't need them, as we can use the current ingress opt
data instead. Setting them in syn_recv_sock() may causes
inconsistent mptcp socket status, as per previous commit.
Fixes: cc7972ea19 ("mptcp: parse and emit MP_CAPABLE option according to v1 spec")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
If multiple CPUs races on the same req_sock in syn_recv_sock(),
flipping such field can cause inconsistent child socket status.
When racing, the CPU losing the req ownership may still change
the mptcp request socket mp_capable flag while the CPU owning
the request is cloning the socket, leaving the child socket with
'is_mptcp' set but no 'mp_capable' flag.
Such socket will stay with 'conn' field cleared, heading to oops
in later mptcp callback.
Address the issue tracking the fallback status in a local variable.
Fixes: 58b0991962 ("mptcp: create msk early")
Co-developed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Following splat can occur during self test:
BUG: KASAN: use-after-free in subflow_data_ready+0x156/0x160
Read of size 8 at addr ffff888100c35c28 by task mptcp_connect/4808
subflow_data_ready+0x156/0x160
tcp_child_process+0x6a3/0xb30
tcp_v4_rcv+0x2231/0x3730
ip_protocol_deliver_rcu+0x5c/0x860
ip_local_deliver_finish+0x220/0x360
ip_local_deliver+0x1c8/0x4e0
ip_rcv_finish+0x1da/0x2f0
ip_rcv+0xd0/0x3c0
__netif_receive_skb_one_core+0xf5/0x160
__netif_receive_skb+0x27/0x1c0
process_backlog+0x21e/0x780
net_rx_action+0x35f/0xe90
do_softirq+0x4c/0x50
[..]
This occurs when accessing subflow_ctx->conn.
Problem is that tcp_child_process() calls listen sockets'
sk_data_ready() notification, but it doesn't hold the listener
lock. Another cpu calling close() on the listener will then cause
transition of refcount to 0.
Fixes: 58b0991962 ("mptcp: create msk early")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
