commit e2f4ac7bab upstream.
When adding a socket option support in MPTCP, both the get and set parts
are supposed to be implemented.
IP(V6)_FREEBIND and IP(V6)_TRANSPARENT support for the setsockopt part
has been added a while ago, but it looks like the get part got
forgotten. It should have been present as a way to verify a setting has
been set as expected, and not to act differently from TCP or any other
socket types.
Everything was in place to expose it, just the last step was missing.
Only new code is added to cover these specific getsockopt(), that seems
safe.
Fixes: c9406a23c1 ("mptcp: sockopt: add SOL_IP freebind & transparent options")
Cc: stable@vger.kernel.org
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20250314-net-mptcp-fix-data-stream-corr-sockopt-v1-3-122dbb249db3@kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
[ Conflict in sockopt.c due to commit e08d0b3d17 ("inet: implement
lockless IP_TOS") not being in this version. The conflict is in the
context and the modification can still be applied in
mptcp_getsockopt_v4() after the IP_TOS case. ]
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 21c02e8272 upstream.
Recently, during a debugging session using local MPTCP connections, I
noticed MPJoinAckHMacFailure was not zero on the server side. The
counter was in fact incremented when the PM rejected new subflows,
because the 'subflow' limit was reached.
The fix is easy, simply dissociating the two cases: only the HMAC
validation check should increase MPTCP_MIB_JOINACKMAC counter.
Fixes: 4cf8b7e48a ("subflow: introduce and use mptcp_can_accept_new_subflow()")
Cc: stable@vger.kernel.org
Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20250407-net-mptcp-hmac-failure-mib-v1-1-3c9ecd0a3a50@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 443041deb5 upstream.
When testing valkey benchmark tool with MPTCP, the kernel panics in
'mptcp_can_accept_new_subflow' because subflow_req->msk is NULL.
Call trace:
mptcp_can_accept_new_subflow (./net/mptcp/subflow.c:63 (discriminator 4)) (P)
subflow_syn_recv_sock (./net/mptcp/subflow.c:854)
tcp_check_req (./net/ipv4/tcp_minisocks.c:863)
tcp_v4_rcv (./net/ipv4/tcp_ipv4.c:2268)
ip_protocol_deliver_rcu (./net/ipv4/ip_input.c:207)
ip_local_deliver_finish (./net/ipv4/ip_input.c:234)
ip_local_deliver (./net/ipv4/ip_input.c:254)
ip_rcv_finish (./net/ipv4/ip_input.c:449)
...
According to the debug log, the same req received two SYN-ACK in a very
short time, very likely because the client retransmits the syn ack due
to multiple reasons.
Even if the packets are transmitted with a relevant time interval, they
can be processed by the server on different CPUs concurrently). The
'subflow_req->msk' ownership is transferred to the subflow the first,
and there will be a risk of a null pointer dereference here.
This patch fixes this issue by moving the 'subflow_req->msk' under the
`own_req == true` conditional.
Note that the !msk check in subflow_hmac_valid() can be dropped, because
the same check already exists under the own_req mpj branch where the
code has been moved to.
Fixes: 9466a1cceb ("mptcp: enable JOIN requests even if cookies are in use")
Cc: stable@vger.kernel.org
Suggested-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Gang Yan <yangang@kylinos.cn>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250328-net-mptcp-misc-fixes-6-15-v1-1-34161a482a7f@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 8c39633759 upstream.
When adding a socket option support in MPTCP, both the get and set parts
are supposed to be implemented.
IPV6_V6ONLY support for the setsockopt part has been added a while ago,
but it looks like the get part got forgotten. It should have been
present as a way to verify a setting has been set as expected, and not
to act differently from TCP or any other socket types.
Not supporting this getsockopt(IPV6_V6ONLY) blocks some apps which want
to check the default value, before doing extra actions. On Linux, the
default value is 0, but this can be changed with the net.ipv6.bindv6only
sysctl knob. On Windows, it is set to 1 by default. So supporting the
get part, like for all other socket options, is important.
Everything was in place to expose it, just the last step was missing.
Only new code is added to cover this specific getsockopt(), that seems
safe.
Fixes: c9b95a1359 ("mptcp: support IPV6_V6ONLY setsockopt")
Cc: stable@vger.kernel.org
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/550
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20250314-net-mptcp-fix-data-stream-corr-sockopt-v1-2-122dbb249db3@kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 2c1f97a52c upstream.
Because of the size restriction in the TCP options space, the MPTCP
ADD_ADDR option is exclusive and cannot be sent with other MPTCP ones.
For this reason, in the linked mptcp_out_options structure, group of
fields linked to different options are part of the same union.
There is a case where the mptcp_pm_add_addr_signal() function can modify
opts->addr, but not ended up sending an ADD_ADDR. Later on, back in
mptcp_established_options, other options will be sent, but with
unexpected data written in other fields due to the union, e.g. in
opts->ext_copy. This could lead to a data stream corruption in the next
packet.
Using an intermediate variable, prevents from corrupting previously
established DSS option. The assignment of the ADD_ADDR option
parameters is now done once we are sure this ADD_ADDR option can be set
in the packet, e.g. after having dropped other suboptions.
Fixes: 1bff1e43a3 ("mptcp: optimize out option generation")
Cc: stable@vger.kernel.org
Suggested-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Arthur Mongodin <amongodin@randorisec.fr>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
[ Matt: the commit message has been updated: long lines splits and some
clarifications. ]
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20250314-net-mptcp-fix-data-stream-corr-sockopt-v1-1-122dbb249db3@kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit db75a16813 ]
Recently, some fallback have been initiated, while the connection was
not supposed to fallback.
Add a safety check with a warning to detect when an wrong attempt to
fallback is being done. This should help detecting any future issues
quicker.
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250224-net-mptcp-misc-fixes-v1-3-f550f636b435@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 022bfe24aa upstream.
If multiple connection requests attempt to create an implicit mptcp
endpoint in parallel, more than one caller may end up in
mptcp_pm_nl_append_new_local_addr because none found the address in
local_addr_list during their call to mptcp_pm_nl_get_local_id. In this
case, the concurrent new_local_addr calls may delete the address entry
created by the previous caller. These deletes use synchronize_rcu, but
this is not permitted in some of the contexts where this function may be
called. During packet recv, the caller may be in a rcu read critical
section and have preemption disabled.
An example stack:
BUG: scheduling while atomic: swapper/2/0/0x00000302
Call Trace:
<IRQ>
dump_stack_lvl (lib/dump_stack.c:117 (discriminator 1))
dump_stack (lib/dump_stack.c:124)
__schedule_bug (kernel/sched/core.c:5943)
schedule_debug.constprop.0 (arch/x86/include/asm/preempt.h:33 kernel/sched/core.c:5970)
__schedule (arch/x86/include/asm/jump_label.h:27 include/linux/jump_label.h:207 kernel/sched/features.h:29 kernel/sched/core.c:6621)
schedule (arch/x86/include/asm/preempt.h:84 kernel/sched/core.c:6804 kernel/sched/core.c:6818)
schedule_timeout (kernel/time/timer.c:2160)
wait_for_completion (kernel/sched/completion.c:96 kernel/sched/completion.c:116 kernel/sched/completion.c:127 kernel/sched/completion.c:148)
__wait_rcu_gp (include/linux/rcupdate.h:311 kernel/rcu/update.c:444)
synchronize_rcu (kernel/rcu/tree.c:3609)
mptcp_pm_nl_append_new_local_addr (net/mptcp/pm_netlink.c:966 net/mptcp/pm_netlink.c:1061)
mptcp_pm_nl_get_local_id (net/mptcp/pm_netlink.c:1164)
mptcp_pm_get_local_id (net/mptcp/pm.c:420)
subflow_check_req (net/mptcp/subflow.c:98 net/mptcp/subflow.c:213)
subflow_v4_route_req (net/mptcp/subflow.c:305)
tcp_conn_request (net/ipv4/tcp_input.c:7216)
subflow_v4_conn_request (net/mptcp/subflow.c:651)
tcp_rcv_state_process (net/ipv4/tcp_input.c:6709)
tcp_v4_do_rcv (net/ipv4/tcp_ipv4.c:1934)
tcp_v4_rcv (net/ipv4/tcp_ipv4.c:2334)
ip_protocol_deliver_rcu (net/ipv4/ip_input.c:205 (discriminator 1))
ip_local_deliver_finish (include/linux/rcupdate.h:813 net/ipv4/ip_input.c:234)
ip_local_deliver (include/linux/netfilter.h:314 include/linux/netfilter.h:308 net/ipv4/ip_input.c:254)
ip_sublist_rcv_finish (include/net/dst.h:461 net/ipv4/ip_input.c:580)
ip_sublist_rcv (net/ipv4/ip_input.c:640)
ip_list_rcv (net/ipv4/ip_input.c:675)
__netif_receive_skb_list_core (net/core/dev.c:5583 net/core/dev.c:5631)
netif_receive_skb_list_internal (net/core/dev.c:5685 net/core/dev.c:5774)
napi_complete_done (include/linux/list.h:37 include/net/gro.h:449 include/net/gro.h:444 net/core/dev.c:6114)
igb_poll (drivers/net/ethernet/intel/igb/igb_main.c:8244) igb
__napi_poll (net/core/dev.c:6582)
net_rx_action (net/core/dev.c:6653 net/core/dev.c:6787)
handle_softirqs (kernel/softirq.c:553)
__irq_exit_rcu (kernel/softirq.c:588 kernel/softirq.c:427 kernel/softirq.c:636)
irq_exit_rcu (kernel/softirq.c:651)
common_interrupt (arch/x86/kernel/irq.c:247 (discriminator 14))
</IRQ>
This problem seems particularly prevalent if the user advertises an
endpoint that has a different external vs internal address. In the case
where the external address is advertised and multiple connections
already exist, multiple subflow SYNs arrive in parallel which tends to
trigger the race during creation of the first local_addr_list entries
which have the internal address instead.
Fix by skipping the replacement of an existing implicit local address if
called via mptcp_pm_nl_get_local_id.
Fixes: d045b9eb95 ("mptcp: introduce implicit endpoints")
Cc: stable@vger.kernel.org
Suggested-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Krister Johansen <kjlx@templeofstupid.com>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250303-net-mptcp-fix-sched-while-atomic-v1-1-f6a216c5a74c@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 8668860b0a upstream.
Before this patch, if the checksum was not used, the subflow was only
reset if map_data_len was != 0. If there were no MPTCP options or an
invalid mapping, map_data_len was not set to the data len, and then the
subflow was not reset as it should have been, leaving the MPTCP
connection in a wrong fallback mode.
This map_data_len condition has been introduced to handle the reception
of the infinite mapping. Instead, a new dedicated mapping error could
have been returned and treated as a special case. However, the commit
31bf11de14 ("mptcp: introduce MAPPING_BAD_CSUM") has been introduced
by Paolo Abeni soon after, and backported later on to stable. It better
handle the csum case, and it means the exception for valid_csum_seen in
subflow_can_fallback(), plus this one for the infinite mapping in
subflow_check_data_avail(), are no longer needed.
In other words, the code can be simplified there: a fallback should only
be done if msk->allow_infinite_fallback is set. This boolean is set to
false once MPTCP-specific operations acting on the whole MPTCP
connection vs the initial path have been done, e.g. a second path has
been created, or an MPTCP re-injection -- yes, possible even with a
single subflow. The subflow_can_fallback() helper can then be dropped,
and replaced by this single condition.
This also makes the code clearer: a fallback should only be done if it
is possible to do so.
While at it, no need to set map_data_len to 0 in get_mapping_status()
for the infinite mapping case: it will be set to skb->len just after, at
the end of subflow_check_data_avail(), and not read in between.
Fixes: f8d4bcacff ("mptcp: infinite mapping receiving")
Cc: stable@vger.kernel.org
Reported-by: Chester A. Unal <chester.a.unal@xpedite-tech.com>
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/544
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Tested-by: Chester A. Unal <chester.a.unal@xpedite-tech.com>
Link: https://patch.msgid.link/20250224-net-mptcp-misc-fixes-v1-2-f550f636b435@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 56b824eb49 upstream.
Currently the skb size after coalescing is only limited by the skb
layout (the skb must not carry frag_list). A single coalesced skb
covering several MSS can potentially fill completely the receive
buffer. In such a case, the snd win will zero until the receive buffer
will be empty again, affecting tput badly.
Fixes: 8268ed4c9d ("mptcp: introduce and use mptcp_try_coalesce()")
Cc: stable@vger.kernel.org # please delay 2 weeks after 6.13-final release
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20241230-net-mptcp-rbuf-fixes-v1-3-8608af434ceb@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit e226d9259d upstream.
The wake-up condition currently implemented by mptcp_epollin_ready()
is wrong, as it could mark the MPTCP socket as readable even when
no data are present and the system is under memory pressure.
Explicitly check for some data being available in the receive queue.
Fixes: 5684ab1a0e ("mptcp: give rcvlowat some love")
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250113-net-mptcp-connect-st-flakes-v1-2-0d986ee7b1b6@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 2ca06a2f65 upstream.
mptcp_cleanup_rbuf() is responsible to send acks when the user-space
reads enough data to update the receive windows significantly.
It tries hard to avoid acquiring the subflow sockets locks by checking
conditions similar to the ones implemented at the TCP level.
To avoid too much code duplication - the MPTCP protocol can't reuse the
TCP helpers as part of the relevant status is maintained into the msk
socket - and multiple costly window size computation, mptcp_cleanup_rbuf
uses a rough estimate for the most recently advertised window size:
the MPTCP receive free space, as recorded as at last-ack time.
Unfortunately the above does not allow mptcp_cleanup_rbuf() to detect
a zero to non-zero win change in some corner cases, skipping the
tcp_cleanup_rbuf call and leaving the peer stuck.
After commit ea66758c17 ("tcp: allow MPTCP to update the announced
window"), MPTCP has actually cheap access to the announced window value.
Use it in mptcp_cleanup_rbuf() for a more accurate ack generation.
Fixes: e3859603ba ("mptcp: better msk receive window updates")
Cc: stable@vger.kernel.org
Reported-by: Jakub Kicinski <kuba@kernel.org>
Closes: https://lore.kernel.org/20250107131845.5e5de3c5@kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250113-net-mptcp-connect-st-flakes-v1-1-0d986ee7b1b6@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 551844f26d upstream.
Under some corner cases the MPTCP protocol can end-up invoking
mptcp_cleanup_rbuf() when no data has been copied, but such helper
assumes the opposite condition.
Explicitly drop such assumption and performs the costly call only
when strictly needed - before releasing the msk socket lock.
Fixes: fd8976790a ("mptcp: be careful on MPTCP-level ack.")
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20241230-net-mptcp-rbuf-fixes-v1-2-8608af434ceb@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 449e6912a2 upstream.
If the recvmsg() blocks after receiving some data - i.e. due to
SO_RCVLOWAT - the MPTCP code will attempt multiple times to
adjust the receive buffer size, wrongly accounting every time the
cumulative of received data - instead of accounting only for the
delta.
Address the issue moving mptcp_rcv_space_adjust just after the
data reception and passing it only the just received bytes.
This also removes an unneeded difference between the TCP and MPTCP
RX code path implementation.
Fixes: 5813022985 ("mptcp: error out earlier on disconnect")
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20241230-net-mptcp-rbuf-fixes-v1-1-8608af434ceb@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit b169e76eba upstream.
In 'mptcp_reset_tout_timer', promote 'probe_timestamp' to unsigned long
to avoid possible integer overflow. Compile tested only.
Found by Linux Verification Center (linuxtesting.org) with SVACE.
Signed-off-by: Dmitry Kandybka <d.kandybka@gmail.com>
Link: https://patch.msgid.link/20241107103657.1560536-1-d.kandybka@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
[ Conflict in this version because commit d866ae9aaa ("mptcp: add a
new sysctl for make after break timeout") is not in this version, and
replaced TCP_TIMEWAIT_LEN in the expression. The fix can still be
applied the same way: by forcing a cast to unsigned long for the first
item. ]
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit db3eab8110 upstream.
In mptcp_pm_create_subflow_or_signal_addr(), rcu_read_(un)lock() are
used as expected to iterate over the list of local addresses, but
list_for_each_entry() was used instead of list_for_each_entry_rcu() in
__lookup_addr(). It is important to use this variant which adds the
required READ_ONCE() (and diagnostic checks if enabled).
Because __lookup_addr() is also used in mptcp_pm_nl_set_flags() where it
is called under the pernet->lock and not rcu_read_lock(), an extra
condition is then passed to help the diagnostic checks making sure
either the associated spin lock or the RCU lock is held.
Fixes: 86e39e0448 ("mptcp: keep track of local endpoint still available for each msk")
Cc: stable@vger.kernel.org
Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20241112-net-mptcp-misc-6-12-pm-v1-3-b835580cefa8@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit af250c27ea upstream.
When the lookup_by_id parameter of __lookup_addr() is true, it's the same
as __lookup_addr_by_id(), it can be replaced by __lookup_addr_by_id()
directly. So drop this parameter, let __lookup_addr() only looks up address
on the local address list by comparing addresses in it, not address ids.
Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://lore.kernel.org/r/20240305-upstream-net-next-20240304-mptcp-misc-cleanup-v1-4-c436ba5e569b@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Stable-dep-of: db3eab8110 ("mptcp: pm: use _rcu variant under rcu_read_lock")
[ Conflicts in pm_netlink.c, because commit 6a42477fe4 ("mptcp: update
set_flags interfaces") is not in this version, and causes too many
conflicts when backporting it. The conflict is easy to resolve: addr
is a pointer here here in mptcp_pm_nl_set_flags(), the rest of the
code is the same. ]
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit f642c5c4d5 upstream.
When traversing userspace_pm_local_addr_list and deleting an entry from
it in mptcp_pm_nl_remove_doit(), msk->pm.lock should be held.
This patch holds this lock before mptcp_userspace_pm_lookup_addr_by_id()
and releases it after list_move() in mptcp_pm_nl_remove_doit().
Fixes: d9a4594eda ("mptcp: netlink: Add MPTCP_PM_CMD_REMOVE")
Cc: stable@vger.kernel.org
Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20241112-net-mptcp-misc-6-12-pm-v1-2-b835580cefa8@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit e026631941 upstream.
Just like in-kernel pm, when userspace pm does set_flags, it needs to send
out MP_PRIO signal, and also modify the flags of the corresponding address
entry in the local address list. This patch implements the missing logic.
Traverse all address entries on userspace_pm_local_addr_list to find the
local address entry, if bkup is true, set the flags of this entry with
FLAG_BACKUP, otherwise, clear FLAG_BACKUP.
Fixes: 892f396c8e ("mptcp: netlink: issue MP_PRIO signals from userspace PMs")
Cc: stable@vger.kernel.org
Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20241112-net-mptcp-misc-6-12-pm-v1-1-b835580cefa8@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
[ Conflicts in pm_userspace.c, because commit 6a42477fe4 ("mptcp:
update set_flags interfaces"), is not in this version, and causes too
many conflicts when backporting it. The same code can still be added
at the same place, before sending the ACK. ]
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 06afe09091 upstream.
Corresponding __lookup_addr_by_id() helper in the in-kernel netlink PM,
this patch adds a new helper mptcp_userspace_pm_lookup_addr_by_id() to
lookup the address entry with the given id on the userspace pm local
address list.
Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Stable-dep-of: f642c5c4d5 ("mptcp: hold pm lock when deleting entry")
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 14cb0e0bf3 upstream.
'(struct sock *)msk' is used several times in mptcp_nl_cmd_announce(),
mptcp_nl_cmd_remove() or mptcp_userspace_pm_set_flags() in pm_userspace.c,
it's worth adding a local variable sk to point it.
Reviewed-by: Matthieu Baerts <matttbe@kernel.org>
Signed-off-by: Geliang Tang <geliang.tang@suse.com>
Signed-off-by: Mat Martineau <martineau@kernel.org>
Link: https://lore.kernel.org/r/20231025-send-net-next-20231025-v1-8-db8f25f798eb@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Stable-dep-of: 06afe09091 ("mptcp: add userspace_pm_lookup_addr_by_id helper")
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit ce7356ae35 ]
Additional active subflows - i.e. created by the in kernel path
manager - are included into the subflow list before starting the
3whs.
A racing recvmsg() spooling data received on an already established
subflow would unconditionally call tcp_cleanup_rbuf() on all the
current subflows, potentially hitting a divide by zero error on
the newly created ones.
Explicitly check that the subflow is in a suitable state before
invoking tcp_cleanup_rbuf().
Fixes: c76c695656 ("mptcp: call tcp_cleanup_rbuf on subflows")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/02374660836e1b52afc91966b7535c8c5f7bafb0.1731060874.git.pabeni@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 99635c91fb upstream.
The local address entries on userspace_pm_local_addr_list are allocated
by sock_kmalloc().
It's then required to use sock_kfree_s() instead of kfree() to free
these entries in order to adjust the allocated size on the sk side.
Fixes: 24430f8bf5 ("mptcp: add address into userspace pm list")
Cc: stable@vger.kernel.org
Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20241104-net-mptcp-misc-6-12-v1-2-c13f2ff1656f@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit db0a37b7ac upstream.
In a previous fix, the in-kernel path-manager has been modified not to
retrigger the removal of a subflow if it was already closed, e.g. when
the initial subflow is removed, but kept in the subflows list.
To be complete, this fix should also skip the subflows that are in any
closing state: mptcp_close_ssk() will initiate the closure, but the
switch to the TCP_CLOSE state depends on the other peer.
Fixes: 58e1b66b4e ("mptcp: pm: do not remove already closed subflows")
Cc: stable@vger.kernel.org
Suggested-by: Paolo Abeni <pabeni@redhat.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20241008-net-mptcp-fallback-fixes-v1-4-c6fb8e93e551@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit e32d262c89 upstream.
Bugged peer implementation can send corrupted DSS options, consistently
hitting a few warning in the data path. Use DEBUG_NET assertions, to
avoid the splat on some builds and handle consistently the error, dumping
related MIBs and performing fallback and/or reset according to the
subflow type.
Fixes: 6771bfd9ee ("mptcp: update mptcp ack sequence from work queue")
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20241008-net-mptcp-fallback-fixes-v1-1-c6fb8e93e551@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 119d51e225 upstream.
As reported by Christoph [1], before this patch, an MPTCP connection was
wrongly reset when a host received a first data packet with MPTCP
options after the 3wHS, but got the next ones without.
According to the MPTCP v1 specs [2], a fallback should happen in this
case, because the host didn't receive a DATA_ACK from the other peer,
nor receive data for more than the initial window which implies a
DATA_ACK being received by the other peer.
The patch here re-uses the same logic as the one used in other places:
by looking at allow_infinite_fallback, which is disabled at the creation
of an additional subflow. It's not looking at the first DATA_ACK (or
implying one received from the other side) as suggested by the RFC, but
it is in continuation with what was already done, which is safer, and it
fixes the reported issue. The next step, looking at this first DATA_ACK,
is tracked in [4].
This patch has been validated using the following Packetdrill script:
0 socket(..., SOCK_STREAM, IPPROTO_MPTCP) = 3
+0 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0
+0 bind(3, ..., ...) = 0
+0 listen(3, 1) = 0
// 3WHS is OK
+0.0 < S 0:0(0) win 65535 <mss 1460, sackOK, nop, nop, nop, wscale 6, mpcapable v1 flags[flag_h] nokey>
+0.0 > S. 0:0(0) ack 1 <mss 1460, nop, nop, sackOK, nop, wscale 8, mpcapable v1 flags[flag_h] key[skey]>
+0.1 < . 1:1(0) ack 1 win 2048 <mpcapable v1 flags[flag_h] key[ckey=2, skey]>
+0 accept(3, ..., ...) = 4
// Data from the client with valid MPTCP options (no DATA_ACK: normal)
+0.1 < P. 1:501(500) ack 1 win 2048 <mpcapable v1 flags[flag_h] key[skey, ckey] mpcdatalen 500, nop, nop>
// From here, the MPTCP options will be dropped by a middlebox
+0.0 > . 1:1(0) ack 501 <dss dack8=501 dll=0 nocs>
+0.1 read(4, ..., 500) = 500
+0 write(4, ..., 100) = 100
// The server replies with data, still thinking MPTCP is being used
+0.0 > P. 1:101(100) ack 501 <dss dack8=501 dsn8=1 ssn=1 dll=100 nocs, nop, nop>
// But the client already did a fallback to TCP, because the two previous packets have been received without MPTCP options
+0.1 < . 501:501(0) ack 101 win 2048
+0.0 < P. 501:601(100) ack 101 win 2048
// The server should fallback to TCP, not reset: it didn't get a DATA_ACK, nor data for more than the initial window
+0.0 > . 101:101(0) ack 601
Note that this script requires Packetdrill with MPTCP support, see [3].
Fixes: dea2b1ea9c ("mptcp: do not reset MP_CAPABLE subflow on mapping errors")
Cc: stable@vger.kernel.org
Reported-by: Christoph Paasch <cpaasch@apple.com>
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/518 [1]
Link: https://datatracker.ietf.org/doc/html/rfc8684#name-fallback [2]
Link: https://github.com/multipath-tcp/packetdrill [3]
Link: https://github.com/multipath-tcp/mptcp_net-next/issues/519 [4]
Reviewed-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20241008-net-mptcp-fallback-fixes-v1-3-c6fb8e93e551@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit b4cd80b033 upstream.
There are two paths to access mptcp_pm_del_add_timer, result in a race
condition:
CPU1 CPU2
==== ====
net_rx_action
napi_poll netlink_sendmsg
__napi_poll netlink_unicast
process_backlog netlink_unicast_kernel
__netif_receive_skb genl_rcv
__netif_receive_skb_one_core netlink_rcv_skb
NF_HOOK genl_rcv_msg
ip_local_deliver_finish genl_family_rcv_msg
ip_protocol_deliver_rcu genl_family_rcv_msg_doit
tcp_v4_rcv mptcp_pm_nl_flush_addrs_doit
tcp_v4_do_rcv mptcp_nl_remove_addrs_list
tcp_rcv_established mptcp_pm_remove_addrs_and_subflows
tcp_data_queue remove_anno_list_by_saddr
mptcp_incoming_options mptcp_pm_del_add_timer
mptcp_pm_del_add_timer kfree(entry)
In remove_anno_list_by_saddr(running on CPU2), after leaving the critical
zone protected by "pm.lock", the entry will be released, which leads to the
occurrence of uaf in the mptcp_pm_del_add_timer(running on CPU1).
Keeping a reference to add_timer inside the lock, and calling
sk_stop_timer_sync() with this reference, instead of "entry->add_timer".
Move list_del(&entry->list) to mptcp_pm_del_add_timer and inside the pm lock,
do not directly access any members of the entry outside the pm lock, which
can avoid similar "entry->x" uaf.
Fixes: 00cfd77b90 ("mptcp: retransmit ADD_ADDR when timeout")
Cc: stable@vger.kernel.org
Reported-and-tested-by: syzbot+f3a31fb909db9b2a5c4d@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=f3a31fb909db9b2a5c4d
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Edward Adam Davis <eadavis@qq.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Link: https://patch.msgid.link/tencent_7142963A37944B4A74EF76CD66EA3C253609@qq.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit cb41b195e6 upstream.
pr_debug() have been added in various places in MPTCP code to help
developers to debug some situations. With the dynamic debug feature, it
is easy to enable all or some of them, and asks users to reproduce
issues with extra debug.
Many of these pr_debug() don't end with a new line, while no 'pr_cont()'
are used in MPTCP code. So the goal was not to display multiple debug
messages on one line: they were then not missing the '\n' on purpose.
Not having the new line at the end causes these messages to be printed
with a delay, when something else needs to be printed. This issue is not
visible when many messages need to be printed, but it is annoying and
confusing when only specific messages are expected, e.g.
# echo "func mptcp_pm_add_addr_echoed +fmp" \
> /sys/kernel/debug/dynamic_debug/control
# ./mptcp_join.sh "signal address"; \
echo "$(awk '{print $1}' /proc/uptime) - end"; \
sleep 5s; \
echo "$(awk '{print $1}' /proc/uptime) - restart"; \
./mptcp_join.sh "signal address"
013 signal address
(...)
10.75 - end
15.76 - restart
013 signal address
[ 10.367935] mptcp:mptcp_pm_add_addr_echoed: MPTCP: msk=(...)
(...)
=> a delay of 5 seconds: printed with a 10.36 ts, but after 'restart'
which was printed at the 15.76 ts.
The 'Fixes' tag here below points to the first pr_debug() used without
'\n' in net/mptcp. This patch could be split in many small ones, with
different Fixes tag, but it doesn't seem worth it, because it is easy to
re-generate this patch with this simple 'sed' command:
git grep -l pr_debug -- net/mptcp |
xargs sed -i "s/\(pr_debug(\".*[^n]\)\(\"[,)]\)/\1\\\n\2/g"
So in case of conflicts, simply drop the modifications, and launch this
command.
Fixes: f870fa0b57 ("mptcp: Add MPTCP socket stubs")
Cc: stable@vger.kernel.org
Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20240826-net-mptcp-close-extra-sf-fin-v1-4-905199fe1172@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
[ As mentioned above, conflicts were expected, and resolved by using the
'sed' command which is visible above. ]
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit d82809b6c5 upstream.
The initial subflow might have already been closed, but still in the
connection list. When the worker is instructed to close the subflows
that have been marked as closed, it might then try to close the initial
subflow again.
A consequence of that is that the SUB_CLOSED event can be seen twice:
# ip mptcp endpoint
1.1.1.1 id 1 subflow dev eth0
2.2.2.2 id 2 subflow dev eth1
# ip mptcp monitor &
[ CREATED] remid=0 locid=0 saddr4=1.1.1.1 daddr4=9.9.9.9
[ ESTABLISHED] remid=0 locid=0 saddr4=1.1.1.1 daddr4=9.9.9.9
[ SF_ESTABLISHED] remid=0 locid=2 saddr4=2.2.2.2 daddr4=9.9.9.9
# ip mptcp endpoint delete id 1
[ SF_CLOSED] remid=0 locid=0 saddr4=1.1.1.1 daddr4=9.9.9.9
[ SF_CLOSED] remid=0 locid=0 saddr4=1.1.1.1 daddr4=9.9.9.9
The first one is coming from mptcp_pm_nl_rm_subflow_received(), and the
second one from __mptcp_close_subflow().
To avoid doing the post-closed processing twice, the subflow is now
marked as closed the first time.
Note that it is not enough to check if we are dealing with the first
subflow and check its sk_state: the subflow might have been reset or
closed before calling mptcp_close_ssk().
Fixes: b911c97c7d ("mptcp: add netlink event support")
Cc: stable@vger.kernel.org
Tested-by: Arınç ÜNAL <arinc.unal@arinc9.com>
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
[ Conflict in protocol.h due to commit f1f26512a9 ("mptcp: use plain
bool instead of custom binary enum") and more that are not in this
version, because they modify the context and the size of __unused. The
conflict is easy to resolve, by not modifying data_avail type. ]
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 87b5896f3f ]
The initial subflow has a special local ID: 0. When an endpoint is being
deleted, it is then important to check if its address is not linked to
the initial subflow to send the right ID.
If there was an endpoint linked to the initial subflow, msk's
mpc_endpoint_id field will be set. We can then use this info when an
endpoint is being removed to see if it is linked to the initial subflow.
So now, the correct IDs are passed to mptcp_pm_nl_rm_addr_or_subflow(),
it is no longer needed to use mptcp_local_id_match().
Fixes: 3ad14f54bd ("mptcp: more accurate MPC endpoint tracking")
Cc: stable@vger.kernel.org
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit e38b117d7f ]
mptcp_pm_remove_addrs_and_subflows() is only used in pm_netlink.c, it's
no longer used in pm_userspace.c any more since the commit 8b1c94da1e
("mptcp: only send RM_ADDR in nl_cmd_remove"). So this patch changes it
to a static function.
Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Stable-dep-of: 87b5896f3f ("mptcp: pm: fix RM_ADDR ID for the initial subflow")
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 57f86203b4 upstream.
The ADD_ADDR 0 with the address from the initial subflow should not be
considered as a new address: this is not something new. If the host
receives it, it simply means that the address is available again.
When receiving an ADD_ADDR for the ID 0, the PM already doesn't consider
it as new by not incrementing the 'add_addr_accepted' counter. But the
'accept_addr' might not be set if the limit has already been reached:
this can be bypassed in this case. But before, it is important to check
that this ADD_ADDR for the ID 0 is for the same address as the initial
subflow. If not, it is not something that should happen, and the
ADD_ADDR can be ignored.
Note that if an ADD_ADDR is received while there is already a subflow
opened using the same address, this ADD_ADDR is ignored as well. It
means that if multiple ADD_ADDR for ID 0 are received, there will not be
any duplicated subflows created by the client.
Fixes: d0876b2284 ("mptcp: add the incoming RM_ADDR support")
Cc: stable@vger.kernel.org
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 9366922adc upstream.
'local_addr_used' and 'add_addr_accepted' are decremented for addresses
not related to the initial subflow (ID0), because the source and
destination addresses of the initial subflows are known from the
beginning: they don't count as "additional local address being used" or
"ADD_ADDR being accepted".
It is then required not to increment them when the entrypoint used by
the initial subflow is removed and re-added during a connection. Without
this modification, this entrypoint cannot be removed and re-added more
than once.
Reported-by: Arınç ÜNAL <arinc.unal@arinc9.com>
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/512
Fixes: 3ad14f54bd ("mptcp: more accurate MPC endpoint tracking")
Reported-by: syzbot+455d38ecd5f655fc45cf@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/00000000000049861306209237f4@google.com
Cc: stable@vger.kernel.org
Tested-by: Arınç ÜNAL <arinc.unal@arinc9.com>
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 58e1b66b4e upstream.
It is possible to have in the list already closed subflows, e.g. the
initial subflow has been already closed, but still in the list. No need
to try to close it again, and increments the related counters again.
Fixes: 0ee4261a36 ("mptcp: implement mptcp_pm_remove_subflow")
Cc: stable@vger.kernel.org
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit c07cc3ed89 upstream.
Taking the first one on the list doesn't work in some cases, e.g. if the
initial subflow is being removed. Pick another one instead of not
sending anything.
Fixes: 84dfe3677a ("mptcp: send out dedicated ADD_ADDR packet")
Cc: stable@vger.kernel.org
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit dce1c6d1e9 upstream.
The initial subflow has a special local ID: 0. It is specific per
connection.
When a global endpoint is deleted and re-added later, it can have a
different ID -- most services managing the endpoints automatically don't
force the ID to be the same as before. It is then important to track
these modifications to be consistent with the ID being used for the
address used by the initial subflow, not to confuse the other peer or to
send the ID 0 for the wrong address.
Now when removing an endpoint, msk->mpc_endpoint_id is reset if it
corresponds to this endpoint. When adding a new endpoint, the same
variable is updated if the address match the one of the initial subflow.
Fixes: 3ad14f54bd ("mptcp: more accurate MPC endpoint tracking")
Cc: stable@vger.kernel.org
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit bc19ff5763 upstream.
The lookup_subflow_by_daddr() helper checks if there is already a
subflow connected to this address. But there could be a subflow that is
closing, but taking time due to some reasons: latency, losses, data to
process, etc.
If an ADD_ADDR is received while the endpoint is being closed, it is
better to try connecting to it, instead of rejecting it: the peer which
has sent the ADD_ADDR will not be notified that the ADD_ADDR has been
rejected for this reason, and the expected subflow will not be created
at the end.
This helper should then only look for subflows that are established, or
going to be, but not the ones being closed.
Fixes: d84ad04941 ("mptcp: skip connecting the connected address")
Cc: stable@vger.kernel.org
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 8b8ed1b429 upstream.
When the endpoint used by the initial subflow is removed and re-added
later, the PM has to force the ID 0, it is a special case imposed by the
MPTCP specs.
Note that the endpoint should then need to be re-added reusing the same
ID.
Fixes: 3ad14f54bd ("mptcp: more accurate MPC endpoint tracking")
Cc: stable@vger.kernel.org
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 2a1f596ebb upstream.
The 'mptcp_subflow_context' structure has two items related to the
backup flags:
- 'backup': the subflow has been marked as backup by the other peer
- 'request_bkup': the backup flag has been set by the host
Looking only at the 'backup' flag can make sense in some cases, but it
is not the behaviour of the default packet scheduler when selecting
paths.
As explained in the commit b6a66e521a ("mptcp: sched: check both
directions for backup"), the packet scheduler should look at both flags,
because that was the behaviour from the beginning: the 'backup' flag was
set by accident instead of the 'request_bkup' one. Now that the latter
has been fixed, get_retrans() needs to be adapted as well.
Fixes: b6a66e521a ("mptcp: sched: check both directions for backup")
Cc: stable@vger.kernel.org
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20240826-net-mptcp-close-extra-sf-fin-v1-3-905199fe1172@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit f09b0ad55a upstream.
When a peer decides to close one subflow in the middle of a connection
having multiple subflows, the receiver of the first FIN should accept
that, and close the subflow on its side as well. If not, the subflow
will stay half closed, and would even continue to be used until the end
of the MPTCP connection or a reset from the network.
The issue has not been seen before, probably because the in-kernel
path-manager always sends a RM_ADDR before closing the subflow. Upon the
reception of this RM_ADDR, the other peer will initiate the closure on
its side as well. On the other hand, if the RM_ADDR is lost, or if the
path-manager of the other peer only closes the subflow without sending a
RM_ADDR, the subflow would switch to TCP_CLOSE_WAIT, but that's it,
leaving the subflow half-closed.
So now, when the subflow switches to the TCP_CLOSE_WAIT state, and if
the MPTCP connection has not been closed before with a DATA_FIN, the
kernel owning the subflow schedules its worker to initiate the closure
on its side as well.
This issue can be easily reproduced with packetdrill, as visible in [1],
by creating an additional subflow, injecting a FIN+ACK before sending
the DATA_FIN, and expecting a FIN+ACK in return.
Fixes: 40947e1399 ("mptcp: schedule worker when subflow is closed")
Cc: stable@vger.kernel.org
Link: https://github.com/multipath-tcp/packetdrill/pull/154 [1]
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20240826-net-mptcp-close-extra-sf-fin-v1-1-905199fe1172@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 48e50dcbcb upstream.
select_local_address() and select_signal_address() both select an
endpoint entry from the list inside an RCU protected section, but return
a reference to it, to be read later on. If the entry is dereferenced
after the RCU unlock, reading info could cause a Use-after-Free.
A simple solution is to copy the required info while inside the RCU
protected section to avoid any risk of UaF later. The address ID might
need to be modified later to handle the ID0 case later, so a copy seems
OK to deal with.
Reported-by: Paolo Abeni <pabeni@redhat.com>
Closes: https://lore.kernel.org/45cd30d3-7710-491c-ae4d-a1368c00beb1@redhat.com
Fixes: 01cacb00b3 ("mptcp: add netlink-based PM")
Cc: stable@vger.kernel.org
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20240819-net-mptcp-pm-reusing-id-v1-14-38035d40de5b@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Matthieu Baerts (NGI0)