linux-stable.git/net, branch v6.18.30 Linux kernel stable tree mptcp: pm: ADD_ADDR rtx: return early if no retrans 2026-05-14T13:30:23+00:00 Matthieu Baerts (NGI0) matttbe@kernel.org 2026-05-05T15:00:56+00:00 464747eae483e9ac9185012b85a7619f06721587 commit 62a9b19dce77e72426f049fb99b9d1d032b9a8ea upstream. No need to iterate over all subflows if there is no retransmission needed. Exit early in this case then. Fixes: 30549eebc4d8 ("mptcp: make ADD_ADDR retransmission timeout adaptive") 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/20260505-net-mptcp-pm-fixes-7-1-rc3-v1-8-fca8091060a4@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 62a9b19dce77e72426f049fb99b9d1d032b9a8ea upstream.

No need to iterate over all subflows if there is no retransmission
needed.

Exit early in this case then.

Fixes: 30549eebc4d8 ("mptcp: make ADD_ADDR retransmission timeout adaptive")
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/20260505-net-mptcp-pm-fixes-7-1-rc3-v1-8-fca8091060a4@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
mptcp: pm: ADD_ADDR rtx: resched blocked ADD_ADDR quicker 2026-05-14T13:30:23+00:00 Matthieu Baerts (NGI0) matttbe@kernel.org 2026-05-05T15:00:54+00:00 107e956ce5441192946f53d2aea186d9ca0bd745 commit 3cf12492891c4b5ff54dda404a2de4ec54c9e1b5 upstream. When an ADD_ADDR needs to be retransmitted and another one has already been prepared -- e.g. multiple ADD_ADDRs have been sent in a row and need to be retransmitted later -- this additional retransmission will need to wait. In this case, the timer was reset to TCP_RTO_MAX / 8, which is ~15 seconds. This delay is unnecessary long: it should just be rescheduled at the next opportunity, e.g. after the retransmission timeout. Without this modification, some issues can be seen from time to time in the selftests when multiple ADD_ADDRs are sent, and the host takes time to process them, e.g. the "signal addresses, ADD_ADDR timeout" MPTCP Join selftest, especially with a debug kernel config. Note that on older kernels, 'timeout' is not available. It should be enough to replace it by one second (HZ). Fixes: 00cfd77b9063 ("mptcp: retransmit ADD_ADDR when timeout") 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/20260505-net-mptcp-pm-fixes-7-1-rc3-v1-6-fca8091060a4@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 3cf12492891c4b5ff54dda404a2de4ec54c9e1b5 upstream.

When an ADD_ADDR needs to be retransmitted and another one has already
been prepared -- e.g. multiple ADD_ADDRs have been sent in a row and
need to be retransmitted later -- this additional retransmission will
need to wait.

In this case, the timer was reset to TCP_RTO_MAX / 8, which is ~15
seconds. This delay is unnecessary long: it should just be rescheduled
at the next opportunity, e.g. after the retransmission timeout.

Without this modification, some issues can be seen from time to time in
the selftests when multiple ADD_ADDRs are sent, and the host takes time
to process them, e.g. the "signal addresses, ADD_ADDR timeout" MPTCP
Join selftest, especially with a debug kernel config.

Note that on older kernels, 'timeout' is not available. It should be
enough to replace it by one second (HZ).

Fixes: 00cfd77b9063 ("mptcp: retransmit ADD_ADDR when timeout")
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/20260505-net-mptcp-pm-fixes-7-1-rc3-v1-6-fca8091060a4@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
mptcp: pm: ADD_ADDR rtx: free sk if last 2026-05-14T13:30:23+00:00 Matthieu Baerts (NGI0) matttbe@kernel.org 2026-05-05T15:00:53+00:00 b74ad20198652b6b39a761c277ba65ae82b1e107 commit b7b9a461569734d33d3259d58d2507adfac107ed upstream. When an ADD_ADDR is retransmitted, the sk is held in sk_reset_timer(), and released at the end. If at that moment, it was the last reference being held, the sk would not be freed. sock_put() should then be called instead of __sock_put(). But that's not enough: if it is the last reference, sock_put() will call sk_free(), which will end up calling sk_stop_timer_sync() on the same timer, and waiting indefinitely to finish. So it is needed to mark that the timer is done at the end of the timer handler when it has not been rescheduled, not to call sk_stop_timer_sync() on "itself". Fixes: 00cfd77b9063 ("mptcp: retransmit ADD_ADDR when timeout") 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/20260505-net-mptcp-pm-fixes-7-1-rc3-v1-5-fca8091060a4@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit b7b9a461569734d33d3259d58d2507adfac107ed upstream.

When an ADD_ADDR is retransmitted, the sk is held in sk_reset_timer(),
and released at the end.

If at that moment, it was the last reference being held, the sk would
not be freed. sock_put() should then be called instead of __sock_put().

But that's not enough: if it is the last reference, sock_put() will call
sk_free(), which will end up calling sk_stop_timer_sync() on the same
timer, and waiting indefinitely to finish. So it is needed to mark that
the timer is done at the end of the timer handler when it has not been
rescheduled, not to call sk_stop_timer_sync() on "itself".

Fixes: 00cfd77b9063 ("mptcp: retransmit ADD_ADDR when timeout")
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/20260505-net-mptcp-pm-fixes-7-1-rc3-v1-5-fca8091060a4@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
mptcp: pm: ADD_ADDR rtx: always decrease sk refcount 2026-05-14T13:30:23+00:00 Matthieu Baerts (NGI0) matttbe@kernel.org 2026-05-05T15:00:52+00:00 acd3d3562315c99f3c0db16f0fcc5f0306638982 commit 9634cb35af17019baec21ca648516ce376fa10e6 upstream. When an ADD_ADDR is retransmitted, the sk is held in sk_reset_timer(). It should then be released in all cases at the end. Some (unlikely) checks were returning directly instead of calling sock_put() to decrease the refcount. Jump to a new 'exit' label to call __sock_put() (which will become sock_put() in the next commit) to fix this potential leak. While at it, drop the '!msk' check which cannot happen because it is never reset, and explicitly mark the remaining one as "unlikely". Fixes: 00cfd77b9063 ("mptcp: retransmit ADD_ADDR when timeout") 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/20260505-net-mptcp-pm-fixes-7-1-rc3-v1-4-fca8091060a4@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 9634cb35af17019baec21ca648516ce376fa10e6 upstream.

When an ADD_ADDR is retransmitted, the sk is held in sk_reset_timer().
It should then be released in all cases at the end.

Some (unlikely) checks were returning directly instead of calling
sock_put() to decrease the refcount. Jump to a new 'exit' label to call
__sock_put() (which will become sock_put() in the next commit) to fix
this potential leak.

While at it, drop the '!msk' check which cannot happen because it is
never reset, and explicitly mark the remaining one as "unlikely".

Fixes: 00cfd77b9063 ("mptcp: retransmit ADD_ADDR when timeout")
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/20260505-net-mptcp-pm-fixes-7-1-rc3-v1-4-fca8091060a4@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
mptcp: pm: ADD_ADDR rtx: fix potential data-race 2026-05-14T13:30:23+00:00 Matthieu Baerts (NGI0) matttbe@kernel.org 2026-05-05T15:00:51+00:00 2ad56e434199ca24a812bb353667aa1c3860f513 commit 5cd6e0ad79d2615264f63929f8b457ad97ae550d upstream. This mptcp_pm_add_timer() helper is executed as a timer callback in softirq context. To avoid any data races, the socket lock needs to be held with bh_lock_sock(). If the socket is in use, retry again soon after, similar to what is done with the keepalive timer. Fixes: 00cfd77b9063 ("mptcp: retransmit ADD_ADDR when timeout") 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/20260505-net-mptcp-pm-fixes-7-1-rc3-v1-3-fca8091060a4@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 5cd6e0ad79d2615264f63929f8b457ad97ae550d upstream.

This mptcp_pm_add_timer() helper is executed as a timer callback in
softirq context. To avoid any data races, the socket lock needs to be
held with bh_lock_sock().

If the socket is in use, retry again soon after, similar to what is done
with the keepalive timer.

Fixes: 00cfd77b9063 ("mptcp: retransmit ADD_ADDR when timeout")
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/20260505-net-mptcp-pm-fixes-7-1-rc3-v1-3-fca8091060a4@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
mptcp: pm: ADD_ADDR rtx: allow ID 0 2026-05-14T13:30:23+00:00 Matthieu Baerts (NGI0) matttbe@kernel.org 2026-05-05T15:00:50+00:00 cffc6fc446a27f3eb35779b6285089e6849259b7 commit 03f324f3f1f7619a47b9c91282cb12775ab0a2f1 upstream. ADD_ADDR can be sent for the ID 0, which corresponds to the local address and port linked to the initial subflow. Indeed, this address could be removed, and re-added later on, e.g. what is done in the "delete re-add signal" MPTCP Join selftests. So no reason to ignore it. Fixes: 00cfd77b9063 ("mptcp: retransmit ADD_ADDR when timeout") 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/20260505-net-mptcp-pm-fixes-7-1-rc3-v1-2-fca8091060a4@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 03f324f3f1f7619a47b9c91282cb12775ab0a2f1 upstream.

ADD_ADDR can be sent for the ID 0, which corresponds to the local
address and port linked to the initial subflow.

Indeed, this address could be removed, and re-added later on, e.g. what
is done in the "delete re-add signal" MPTCP Join selftests. So no reason
to ignore it.

Fixes: 00cfd77b9063 ("mptcp: retransmit ADD_ADDR when timeout")
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/20260505-net-mptcp-pm-fixes-7-1-rc3-v1-2-fca8091060a4@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
mptcp: pm: kernel: correctly retransmit ADD_ADDR ID 0 2026-05-14T13:30:23+00:00 Matthieu Baerts (NGI0) matttbe@kernel.org 2026-05-05T15:00:49+00:00 07c2f3c29a8a03e80cdc073838448f58c5182855 commit b12014d2d36eaed4e4bec5f1ac7e91110eeb100d upstream. When adding the ADD_ADDR to the list, the address including the IP, port and ID are copied. On the other hand, when the endpoint corresponds to the one from the initial subflow, the ID is set to 0, as specified by the MPTCP protocol. The issue is that the ID was reset after having copied the ID in the ADD_ADDR entry. So the retransmission was done, but using a different ID than the initial one. Fixes: 8b8ed1b429f8 ("mptcp: pm: reuse ID 0 after delete and re-add") 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/20260505-net-mptcp-pm-fixes-7-1-rc3-v1-1-fca8091060a4@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit b12014d2d36eaed4e4bec5f1ac7e91110eeb100d upstream.

When adding the ADD_ADDR to the list, the address including the IP, port
and ID are copied. On the other hand, when the endpoint corresponds to
the one from the initial subflow, the ID is set to 0, as specified by
the MPTCP protocol.

The issue is that the ID was reset after having copied the ID in the
ADD_ADDR entry. So the retransmission was done, but using a different ID
than the initial one.

Fixes: 8b8ed1b429f8 ("mptcp: pm: reuse ID 0 after delete and re-add")
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/20260505-net-mptcp-pm-fixes-7-1-rc3-v1-1-fca8091060a4@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
mptcp: pm: prio: skip closed subflows 2026-05-14T13:30:23+00:00 Matthieu Baerts (NGI0) matttbe@kernel.org 2026-05-05T15:00:57+00:00 6f5ba49da8b1ab9e0edcc8a69bdc074f1794b5ab commit 166b78344031bf7ac9f55cb5282776cfd85f220e upstream. When sending an MP_PRIO, closed subflows need to be skipped. This fixes the case where the initial subflow got closed, re-opened later, then an MP_PRIO is needed for the same local address. Note that explicit MP_PRIO cannot be sent during the 3WHS, so it is fine to use __mptcp_subflow_active(). Fixes: 067065422fcd ("mptcp: add the outgoing MP_PRIO support") Cc: stable@vger.kernel.org Fixes: b29fcfb54cd7 ("mptcp: full disconnect implementation") Reviewed-by: Mat Martineau <martineau@kernel.org> Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Link: https://patch.msgid.link/20260505-net-mptcp-pm-fixes-7-1-rc3-v1-9-fca8091060a4@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 166b78344031bf7ac9f55cb5282776cfd85f220e upstream.

When sending an MP_PRIO, closed subflows need to be skipped.

This fixes the case where the initial subflow got closed, re-opened
later, then an MP_PRIO is needed for the same local address.

Note that explicit MP_PRIO cannot be sent during the 3WHS, so it is fine
to use __mptcp_subflow_active().

Fixes: 067065422fcd ("mptcp: add the outgoing MP_PRIO support")
Cc: stable@vger.kernel.org
Fixes: b29fcfb54cd7 ("mptcp: full disconnect implementation")
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260505-net-mptcp-pm-fixes-7-1-rc3-v1-9-fca8091060a4@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
mptcp: fix scheduling with atomic in timestamp sockopt 2026-05-14T13:30:22+00:00 Gang Yan yangang@kylinos.cn 2026-04-27T19:54:34+00:00 8a005fe451c73fd2b3d1faa5643c11e6bd07acfc commit b5c52908d52c6c8eb8933264aa6087a0600fd892 upstream. Using lock_sock_fast() (atomic context) around sock_set_timestamp() and sock_set_timestamping() is unsafe, as both helpers can sleep. Replace lock_sock_fast() with sleepable lock_sock()/release_sock() to avoid scheduling while atomic panic. Fixes: 9061f24bf82e ("mptcp: sockopt: propagate timestamp request to subflows") Cc: stable@vger.kernel.org Reported-by: Sashiko <sashiko-bot@kernel.org> Closes: https://sashiko.dev/#/patchset/20260420093343.16443-1-gang.yan@linux.dev 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/20260427-net-mptcp-misc-fixes-7-1-rc2-v1-2-7432b7f279fa@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit b5c52908d52c6c8eb8933264aa6087a0600fd892 upstream.

Using lock_sock_fast() (atomic context) around sock_set_timestamp()
and sock_set_timestamping() is unsafe, as both helpers can sleep.

Replace lock_sock_fast() with sleepable lock_sock()/release_sock()
to avoid scheduling while atomic panic.

Fixes: 9061f24bf82e ("mptcp: sockopt: propagate timestamp request to subflows")
Cc: stable@vger.kernel.org
Reported-by: Sashiko <sashiko-bot@kernel.org>
Closes: https://sashiko.dev/#/patchset/20260420093343.16443-1-gang.yan@linux.dev
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/20260427-net-mptcp-misc-fixes-7-1-rc2-v1-2-7432b7f279fa@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
mptcp: fix rx timestamp corruption on fastopen 2026-05-14T13:30:22+00:00 Paolo Abeni pabeni@redhat.com 2026-05-01T19:35:36+00:00 e6ad28d9d5bff3f7eb8212be8658fae31f3d273e commit 6254a16d6f0c672e3809ca5d7c9a28a55d71f764 upstream. The skb cb offset containing the timestamp presence flag is cleared before loading such information. Cache such value before MPTCP CB initialization. Fixes: 36b122baf6a8 ("mptcp: add subflow_v(4,6)_send_synack()") 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/20260501-net-mptcp-misc-fixes-7-1-rc3-v1-3-b70118df778e@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 6254a16d6f0c672e3809ca5d7c9a28a55d71f764 upstream.

The skb cb offset containing the timestamp presence flag is cleared
before loading such information. Cache such value before MPTCP CB
initialization.

Fixes: 36b122baf6a8 ("mptcp: add subflow_v(4,6)_send_synack()")
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/20260501-net-mptcp-misc-fixes-7-1-rc3-v1-3-b70118df778e@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>