[Weekly meetings] MoM - 3rd of December 2025

[Matthieu Baerts <matttbe@kernel.org>]

Hello everyone,

This week, we had our new meeting with Mat (Cruise), and myself (NGI0 Core).


Thanks again for this new good meeting!


Here are the minutes of the meeting:



Accepted patches:
    - The list of accepted patches can be seen on PatchWork:
      https://patchwork.kernel.org/project/mptcp/list/?state=3


    netdev (if mptcp ML is in cc) (by: Matthieu Baerts):

14298196: [6.12.y] mptcp: fix MSG_PEEK stream corruption:
    - Submitter: Matthieu Baerts
    - URL: https://patchwork.kernel.org/project/mptcp/patch/20251104121515.1093006-2-matttbe@kernel.org/

14318742: [net,01/11] mptcp: fix ack generation for fallback msk
14318743: [net,02/11] mptcp: avoid unneeded subflow-level drops
14318744: [net,03/11] mptcp: fix premature close in case of fallback
14318745: [net,04/11] mptcp: do not fallback when OoO is present
14318746: [net,05/11] mptcp: decouple mptcp fastclose from tcp close
14318747: [net,06/11] mptcp: fix duplicate reset on fastclose
14318748: [net,07/11] selftests: mptcp: join: fastclose: remove flaky marks
14318749: [net,08/11] selftests: mptcp: join: endpoints: longer timeout
14318750: [net,09/11] selftests: mptcp: join: userspace: longer timeout
14318751: [net,10/11] mptcp: fix address removal logic in mptcp_pm_nl_rm_addr
14318752: [net,11/11] selftests: mptcp: add a check for 'add_addr_accepted':
    - Series: mptcp: misc fixes for v6.18-rc7
    - Submitter: Matthieu Baerts
    - URL: https://patchwork.kernel.org/project/mptcp/list/?series=1024685&state=*&archive=both

14325528: [net-next,01/14] net: factor-out _sk_charge() helper
14325529: [net-next,02/14] mptcp: factor-out cgroup data inherit helper
14325530: [net-next,03/14] mptcp: grafting MPJ subflow earlier
14325531: [net-next,04/14] mptcp: fix memcg accounting for passive sockets
14325532: [net-next,05/14] mptcp: cleanup fallback data fin reception
14325533: [net-next,06/14] mptcp: cleanup fallback dummy mapping generation
14325534: [net-next,07/14] mptcp: ensure the kernel PM does not take action too late
14325535: [net-next,08/14] mptcp: do not miss early first subflow close event notification
14325536: [net-next,09/14] mptcp: make mptcp_destroy_common() static
14325537: [net-next,10/14] mptcp: drop the __mptcp_data_ready() helper
14325538: [net-next,11/14] mptcp: handle first subflow closing consistently
14325539: [net-next,12/14] mptcp: borrow forward memory from subflow
14325540: [net-next,13/14] mptcp: introduce mptcp-level backlog
14325541: [net-next,14/14] mptcp: leverage the backlog for RX packet processing:
    - Series: mptcp: memcg accounting for passive sockets & backlog processing
    - Submitter: Matthieu Baerts
    - URL: https://patchwork.kernel.org/project/mptcp/list/?series=1026445&state=*&archive=both

14329194: [net] mptcp: clear scheduled subflows on retransmit:
    - Submitter: Matthieu Baerts
    - URL: https://patchwork.kernel.org/project/mptcp/patch/20251125-net-mptcp-clear-sched-rtx-v1-1-1cea4ad2165f@kernel.org/

14327388: [iproute2-net,1/6] MAINTAINERS: add entry for mptcp
14327389: [iproute2-net,2/6] man: mptcp: fix minor typos
14327390: [iproute2-net,3/6] mptcp: add 'laminar' endpoint support
14327391: [iproute2-net,4/6] mptcp: monitor: add 'server side' info
14327392: [iproute2-net,5/6] mptcp: monitor: add 'deny join id0' info
14327393: [iproute2-net,6/6] mptcp: monitor: support 'server side' as a flag:
    - Series: mptcp: new endpoint type and info flags
    - Submitter: Matthieu Baerts
    - URL: https://patchwork.kernel.org/project/mptcp/list/?series=1026908&state=*&archive=both

14323749: [net-next,1/2] tools: ynl-gen: add function prefix argument
14323748: [net-next,2/2] tools: ynl-gen: add regeneration comment:
    - State: New
    - Series: tools: ynl-gen: regeneration comment + function prefix
    - Submitter: Asbjørn Sloth Tønnesen
    - URL: https://patchwork.kernel.org/project/mptcp/list/?series=1025958&state=*&archive=both

14332241: [6.6.y] mptcp: fix duplicate reset on fastclose:
    - Submitter: Matthieu Baerts
    - URL: https://patchwork.kernel.org/project/mptcp/patch/20251127182741.3577840-2-matttbe@kernel.org/

14332242: [6.6.y] selftests: mptcp: join: properly kill background tasks:
    - Submitter: Matthieu Baerts
    - URL: https://patchwork.kernel.org/project/mptcp/patch/20251127182810.3578622-2-matttbe@kernel.org/

14333963: [6.1.y] selftests: mptcp: join: endpoints: longer transfer:
    - Submitter: Matthieu Baerts
    - URL: https://patchwork.kernel.org/project/mptcp/patch/20251129165510.2124040-2-matttbe@kernel.org/

14333964: [6.1.y] mptcp: fix duplicate reset on fastclose:
    - Submitter: Matthieu Baerts
    - URL: https://patchwork.kernel.org/project/mptcp/patch/20251129165612.2125498-2-matttbe@kernel.org/

14333965: [5.15.y] selftests: mptcp: join: rm: set backup flag:
    - Submitter: Matthieu Baerts
    - URL: https://patchwork.kernel.org/project/mptcp/patch/20251129165729.2127525-2-matttbe@kernel.org/

14333966: [5.15.y] mptcp: avoid unneeded subflow-level drops:
    - Submitter: Matthieu Baerts
    - URL: https://patchwork.kernel.org/project/mptcp/patch/20251129165825.2129168-2-matttbe@kernel.org/

14334750: [6.1.y] mptcp: Fix proto fallback detection with BPF:
    - Submitter: Matthieu Baerts
    - URL: https://patchwork.kernel.org/project/mptcp/patch/20251201104459.3440448-2-matttbe@kernel.org/

14334838: [5.15.y] mptcp: Fix proto fallback detection with BPF:
    - Submitter: Matthieu Baerts
    - URL: https://patchwork.kernel.org/project/mptcp/patch/20251201112712.3573321-2-matttbe@kernel.org/

14334874: [5.10.y] mptcp: Fix proto fallback detection with BPF:
    - Submitter: Matthieu Baerts
    - URL: https://patchwork.kernel.org/project/mptcp/patch/20251201113457.3641925-2-matttbe@kernel.org/


    our repo (by: Ankit Khushwaha, Matthieu Baerts, Paolo Abeni):

14322543: [v7,mptcp-next,1/6] trace: mptcp: add mptcp_rcvbuf_grow tracepoint
14322544: [v7,mptcp-next,2/6] mptcp: do not account for OoO in mptcp_rcvbuf_grow()
14322546: [v7,mptcp-next,3/6] mptcp: fix receive space timestamp initialization.
14322545: [v7,mptcp-next,4/6] mptcp: consolidate rcv space init
14322547: [v7,mptcp-next,5/6] mptcp: better mptcp-level RTT estimator
14322548: [v7,mptcp-next,6/6] mptcp: add receive queue awareness in tcp_rcv_space_adjust():
    - Series: mptcp: autotune related improvement
    - Submitter: Paolo Abeni
    - URL: https://patchwork.kernel.org/project/mptcp/list/?series=1025709&state=*&archive=both

14324060: [mptcp-net] mptcp: clear scheduled subflows on retransmit:
    - Submitter: Paolo Abeni
    - URL: https://patchwork.kernel.org/project/mptcp/patch/30e5325f37026b870cd0d0765d5d47c8a68fced9.1763676964.git.pabeni@redhat.com/

14324638: [mptcp-net] mptcp: schedule rtx timer only after pushing data:
    - Submitter: Paolo Abeni
    - URL: https://patchwork.kernel.org/project/mptcp/patch/9f5e5b6c05fa0e6d303126c6a68a19305d166d36.1763715034.git.pabeni@redhat.com/

14330673: selftests: mptcp: initialize raw_addr to Null:
    - Submitter: Ankit Khushwaha
    - URL: https://patchwork.kernel.org/project/mptcp/patch/20251126163046.58615-1-ankitkhushwaha.linux@gmail.com/

14330887: [mptcp-net,1/3] mptcp: pm: ignore unknown endpoint flags
14330888: [mptcp-net,2/3] selftests: mptcp: pm: ensure unknown flags are ignored
14330889: [mptcp-net,3/3] mptcp: pm: align endpoint flags size with the NL specs:
    - Series: mptcp: pm: ignore unknown endpoint flags
    - Submitter: Matthieu Baerts
    - URL: https://patchwork.kernel.org/project/mptcp/list/?series=1027994&state=*&archive=both



Pending patches:
    - The list of pending patches can be seen on PatchWork:
      https://patchwork.kernel.org/project/mptcp/list/?state=*


    netdev (if mptcp ML is in cc) (by: Matthieu Baerts):

14321880: [44/44] net/mptcp: Change some dubious min_t(int, ...) to min():
    - State: New
    - Series: Change a lot of min_t() that might mask high bits
    - Submitter: David Laight
    - URL: https://patchwork.kernel.org/project/mptcp/list/?series=1025544&state=*&archive=both
    - TODO: Matt: check status

14333645: [net-next,v2] selftests: mptcp: Mark xerror __noreturn:
    - State: Changes requested
    - Submitter: Ankit Khushwaha
    - URL: https://patchwork.kernel.org/project/mptcp/patch/20251129043808.16714-1-ankitkhushwaha.linux@gmail.com/
    - new version expected in January


    our repo (by: Ankit Khushwaha, Asbjørn Sloth Tønnesen, Christoph Paasch, David Laight, Gang Yan, GangYan, Geliang Tang, Gregory Detal, Matthieu Baerts, Paolo Abeni):

12282223: [RESEND,RFC,mptpcp-next] mptcp: add ooo prune support:
13070467: [mptcp-next,v4,1/2] mptcp: update mptcp_push_release
13070468: [mptcp-next,v4,2/2] mptcp: retrans for redundant sends:
    - State: Changes requested
    - Series: BPF redundant scheduler, part 3
    - Submitter: Geliang Tang
    - URL: https://patchwork.kernel.org/project/mptcp/list/?series=703615&state=*&archive=both
    - Status: same as before

13305089: [mptcp-next,1/6] mptcp: sockopt: move tcp_inq code to a dedicated function
13305091: [mptcp-next,2/6] mptcp: sockopt: update supported list
13305093: [mptcp-next,3/6] mptcp: sockopt: get val in a generic way
13305090: [mptcp-next,4/6] mptcp: sockopt: add missing getsockopt() options
13305094: [mptcp-next,5/6] mptcp: sockopt: set val in a generic way
13305092: [mptcp-next,6/6] mptcp: sockopt: support IP_TTL & IPV6_UNICAST_HOPS:
    - State: Changes requested
    - Series: mptcp: sockopt: uniform code to get/set values
    - Submitter: Matthieu Baerts
    - URL: https://patchwork.kernel.org/project/mptcp/list/?series=763505&state=*&archive=both
    - Status: same as before

13583230: [RFC] mptcp: react scheduler when subflow events pop up:
    - State: Changes requested
    - Submitter: Geliang Tang
    - URL: https://patchwork.kernel.org/project/mptcp/patch/433320c3a9db77bea53a34fc9c43a3c7e3320399.1709693691.git.tanggeliang@kylinos.cn/
    - Status: same as before

13675217: [mptcp-next,RFC,1/4] mptcp: add push sched callback
13675218: [mptcp-next,RFC,2/4] mptcp: use new push callback to schedule chunks
13675219: [mptcp-next,RFC,3/4] mptcp: bpf: allow to write to mptcp_sched_chunk
13675220: [mptcp-next,RFC,4/4] selftests/bpf: mptcp RR: send 1 MSS on each subflow:
    - State: RFC
    - Series: mptcp: update scheduler API
    - Submitter: Gregory Detal
    - URL: https://patchwork.kernel.org/project/mptcp/list/?series=856158&state=*&archive=both
    - Status: same as before

13932555: [1/3] mptcp: fix invalid addr occupy 'add_addr_accepted'
13932556: [2/3] selftests: mptcp: relax conditions in SYN_TX validation
13932546: [3/3] selftests: mptcp: add a testcase for invalid addr timeout:
    - State: Changes requested
    - Series: [1/3] mptcp: fix invalid addr occupy 'add_addr_accepted'
    - Submitter: Gang Yan
    - URL: https://patchwork.kernel.org/project/mptcp/list/?series=923771&state=*&archive=both
    - Status: same as before

14024767: [mptcp-next,v1,1/4] bpf: Add mptcp path manager struct_ops
14024768: [mptcp-next,v1,2/4] bpf: Export mptcp path manager kfuncs
14024769: [mptcp-next,v1,3/4] selftests/bpf: Add mptcp netlink pm subtest
14024770: [mptcp-next,v1,4/4] selftests/bpf: Add mptcp bpf_netlink pm subtest:
    - State: Changes requested
    - Series: BPF path manager, part 7
    - Submitter: Geliang Tang
    - URL: https://patchwork.kernel.org/project/mptcp/list/?series=946095&state=*&archive=both
    - Status: same as before

14053397: [mptcp-next,v3,1/3] mptcp: pm: userspace: drop delete_local_addr helper
14053398: [mptcp-next,v3,2/3] selftests: mptcp: join: update userspace dump_addr outputs
14053399: [mptcp-next,v3,3/3] selftests: mptcp: userspace: send RM_ADDR between server and client:
    - State: Under review
    - Series: only remove entry from local_addr_list when sending a REMOVE_ADDR
    - Submitter: Geliang Tang
    - URL: https://patchwork.kernel.org/project/mptcp/list/?series=953862&state=*&archive=both
    - Status: same as before

14167004: [mptcp-next] mptcp: remove redundant orig_offset in carve_data_frag:
    - State: Changes requested
    - Submitter: Geliang Tang
    - URL: https://patchwork.kernel.org/project/mptcp/patch/9c663fc37767d9036379afdbc83cd8874a7b2fc9.1753337130.git.tanggeliang@kylinos.cn/
    - Status: same as before

14175678: [mptcp-next,1/2] mptcp: Add support for SO_MAX_PACING_RATE
14175679: [mptcp-next,2/2] selftests: Add tests for SO_MAX_PACING_RATE:
    - State: Changes requested
    - Series: mptcp: Add support for SO_MAX_PACING_RATE
    - Submitter: Christoph Paasch
    - URL: https://patchwork.kernel.org/project/mptcp/list/?series=987909&state=*&archive=both
    - Status: same as before

14185125: [mptcp-next,1/6] mptcp: add helper for setsockopt on first subflow only
14185126: [mptcp-next,2/6] mptcp: handle SOL_SOCKET options on first subflow only
14185128: [mptcp-next,3/6] mptcp: refactor IP socket option handling for first subflow
14185127: [mptcp-next,4/6] mptcp: extract IPv6 socket option handling for first subflow
14185129: [mptcp-next,5/6] mptcp: handle SOL_TCP options on all subflows
14185130: [mptcp-next,6/6] mptcp: handle IP socket options on all subflows:
    - State: Needs ack
    - Series: refactor MPTCP socket option handling
    - Submitter: Geliang Tang
    - URL: https://patchwork.kernel.org/project/mptcp/list/?series=990414&state=*&archive=both
    - Status: same as before

14185142: [mptcp-next,v2,1/3] mptcp: add IPV6_TCLASS socket option support
14185143: [mptcp-next,v2,2/3] mptcp: add IP_TTL socket option support
14185144: [mptcp-next,v2,3/3] mptcp: add IPV6_UNICAST_HOPS socket option support:
    - State: Needs ack
    - Series: mptcp: add more sockopts
    - Submitter: Geliang Tang
    - URL: https://patchwork.kernel.org/project/mptcp/list/?series=990418&state=*&archive=both
    - Status: same as before

14197780: [mptcp-next,v2,01/10] selftests: mptcp: sockopt: improve test output clarity
14197781: [mptcp-next,v2,02/10] selftests: mptcp: sockopt: add SO_REUSEADDR test helper
14197782: [mptcp-next,v2,03/10] selftests: mptcp: sockopt: add SO_REUSEPORT test
14197783: [mptcp-next,v2,04/10] selftests: mptcp: sockopt: add SO_BINDTODEVICE test
14197784: [mptcp-next,v2,05/10] selftests: mptcp: sockopt: add SO_BINDTOIFINDEX test
14197785: [mptcp-next,v2,06/10] selftests: mptcp: sockopt: add IP_FREEBIND tests
14197786: [mptcp-next,v2,07/10] selftests: mptcp: sockopt: add IP_TRANSPARENT tests
14197787: [mptcp-next,v2,08/10] selftests: mptcp: sockopt: add IP_BIND_ADDRESS_NO_PORT test
14197788: [mptcp-next,v2,09/10] selftests: mptcp: sockopt: add IP_LOCAL_PORT_RANGE test
14197789: [mptcp-next,v2,10/10] selftests: mptcp: sockopt: add IPV6_V6ONLY test:
    - State: Changes requested
    - Series: selftests: cover more MPTCP socket options
    - Submitter: Geliang Tang
    - URL: https://patchwork.kernel.org/project/mptcp/list/?series=993905&state=*&archive=both
    - Status: same as before

14215849: [mptcp-net,v2,1/3] selftests: mptcp: close server file descriptor
14215850: [mptcp-net,v2,2/3] selftests: mptcp: close IPC descriptor on server side
14229120: [mptcp-next,v4,1/9] selftests: mptcp: sockopt: replace /dev/urandom with getrandom
14229121: [mptcp-next,v4,2/9] selftests: mptcp: sockopt: add protocol arguments
14229122: [mptcp-next,v4,3/9] selftests: mptcp: sockopt: add inq argument
14229123: [mptcp-next,v4,4/9] selftests: mptcp: sockopt: rename pipefd to ipcfd
14229124: [mptcp-next,v4,5/9] selftests: mptcp: sockopt: set TCP_INQ sockopt
14229125: [mptcp-next,v4,6/9] selftests: mptcp: sockopt: handle INQ on server side
14229126: [mptcp-next,v4,7/9] selftests: mptcp: sockopt: handle INQ on client side
14229127: [mptcp-next,v4,8/9] selftests: mptcp: sockopt: replace mptcp_inq with sockopt
14229128: [mptcp-next,v4,9/9] selftests: mptcp: sockopt: remove obsolete mptcp_inq:
    - State: Changes requested
    - Series: selftests: consolidate TCP_INQ testing into sockopt
    - Submitter: Geliang Tang
    - URL: https://patchwork.kernel.org/project/mptcp/list/?series=1001827&state=*&archive=both
    - Status: same as before

14326164: [RFC,mptcp-next,v3,1/8] selftests: mptcp: sockopt: add protocol arguments
14326165: [RFC,mptcp-next,v3,2/8] selftests: mptcp: sockopt: enhance compatibility with TCP tests
14326166: [RFC,mptcp-next,v3,3/8] selftests: mptcp: sockopt: implement TCP TLS tests
14326167: [RFC,mptcp-next,v3,4/8] tls: add MPTCP protocol support
14326168: [RFC,mptcp-next,v3,5/8] mptcp: update ULP getsockopt
14326169: [RFC,mptcp-next,v3,6/8] mptcp: enable TLS setsockopt
14326170: [RFC,mptcp-next,v3,7/8] selftests: mptcp: connect: update sock_test_tcpulp
14326171: [RFC,mptcp-next,v3,8/8] selftests: mptcp: sockopt: cover MPTCP KTLS test cases:
    - State: New
    - Series: MPTCP KTLS support
    - Submitter: Geliang Tang
    - URL: https://patchwork.kernel.org/project/mptcp/list/?series=1026573&state=*&archive=both
    - Depends on the "mptcp read_sock" one, will be reviewed after

14327146: [mptcp-next,v14,1/8] mptcp: add eat_recv_skb helper
14327147: [mptcp-next,v14,2/8] mptcp: implement .read_sock
14327148: [mptcp-next,v14,3/8] tcp: add recv_should_stop helper
14327149: [mptcp-next,v14,4/8] mptcp: use recv_should_stop helper
14327150: [mptcp-next,v14,5/8] tcp: export tcp_splice_state
14327151: [mptcp-next,v14,6/8] mptcp: implement .splice_read
14327152: [mptcp-next,v14,7/8] selftests: mptcp: add splice io mode
14327153: [mptcp-next,v14,8/8] selftests: mptcp: connect: cover splice mode:
    - State: New
    - Series: implement mptcp read_sock
    - Submitter: Geliang Tang
    - URL: https://patchwork.kernel.org/project/mptcp/list/?series=1026854&state=*&archive=both
    - To be reviewed

14330153: [RFC,mptcp-next,v2,1/7] mptcp: allow overridden write_space to be invoked
14330154: [RFC,mptcp-next,v2,2/7] mptcp: add sock_set_reuseaddr
14330155: [RFC,mptcp-next,v2,3/7] mptcp: add sock_set_nodelay
14330156: [RFC,mptcp-next,v2,4/7] nvmet-tcp: add mptcp support
14330157: [RFC,mptcp-next,v2,5/7] mptcp: add sock_set_syncnt
14330158: [RFC,mptcp-next,v2,6/7] nvme-tcp: add mptcp support
14330159: [RFC,mptcp-next,v2,7/7] selftests: mptcp: add NVMe-over-MPTCP test:
    - State: New
    - Series: NVME over MPTCP
    - Submitter: Geliang Tang
    - URL: https://patchwork.kernel.org/project/mptcp/list/?series=1027779&state=*&archive=both
    - Depends on the "mptcp read_sock" one, will be reviewed after

14331259: libnvme: add mptcp trtype:
    - State: New
    - Series: libnvme: add mptcp trtype
    - Submitter: Geliang Tang
    - URL: https://patchwork.kernel.org/project/mptcp/list/?series=1028094&state=*&archive=both
    - one question for libnvme maintainer

14332026: [RFC,mptcp-next] mptcp: support net.ipv4.tcp_rcvbuf_low_rtt:
    - State: RFC
    - Submitter: Matthieu Baerts
    - URL: https://patchwork.kernel.org/project/mptcp/patch/20251127-mptcp-tcp_rcvbuf_low_rtt-v1-1-fa080d67f2e5@kernel.org/
    - we should share more code with TCP not to have to adapt MPTCP each time TCP is being modified.

14332838: [mptcp-net] mptcp: sync the msk->sndbuf at accept() time:
    - State: Changes requested
    - Submitter: GangYan
    - URL: https://patchwork.kernel.org/project/mptcp/patch/20251128094417.14463-1-gang.yan@linux.dev/
    - might be due to WIP patches?

14332987: [mptcp-net] mptcp: fallback earlier on simult connection:
    - State: New
    - Submitter: Paolo Abeni
    - URL: https://patchwork.kernel.org/project/mptcp/patch/36b926c5d55933a6f2d2a7f6ff8d8a091c0de719.1764332508.git.pabeni@redhat.com/
    - Matth can still reproduce his issue, which seems to have a slightly different root cause, probably a v2 or an  extra fix will be needed

14332999: [net-next] tls: check return value of strp_load_anchor_with_queue:
    - State: Changes requested
    - Submitter: Geliang Tang
    - URL: https://patchwork.kernel.org/project/mptcp/patch/ce74452f4c095a1761ef493b767b4bd9f9c14359.1764333805.git.tanggeliang@kylinos.cn/
    - Looks like the issue is due to WIP code, probably the fix should be in these other patches.



Issues on GitHub:
    https://github.com/multipath-tcp/mptcp_net-next/issues/

    Recently opened (latest from the last meeting: 601):

  602  A query about the update of 'msk->sk_sndbuf' [question]:
      - See the patch that has been sent about that: maybe an issue in the WIP patches?


    Recently discussed:

  600  mptcp: avoid dropping partial packets [bug]:
      - renamed: goal now is to reapply a fix and... fix it

  599  [syzbot] possible deadlock in `mptcp_subflow_create_socket`: `nbd` has a lockdep dependency between `reclaim` and `af_socket` [bug] [syzkaller]:
      - more details about the issue has been added

  586  [syzkaller] WARNING in `subflow_data_ready` [bug] [syzkaller]:
      - Paolo sent a patch

  581  Default scheduler under-utilizes newly restored subflows on long-lived flows after WAN failback [bug]

  491  selftests: `mptcp_join`: tests `Infinite map` & `MP_FAIL MP_RST` are unstable [bug] [selftests]:
      - still happening

  213  add MPTCP man page [enhancement]:
      - some new hints for those who want to look at it


    Bugs (opened, flagged as "bug" and assigned)

  575  sockopt: support `TCP_MD5SIG` and `TCP_MD5SIG_EXT` for transparent integrations [bug] @geliangtang
  498  in-kernel PM: closed subflows before `RM_ADDR` will not decrement `add_addr_accepted` [bug] [pm] @geliangtang
  484  BPF: `setsockopt` on an MPTCP socket: check support [bug] [bpf] @geliangtang
  445  MPTCP Info counters: start seq numbers ones from 0 [bug] @geliangtang
  403  userspace pm: only remove entry from `local_addr_list` when sending a `REMOVE_ADDR` [bug] [pm] @geliangtang
  343  scheduler: react when subflow-level events pop up (ACK/RTO) [bug] [sched] @geliangtang


    Bugs (opened and flagged as "bug" and not assigned)

  600  mptcp: avoid dropping partial packets [bug]
  599  [syzbot] possible deadlock in `mptcp_subflow_create_socket`: `nbd` has a lockdep dependency between `reclaim` and `af_socket` [bug] [syzkaller]
  592  Lower throughput with MPTCP vs TCP [bug]
  587  in-kernel PM: Server is only using single IP to establish subflows [bug]
  586  [syzkaller] WARNING in `subflow_data_ready` [bug] [syzkaller]
  583  KMemLeak: from `mptcp_sk_clone_init()` [bug] [selftests]
  581  Default scheduler under-utilizes newly restored subflows on long-lived flows after WAN failback [bug]
  572  [syzkaller] WARNING in `skb_try_coalesce` [bug] [syzkaller]
  567  [syzbot] WARNING in `__mark_subflow_endp_available` [bug] [syzkaller] [reproducer]
  549  pm: in-kernel: set `msk->pm.work_pending` back to `true` [bug] [pm]
  492  userspace pm: subflows counter: not updated when a subflows is removed from the other end [bug]
  491  selftests: `mptcp_join`: tests `Infinite map` & `MP_FAIL MP_RST` are unstable [bug] [selftests]
  483  [6.1] selftests: `mptcp_connect.sh` failures with `copyfd_io_poll: poll timed out` errors [bug] [selftests]
  475  `simult_flows`: unbalanced bwidth tests are unstable [bug] [selftests]
  439  mptcp vs net.ipv4.tcp_shrink_window [bug]
  336  Issues with BPF packet scheduler [bug] [sched] [bpf]


    In Progress (opened, new feature and assigned)

  568  socket option: support `IPV6_TCLASS` [enhancement] @geliangtang
  480  MPTCP and KTLS support [enhancement] @geliangtang
  434  in-kernel PM: increase subflows limit [enhancement] [pm] @matttbe
  353  sockopt: uniform code to get/set values [enhancement] @matttbe
  349  scheduler: (un)mark a subflow as "stale" [enhancement] [sched] @geliangtang
  296  Support IP_TTL & IPV6_UNICAST_HOPS [enhancement] @matttbe
  167  packetdrill: add coverage for RM_ADDR [enhancement] [packetdrill] @dcaratti
   75  BPF: packet scheduler [enhancement] [sched] [bpf] @geliangtang
   74  BPF: path manager [enhancement] [pm] [bpf] @geliangtang


    Assigned Questions (opened, questions and assigned)

  548  disable mptcp for an interface [question] @matttbe


    Open questions (opened, questions and not assigned)

  602  A query about the update of 'msk->sk_sndbuf' [question]
  562  [performance] How much is the overhead of MPTCP？ [question]


    For later (opened and not assigned)

  590  in-kernel PM: use either `subflow` or `signal` depending on connector/listener app [enhancement]
  588  in-kernel PM: support NUMA awareness [enhancement] [feedback-needed]
  584  [syzkaller] improve coverage [syzkaller]
  578  sockopt: support `SO_MAX_PACING_RATE` to limit the whole MPTCP connection [enhancement]
  566  pm: use `signal` + `subflow` + `fullmesh` [enhancement] [pm]
  556  Implement all required bits to C/R MPTCP connections from user-space (CRIU) [enhancement]
  552  pm: in-kernel: delay before creating new subflows [enhancement]
  545  Deal with multiple pure TCP ACK without MPTCP options [enhancement]
  543  TCPDump: display `MP_TCPRST` info [enhancement]
  542  in-kernel PM: limit to one subflow per network interface for each connection [enhancement] [pm]
  535  TCPDump: display `MP_CAPABLE` C flag [enhancement]
  525  tests: cover more MPTCP socket options [enhancement] [packetdrill] [selftests]
  521  Implement psock_update_sk_prot, for eBPF SOCKMAP support [enhancement]
  519  Reset the connection once "MPTCP has been verified" instead of a fallback [enhancement]
  511  Add MIB counters for sent `MPTCP_RST_EMPTCP` [enhancement]
  497  in-kernel PM: check to create new subflows when some are destroyed [enhancement] [pm]
  496  in-kernel PM: store received `ADD_ADDR` [enhancement] [pm]
  481  remove refcount on TCP sockets for the timers [enhancement]
  467  Scheduler: add redundant scheduler support in BPF [enhancement] [sched]
  462  selftests: print (and set?) random seed [enhancement] [selftests]
  461  Protocol: extend Data-Level Length field [enhancement] [protocol]
  448  Allow sending ADD_ADDR IPv6 with port-number if TCP-timestamps are enabled [enhancement]
  441  optimize established options generation [enhancement]
  440  in-kernel PM: re-establish subflows after "network" errors [enhancement] [pm]
  426  selftests: validate listener sockets with multiple accepts [enhancement] [selftests]
  396  ci: periodically run selftests from the export branch on stable kernels [enhancement] [selftests]
  389  packetdrill: increase coverage for "early `close()`" cases [enhancement] [packetdrill]
  350  scheduler: API changes (tasks) [enhancement] [sched]
  348  scheduler: frequently probe "stale" subflow with reinjected data [enhancement] [sched]
  345  scheduler: "penalise" some subflows by sending less than their cwnd [enhancement] [sched]
  344  scheduler: new callback to initiate optimisations [enhancement] [sched]
  337  in-kernel PM: listen socket: support "behind a NAT" use case  [enhancement] [pm]
  335  Server to Client subflows: option to allow joining the initial address and port [enhancement] [pm]
  334  in-kernel PM: send >1 ADD_ADDR before the establishment of a new subflow [enhancement] [pm]
  332  scheduler: implement a "opportunistic retransmission" [enhancement] [sched]
  289  mptcp: audit comments for non inclusive language [enhancement]
  273  Packetdrill: test outgoing MP_FASTCLOSE [enhancement] [packetdrill]
  266  Packetdrill: add MP_FAIL coverage [packetdrill]
  236  Review supported sockopts list [enhancement]
  234  Packetdrill: Support MPC+DATA+checksum error [enhancement] [packetdrill]
  222  Netlink event API: add SUBFLOW_CREATED event [enhancement]
  215  TCP Urgent pointer and MPTCP [enhancement]
  213  add MPTCP man page [enhancement]
  208  better handing of ssk memory pressure in the TX path [enhancement]
  202  Add sendmsg support for ancillary data [enhancement]
  180  Get an update when MPTCP fall back to TCP [enhancement]
  177  improve retransmit subflow selection [enhancement]
  169  packetdrill: add coverage for ADD_ADDR and MP_JOIN on a different port [enhancement] [packetdrill]
  150  remove completely workqueue usage [enhancement]
  141  avoid acquiring mptcp_data_lock() twice in the receive path [enhancement]
   78  notify the application (userspace) when a subflow is added/removed [enhancement]
   41  reduce indirect call usage [enhancement]
   24  Revisit layout of struct mptcp_subflow_context [enhancement]


    Recently closed (since 2025-11-19)

  595  selftests: `mptcp_connect`: MPTCP -> MPTCP timeout during closing time [bug] [selftests]
  574  [selftests] `mptcp_connect.sh`: `copyfd_io_poll`: poll timed out [bug] [selftests]
  561  [syzkaller]  WARNING in `mptcp_pm_alloc_anno_list` [bug] [syzkaller]
  530  about mptcp subflow creation question [question] [feedback-needed]
  520  Question about proper MPTCP configuration over VPN. [question] [feedback-needed]
  508  Divide error on device removal [bug] [feedback-needed]
  505  Subflows won't be used when the interface for the main flow is a subinterface [bug] [feedback-needed]
  495  [syzkaller] KASAN: slab-use-after-free Read in `__inet6_lookup_established` [bug] [syzkaller]
  494  [syzkaller] WARNING in `__skb_flow_dissect` [bug] [syzkaller]
  476  packetdrill: coalescing feature doesn't take into account MPTCP options [bug] [packetdrill]
  412  shadowsocks-libev not working, need guidance for PM configuration [question] [feedback-needed]
  325  selftests: `mptcp_join`: test 18 `signal addresses race test` is sometimes failing [bug] [selftests]
  324  selftests: `mptcp_join`: tests `fastclose test` & `fastclose server test` are sometimes failing [bug] [selftests] @matttbe
  315  Issues with backup flow [bug]
  197  more mibs needed [enhancement]


    Packetdrill PRs

  184  2 days ago     matttbe      mptcp: fallback earlier on simult connection:
      - Linked to Paolo's patch

  162  20 days ago    geliangtang  mptcp: add splice test
  52   10 months ago  dcaratti     Add initial coverage for RM_ADDR


    mptcp.dev PRs: /


    mptcpd PRs:

  329  5 days ago  matttbe  flags: define "implicit":
      - merged!




FYI: Current Roadmap:
    - Bugs: https://github.com/multipath-tcp/mptcp_net-next/issues?q=is%3Aissue+is%3Aopen+label%3Abug
    - Current/Coming merge window (6.19): https://github.com/orgs/multipath-tcp/projects/17
    - For later: https://github.com/orgs/multipath-tcp/projects/1
    - TODO: Matth: update changelog + new projects + change links → Done
        https://github.com/multipath-tcp/mptcp_net-next/wiki#changelog



Patches to send to NetDev:

    - Fixes for other trees:

        - [2505e1b4bea4] selftests: bpf: fix recent compilation errors (Matthieu Baerts (NGI0))
        - [08d7b3f6fe89] selftests: mptcp: initialize raw_addr to Null (Ankit Khushwaha)

    - Fixes for -net:

        - [5a048c302a7a] mptcp: schedule rtx timer only after pushing data (Paolo Abeni):
            - was delayed after a request from Paolo, can be sent now.

        - [197a6e0e0dda] mptcp: pm: ignore unknown endpoint flags (Matthieu Baerts (NGI0))
        - [f5661a6157d5] selftests: mptcp: pm: ensure unknown flags are ignored (Matthieu Baerts (NGI0)):
            - can be sent


    - Fixes for net-next: /


    - Features for net-next:

        - [e2716470e392] mptcp: pm: init and release mptcp_pm_ops (Geliang Tang)
        - [1d6e4e112d0a] mptcp: pm: add get_local_id() interface (Geliang Tang)
        - [42bbbc6012e1] mptcp: pm: add get_priority() interface (Geliang Tang)
        - [83dde12cadbe] mptcp: pm: align endpoint flags size with the NL specs (Matthieu Baerts (NGI0))
        - [d2108181d983] trace: mptcp: add mptcp_rcvbuf_grow tracepoint (Paolo Abeni)
        - [ff42ffc6c36e] mptcp: do not account for OoO in mptcp_rcvbuf_grow() (Paolo Abeni)
        - [f78d06d9dca9] mptcp: fix receive space timestamp initialization (Paolo Abeni)
        - [e626c5eb154b] mptcp: consolidate rcv space init (Paolo Abeni)
        - [710614b1f552] mptcp: better mptcp-level RTT estimator (Paolo Abeni)
        - [bee53f521f91] mptcp: add receive queue awareness in tcp_rcv_space_adjust() (Paolo Abeni):
            - net-next is closed


    - Features for net-next (next): /


    - Features for other trees:

        - [33e6f24a7ddd] bpf: Add mptcp_subflow bpf_iter (Geliang Tang)
        - [5c216569692b] selftests/bpf: More endpoints for endpoint_init (Geliang Tang)
        - [74d3e560d5bc] selftests/bpf: Drop cgroup_fd of run_mptcpify (Geliang Tang)
        - [cbee01cd828c] bpf: Add mptcp packet scheduler struct_ops (Geliang Tang)
        - [3150383b5113] bpf: Export mptcp packet scheduler helpers (Geliang Tang)
        - [ae9aa73c9e11] selftests/bpf: Add bpf scheduler test (Geliang Tang)
        - [c4e0a40004ba] selftests/bpf: Add bpf_first scheduler & test (Geliang Tang)
        - [729063f85404] selftests/bpf: Add bpf_bkup scheduler & test (Geliang Tang)
        - [4a35b1194f96] selftests/bpf: Add bpf_rr scheduler & test (Geliang Tang)
        - [dab71ebd7228] selftests/bpf: Add bpf_red scheduler & test (Geliang Tang)
        - [12152a05a4c6] selftests/bpf: Add bpf_burst scheduler & test (Geliang Tang)



Extra tests:
    - news about Syzkaller? (Matth):
        - New issues found, Matth will try to sort that out

    - Packetdrill (Davide):
        - /

    - Patchew (Davide):
        - /

    - CI (Matth):
        - https://ci-results.mptcp.dev/flakes.html
        - https://netdev.bots.linux.dev/flakes.html?tn-needle=mptcp
        - Jakub's message → Done
        - Some issues with simult flows
        - Also issues with packetdrill:
            - TODO Matth → Done



Next meeting:
    - Next one on Wednesday, the 17th of December.
    - /!\ Note: this meeting will maybe be cancelled: net-next will still be closed, post LPC, pre holiday period, etc.
    - /!\ The one on the 31st of December will be cancelled. Next one on the 14st of January
    - 17:30 UTC (8.30am PDT, 5.30pm CEST, 11.30pm CST)
    - Still open to everyone!
    - https://annuel2.framapad.org/p/mptcp_upstreaming_20251217
    - https://annuel2.framapad.org/p/mptcp_upstreaming_20260114



Feel free to comment on these topics and suggest new ones for the next
meeting!

Talk to you soon,
Matt
-- 
Sponsored by the NGI0 Core fund.