From: "Matthieu Baerts (NGI0)" <matttbe@xxxxxxxxxx> commit 8b8ed1b429f8fa7ebd5632555e7b047bc0620075 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: 3ad14f54bd74 ("mptcp: more accurate MPC endpoint tracking") Cc: stable@xxxxxxxxxxxxxxx Reviewed-by: Mat Martineau <martineau@xxxxxxxxxx> Signed-off-by: Matthieu Baerts (NGI0) <matttbe@xxxxxxxxxx> Signed-off-by: Paolo Abeni <pabeni@xxxxxxxxxx> Signed-off-by: Matthieu Baerts (NGI0) <matttbe@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/mptcp/pm_netlink.c | 10 ++++++++++ 1 file changed, 10 insertions(+) --- a/net/mptcp/pm_netlink.c +++ b/net/mptcp/pm_netlink.c @@ -600,6 +600,11 @@ static void mptcp_pm_create_subflow_or_s __clear_bit(local.addr.id, msk->pm.id_avail_bitmap); msk->pm.add_addr_signaled++; + + /* Special case for ID0: set the correct ID */ + if (local.addr.id == msk->mpc_endpoint_id) + local.addr.id = 0; + mptcp_pm_announce_addr(msk, &local.addr, false); mptcp_pm_nl_addr_send_ack(msk); @@ -624,6 +629,11 @@ subflow: msk->pm.local_addr_used++; __clear_bit(local.addr.id, msk->pm.id_avail_bitmap); + + /* Special case for ID0: set the correct ID */ + if (local.addr.id == msk->mpc_endpoint_id) + local.addr.id = 0; + nr = fill_remote_addresses_vec(msk, &local.addr, fullmesh, addrs); if (nr == 0) continue; Patches currently in stable-queue which might be from matttbe@xxxxxxxxxx are queue-6.1/mptcp-pm-fix-rm_addr-id-for-the-initial-subflow.patch queue-6.1/selftests-mptcp-join-validate-fullmesh-endp-on-1st-sf.patch queue-6.1/mptcp-pm-fix-id-0-endp-usage-after-multiple-re-creations.patch queue-6.1/mptcp-make-pm_remove_addrs_and_subflows-static.patch queue-6.1/mptcp-pm-avoid-possible-uaf-when-selecting-endp.patch queue-6.1/mptcp-pm-reuse-id-0-after-delete-and-re-add.patch queue-6.1/selftests-mptcp-join-check-re-adding-init-endp-with-id.patch queue-6.1/selftests-mptcp-join-test-for-flush-re-add-endpoints.patch queue-6.1/selftests-mptcp-add-explicit-test-case-for-remove-re.patch queue-6.1/selftests-mptcp-add-explicit-test-case-for-remove-readd.patch queue-6.1/selftests-mptcp-join-check-re-adding-init-endp-with-.patch queue-6.1/selftests-mptcp-join-check-re-using-id-of-closed-subflow.patch queue-6.1/mptcp-pm-fullmesh-select-the-right-id-later.patch queue-6.1/mptcp-pr_debug-add-missing-n-at-the-end.patch queue-6.1/selftests-mptcp-join-check-re-using-id-of-unused-add.patch queue-6.1/selftests-mptcp-join-check-re-using-id-of-unused-add_addr.patch