If no subflow is attached to the 'subflow' endpoint that is being removed, the addr ID will not be marked as available again. Mark the linked ID as available when removing the 'subflow' endpoint if no subflow is attached to it. While at it, the local_addr_used counter is decremented if the ID was marked as being used to reflect the reality, but also to allow adding new endpoints after that. Fixes: b6c08380860b ("mptcp: remove addr and subflow in PM netlink") Cc: stable@xxxxxxxxxxxxxxx Reviewed-by: Mat Martineau <martineau@xxxxxxxxxx> Signed-off-by: Matthieu Baerts (NGI0) <matttbe@xxxxxxxxxx> --- net/mptcp/pm_netlink.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c index 26f0329e16bb..8b232a210a06 100644 --- a/net/mptcp/pm_netlink.c +++ b/net/mptcp/pm_netlink.c @@ -1469,8 +1469,17 @@ static int mptcp_nl_remove_subflow_and_signal_addr(struct net *net, remove_subflow = lookup_subflow_by_saddr(&msk->conn_list, addr); mptcp_pm_remove_anno_addr(msk, addr, remove_subflow && !(entry->flags & MPTCP_PM_ADDR_FLAG_IMPLICIT)); - if (remove_subflow) + + if (remove_subflow) { mptcp_pm_remove_subflow(msk, &list); + } else if (entry->flags & MPTCP_PM_ADDR_FLAG_SUBFLOW) { + /* If the subflow has been used, but now closed */ + spin_lock_bh(&msk->pm.lock); + if (!__test_and_set_bit(entry->addr.id, msk->pm.id_avail_bitmap)) + msk->pm.local_addr_used--; + spin_unlock_bh(&msk->pm.lock); + } + release_sock(sk); next: -- 2.45.2