From 7b64bdbfcf6f0f5b0dea97cfc20da7723c1c2d41 Mon Sep 17 00:00:00 2001 From: "Matthieu Baerts (NGI0)" Date: Mon, 19 Aug 2024 21:45:21 +0200 Subject: [PATCH] mptcp: pm: re-using ID of unused removed subflows commit edd8b5d868a4d459f3065493001e293901af758d upstream. 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@vger.kernel.org Reviewed-by: Mat Martineau Signed-off-by: Matthieu Baerts (NGI0) Link: https://patch.msgid.link/20240819-net-mptcp-pm-reusing-id-v1-3-38035d40de5b@kernel.org Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman --- 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 34e1b1024174..5f1e55c1eaa0 100644 --- a/net/mptcp/pm_netlink.c +++ b/net/mptcp/pm_netlink.c @@ -1500,8 +1500,17 @@ 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: