5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: "Matthieu Baerts (NGI0)" <matttbe@xxxxxxxxxx> commit ef34a6ea0cab1800f4b3c9c3c2cefd5091e03379 upstream. If no subflows are attached to the 'subflow' endpoints that are being flushed, the corresponding addr IDs will not be marked as available again. Mark all ID as being available when flushing all the 'subflow' endpoints, and reset local_addr_used counter to cover these cases. Note that mptcp_pm_remove_addrs_and_subflows() helper is only called for flushing operations, not to remove a specific set of addresses and subflows. Fixes: 06faa2271034 ("mptcp: remove multi addresses and subflows in PM") Cc: stable@xxxxxxxxxxxxxxx Reviewed-by: Mat Martineau <martineau@xxxxxxxxxx> Signed-off-by: Matthieu Baerts (NGI0) <matttbe@xxxxxxxxxx> Link: https://patch.msgid.link/20240819-net-mptcp-pm-reusing-id-v1-5-38035d40de5b@xxxxxxxxxx Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx> [ No conflicts, but the line modifying msk->pm.id_avail_bitmap has been removed, as it is not in this version, introduced later in commit 86e39e04482b ("mptcp: keep track of local endpoint still available for each msk") and depending on other ones. The best we can do in this version is to reset local_addr_used counter, better than nothing. ] Signed-off-by: Matthieu Baerts (NGI0) <matttbe@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/mptcp/pm_netlink.c | 6 ++++++ 1 file changed, 6 insertions(+) --- a/net/mptcp/pm_netlink.c +++ b/net/mptcp/pm_netlink.c @@ -1498,8 +1498,14 @@ static void mptcp_pm_remove_addrs_and_su mptcp_pm_remove_addr(msk, &alist); spin_unlock_bh(&msk->pm.lock); } + if (slist.nr) mptcp_pm_remove_subflow(msk, &slist); + + /* Reset counters: maybe some subflows have been removed before */ + spin_lock_bh(&msk->pm.lock); + msk->pm.local_addr_used = 0; + spin_unlock_bh(&msk->pm.lock); } static void mptcp_nl_remove_addrs_list(struct net *net,