From: Daniel Borkmann <daniel@xxxxxxxxxxxxx> [ Upstream commit ed6cd6a17896561b9f51ab4c0d9bbb29e762b597 ] Yuwei reported that plain reuse of DELAY_PROBE_TIME to rearm work queue in neigh_managed_work is problematic if user explicitly configures the DELAY_PROBE_TIME to 0 for a neighbor table. Such misconfig can then hog CPU to 100% processing the system work queue. Instead, set lower interval bound to HZ which is totally sufficient. Yuwei is additionally looking into making the interval separately configurable from DELAY_PROBE_TIME. Reported-by: Yuwei Wang <wangyuweihx@xxxxxxxxx> Signed-off-by: Daniel Borkmann <daniel@xxxxxxxxxxxxx> Link: https://lore.kernel.org/netdev/797c3c53-ce1b-9f60-e253-cda615788f4a@xxxxxxxxxxxxx Reviewed-by: Nikolay Aleksandrov <razor@xxxxxxxxxxxxx> Link: https://lore.kernel.org/r/3b8c5aa906c52c3a8c995d1b2e8ccf650ea7c716.1653432794.git.daniel@xxxxxxxxxxxxx Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- net/core/neighbour.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/core/neighbour.c b/net/core/neighbour.c index f64ebd050f6c..fd69133dc7c5 100644 --- a/net/core/neighbour.c +++ b/net/core/neighbour.c @@ -1579,7 +1579,7 @@ static void neigh_managed_work(struct work_struct *work) list_for_each_entry(neigh, &tbl->managed_list, managed_list) neigh_event_send_probe(neigh, NULL, false); queue_delayed_work(system_power_efficient_wq, &tbl->managed_work, - NEIGH_VAR(&tbl->parms, DELAY_PROBE_TIME)); + max(NEIGH_VAR(&tbl->parms, DELAY_PROBE_TIME), HZ)); write_unlock_bh(&tbl->lock); } -- 2.35.1
