Commit 4185701f authored by Stephen Hemminger's avatar Stephen Hemminger Committed by Jakub Kicinski
Browse files

net/sched: netem: fix queue limit check to include reordered packets 



The queue limit check in netem_enqueue() uses q->t_len which only
counts packets in the internal tfifo. Packets placed in sch->q by
the reorder path (__qdisc_enqueue_head) are not counted, allowing
the total queue occupancy to exceed sch->limit under reordering.

Include sch->q.qlen in the limit check.

Fixes: f8d4bc45 ("net/sched: netem: account for backlog updates from child qdisc")
Signed-off-by: default avatarStephen Hemminger <stephen@networkplumber.org>
Reviewed-by: default avatarSimon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20260418032027.900913-3-stephen@networkplumber.org


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 732b4634

net/sched/sch_netem.c

+1 −1
Original line number Diff line number Diff line
@@ -524,7 +524,7 @@ static int netem_enqueue(struct sk_buff *skb, struct Qdisc *sch, 
				1 << get_random_u32_below(8);

	}



	if (unlikely(q->t_len >= sch->limit)) {

	if (unlikely(sch->q.qlen >= sch->limit)) {

		/* re-link segs, so that qdisc_drop_all() frees them all */

		skb->next = segs;

		qdisc_drop_all(skb, sch, to_free);