From: Stephen Hemminger <stephen@networkplumber.org>
To: netdev@vger.kernel.org
Cc: Stephen Hemminger <stephen@networkplumber.org>
Subject: [PATCH 07/12] net/sched: netem: fix queue limit check to include reordered packets
Date: Fri, 13 Mar 2026 14:15:07 -0700 [thread overview]
Message-ID: <20260313211646.12549-8-stephen@networkplumber.org> (raw)
In-Reply-To: <20260313211646.12549-1-stephen@networkplumber.org>
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: 50612537e9ab ("netem: fix classful handling")
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
---
net/sched/sch_netem.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/sched/sch_netem.c b/net/sched/sch_netem.c
index afb89d318f41..df9049816623 100644
--- a/net/sched/sch_netem.c
+++ b/net/sched/sch_netem.c
@@ -542,7 +542,7 @@ 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);
--
2.51.0
next prev parent reply other threads:[~2026-03-13 21:17 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-03-13 21:15 [PATCH 00/12] netem: fixes, cleanup, and selftest Stephen Hemminger
2026-03-13 21:15 ` [PATCH 01/12] selftests: net: add netem qdisc test Stephen Hemminger
2026-03-13 21:15 ` [PATCH 02/12] Revert "net/sched: Restrict conditions for adding duplicating netems to qdisc tree" Stephen Hemminger
2026-03-13 21:15 ` [PATCH 03/12] net/sched: netem: add per-CPU recursion guard for duplication Stephen Hemminger
2026-03-14 19:29 ` William Liu
2026-03-15 16:06 ` Stephen Hemminger
2026-03-15 16:19 ` Jamal Hadi Salim
2026-03-15 17:18 ` Stephen Hemminger
2026-03-16 17:52 ` Jamal Hadi Salim
2026-03-13 21:15 ` [PATCH 04/12] net/sched: netem: restructure dequeue to avoid re-entrancy with child qdisc Stephen Hemminger
2026-03-13 21:15 ` [PATCH 05/12] net/sched: netem: fix probability gaps in 4-state loss model Stephen Hemminger
2026-03-13 21:15 ` [PATCH 06/12] net/sched: netem: fix slot delay calculation overflow Stephen Hemminger
2026-03-13 21:15 ` Stephen Hemminger [this message]
2026-03-13 21:15 ` [PATCH 08/12] net/sched: netem: null-terminate tfifo linear queue tail Stephen Hemminger
2026-03-13 21:15 ` [PATCH 09/12] net/sched: netem: only reseed PRNG when seed is explicitly provided Stephen Hemminger
2026-03-13 21:15 ` [PATCH 10/12] net/sched: netem: move state enums out of struct netem_sched_data Stephen Hemminger
2026-03-13 21:15 ` [PATCH 11/12] net/sched: netem: remove useless VERSION Stephen Hemminger
2026-03-13 21:15 ` [PATCH 12/12] net/sched: netem: replace pr_info with netlink extack error messages Stephen Hemminger
2026-03-14 14:09 ` [PATCH 00/12] netem: fixes, cleanup, and selftest Jakub Kicinski
2026-03-14 15:39 ` Stephen Hemminger
2026-03-14 15:51 ` Stephen Hemminger
2026-03-14 16:00 ` Jakub Kicinski
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