5.10-stable review patch. If anyone has any objections, please let me know.
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From: Cong Wang xiyou.wangcong@gmail.com
[ Upstream commit a7a15f39c682ac4268624da2abdb9114bdde96d5 ]
est_qlen_notify() deletes its class from its active list with list_del() when qlen is 0, therefore, it is not idempotent and not friendly to its callers, like fq_codel_dequeue().
Let's make it idempotent to ease qdisc_tree_reduce_backlog() callers' life. Also change other list_del()'s to list_del_init() just to be extra safe.
Reported-by: Gerrard Tai gerrard.tai@starlabs.sg Signed-off-by: Cong Wang xiyou.wangcong@gmail.com Link: https://patch.msgid.link/20250403211033.166059-6-xiyou.wangcong@gmail.com Acked-by: Jamal Hadi Salim jhs@mojatatu.com Signed-off-by: Paolo Abeni pabeni@redhat.com Stable-dep-of: d92adacdd8c2 ("net_sched: ets: fix a race in ets_qdisc_change()") Signed-off-by: Sasha Levin sashal@kernel.org --- net/sched/sch_ets.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/net/sched/sch_ets.c b/net/sched/sch_ets.c index 35b8577aef7dc..55b3362d27106 100644 --- a/net/sched/sch_ets.c +++ b/net/sched/sch_ets.c @@ -298,7 +298,7 @@ static void ets_class_qlen_notify(struct Qdisc *sch, unsigned long arg) * to remove them. */ if (!ets_class_is_strict(q, cl) && sch->q.qlen) - list_del(&cl->alist); + list_del_init(&cl->alist); }
static int ets_class_dump(struct Qdisc *sch, unsigned long arg, @@ -499,7 +499,7 @@ static struct sk_buff *ets_qdisc_dequeue(struct Qdisc *sch) if (unlikely(!skb)) goto out; if (cl->qdisc->q.qlen == 0) - list_del(&cl->alist); + list_del_init(&cl->alist); return ets_qdisc_dequeue_skb(sch, skb); }
@@ -674,7 +674,7 @@ static int ets_qdisc_change(struct Qdisc *sch, struct nlattr *opt, } for (i = q->nbands; i < oldbands; i++) { if (i >= q->nstrict && q->classes[i].qdisc->q.qlen) - list_del(&q->classes[i].alist); + list_del_init(&q->classes[i].alist); qdisc_tree_flush_backlog(q->classes[i].qdisc); } q->nstrict = nstrict; @@ -723,7 +723,7 @@ static void ets_qdisc_reset(struct Qdisc *sch)
for (band = q->nstrict; band < q->nbands; band++) { if (q->classes[band].qdisc->q.qlen) - list_del(&q->classes[band].alist); + list_del_init(&q->classes[band].alist); } for (band = 0; band < q->nbands; band++) qdisc_reset(q->classes[band].qdisc);