5.4-stable review patch. If anyone has any objections, please let me know.
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From: Cong Wang xiyou.wangcong@gmail.com
commit 55f9eca4bfe30a15d8656f915922e8c98b7f0728 upstream.
qfq_qlen_notify() always deletes its class from its active list with list_del_init() _and_ calls qfq_deactivate_agg() when the whole list becomes empty.
To make it idempotent, just skip everything when it is not in the active list.
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 Reviewed-by: Simon Horman horms@kernel.org Link: https://patch.msgid.link/20250403211033.166059-5-xiyou.wangcong@gmail.com Acked-by: Jamal Hadi Salim jhs@mojatatu.com Signed-off-by: Paolo Abeni pabeni@redhat.com Signed-off-by: Siddh Raman Pant siddh.raman.pant@oracle.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/sched/sch_qfq.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-)
--- a/net/sched/sch_qfq.c +++ b/net/sched/sch_qfq.c @@ -348,7 +348,7 @@ static void qfq_deactivate_class(struct struct qfq_aggregate *agg = cl->agg;
- list_del(&cl->alist); /* remove from RR queue of the aggregate */ + list_del_init(&cl->alist); /* remove from RR queue of the aggregate */ if (list_empty(&agg->active)) /* agg is now inactive */ qfq_deactivate_agg(q, agg); } @@ -482,6 +482,7 @@ static int qfq_change_class(struct Qdisc
cl->common.classid = classid; cl->deficit = lmax; + INIT_LIST_HEAD(&cl->alist);
cl->qdisc = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops, classid, NULL); @@ -1001,7 +1002,7 @@ static struct sk_buff *agg_dequeue(struc cl->deficit -= (int) len;
if (cl->qdisc->q.qlen == 0) /* no more packets, remove from list */ - list_del(&cl->alist); + list_del_init(&cl->alist); else if (cl->deficit < qdisc_pkt_len(cl->qdisc->ops->peek(cl->qdisc))) { cl->deficit += agg->lmax; list_move_tail(&cl->alist, &agg->active); @@ -1433,6 +1434,8 @@ static void qfq_qlen_notify(struct Qdisc struct qfq_sched *q = qdisc_priv(sch); struct qfq_class *cl = (struct qfq_class *)arg;
+ if (list_empty(&cl->alist)) + return; qfq_deactivate_class(q, cl); }