From: Cong Wang <xiyou.wangcong@gmail.com> mainline inclusion from mainline-v6.15-rc2 commit a7a15f39c682ac4268624da2abdb9114bdde96d5 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IC5D94 CVE: CVE-2025-37798 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- 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> Conflicts: net/sched/sch_ets.c [commit c5f1dde7f731 is not backport] Signed-off-by: Dong Chenchen <dongchenchen2@huawei.com> --- 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 0afd9187f836..d50ba5eb4576 100644 --- a/net/sched/sch_ets.c +++ b/net/sched/sch_ets.c @@ -293,7 +293,7 @@ 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, @@ -496,7 +496,7 @@ 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); } @@ -671,7 +671,7 @@ 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; @@ -720,7 +720,7 @@ 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); -- 2.25.1