From 8c5713ce1ced75f9e9ed5c642ea3d2ba06ead69c Mon Sep 17 00:00:00 2001 From: Hyunwoo Kim Date: Fri, 13 Jun 2025 20:54:57 -0400 Subject: [PATCH] net/sched: fix use-after-free in taprio_dev_notifier MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit commit b160766e26d4e2e2d6fe2294e0b02f92baefcec5 upstream. Since taprio’s taprio_dev_notifier() isn’t protected by an RCU read-side critical section, a race with advance_sched() can lead to a use-after-free. Adding rcu_read_lock() inside taprio_dev_notifier() prevents this. Fixes: fed87cc6718a ("net/sched: taprio: automatically calculate queueMaxSDU based on TC gate durations") Cc: stable@vger.kernel.org Signed-off-by: Hyunwoo Kim Reviewed-by: Simon Horman Reviewed-by: Eric Dumazet Link: https://patch.msgid.link/aEzIYYxt0is9upYG@v4bel-B760M-AORUS-ELITE-AX Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman --- net/sched/sch_taprio.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/net/sched/sch_taprio.c b/net/sched/sch_taprio.c index 951a87909c29..d162e2dd8602 100644 --- a/net/sched/sch_taprio.c +++ b/net/sched/sch_taprio.c @@ -1338,13 +1338,15 @@ static int taprio_dev_notifier(struct notifier_block *nb, unsigned long event, stab = rtnl_dereference(q->root->stab); - oper = rtnl_dereference(q->oper_sched); + rcu_read_lock(); + oper = rcu_dereference(q->oper_sched); if (oper) taprio_update_queue_max_sdu(q, oper, stab); - admin = rtnl_dereference(q->admin_sched); + admin = rcu_dereference(q->admin_sched); if (admin) taprio_update_queue_max_sdu(q, admin, stab); + rcu_read_unlock(); break; }