6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Weiming Shi [ Upstream commit e6662f2100f8d33b0f4d0047c219efd6bba186ea ] An RTM_NEWQDISC request can make clsact bind a populated shared ingress block during ->init(), publishing an embedded mini_Qdisc to lockless readers. If the same request has an invalid TCA_RATE, estimator setup fails after ->init(); the unwind removes the pointer but synchronously frees its containing qdisc while tc_run() may still hold it. Retire failed qdiscs through the same RCU helper as normal destruction. Inline the synchronous free into the callback now that no direct callers remain. Fixes: 51ab2994c387 ("net: sched: allow ingress and clsact qdiscs to share filter blocks") Reported-by: Xiang Mei Link: https://lore.kernel.org/netdev/20260805102505.740806-1-david.lee@trailofbits.com/ Signed-off-by: Weiming Shi Link: https://patch.msgid.link/20260902155231.2149915-2-bestswngs@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- include/net/sch_generic.h | 2 +- net/sched/sch_api.c | 2 +- net/sched/sch_generic.c | 20 ++++++++++---------- 3 files changed, 12 insertions(+), 12 deletions(-) diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h index 0ec685beb2fc5..9d623fc8b1fc2 100644 --- a/include/net/sch_generic.h +++ b/include/net/sch_generic.h @@ -755,7 +755,7 @@ void qdisc_offload_query_caps(struct net_device *dev, struct Qdisc *qdisc_alloc(struct netdev_queue *dev_queue, const struct Qdisc_ops *ops, struct netlink_ext_ack *extack); -void qdisc_free(struct Qdisc *qdisc); +void qdisc_free_rcu(struct Qdisc *qdisc); struct Qdisc *qdisc_create_dflt(struct netdev_queue *dev_queue, const struct Qdisc_ops *ops, u32 parentid, struct netlink_ext_ack *extack); diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c index 6aa39c3c6ff44..a62f8b3efdf7f 100644 --- a/net/sched/sch_api.c +++ b/net/sched/sch_api.c @@ -1379,7 +1379,7 @@ static struct Qdisc *qdisc_create(struct net_device *dev, err_out3: lockdep_unregister_key(&sch->root_lock_key); netdev_put(dev, &sch->dev_tracker); - qdisc_free(sch); + qdisc_free_rcu(sch); err_out2: module_put(ops->owner); err_out: diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c index 98c339b03bf5c..3d695ed25d322 100644 --- a/net/sched/sch_generic.c +++ b/net/sched/sch_generic.c @@ -1047,21 +1047,21 @@ void qdisc_reset(struct Qdisc *qdisc) } EXPORT_SYMBOL(qdisc_reset); -void qdisc_free(struct Qdisc *qdisc) +static void qdisc_free_cb(struct rcu_head *head) { - if (qdisc_is_percpu_stats(qdisc)) { - free_percpu(qdisc->cpu_bstats); - free_percpu(qdisc->cpu_qstats); + struct Qdisc *q = container_of(head, struct Qdisc, rcu); + + if (qdisc_is_percpu_stats(q)) { + free_percpu(q->cpu_bstats); + free_percpu(q->cpu_qstats); } - kfree(qdisc); + kfree(q); } -static void qdisc_free_cb(struct rcu_head *head) +void qdisc_free_rcu(struct Qdisc *qdisc) { - struct Qdisc *q = container_of(head, struct Qdisc, rcu); - - qdisc_free(q); + call_rcu(&qdisc->rcu, qdisc_free_cb); } static void __qdisc_destroy(struct Qdisc *qdisc) @@ -1086,7 +1086,7 @@ static void __qdisc_destroy(struct Qdisc *qdisc) trace_qdisc_destroy(qdisc); - call_rcu(&qdisc->rcu, qdisc_free_cb); + qdisc_free_rcu(qdisc); } void qdisc_destroy(struct Qdisc *qdisc) -- 2.53.0