diff options
| author | Weiming Shi <bestswngs@gmail.com> | 2026-09-02 23:52:31 +0800 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2026-09-05 12:40:05 -0700 |
| commit | e6662f2100f8d33b0f4d0047c219efd6bba186ea (patch) | |
| tree | 2c73792c48a255b313d83344484efdbb259fcff3 | |
| parent | 2b4707a149a55e8fa75c9ef32b359d60f470a566 (diff) | |
net/sched: defer qdisc freeing after failed creation
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 <xmei5@asu.edu>
Link: https://lore.kernel.org/netdev/20260805102505.740806-1-david.lee@trailofbits.com/
Signed-off-by: Weiming Shi <bestswngs@gmail.com>
Link: https://patch.msgid.link/20260902155231.2149915-2-bestswngs@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| -rw-r--r-- | include/net/sch_generic.h | 2 | ||||
| -rw-r--r-- | net/sched/sch_api.c | 2 | ||||
| -rw-r--r-- | 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 cbc248776511..f35bd06a6bad 100644 --- a/include/net/sch_generic.h +++ b/include/net/sch_generic.h @@ -793,7 +793,7 @@ 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 90503e59e6e3..463ededcdcfe 100644 --- a/net/sched/sch_api.c +++ b/net/sched/sch_api.c @@ -1385,7 +1385,7 @@ err_out4: err_out3: qdisc_lock_uninit(sch, ops); netdev_put(dev, &sch->dev_tracker); - qdisc_free(sch); + qdisc_free_rcu(sch); err_out2: bpf_module_put(ops, ops->owner); err_out: diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c index 4539dc2c6d38..6f6a6f0d5eb0 100644 --- a/net/sched/sch_generic.c +++ b/net/sched/sch_generic.c @@ -1086,21 +1086,21 @@ 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) @@ -1127,7 +1127,7 @@ 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) |