From 6668ed271eaefaa63e686bdfbedaeb7b8e492722 Mon Sep 17 00:00:00 2001 From: Kumar Kartikeya Dwivedi Date: Fri, 4 Sep 2026 10:43:19 +0200 Subject: selftests/bpf: Reject graph kptr use after RCU unlock Add a sleepable verifier test that loads a graph-node local kptr in an explicit RCU read-side critical section, then passes its node to bpf_rbtree_remove() after the section ends. Before the verifier fix, the stale NON_OWN_REF flag makes the node look like a live borrowed reference and the program is accepted. After the fix, the pointer is demoted without NON_OWN_REF and the graph kfunc argument is rejected. Also exercise a graph kptr loaded while a spin lock provides implicit RCU protection. The pointer must be invalidated when the lock is released, which guards the required ordering between non-owning-reference invalidation and RCU demotion. Update the existing fault-protected load test state description. The post-unlock pointer no longer carries NON_OWN_REF, but remains readable because the load is rewritten to use BPF_PROBE_MEM. Signed-off-by: Kumar Kartikeya Dwivedi Link: https://lore.kernel.org/r/20260904084325.52250-7-memxor@gmail.com Signed-off-by: Alexei Starovoitov --- include/net/sch_priv.h | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) create mode 100644 include/net/sch_priv.h (limited to 'include/net/sch_priv.h') diff --git a/include/net/sch_priv.h b/include/net/sch_priv.h new file mode 100644 index 000000000..4789f668a --- /dev/null +++ b/include/net/sch_priv.h @@ -0,0 +1,27 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __NET_SCHED_PRIV_H +#define __NET_SCHED_PRIV_H + +#include + +struct mq_sched { + struct Qdisc **qdiscs; +}; + +int mq_init_common(struct Qdisc *sch, struct nlattr *opt, + struct netlink_ext_ack *extack, + const struct Qdisc_ops *qdisc_ops); +void mq_destroy_common(struct Qdisc *sch); +void mq_attach(struct Qdisc *sch); +void mq_dump_common(struct Qdisc *sch, struct sk_buff *skb); +struct netdev_queue *mq_select_queue(struct Qdisc *sch, + struct tcmsg *tcm); +struct Qdisc *mq_leaf(struct Qdisc *sch, unsigned long cl); +unsigned long mq_find(struct Qdisc *sch, u32 classid); +int mq_dump_class(struct Qdisc *sch, unsigned long cl, + struct sk_buff *skb, struct tcmsg *tcm); +int mq_dump_class_stats(struct Qdisc *sch, unsigned long cl, + struct gnet_dump *d); +void mq_walk(struct Qdisc *sch, struct qdisc_walker *arg); + +#endif -- cgit v1.3.1