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/dcbevent.h | 39 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 39 insertions(+) create mode 100644 include/net/dcbevent.h (limited to 'include/net/dcbevent.h') diff --git a/include/net/dcbevent.h b/include/net/dcbevent.h new file mode 100644 index 000000000..02700262f --- /dev/null +++ b/include/net/dcbevent.h @@ -0,0 +1,39 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (c) 2010, Intel Corporation. + * + * Author: John Fastabend + */ + +#ifndef _DCB_EVENT_H +#define _DCB_EVENT_H + +struct notifier_block; + +enum dcbevent_notif_type { + DCB_APP_EVENT = 1, +}; + +#ifdef CONFIG_DCB +int register_dcbevent_notifier(struct notifier_block *nb); +int unregister_dcbevent_notifier(struct notifier_block *nb); +int call_dcbevent_notifiers(unsigned long val, void *v); +#else +static inline int +register_dcbevent_notifier(struct notifier_block *nb) +{ + return 0; +} + +static inline int unregister_dcbevent_notifier(struct notifier_block *nb) +{ + return 0; +} + +static inline int call_dcbevent_notifiers(unsigned long val, void *v) +{ + return 0; +} +#endif /* CONFIG_DCB */ + +#endif -- cgit v1.3.1