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 --- drivers/base/trace.h | 56 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 56 insertions(+) create mode 100644 drivers/base/trace.h (limited to 'drivers/base/trace.h') diff --git a/drivers/base/trace.h b/drivers/base/trace.h new file mode 100644 index 000000000..3b83b13a5 --- /dev/null +++ b/drivers/base/trace.h @@ -0,0 +1,56 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Device core Trace Support + * Copyright (C) 2021, Intel Corporation + * + * Author: Andy Shevchenko + */ + +#undef TRACE_SYSTEM +#define TRACE_SYSTEM dev + +#if !defined(__DEV_TRACE_H) || defined(TRACE_HEADER_MULTI_READ) +#define __DEV_TRACE_H + +#include +#include +#include + +DECLARE_EVENT_CLASS(devres, + TP_PROTO(struct device *dev, const char *op, void *node, const char *name, size_t size), + TP_ARGS(dev, op, node, name, size), + TP_STRUCT__entry( + __string(devname, dev_name(dev)) + __field(struct device *, dev) + __field(const char *, op) + __field(void *, node) + __string(name, name) + __field(size_t, size) + ), + TP_fast_assign( + __assign_str(devname); + __entry->op = op; + __entry->node = node; + __assign_str(name); + __entry->size = size; + ), + TP_printk("%s %3s %p %s (%zu bytes)", __get_str(devname), + __entry->op, __entry->node, __get_str(name), __entry->size) +); + +DEFINE_EVENT(devres, devres_log, + TP_PROTO(struct device *dev, const char *op, void *node, const char *name, size_t size), + TP_ARGS(dev, op, node, name, size) +); + +#endif /* __DEV_TRACE_H */ + +/* this part has to be here */ + +#undef TRACE_INCLUDE_PATH +#define TRACE_INCLUDE_PATH . + +#undef TRACE_INCLUDE_FILE +#define TRACE_INCLUDE_FILE trace + +#include -- cgit v1.3.1