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 --- tools/perf/util/aslr.h | 44 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 44 insertions(+) create mode 100644 tools/perf/util/aslr.h (limited to 'tools/perf/util/aslr.h') diff --git a/tools/perf/util/aslr.h b/tools/perf/util/aslr.h new file mode 100644 index 000000000..522e31c8e --- /dev/null +++ b/tools/perf/util/aslr.h @@ -0,0 +1,44 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __PERF_ASLR_H +#define __PERF_ASLR_H + +#include + +#define ASLR_SUPPORTED_SAMPLE_TYPE ( \ + PERF_SAMPLE_IDENTIFIER | \ + PERF_SAMPLE_IP | \ + PERF_SAMPLE_TID | \ + PERF_SAMPLE_TIME | \ + PERF_SAMPLE_ADDR | \ + PERF_SAMPLE_ID | \ + PERF_SAMPLE_STREAM_ID | \ + PERF_SAMPLE_CPU | \ + PERF_SAMPLE_PERIOD | \ + PERF_SAMPLE_READ | \ + PERF_SAMPLE_CALLCHAIN | \ + PERF_SAMPLE_RAW | \ + PERF_SAMPLE_BRANCH_STACK | \ + PERF_SAMPLE_STACK_USER | \ + PERF_SAMPLE_WEIGHT_TYPE | \ + PERF_SAMPLE_DATA_SRC | \ + PERF_SAMPLE_TRANSACTION | \ + PERF_SAMPLE_PHYS_ADDR | \ + PERF_SAMPLE_CGROUP | \ + PERF_SAMPLE_DATA_PAGE_SIZE | \ + PERF_SAMPLE_CODE_PAGE_SIZE | \ + PERF_SAMPLE_AUX) + +struct perf_tool; +struct evsel; +struct evlist; +union perf_event; + +struct perf_tool *aslr_tool__new(struct perf_tool *delegate); +void aslr_tool__delete(struct perf_tool *tool); + +void aslr_tool__strip_attr_event(union perf_event *event, struct evlist *evlist); +int aslr_tool__cache_orig_attrs(struct perf_tool *tool, struct evsel *evsel); +void aslr_tool__strip_evlist(const struct perf_tool *tool, struct evlist *evlist); +void aslr_tool__restore_evlist(const struct perf_tool *tool, struct evlist *evlist); + +#endif /* __PERF_ASLR_H */ -- cgit v1.3.1