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/tests/pe-file.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) create mode 100644 tools/perf/tests/pe-file.c (limited to 'tools/perf/tests/pe-file.c') diff --git a/tools/perf/tests/pe-file.c b/tools/perf/tests/pe-file.c new file mode 100644 index 000000000..eb3df5e98 --- /dev/null +++ b/tools/perf/tests/pe-file.c @@ -0,0 +1,14 @@ +// SPDX-License-Identifier: GPL-2.0 + +// pe-file.exe and pe-file.exe.debug built with; +// x86_64-w64-mingw32-gcc -o pe-file.exe pe-file.c +// -Wl,--file-alignment,4096 -Wl,--build-id +// x86_64-w64-mingw32-objcopy --only-keep-debug +// --compress-debug-sections pe-file.exe pe-file.exe.debug +// x86_64-w64-mingw32-objcopy --strip-debug +// --add-gnu-debuglink=pe-file.exe.debug pe-file.exe + +int main(int argc, char const *argv[]) +{ + return 0; +} -- cgit v1.3.1