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 --- lib/kunit/try-catch-impl.h | 29 +++++++++++++++++++++++++++++ 1 file changed, 29 insertions(+) create mode 100644 lib/kunit/try-catch-impl.h (limited to 'lib/kunit/try-catch-impl.h') diff --git a/lib/kunit/try-catch-impl.h b/lib/kunit/try-catch-impl.h new file mode 100644 index 000000000..6f401b97c --- /dev/null +++ b/lib/kunit/try-catch-impl.h @@ -0,0 +1,29 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Internal kunit try catch implementation to be shared with tests. + * + * Copyright (C) 2019, Google LLC. + * Author: Brendan Higgins + */ + +#ifndef _KUNIT_TRY_CATCH_IMPL_H +#define _KUNIT_TRY_CATCH_IMPL_H + +#include +#include + +struct kunit; + +static inline void kunit_try_catch_init(struct kunit_try_catch *try_catch, + struct kunit *test, + kunit_try_catch_func_t try, + kunit_try_catch_func_t catch, + unsigned long timeout) +{ + try_catch->test = test; + try_catch->try = try; + try_catch->catch = catch; + try_catch->timeout = timeout; +} + +#endif /* _KUNIT_TRY_CATCH_IMPL_H */ -- cgit v1.3.1