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 --- fs/nilfs2/direct.h | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) create mode 100644 fs/nilfs2/direct.h (limited to 'fs/nilfs2/direct.h') diff --git a/fs/nilfs2/direct.h b/fs/nilfs2/direct.h new file mode 100644 index 000000000..b7ca89626 --- /dev/null +++ b/fs/nilfs2/direct.h @@ -0,0 +1,28 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ +/* + * NILFS direct block pointer. + * + * Copyright (C) 2006-2008 Nippon Telegraph and Telephone Corporation. + * + * Written by Koji Sato. + */ + +#ifndef _NILFS_DIRECT_H +#define _NILFS_DIRECT_H + +#include +#include +#include "bmap.h" + + +#define NILFS_DIRECT_NBLOCKS (NILFS_BMAP_SIZE / sizeof(__le64) - 1) +#define NILFS_DIRECT_KEY_MIN 0 +#define NILFS_DIRECT_KEY_MAX (NILFS_DIRECT_NBLOCKS - 1) + + +int nilfs_direct_init(struct nilfs_bmap *); +int nilfs_direct_delete_and_convert(struct nilfs_bmap *, __u64, __u64 *, + __u64 *, int); + + +#endif /* _NILFS_DIRECT_H */ -- cgit v1.3.1