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/ntfs3/lib/lib.h | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) create mode 100644 fs/ntfs3/lib/lib.h (limited to 'fs/ntfs3/lib/lib.h') diff --git a/fs/ntfs3/lib/lib.h b/fs/ntfs3/lib/lib.h new file mode 100644 index 000000000..90309a5ae --- /dev/null +++ b/fs/ntfs3/lib/lib.h @@ -0,0 +1,32 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * Adapted for linux kernel by Alexander Mamaev: + * - remove implementations of get_unaligned_ + * - assume GCC is always defined + * - ISO C90 + * - linux kernel code style + */ + +#ifndef _LINUX_NTFS3_LIB_LIB_H +#define _LINUX_NTFS3_LIB_LIB_H + +#include + +/* globals from xpress_decompress.c */ +struct xpress_decompressor *xpress_allocate_decompressor(void); +void xpress_free_decompressor(struct xpress_decompressor *d); +int xpress_decompress(struct xpress_decompressor *__restrict d, + const void *__restrict compressed_data, + size_t compressed_size, + void *__restrict uncompressed_data, + size_t uncompressed_size); + +/* globals from lzx_decompress.c */ +struct lzx_decompressor *lzx_allocate_decompressor(void); +void lzx_free_decompressor(struct lzx_decompressor *d); +int lzx_decompress(struct lzx_decompressor *__restrict d, + const void *__restrict compressed_data, + size_t compressed_size, void *__restrict uncompressed_data, + size_t uncompressed_size); + +#endif /* _LINUX_NTFS3_LIB_LIB_H */ -- cgit v1.3.1