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/squashfs/decompressor.h | 54 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 54 insertions(+) create mode 100644 fs/squashfs/decompressor.h (limited to 'fs/squashfs/decompressor.h') diff --git a/fs/squashfs/decompressor.h b/fs/squashfs/decompressor.h new file mode 100644 index 000000000..19ab60834 --- /dev/null +++ b/fs/squashfs/decompressor.h @@ -0,0 +1,54 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +#ifndef DECOMPRESSOR_H +#define DECOMPRESSOR_H +/* + * Squashfs - a compressed read only filesystem for Linux + * + * Copyright (c) 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 + * Phillip Lougher + * + * decompressor.h + */ + +#include + +struct squashfs_decompressor { + void *(*init)(struct squashfs_sb_info *, void *); + void *(*comp_opts)(struct squashfs_sb_info *, void *, int); + void (*free)(void *); + int (*decompress)(struct squashfs_sb_info *, void *, + struct bio *, int, int, struct squashfs_page_actor *); + int id; + char *name; + int alloc_buffer; + int supported; +}; + +static inline void *squashfs_comp_opts(struct squashfs_sb_info *msblk, + void *buff, int length) +{ + return msblk->decompressor->comp_opts ? + msblk->decompressor->comp_opts(msblk, buff, length) : NULL; +} + +#ifdef CONFIG_SQUASHFS_XZ +extern const struct squashfs_decompressor squashfs_xz_comp_ops; +#endif + +#ifdef CONFIG_SQUASHFS_LZ4 +extern const struct squashfs_decompressor squashfs_lz4_comp_ops; +#endif + +#ifdef CONFIG_SQUASHFS_LZO +extern const struct squashfs_decompressor squashfs_lzo_comp_ops; +#endif + +#ifdef CONFIG_SQUASHFS_ZLIB +extern const struct squashfs_decompressor squashfs_zlib_comp_ops; +#endif + +#ifdef CONFIG_SQUASHFS_ZSTD +extern const struct squashfs_decompressor squashfs_zstd_comp_ops; +#endif + +#endif -- cgit v1.3.1