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/ntfs/index.h | 119 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 119 insertions(+) create mode 100644 fs/ntfs/index.h (limited to 'fs/ntfs/index.h') diff --git a/fs/ntfs/index.h b/fs/ntfs/index.h new file mode 100644 index 000000000..9a03f53bb --- /dev/null +++ b/fs/ntfs/index.h @@ -0,0 +1,119 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * Defines for NTFS kernel index handling. + * + * Copyright (c) 2004 Anton Altaparmakov + */ + +#ifndef _LINUX_NTFS_INDEX_H +#define _LINUX_NTFS_INDEX_H + +#include + +#include "attrib.h" +#include "mft.h" + +#define VCN_INDEX_ROOT_PARENT ((s64)-2) + +#define MAX_PARENT_VCN 32 + +/* + * @idx_ni: index inode containing the @entry described by this context + * @name: Unicode name of the indexed attribute + * (usually $I30 for directories) + * @name_len: length of @name in Unicode characters + * @entry: index entry (points into @ir or @ia) + * @cr: creation time of the entry (for sorting/validation) + * @data: index entry data (points into @entry) + * @data_len: length in bytes of @data + * @is_in_root: 'true' if @entry is in @ir and 'false' if it is in @ia + * @ir: index root if @is_in_root and NULL otherwise + * @actx: attribute search context if @is_in_root and NULL otherwise + * @ib: index block header (valid when @is_in_root is 'false') + * @ia_ni: index allocation inode (extent inode) for @ia + * @parent_pos: array of parent entry positions in the B-tree nodes + * @parent_vcn: VCNs of parent index blocks in the B-tree traversal + * @pindex: current depth (number of parent nodes) in the traversal + * (maximum is MAX_PARENT_VCN) + * @ib_dirty: true if the current index block (@ia/@ib) was modified + * @block_size: size of index blocks in bytes (from $INDEX_ROOT or $Boot) + * @vcn_size_bits: log2(cluster size) + * @sync_write: true if synchronous writeback is requested for this context + * + * @idx_ni is the index inode this context belongs to. + * + * @entry is the index entry described by this context. @data and @data_len + * are the index entry data and its length in bytes, respectively. @data + * simply points into @entry. This is probably what the user is interested in. + * + * If @is_in_root is 'true', @entry is in the index root attribute @ir described + * by the attribute search context @actx and the base inode @base_ni. @ia and + * @page are NULL in this case. + * + * If @is_in_root is 'false', @entry is in the index allocation attribute and @ia + * and @page point to the index allocation block and the mapped, locked page it + * is in, respectively. @ir, @actx and @base_ni are NULL in this case. + * + * To obtain a context call ntfs_index_ctx_get(). + * + * We use this context to allow ntfs_index_lookup() to return the found index + * @entry and its @data without having to allocate a buffer and copy the @entry + * and/or its @data into it. + * + * When finished with the @entry and its @data, call ntfs_index_ctx_put() to + * free the context and other associated resources. + * + * If the index entry was modified, ntfs_index_entry_mark_dirty() + * or ntfs_index_entry_write() before the call to ntfs_index_ctx_put() to + * ensure that the changes are written to disk. + */ +struct ntfs_index_context { + struct ntfs_inode *idx_ni; + __le16 *name; + u32 name_len; + struct index_entry *entry; + __le32 cr; + void *data; + u16 data_len; + bool is_in_root; + struct index_root *ir; + struct ntfs_attr_search_ctx *actx; + struct index_block *ib; + struct ntfs_inode *ia_ni; + int parent_pos[MAX_PARENT_VCN]; + s64 parent_vcn[MAX_PARENT_VCN]; + int pindex; + bool ib_dirty; + u32 block_size; + u8 vcn_size_bits; + bool sync_write; +}; + +int ntfs_index_root_inconsistent(struct ntfs_volume *vol, + const struct attr_record *a, + const struct index_root *ir, u64 inum); +int ntfs_index_block_inconsistent(struct ntfs_volume *vol, + const struct index_block *ib, + u32 block_size, s64 vcn, + __le32 cr, u64 inum); +int ntfs_index_entries_inconsistent(const struct ntfs_volume *vol, + const struct index_header *ih, + __le32 collation_rule, u64 inum); +struct ntfs_index_context *ntfs_index_ctx_get(struct ntfs_inode *ni, __le16 *name, + u32 name_len); +void ntfs_index_ctx_put(struct ntfs_index_context *ictx); +int ntfs_index_lookup(const void *key, const u32 key_len, + struct ntfs_index_context *ictx); + +void ntfs_index_entry_mark_dirty(struct ntfs_index_context *ictx); +int ntfs_index_add_filename(struct ntfs_inode *ni, struct file_name_attr *fn, u64 mref); +int ntfs_index_remove(struct ntfs_inode *ni, const void *key, const u32 keylen); +struct ntfs_inode *ntfs_ia_open(struct ntfs_index_context *icx, struct ntfs_inode *ni); +struct index_entry *ntfs_index_walk_down(struct index_entry *ie, struct ntfs_index_context *ictx); +struct index_entry *ntfs_index_next(struct index_entry *ie, struct ntfs_index_context *ictx); +int ntfs_index_rm(struct ntfs_index_context *icx); +void ntfs_index_ctx_reinit(struct ntfs_index_context *icx); +int ntfs_ie_add(struct ntfs_index_context *icx, struct index_entry *ie); +int ntfs_icx_ib_sync_write(struct ntfs_index_context *icx); + +#endif /* _LINUX_NTFS_INDEX_H */ -- cgit v1.3.1