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/gfs2/meta_io.h | 78 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 78 insertions(+) create mode 100644 fs/gfs2/meta_io.h (limited to 'fs/gfs2/meta_io.h') diff --git a/fs/gfs2/meta_io.h b/fs/gfs2/meta_io.h new file mode 100644 index 000000000..ec76215bf --- /dev/null +++ b/fs/gfs2/meta_io.h @@ -0,0 +1,78 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved. + * Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved. + */ + +#ifndef __DIO_DOT_H__ +#define __DIO_DOT_H__ + +#include +#include +#include "incore.h" + +static inline void gfs2_buffer_clear(struct buffer_head *bh) +{ + memset(bh->b_data, 0, bh->b_size); +} + +static inline void gfs2_buffer_clear_tail(struct buffer_head *bh, int head) +{ + BUG_ON(head > bh->b_size); + memset(bh->b_data + head, 0, bh->b_size - head); +} + +static inline void gfs2_buffer_copy_tail(struct buffer_head *to_bh, + int to_head, + struct buffer_head *from_bh, + int from_head) +{ + BUG_ON(from_head < to_head); + memcpy(to_bh->b_data + to_head, from_bh->b_data + from_head, + from_bh->b_size - from_head); + memset(to_bh->b_data + to_bh->b_size + to_head - from_head, + 0, from_head - to_head); +} + +extern const struct address_space_operations gfs2_meta_aops; +extern const struct address_space_operations gfs2_rgrp_aops; + +static inline struct gfs2_sbd *gfs2_mapping2sbd(struct address_space *mapping) +{ + struct inode *inode = mapping->host; + if (mapping->a_ops == &gfs2_meta_aops) { + struct gfs2_glock_aspace *gla = + container_of(mapping, struct gfs2_glock_aspace, mapping); + return glock_sbd(&gla->glock); + } else + return inode->i_sb->s_fs_info; +} + +struct buffer_head *gfs2_meta_new(struct gfs2_glock *gl, u64 blkno); +int gfs2_meta_read(struct gfs2_glock *gl, u64 blkno, int flags, + int rahead, struct buffer_head **bhp); +int gfs2_meta_wait(struct gfs2_sbd *sdp, struct buffer_head *bh); +struct buffer_head *gfs2_getbuf(struct gfs2_glock *gl, u64 blkno, + int create); +enum { + REMOVE_JDATA = 0, + REMOVE_META = 1, +}; + +void gfs2_journal_wipe(struct gfs2_inode *ip, u64 bstart, u32 blen); +int gfs2_meta_buffer(struct gfs2_inode *ip, u32 mtype, u64 num, + struct buffer_head **bhp); + +static inline int gfs2_meta_inode_buffer(struct gfs2_inode *ip, + struct buffer_head **bhp) +{ + return gfs2_meta_buffer(ip, GFS2_METATYPE_DI, ip->i_no_addr, bhp); +} + +struct buffer_head *gfs2_meta_ra(struct gfs2_glock *gl, u64 dblock, u32 extlen); + +#define buffer_busy(bh) \ +((bh)->b_state & ((1ul << BH_Dirty) | (1ul << BH_Lock) | (1ul << BH_Pinned))) + +#endif /* __DIO_DOT_H__ */ + -- cgit v1.3.1