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/xfs/xfs_rtalloc.h | 80 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 80 insertions(+) create mode 100644 fs/xfs/xfs_rtalloc.h (limited to 'fs/xfs/xfs_rtalloc.h') diff --git a/fs/xfs/xfs_rtalloc.h b/fs/xfs/xfs_rtalloc.h new file mode 100644 index 000000000..78a690b48 --- /dev/null +++ b/fs/xfs/xfs_rtalloc.h @@ -0,0 +1,80 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) 2000-2003,2005 Silicon Graphics, Inc. + * All Rights Reserved. + */ +#ifndef __XFS_RTALLOC_H__ +#define __XFS_RTALLOC_H__ + +/* kernel only definitions and functions */ + +struct xfs_mount; +struct xfs_trans; + +#ifdef CONFIG_XFS_RT +/* rtgroup superblock initialization */ +int xfs_rtmount_readsb(struct xfs_mount *mp); +void xfs_rtmount_freesb(struct xfs_mount *mp); + +/* + * Initialize realtime fields in the mount structure. + */ +int /* error */ +xfs_rtmount_init( + struct xfs_mount *mp); /* file system mount structure */ +void +xfs_rtunmount_inodes( + struct xfs_mount *mp); + +/* + * Get the bitmap and summary inodes into the mount structure + * at mount time. + */ +int /* error */ +xfs_rtmount_inodes( + struct xfs_mount *mp); /* file system mount structure */ + +/* + * Grow the realtime area of the filesystem. + */ +int +xfs_growfs_rt( + struct xfs_mount *mp, /* file system mount structure */ + xfs_growfs_rt_t *in); /* user supplied growfs struct */ + +int xfs_rtalloc_reinit_frextents(struct xfs_mount *mp); +int xfs_growfs_check_rtgeom(const struct xfs_mount *mp, xfs_rfsblock_t dblocks, + xfs_rfsblock_t rblocks, xfs_agblock_t rextsize); +#else +# define xfs_growfs_rt(mp,in) (-ENOSYS) +# define xfs_rtalloc_reinit_frextents(m) (0) +# define xfs_rtmount_readsb(mp) (0) +# define xfs_rtmount_freesb(mp) ((void)0) +static inline int /* error */ +xfs_rtmount_init( + xfs_mount_t *mp) /* file system mount structure */ +{ + if (mp->m_sb.sb_rblocks == 0) + return 0; + + xfs_warn(mp, "Not built with CONFIG_XFS_RT"); + return -ENOSYS; +} +# define xfs_rtmount_inodes(m) (((mp)->m_sb.sb_rblocks == 0)? 0 : (-ENOSYS)) +# define xfs_rtunmount_inodes(m) + +static inline int +xfs_growfs_check_rtgeom(const struct xfs_mount *mp, + xfs_rfsblock_t dblocks, xfs_rfsblock_t rblocks, + xfs_extlen_t rextsize) +{ + return 0; +} +#endif /* CONFIG_XFS_RT */ + +int xfs_rtallocate_rtgs(struct xfs_trans *tp, xfs_fsblock_t bno_hint, + xfs_rtxlen_t minlen, xfs_rtxlen_t maxlen, xfs_rtxlen_t prod, + bool wasdel, bool initial_user_data, xfs_rtblock_t *bno, + xfs_extlen_t *blen); + +#endif /* __XFS_RTALLOC_H__ */ -- cgit v1.3.1