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/btrfs/verity.h | 35 +++++++++++++++++++++++++++++++++++ 1 file changed, 35 insertions(+) create mode 100644 fs/btrfs/verity.h (limited to 'fs/btrfs/verity.h') diff --git a/fs/btrfs/verity.h b/fs/btrfs/verity.h new file mode 100644 index 000000000..d696659e4 --- /dev/null +++ b/fs/btrfs/verity.h @@ -0,0 +1,35 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef BTRFS_VERITY_H +#define BTRFS_VERITY_H + +struct inode; +struct btrfs_inode; + +#ifdef CONFIG_FS_VERITY + +#include + +extern const struct fsverity_operations btrfs_verityops; + +int btrfs_drop_verity_items(struct btrfs_inode *inode); +int btrfs_get_verity_descriptor(struct inode *inode, void *buf, size_t buf_size); + +#else + +#include + +static inline int btrfs_drop_verity_items(struct btrfs_inode *inode) +{ + return 0; +} + +static inline int btrfs_get_verity_descriptor(struct inode *inode, void *buf, + size_t buf_size) +{ + return -EPERM; +} + +#endif + +#endif -- cgit v1.3.1