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/erofs/xattr.h | 36 ++++++++++++++++++++++++++++++++++++ 1 file changed, 36 insertions(+) create mode 100644 fs/erofs/xattr.h (limited to 'fs/erofs/xattr.h') diff --git a/fs/erofs/xattr.h b/fs/erofs/xattr.h new file mode 100644 index 000000000..4465f7018 --- /dev/null +++ b/fs/erofs/xattr.h @@ -0,0 +1,36 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (C) 2017-2018 HUAWEI, Inc. + * https://www.huawei.com/ + */ +#ifndef __EROFS_XATTR_H +#define __EROFS_XATTR_H + +#include "internal.h" +#include +#include + +#ifdef CONFIG_EROFS_FS_XATTR +extern const struct xattr_handler * const erofs_xattr_handlers[]; + +int erofs_xattr_prefixes_init(struct super_block *sb); +void erofs_xattr_prefixes_cleanup(struct super_block *sb); +ssize_t erofs_listxattr(struct dentry *, char *, size_t); +#else +static inline int erofs_xattr_prefixes_init(struct super_block *sb) { return 0; } +static inline void erofs_xattr_prefixes_cleanup(struct super_block *sb) {} + +#define erofs_listxattr (NULL) +#define erofs_xattr_handlers (NULL) +#endif /* !CONFIG_EROFS_FS_XATTR */ + +#ifdef CONFIG_EROFS_FS_POSIX_ACL +struct posix_acl *erofs_get_acl(struct inode *inode, int type, bool rcu); +#else +#define erofs_get_acl (NULL) +#endif + +int erofs_xattr_fill_inode_fingerprint(struct erofs_inode_fingerprint *fp, + struct inode *inode, const char *domain_id); +bool erofs_inode_has_noacl(struct inode *inode, void *kaddr, unsigned int ofs); +#endif -- cgit v1.3.1