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/smb/client/fscache.h | 106 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 106 insertions(+) create mode 100644 fs/smb/client/fscache.h (limited to 'fs/smb/client/fscache.h') diff --git a/fs/smb/client/fscache.h b/fs/smb/client/fscache.h new file mode 100644 index 000000000..352122288 --- /dev/null +++ b/fs/smb/client/fscache.h @@ -0,0 +1,106 @@ +/* SPDX-License-Identifier: LGPL-2.1 */ +/* + * CIFS filesystem cache interface definitions + * + * Copyright (c) 2010 Novell, Inc. + * Authors(s): Suresh Jayaraman (sjayaraman@suse.de> + * + */ +#ifndef _CIFS_FSCACHE_H +#define _CIFS_FSCACHE_H + +#include +#include + +#include "cifsglob.h" + +/* + * Coherency data attached to CIFS volume within the cache + */ +struct cifs_fscache_volume_coherency_data { + __le64 resource_id; /* unique server resource id */ + __le64 vol_create_time; + __le32 vol_serial_number; +} __packed; + +/* + * Coherency data attached to CIFS inode within the cache. + */ +struct cifs_fscache_inode_coherency_data { + __le64 last_write_time_sec; + __le64 last_change_time_sec; + __le32 last_write_time_nsec; + __le32 last_change_time_nsec; +}; + +#ifdef CONFIG_CIFS_FSCACHE + +/* + * fscache.c + */ +int cifs_fscache_get_super_cookie(struct cifs_tcon *tcon); +void cifs_fscache_release_super_cookie(struct cifs_tcon *tcon); +void cifs_fscache_get_inode_cookie(struct inode *inode); +void cifs_fscache_unuse_inode_cookie(struct inode *inode, bool update); +void cifs_fscache_release_inode_cookie(struct inode *inode); +int cifs_fscache_get_super_cookie(struct cifs_tcon *tcon); +void cifs_fscache_release_super_cookie(struct cifs_tcon *tcon); + +void cifs_fscache_get_inode_cookie(struct inode *inode); +void cifs_fscache_release_inode_cookie(struct inode *inode); +void cifs_fscache_unuse_inode_cookie(struct inode *inode, bool update); + +static inline +void cifs_fscache_fill_coherency(struct inode *inode, + struct cifs_fscache_inode_coherency_data *cd) +{ + struct timespec64 ctime = inode_get_ctime(inode); + struct timespec64 mtime = inode_get_mtime(inode); + + memset(cd, 0, sizeof(*cd)); + cd->last_write_time_sec = cpu_to_le64(mtime.tv_sec); + cd->last_write_time_nsec = cpu_to_le32(mtime.tv_nsec); + cd->last_change_time_sec = cpu_to_le64(ctime.tv_sec); + cd->last_change_time_nsec = cpu_to_le32(ctime.tv_nsec); +} + + +static inline struct fscache_cookie *cifs_inode_cookie(struct inode *inode) +{ + return netfs_i_cookie(&CIFS_I(inode)->netfs); +} + +static inline void cifs_invalidate_cache(struct inode *inode, unsigned int flags) +{ + struct cifs_fscache_inode_coherency_data cd; + + cifs_fscache_fill_coherency(inode, &cd); + fscache_invalidate(cifs_inode_cookie(inode), &cd, + i_size_read(inode), flags); +} + +static inline bool cifs_fscache_enabled(struct inode *inode) +{ + return fscache_cookie_enabled(cifs_inode_cookie(inode)); +} + +#else /* CONFIG_CIFS_FSCACHE */ +static inline +void cifs_fscache_fill_coherency(struct inode *inode, + struct cifs_fscache_inode_coherency_data *cd) +{ +} + +static inline int cifs_fscache_get_super_cookie(struct cifs_tcon *tcon) { return 0; } +static inline void cifs_fscache_release_super_cookie(struct cifs_tcon *tcon) {} + +static inline void cifs_fscache_get_inode_cookie(struct inode *inode) {} +static inline void cifs_fscache_release_inode_cookie(struct inode *inode) {} +static inline void cifs_fscache_unuse_inode_cookie(struct inode *inode, bool update) {} +static inline struct fscache_cookie *cifs_inode_cookie(struct inode *inode) { return NULL; } +static inline void cifs_invalidate_cache(struct inode *inode, unsigned int flags) {} +static inline bool cifs_fscache_enabled(struct inode *inode) { return false; } + +#endif /* CONFIG_CIFS_FSCACHE */ + +#endif /* _CIFS_FSCACHE_H */ -- cgit v1.3.1