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/udf/udf_i.h | 65 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 65 insertions(+) create mode 100644 fs/udf/udf_i.h (limited to 'fs/udf/udf_i.h') diff --git a/fs/udf/udf_i.h b/fs/udf/udf_i.h new file mode 100644 index 000000000..fdaa88c49 --- /dev/null +++ b/fs/udf/udf_i.h @@ -0,0 +1,65 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _UDF_I_H +#define _UDF_I_H + +struct extent_position { + struct buffer_head *bh; + uint32_t offset; + struct kernel_lb_addr block; +}; + +struct udf_ext_cache { + /* Extent position */ + struct extent_position epos; + /* Start logical offset in bytes */ + loff_t lstart; +}; + +/* + * The i_data_sem and i_mutex serve for protection of allocation information + * of a regular files and symlinks. This includes all extents belonging to + * the file/symlink, a fact whether data are in-inode or in external data + * blocks, preallocation, goal block information... When extents are read, + * i_mutex or i_data_sem must be held (for reading is enough in case of + * i_data_sem). When extents are changed, i_data_sem must be held for writing + * and also i_mutex must be held. + * + * For directories i_mutex is used for all the necessary protection. + */ + +struct udf_inode_info { + struct timespec64 i_crtime; + /* Physical address of inode */ + struct kernel_lb_addr i_location; + __u64 i_unique; + __u32 i_lenEAttr; + __u32 i_lenAlloc; + __u64 i_lenExtents; + __u32 i_next_alloc_block; + __u32 i_next_alloc_goal; + __u32 i_checkpoint; + __u32 i_extraPerms; + unsigned i_alloc_type : 3; + unsigned i_efe : 1; /* extendedFileEntry */ + unsigned i_use : 1; /* unallocSpaceEntry */ + unsigned i_strat4096 : 1; + unsigned i_streamdir : 1; + unsigned i_hidden : 1; /* hidden system inode */ + unsigned reserved : 24; + __u8 *i_data; + struct kernel_lb_addr i_locStreamdir; + __u64 i_lenStreams; + struct rw_semaphore i_data_sem; + struct mapping_metadata_bhs i_metadata_bhs; + struct udf_ext_cache cached_extent; + /* Spinlock for protecting extent cache */ + spinlock_t i_extent_cache_lock; + struct inode vfs_inode; +}; + +static inline struct udf_inode_info *UDF_I(struct inode *inode) +{ + return container_of(inode, struct udf_inode_info, vfs_inode); +} + +#endif /* _UDF_I_H) */ -- cgit v1.3.1