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/adfs/dir_f.h | 61 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 61 insertions(+) create mode 100644 fs/adfs/dir_f.h (limited to 'fs/adfs/dir_f.h') diff --git a/fs/adfs/dir_f.h b/fs/adfs/dir_f.h new file mode 100644 index 000000000..4e6c53d59 --- /dev/null +++ b/fs/adfs/dir_f.h @@ -0,0 +1,61 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * linux/fs/adfs/dir_f.h + * + * Copyright (C) 1999 Russell King + * + * Structures of directories on the F format disk + */ +#ifndef ADFS_DIR_F_H +#define ADFS_DIR_F_H + +/* + * Directory header + */ +struct adfs_dirheader { + __u8 startmasseq; + __u8 startname[4]; +} __attribute__((packed)); + +#define ADFS_NEWDIR_SIZE 2048 +#define ADFS_NUM_DIR_ENTRIES 77 + +/* + * Directory entries + */ +struct adfs_direntry { +#define ADFS_F_NAME_LEN 10 + char dirobname[ADFS_F_NAME_LEN]; + __u8 dirload[4]; + __u8 direxec[4]; + __u8 dirlen[4]; + __u8 dirinddiscadd[3]; + __u8 newdiratts; +} __attribute__((packed)); + +/* + * Directory tail + */ +struct adfs_olddirtail { + __u8 dirlastmask; + char dirname[10]; + __u8 dirparent[3]; + char dirtitle[19]; + __u8 reserved[14]; + __u8 endmasseq; + __u8 endname[4]; + __u8 dircheckbyte; +} __attribute__((packed)); + +struct adfs_newdirtail { + __u8 dirlastmask; + __u8 reserved[2]; + __u8 dirparent[3]; + char dirtitle[19]; + char dirname[10]; + __u8 endmasseq; + __u8 endname[4]; + __u8 dircheckbyte; +} __attribute__((packed)); + +#endif -- cgit v1.3.1