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/file.c | 36 ++++++++++++++++++++++++++++++++++++ 1 file changed, 36 insertions(+) create mode 100644 fs/adfs/file.c (limited to 'fs/adfs/file.c') diff --git a/fs/adfs/file.c b/fs/adfs/file.c new file mode 100644 index 000000000..d056d48c6 --- /dev/null +++ b/fs/adfs/file.c @@ -0,0 +1,36 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * linux/fs/adfs/file.c + * + * Copyright (C) 1997-1999 Russell King + * from: + * + * linux/fs/ext2/file.c + * + * Copyright (C) 1992, 1993, 1994, 1995 + * Remy Card (card@masi.ibp.fr) + * Laboratoire MASI - Institut Blaise Pascal + * Universite Pierre et Marie Curie (Paris VI) + * + * from + * + * linux/fs/minix/file.c + * + * Copyright (C) 1991, 1992 Linus Torvalds + * + * adfs regular file handling primitives + */ +#include "adfs.h" + +const struct file_operations adfs_file_operations = { + .llseek = generic_file_llseek, + .read_iter = generic_file_read_iter, + .mmap_prepare = generic_file_mmap_prepare, + .fsync = simple_fsync, + .write_iter = generic_file_write_iter, + .splice_read = filemap_splice_read, +}; + +const struct inode_operations adfs_file_inode_operations = { + .setattr = adfs_setattr, +}; -- cgit v1.3.1