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/autofs/init.c | 42 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 42 insertions(+) create mode 100644 fs/autofs/init.c (limited to 'fs/autofs/init.c') diff --git a/fs/autofs/init.c b/fs/autofs/init.c new file mode 100644 index 000000000..1d644a35f --- /dev/null +++ b/fs/autofs/init.c @@ -0,0 +1,42 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved + */ + +#include +#include +#include "autofs_i.h" + +struct file_system_type autofs_fs_type = { + .owner = THIS_MODULE, + .name = "autofs", + .init_fs_context = autofs_init_fs_context, + .parameters = autofs_param_specs, + .kill_sb = autofs_kill_sb, +}; +MODULE_ALIAS_FS("autofs"); +MODULE_ALIAS("autofs"); + +static int __init init_autofs_fs(void) +{ + int err; + + autofs_dev_ioctl_init(); + + err = register_filesystem(&autofs_fs_type); + if (err) + autofs_dev_ioctl_exit(); + + return err; +} + +static void __exit exit_autofs_fs(void) +{ + autofs_dev_ioctl_exit(); + unregister_filesystem(&autofs_fs_type); +} + +module_init(init_autofs_fs) +module_exit(exit_autofs_fs) +MODULE_DESCRIPTION("Kernel automounter support"); +MODULE_LICENSE("GPL"); -- cgit v1.3.1