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/ocfs2/cluster/sys.c | 65 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 65 insertions(+) create mode 100644 fs/ocfs2/cluster/sys.c (limited to 'fs/ocfs2/cluster/sys.c') diff --git a/fs/ocfs2/cluster/sys.c b/fs/ocfs2/cluster/sys.c new file mode 100644 index 000000000..022f716c7 --- /dev/null +++ b/fs/ocfs2/cluster/sys.c @@ -0,0 +1,65 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * sys.c + * + * OCFS2 cluster sysfs interface + * + * Copyright (C) 2005 Oracle. All rights reserved. + */ + +#include +#include +#include +#include +#include + +#include "ocfs2_nodemanager.h" +#include "masklog.h" +#include "sys.h" + + +static ssize_t version_show(struct kobject *kobj, struct kobj_attribute *attr, + char *buf) +{ + return snprintf(buf, PAGE_SIZE, "%u\n", O2NM_API_VERSION); +} +static struct kobj_attribute attr_version = + __ATTR(interface_revision, S_IRUGO, version_show, NULL); + +static struct attribute *o2cb_attrs[] = { + &attr_version.attr, + NULL, +}; + +static struct attribute_group o2cb_attr_group = { + .attrs = o2cb_attrs, +}; + +static struct kset *o2cb_kset; + +void o2cb_sys_shutdown(void) +{ + mlog_sys_shutdown(); + kset_unregister(o2cb_kset); +} + +int o2cb_sys_init(void) +{ + int ret; + + o2cb_kset = kset_create_and_add("o2cb", NULL, fs_kobj); + if (!o2cb_kset) + return -ENOMEM; + + ret = sysfs_create_group(&o2cb_kset->kobj, &o2cb_attr_group); + if (ret) + goto error; + + ret = mlog_sys_init(o2cb_kset); + if (ret) + goto error; + return 0; +error: + kset_unregister(o2cb_kset); + return ret; +} -- cgit v1.3.1