selftests/bpf: Reject graph kptr use after RCU unlockgrafted

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 <memxor@gmail.com>
Link: https://lore.kernel.org/r/20260904084325.52250-7-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

1 files changed, 50 insertions, 0 deletions

diff --git a/net/bluetooth/hci_debugfs.h b/net/bluetooth/hci_debugfs.h
new file mode 100644
index 000000000..92365cbc9
--- /dev/null
+++ b/net/bluetooth/hci_debugfs.h
@@ -0,0 +1,50 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+   BlueZ - Bluetooth protocol stack for Linux
+   Copyright (C) 2014 Intel Corporation
+
+   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+   OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+   FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF THIRD PARTY RIGHTS.
+   IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) AND AUTHOR(S) BE LIABLE FOR ANY
+   CLAIM, OR ANY SPECIAL INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES
+   WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+   ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+   OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+
+   ALL LIABILITY, INCLUDING LIABILITY FOR INFRINGEMENT OF ANY PATENTS,
+   COPYRIGHTS, TRADEMARKS OR OTHER RIGHTS, RELATING TO USE OF THIS
+   SOFTWARE IS DISCLAIMED.
+*/
+
+#if IS_ENABLED(CONFIG_BT_DEBUGFS)
+
+void hci_debugfs_create_common(struct hci_dev *hdev);
+void hci_debugfs_create_bredr(struct hci_dev *hdev);
+void hci_debugfs_create_le(struct hci_dev *hdev);
+void hci_debugfs_create_conn(struct hci_conn *conn);
+void hci_debugfs_create_basic(struct hci_dev *hdev);
+
+#else
+
+static inline void hci_debugfs_create_common(struct hci_dev *hdev)
+{
+}
+
+static inline void hci_debugfs_create_bredr(struct hci_dev *hdev)
+{
+}
+
+static inline void hci_debugfs_create_le(struct hci_dev *hdev)
+{
+}
+
+static inline void hci_debugfs_create_conn(struct hci_conn *conn)
+{
+}
+
+static inline void hci_debugfs_create_basic(struct hci_dev *hdev)
+{
+}
+
+#endif