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, 55 insertions, 0 deletions

diff --git a/drivers/hid/hid-jabra.c b/drivers/hid/hid-jabra.c
new file mode 100644
index 000000000..41dc30fe2
--- /dev/null
+++ b/drivers/hid/hid-jabra.c
@@ -0,0 +1,55 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  Jabra USB HID Driver
+ *
+ *  Copyright (c) 2017 Niels Skou Olsen <nolsen@jabra.com>
+ */
+
+/*
+ */
+
+#include <linux/hid.h>
+#include <linux/module.h>
+
+#include "hid-ids.h"
+
+#define HID_UP_VENDOR_DEFINED_MIN	0xff000000
+#define HID_UP_VENDOR_DEFINED_MAX	0xffff0000
+
+static int jabra_input_mapping(struct hid_device *hdev,
+			       struct hid_input *hi,
+			       struct hid_field *field,
+			       struct hid_usage *usage,
+			       unsigned long **bit, int *max)
+{
+	int is_vendor_defined =
+		((usage->hid & HID_USAGE_PAGE) >= HID_UP_VENDOR_DEFINED_MIN &&
+		 (usage->hid & HID_USAGE_PAGE) <= HID_UP_VENDOR_DEFINED_MAX);
+
+	dbg_hid("hid=0x%08x appl=0x%08x coll_idx=0x%02x usage_idx=0x%02x: %s\n",
+		usage->hid,
+		field->application,
+		usage->collection_index,
+		usage->usage_index,
+		is_vendor_defined ? "ignored" : "defaulted");
+
+	/* Ignore vendor defined usages, default map standard usages */
+	return is_vendor_defined ? -1 : 0;
+}
+
+static const struct hid_device_id jabra_devices[] = {
+	{ HID_USB_DEVICE(USB_VENDOR_ID_JABRA, HID_ANY_ID) },
+	{ }
+};
+MODULE_DEVICE_TABLE(hid, jabra_devices);
+
+static struct hid_driver jabra_driver = {
+	.name = "jabra",
+	.id_table = jabra_devices,
+	.input_mapping = jabra_input_mapping,
+};
+module_hid_driver(jabra_driver);
+
+MODULE_AUTHOR("Niels Skou Olsen <nolsen@jabra.com>");
+MODULE_DESCRIPTION("Jabra USB HID Driver");
+MODULE_LICENSE("GPL");