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, 460 insertions, 0 deletions

diff --git a/drivers/hid/hid-roccat-arvo.c b/drivers/hid/hid-roccat-arvo.c
new file mode 100644
index 000000000..0cf2f0008
--- /dev/null
+++ b/drivers/hid/hid-roccat-arvo.c
@@ -0,0 +1,460 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Roccat Arvo driver for Linux
+ *
+ * Copyright (c) 2011 Stefan Achatz <erazor_de@users.sourceforge.net>
+ */
+
+/*
+ */
+
+/*
+ * Roccat Arvo is a gamer keyboard with 5 macro keys that can be configured in
+ * 5 profiles.
+ */
+
+#include <linux/device.h>
+#include <linux/input.h>
+#include <linux/hid.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/hid-roccat.h>
+#include "hid-ids.h"
+#include "hid-roccat-common.h"
+#include "hid-roccat-arvo.h"
+
+static ssize_t arvo_sysfs_show_mode_key(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct arvo_device *arvo =
+			hid_get_drvdata(dev_get_drvdata(dev->parent->parent));
+	struct usb_device *usb_dev =
+			interface_to_usbdev(to_usb_interface(dev->parent->parent));
+	struct arvo_mode_key temp_buf;
+	int retval;
+
+	mutex_lock(&arvo->arvo_lock);
+	retval = roccat_common2_receive(usb_dev, ARVO_COMMAND_MODE_KEY,
+			&temp_buf, sizeof(struct arvo_mode_key));
+	mutex_unlock(&arvo->arvo_lock);
+	if (retval)
+		return retval;
+
+	return sysfs_emit(buf, "%d\n", temp_buf.state);
+}
+
+static ssize_t arvo_sysfs_set_mode_key(struct device *dev,
+		struct device_attribute *attr, char const *buf, size_t size)
+{
+	struct arvo_device *arvo =
+			hid_get_drvdata(dev_get_drvdata(dev->parent->parent));
+	struct usb_device *usb_dev =
+			interface_to_usbdev(to_usb_interface(dev->parent->parent));
+	struct arvo_mode_key temp_buf;
+	unsigned long state;
+	int retval;
+
+	retval = kstrtoul(buf, 10, &state);
+	if (retval)
+		return retval;
+
+	temp_buf.command = ARVO_COMMAND_MODE_KEY;
+	temp_buf.state = state;
+
+	mutex_lock(&arvo->arvo_lock);
+	retval = roccat_common2_send(usb_dev, ARVO_COMMAND_MODE_KEY,
+			&temp_buf, sizeof(struct arvo_mode_key));
+	mutex_unlock(&arvo->arvo_lock);
+	if (retval)
+		return retval;
+
+	return size;
+}
+static DEVICE_ATTR(mode_key, 0660,
+		   arvo_sysfs_show_mode_key, arvo_sysfs_set_mode_key);
+
+static ssize_t arvo_sysfs_show_key_mask(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct arvo_device *arvo =
+			hid_get_drvdata(dev_get_drvdata(dev->parent->parent));
+	struct usb_device *usb_dev =
+			interface_to_usbdev(to_usb_interface(dev->parent->parent));
+	struct arvo_key_mask temp_buf;
+	int retval;
+
+	mutex_lock(&arvo->arvo_lock);
+	retval = roccat_common2_receive(usb_dev, ARVO_COMMAND_KEY_MASK,
+			&temp_buf, sizeof(struct arvo_key_mask));
+	mutex_unlock(&arvo->arvo_lock);
+	if (retval)
+		return retval;
+
+	return sysfs_emit(buf, "%d\n", temp_buf.key_mask);
+}
+
+static ssize_t arvo_sysfs_set_key_mask(struct device *dev,
+		struct device_attribute *attr, char const *buf, size_t size)
+{
+	struct arvo_device *arvo =
+			hid_get_drvdata(dev_get_drvdata(dev->parent->parent));
+	struct usb_device *usb_dev =
+			interface_to_usbdev(to_usb_interface(dev->parent->parent));
+	struct arvo_key_mask temp_buf;
+	unsigned long key_mask;
+	int retval;
+
+	retval = kstrtoul(buf, 10, &key_mask);
+	if (retval)
+		return retval;
+
+	temp_buf.command = ARVO_COMMAND_KEY_MASK;
+	temp_buf.key_mask = key_mask;
+
+	mutex_lock(&arvo->arvo_lock);
+	retval = roccat_common2_send(usb_dev, ARVO_COMMAND_KEY_MASK,
+			&temp_buf, sizeof(struct arvo_key_mask));
+	mutex_unlock(&arvo->arvo_lock);
+	if (retval)
+		return retval;
+
+	return size;
+}
+static DEVICE_ATTR(key_mask, 0660,
+		   arvo_sysfs_show_key_mask, arvo_sysfs_set_key_mask);
+
+/* retval is 1-5 on success, < 0 on error */
+static int arvo_get_actual_profile(struct usb_device *usb_dev)
+{
+	struct arvo_actual_profile temp_buf;
+	int retval;
+
+	retval = roccat_common2_receive(usb_dev, ARVO_COMMAND_ACTUAL_PROFILE,
+			&temp_buf, sizeof(struct arvo_actual_profile));
+
+	if (retval)
+		return retval;
+
+	return temp_buf.actual_profile;
+}
+
+static ssize_t arvo_sysfs_show_actual_profile(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct arvo_device *arvo =
+			hid_get_drvdata(dev_get_drvdata(dev->parent->parent));
+
+	return sysfs_emit(buf, "%d\n", arvo->actual_profile);
+}
+
+static ssize_t arvo_sysfs_set_actual_profile(struct device *dev,
+		struct device_attribute *attr, char const *buf, size_t size)
+{
+	struct arvo_device *arvo =
+			hid_get_drvdata(dev_get_drvdata(dev->parent->parent));
+	struct usb_device *usb_dev =
+			interface_to_usbdev(to_usb_interface(dev->parent->parent));
+	struct arvo_actual_profile temp_buf;
+	unsigned long profile;
+	int retval;
+
+	retval = kstrtoul(buf, 10, &profile);
+	if (retval)
+		return retval;
+
+	if (profile < 1 || profile > 5)
+		return -EINVAL;
+
+	temp_buf.command = ARVO_COMMAND_ACTUAL_PROFILE;
+	temp_buf.actual_profile = profile;
+
+	mutex_lock(&arvo->arvo_lock);
+	retval = roccat_common2_send(usb_dev, ARVO_COMMAND_ACTUAL_PROFILE,
+			&temp_buf, sizeof(struct arvo_actual_profile));
+	if (!retval) {
+		arvo->actual_profile = profile;
+		retval = size;
+	}
+	mutex_unlock(&arvo->arvo_lock);
+	return retval;
+}
+static DEVICE_ATTR(actual_profile, 0660,
+		   arvo_sysfs_show_actual_profile,
+		   arvo_sysfs_set_actual_profile);
+
+static ssize_t arvo_sysfs_write(struct file *fp,
+		struct kobject *kobj, void const *buf,
+		loff_t off, size_t count, size_t real_size, uint command)
+{
+	struct device *dev = kobj_to_dev(kobj)->parent->parent;
+	struct arvo_device *arvo = hid_get_drvdata(dev_get_drvdata(dev));
+	struct usb_device *usb_dev = interface_to_usbdev(to_usb_interface(dev));
+	int retval;
+
+	if (off != 0 || count != real_size)
+		return -EINVAL;
+
+	mutex_lock(&arvo->arvo_lock);
+	retval = roccat_common2_send(usb_dev, command, buf, real_size);
+	mutex_unlock(&arvo->arvo_lock);
+
+	return (retval ? retval : real_size);
+}
+
+static ssize_t arvo_sysfs_read(struct file *fp,
+		struct kobject *kobj, void *buf, loff_t off,
+		size_t count, size_t real_size, uint command)
+{
+	struct device *dev = kobj_to_dev(kobj)->parent->parent;
+	struct arvo_device *arvo = hid_get_drvdata(dev_get_drvdata(dev));
+	struct usb_device *usb_dev = interface_to_usbdev(to_usb_interface(dev));
+	int retval;
+
+	if (off >= real_size)
+		return 0;
+
+	if (off != 0 || count != real_size)
+		return -EINVAL;
+
+	mutex_lock(&arvo->arvo_lock);
+	retval = roccat_common2_receive(usb_dev, command, buf, real_size);
+	mutex_unlock(&arvo->arvo_lock);
+
+	return (retval ? retval : real_size);
+}
+
+static ssize_t arvo_sysfs_write_button(struct file *fp,
+		struct kobject *kobj, const struct bin_attribute *attr,
+		char *buf, loff_t off, size_t count)
+{
+	return arvo_sysfs_write(fp, kobj, buf, off, count,
+			sizeof(struct arvo_button), ARVO_COMMAND_BUTTON);
+}
+static const BIN_ATTR(button, 0220, NULL, arvo_sysfs_write_button,
+		      sizeof(struct arvo_button));
+
+static ssize_t arvo_sysfs_read_info(struct file *fp,
+		struct kobject *kobj, const struct bin_attribute *attr,
+		char *buf, loff_t off, size_t count)
+{
+	return arvo_sysfs_read(fp, kobj, buf, off, count,
+			sizeof(struct arvo_info), ARVO_COMMAND_INFO);
+}
+static const BIN_ATTR(info, 0440, arvo_sysfs_read_info, NULL,
+		      sizeof(struct arvo_info));
+
+static struct attribute *arvo_attrs[] = {
+	&dev_attr_mode_key.attr,
+	&dev_attr_key_mask.attr,
+	&dev_attr_actual_profile.attr,
+	NULL,
+};
+
+static const struct bin_attribute *const arvo_bin_attributes[] = {
+	&bin_attr_button,
+	&bin_attr_info,
+	NULL,
+};
+
+static const struct attribute_group arvo_group = {
+	.attrs = arvo_attrs,
+	.bin_attrs = arvo_bin_attributes,
+};
+
+static const struct attribute_group *arvo_groups[] = {
+	&arvo_group,
+	NULL,
+};
+
+static const struct class arvo_class = {
+	.name = "arvo",
+	.dev_groups = arvo_groups,
+};
+
+static int arvo_init_arvo_device_struct(struct usb_device *usb_dev,
+		struct arvo_device *arvo)
+{
+	int retval;
+
+	mutex_init(&arvo->arvo_lock);
+
+	retval = arvo_get_actual_profile(usb_dev);
+	if (retval < 0)
+		return retval;
+	arvo->actual_profile = retval;
+
+	return 0;
+}
+
+static int arvo_init_specials(struct hid_device *hdev)
+{
+	struct usb_interface *intf = to_usb_interface(hdev->dev.parent);
+	struct usb_device *usb_dev = interface_to_usbdev(intf);
+	struct arvo_device *arvo;
+	int retval;
+
+	if (intf->cur_altsetting->desc.bInterfaceProtocol
+			== USB_INTERFACE_PROTOCOL_KEYBOARD) {
+		hid_set_drvdata(hdev, NULL);
+		return 0;
+	}
+
+	arvo = kzalloc_obj(*arvo);
+	if (!arvo) {
+		hid_err(hdev, "can't alloc device descriptor\n");
+		return -ENOMEM;
+	}
+	hid_set_drvdata(hdev, arvo);
+
+	retval = arvo_init_arvo_device_struct(usb_dev, arvo);
+	if (retval) {
+		hid_err(hdev, "couldn't init struct arvo_device\n");
+		goto exit_free;
+	}
+
+	retval = roccat_connect(&arvo_class, hdev,
+			sizeof(struct arvo_roccat_report));
+	if (retval < 0) {
+		hid_err(hdev, "couldn't init char dev\n");
+	} else {
+		arvo->chrdev_minor = retval;
+		arvo->roccat_claimed = 1;
+	}
+
+	return 0;
+exit_free:
+	kfree(arvo);
+	return retval;
+}
+
+static void arvo_remove_specials(struct hid_device *hdev)
+{
+	struct usb_interface *intf = to_usb_interface(hdev->dev.parent);
+	struct arvo_device *arvo;
+
+	if (intf->cur_altsetting->desc.bInterfaceProtocol
+			== USB_INTERFACE_PROTOCOL_KEYBOARD)
+		return;
+
+	arvo = hid_get_drvdata(hdev);
+	if (arvo->roccat_claimed)
+		roccat_disconnect(arvo->chrdev_minor);
+	kfree(arvo);
+}
+
+static int arvo_probe(struct hid_device *hdev,
+		const struct hid_device_id *id)
+{
+	int retval;
+
+	if (!hid_is_usb(hdev))
+		return -EINVAL;
+
+	retval = hid_parse(hdev);
+	if (retval) {
+		hid_err(hdev, "parse failed\n");
+		goto exit;
+	}
+
+	retval = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
+	if (retval) {
+		hid_err(hdev, "hw start failed\n");
+		goto exit;
+	}
+
+	retval = arvo_init_specials(hdev);
+	if (retval) {
+		hid_err(hdev, "couldn't install keyboard\n");
+		goto exit_stop;
+	}
+
+	return 0;
+
+exit_stop:
+	hid_hw_stop(hdev);
+exit:
+	return retval;
+}
+
+static void arvo_remove(struct hid_device *hdev)
+{
+	arvo_remove_specials(hdev);
+	hid_hw_stop(hdev);
+}
+
+static void arvo_report_to_chrdev(struct arvo_device const *arvo,
+		u8 const *data)
+{
+	struct arvo_special_report const *special_report;
+	struct arvo_roccat_report roccat_report;
+
+	special_report = (struct arvo_special_report const *)data;
+
+	roccat_report.profile = arvo->actual_profile;
+	roccat_report.button = special_report->event &
+			ARVO_SPECIAL_REPORT_EVENT_MASK_BUTTON;
+	if ((special_report->event & ARVO_SPECIAL_REPORT_EVENT_MASK_ACTION) ==
+			ARVO_SPECIAL_REPORT_EVENT_ACTION_PRESS)
+		roccat_report.action = ARVO_ROCCAT_REPORT_ACTION_PRESS;
+	else
+		roccat_report.action = ARVO_ROCCAT_REPORT_ACTION_RELEASE;
+
+	roccat_report_event(arvo->chrdev_minor,
+			(uint8_t const *)&roccat_report);
+}
+
+static int arvo_raw_event(struct hid_device *hdev,
+		struct hid_report *report, u8 *data, int size)
+{
+	struct arvo_device *arvo = hid_get_drvdata(hdev);
+
+	if (size != 3)
+		return 0;
+
+	if (arvo && arvo->roccat_claimed)
+		arvo_report_to_chrdev(arvo, data);
+
+	return 0;
+}
+
+static const struct hid_device_id arvo_devices[] = {
+	{ HID_USB_DEVICE(USB_VENDOR_ID_ROCCAT, USB_DEVICE_ID_ROCCAT_ARVO) },
+	{ }
+};
+
+MODULE_DEVICE_TABLE(hid, arvo_devices);
+
+static struct hid_driver arvo_driver = {
+	.name = "arvo",
+	.id_table = arvo_devices,
+	.probe = arvo_probe,
+	.remove = arvo_remove,
+	.raw_event = arvo_raw_event
+};
+
+static int __init arvo_init(void)
+{
+	int retval;
+
+	retval = class_register(&arvo_class);
+	if (retval)
+		return retval;
+
+	retval = hid_register_driver(&arvo_driver);
+	if (retval)
+		class_unregister(&arvo_class);
+	return retval;
+}
+
+static void __exit arvo_exit(void)
+{
+	hid_unregister_driver(&arvo_driver);
+	class_unregister(&arvo_class);
+}
+
+module_init(arvo_init);
+module_exit(arvo_exit);
+
+MODULE_AUTHOR("Stefan Achatz");
+MODULE_DESCRIPTION("USB Roccat Arvo driver");
+MODULE_LICENSE("GPL v2");