staging: rtl8723bs: fix OOB read in rtw_action_frame_parse()grafted

rtw_action_frame_parse() takes a frame_len parameter but never
actually checks it before indexing into the frame body:

	const u8 *frame_body = frame + sizeof(struct ieee80211_hdr_3addr);
	...
	c = frame_body[0];
	...
	a = frame_body[1];

frame_body already points 24 bytes (sizeof(struct
ieee80211_hdr_3addr)) into frame, so reading frame_body[0] and
frame_body[1] requires frame_len >= 26. A management action frame
shorter than that (e.g. exactly 24 bytes, the minimum a malicious
peer can send) causes a 1-2 byte out-of-bounds read.

This is reachable from rtw_cfg80211_monitor_if_xmit_entry() and
cfg80211_rtw_mgmt_tx() in ioctl_cfg80211.c, both of which pass
attacker/user-influenced frame buffers and lengths straight through.

Add the missing length check before frame_body is dereferenced.

Fixes: 554c0a3abf216 ("staging: Add rtl8723bs sdio wifi driver")
Cc: stable@vger.kernel.org
Signed-off-by: Muhammad Bilal <meatuni001@gmail.com>
Link: https://patch.msgid.link/20260728125456.32359-3-meatuni001@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 253 insertions, 0 deletions

diff --git a/drivers/input/misc/pwm-beeper.c b/drivers/input/misc/pwm-beeper.c
new file mode 100644
index 000000000..0e19e97d9
--- /dev/null
+++ b/drivers/input/misc/pwm-beeper.c
@@ -0,0 +1,253 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  Copyright (C) 2010, Lars-Peter Clausen <lars@metafoo.de>
+ *  PWM beeper driver
+ */
+
+#include <linux/input.h>
+#include <linux/regulator/consumer.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/property.h>
+#include <linux/pwm.h>
+#include <linux/slab.h>
+#include <linux/workqueue.h>
+
+struct pwm_beeper {
+	struct input_dev *input;
+	struct pwm_device *pwm;
+	struct regulator *amplifier;
+	struct work_struct work;
+	unsigned long period;
+	unsigned int bell_frequency;
+	bool suspended;
+	bool amplifier_on;
+};
+
+#define HZ_TO_NANOSECONDS(x) (1000000000UL/(x))
+
+static int pwm_beeper_on(struct pwm_beeper *beeper, unsigned long period)
+{
+	struct pwm_state state;
+	int error;
+
+	pwm_get_state(beeper->pwm, &state);
+
+	state.enabled = true;
+	state.period = period;
+	pwm_set_relative_duty_cycle(&state, 50, 100);
+
+	error = pwm_apply_might_sleep(beeper->pwm, &state);
+	if (error)
+		return error;
+
+	if (!beeper->amplifier_on) {
+		error = regulator_enable(beeper->amplifier);
+		if (error) {
+			pwm_disable(beeper->pwm);
+			return error;
+		}
+
+		beeper->amplifier_on = true;
+	}
+
+	return 0;
+}
+
+static void pwm_beeper_off(struct pwm_beeper *beeper)
+{
+	if (beeper->amplifier_on) {
+		regulator_disable(beeper->amplifier);
+		beeper->amplifier_on = false;
+	}
+
+	pwm_disable(beeper->pwm);
+}
+
+static void pwm_beeper_work(struct work_struct *work)
+{
+	struct pwm_beeper *beeper = container_of(work, struct pwm_beeper, work);
+	unsigned long period = READ_ONCE(beeper->period);
+
+	if (period)
+		pwm_beeper_on(beeper, period);
+	else
+		pwm_beeper_off(beeper);
+}
+
+static int pwm_beeper_event(struct input_dev *input,
+			    unsigned int type, unsigned int code, int value)
+{
+	struct pwm_beeper *beeper = input_get_drvdata(input);
+
+	if (type != EV_SND || value < 0)
+		return -EINVAL;
+
+	switch (code) {
+	case SND_BELL:
+		value = value ? beeper->bell_frequency : 0;
+		break;
+	case SND_TONE:
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	if (value == 0)
+		beeper->period = 0;
+	else
+		beeper->period = HZ_TO_NANOSECONDS(value);
+
+	if (!beeper->suspended)
+		schedule_work(&beeper->work);
+
+	return 0;
+}
+
+static void pwm_beeper_stop(struct pwm_beeper *beeper)
+{
+	cancel_work_sync(&beeper->work);
+	pwm_beeper_off(beeper);
+}
+
+static void pwm_beeper_close(struct input_dev *input)
+{
+	struct pwm_beeper *beeper = input_get_drvdata(input);
+
+	pwm_beeper_stop(beeper);
+}
+
+static int pwm_beeper_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct pwm_beeper *beeper;
+	struct pwm_state state;
+	u32 bell_frequency;
+	int error;
+
+	beeper = devm_kzalloc(dev, sizeof(*beeper), GFP_KERNEL);
+	if (!beeper)
+		return -ENOMEM;
+
+	beeper->pwm = devm_pwm_get(dev, NULL);
+	if (IS_ERR(beeper->pwm))
+		return dev_err_probe(dev, PTR_ERR(beeper->pwm), "Failed to request PWM device\n");
+
+	/* Sync up PWM state and ensure it is off. */
+	pwm_init_state(beeper->pwm, &state);
+	state.enabled = false;
+	error = pwm_apply_might_sleep(beeper->pwm, &state);
+	if (error) {
+		dev_err(dev, "failed to apply initial PWM state: %d\n",
+			error);
+		return error;
+	}
+
+	beeper->amplifier = devm_regulator_get(dev, "amp");
+	if (IS_ERR(beeper->amplifier))
+		return dev_err_probe(dev, PTR_ERR(beeper->amplifier),
+				     "Failed to get 'amp' regulator\n");
+
+	INIT_WORK(&beeper->work, pwm_beeper_work);
+
+	error = device_property_read_u32(dev, "beeper-hz", &bell_frequency);
+	if (error) {
+		bell_frequency = 1000;
+		dev_dbg(dev,
+			"failed to parse 'beeper-hz' property, using default: %uHz\n",
+			bell_frequency);
+	}
+
+	beeper->bell_frequency = bell_frequency;
+
+	beeper->input = devm_input_allocate_device(dev);
+	if (!beeper->input) {
+		dev_err(dev, "Failed to allocate input device\n");
+		return -ENOMEM;
+	}
+
+	beeper->input->name = "pwm-beeper";
+	beeper->input->phys = "pwm/input0";
+	beeper->input->id.bustype = BUS_HOST;
+	beeper->input->id.vendor = 0x001f;
+	beeper->input->id.product = 0x0001;
+	beeper->input->id.version = 0x0100;
+
+	input_set_capability(beeper->input, EV_SND, SND_TONE);
+	input_set_capability(beeper->input, EV_SND, SND_BELL);
+
+	beeper->input->event = pwm_beeper_event;
+	beeper->input->close = pwm_beeper_close;
+
+	input_set_drvdata(beeper->input, beeper);
+
+	error = input_register_device(beeper->input);
+	if (error) {
+		dev_err(dev, "Failed to register input device: %d\n", error);
+		return error;
+	}
+
+	platform_set_drvdata(pdev, beeper);
+
+	return 0;
+}
+
+static int pwm_beeper_suspend(struct device *dev)
+{
+	struct pwm_beeper *beeper = dev_get_drvdata(dev);
+
+	/*
+	 * Spinlock is taken here is not to protect write to
+	 * beeper->suspended, but to ensure that pwm_beeper_event
+	 * does not re-submit work once flag is set.
+	 */
+	scoped_guard(spinlock_irq, &beeper->input->event_lock) {
+		beeper->suspended = true;
+	}
+
+	pwm_beeper_stop(beeper);
+
+	return 0;
+}
+
+static int pwm_beeper_resume(struct device *dev)
+{
+	struct pwm_beeper *beeper = dev_get_drvdata(dev);
+
+	scoped_guard(spinlock_irq, &beeper->input->event_lock) {
+		beeper->suspended = false;
+	}
+
+	/* Let worker figure out if we should resume beeping */
+	schedule_work(&beeper->work);
+
+	return 0;
+}
+
+static DEFINE_SIMPLE_DEV_PM_OPS(pwm_beeper_pm_ops,
+				pwm_beeper_suspend, pwm_beeper_resume);
+
+#ifdef CONFIG_OF
+static const struct of_device_id pwm_beeper_match[] = {
+	{ .compatible = "pwm-beeper", },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, pwm_beeper_match);
+#endif
+
+static struct platform_driver pwm_beeper_driver = {
+	.probe	= pwm_beeper_probe,
+	.driver = {
+		.name	= "pwm-beeper",
+		.pm	= pm_sleep_ptr(&pwm_beeper_pm_ops),
+		.of_match_table = of_match_ptr(pwm_beeper_match),
+	},
+};
+module_platform_driver(pwm_beeper_driver);
+
+MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
+MODULE_DESCRIPTION("PWM beeper driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:pwm-beeper");