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, 153 insertions, 0 deletions

diff --git a/drivers/input/misc/qnap-mcu-input.c b/drivers/input/misc/qnap-mcu-input.c
new file mode 100644
index 000000000..3be899bfc
--- /dev/null
+++ b/drivers/input/misc/qnap-mcu-input.c
@@ -0,0 +1,153 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+/*
+ * Driver for input events on QNAP-MCUs
+ *
+ * Copyright (C) 2024 Heiko Stuebner <heiko@sntech.de>
+ */
+
+#include <linux/input.h>
+#include <linux/mfd/qnap-mcu.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <uapi/linux/input-event-codes.h>
+
+/*
+ * The power-key needs to be pressed for a while to create an event,
+ * so there is no use for overly frequent polling.
+ */
+#define POLL_INTERVAL		500
+
+struct qnap_mcu_input_dev {
+	struct input_dev *input;
+	struct qnap_mcu *mcu;
+	struct device *dev;
+
+	struct work_struct beep_work;
+	int beep_type;
+};
+
+static void qnap_mcu_input_poll(struct input_dev *input)
+{
+	struct qnap_mcu_input_dev *idev = input_get_drvdata(input);
+	static const u8 cmd[] = { '@', 'C', 'V' };
+	u8 reply[4];
+	int state, ret;
+
+	/* poll the power button */
+	ret = qnap_mcu_exec(idev->mcu, cmd, sizeof(cmd), reply, sizeof(reply));
+	if (ret)
+		return;
+
+	/* First bytes must mirror the sent command */
+	if (memcmp(cmd, reply, sizeof(cmd))) {
+		dev_err(idev->dev, "malformed data received\n");
+		return;
+	}
+
+	state = reply[3] - 0x30;
+	input_event(input, EV_KEY, KEY_POWER, state);
+	input_sync(input);
+}
+
+static void qnap_mcu_input_beeper_work(struct work_struct *work)
+{
+	struct qnap_mcu_input_dev *idev =
+		container_of(work, struct qnap_mcu_input_dev, beep_work);
+	const u8 cmd[] = { '@', 'C', (idev->beep_type == SND_TONE) ? '3' : '2' };
+
+	qnap_mcu_exec_with_ack(idev->mcu, cmd, sizeof(cmd));
+}
+
+static int qnap_mcu_input_event(struct input_dev *input, unsigned int type,
+				unsigned int code, int value)
+{
+	struct qnap_mcu_input_dev *idev = input_get_drvdata(input);
+
+	if (type != EV_SND || (code != SND_BELL && code != SND_TONE))
+		return -EOPNOTSUPP;
+
+	if (value < 0)
+		return -EINVAL;
+
+	/* beep runtime is determined by the MCU */
+	if (value == 0)
+		return 0;
+
+	/* Schedule work to actually turn the beeper on */
+	idev->beep_type = code;
+	schedule_work(&idev->beep_work);
+
+	return 0;
+}
+
+static void qnap_mcu_input_close(struct input_dev *input)
+{
+	struct qnap_mcu_input_dev *idev = input_get_drvdata(input);
+
+	cancel_work_sync(&idev->beep_work);
+}
+
+static int qnap_mcu_input_probe(struct platform_device *pdev)
+{
+	struct qnap_mcu *mcu = dev_get_drvdata(pdev->dev.parent);
+	struct qnap_mcu_input_dev *idev;
+	struct device *dev = &pdev->dev;
+	struct input_dev *input;
+	int ret;
+
+	idev = devm_kzalloc(dev, sizeof(*idev), GFP_KERNEL);
+	if (!idev)
+		return -ENOMEM;
+
+	input = devm_input_allocate_device(dev);
+	if (!input)
+		return -ENOMEM;
+
+	idev->input = input;
+	idev->dev = dev;
+	idev->mcu = mcu;
+
+	input_set_drvdata(input, idev);
+
+	input->name		= "qnap-mcu";
+	input->phys		= "qnap-mcu-input/input0";
+	input->id.bustype	= BUS_HOST;
+	input->id.vendor	= 0x0001;
+	input->id.product	= 0x0001;
+	input->id.version	= 0x0100;
+	input->event		= qnap_mcu_input_event;
+	input->close		= qnap_mcu_input_close;
+
+	input_set_capability(input, EV_KEY, KEY_POWER);
+	input_set_capability(input, EV_SND, SND_BELL);
+	input_set_capability(input, EV_SND, SND_TONE);
+
+	INIT_WORK(&idev->beep_work, qnap_mcu_input_beeper_work);
+
+	ret = input_setup_polling(input, qnap_mcu_input_poll);
+	if (ret)
+		return dev_err_probe(dev, ret, "unable to set up polling\n");
+
+	input_set_poll_interval(input, POLL_INTERVAL);
+
+	ret = input_register_device(input);
+	if (ret)
+		return dev_err_probe(dev, ret, "unable to register input device\n");
+
+	return 0;
+}
+
+static struct platform_driver qnap_mcu_input_driver = {
+	.probe = qnap_mcu_input_probe,
+	.driver = {
+		.name = "qnap-mcu-input",
+	},
+};
+module_platform_driver(qnap_mcu_input_driver);
+
+MODULE_ALIAS("platform:qnap-mcu-input");
+MODULE_AUTHOR("Heiko Stuebner <heiko@sntech.de>");
+MODULE_DESCRIPTION("QNAP MCU input driver");
+MODULE_LICENSE("GPL");