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, 262 insertions, 0 deletions

diff --git a/drivers/macintosh/mac_hid.c b/drivers/macintosh/mac_hid.c
new file mode 100644
index 000000000..1fdf3855f
--- /dev/null
+++ b/drivers/macintosh/mac_hid.c
@@ -0,0 +1,262 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * drivers/macintosh/mac_hid.c
+ *
+ * HID support stuff for Macintosh computers.
+ *
+ * Copyright (C) 2000 Franz Sirl.
+ *
+ * This file will soon be removed in favor of an uinput userspace tool.
+ */
+
+#include <linux/init.h>
+#include <linux/proc_fs.h>
+#include <linux/sysctl.h>
+#include <linux/input.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+
+MODULE_DESCRIPTION("Mouse button 2+3 emulation");
+MODULE_LICENSE("GPL");
+
+static int mouse_emulate_buttons;
+static int mouse_button2_keycode = KEY_RIGHTCTRL;	/* right control key */
+static int mouse_button3_keycode = KEY_RIGHTALT;	/* right option key */
+
+static struct input_dev *mac_hid_emumouse_dev;
+
+static DEFINE_MUTEX(mac_hid_emumouse_mutex);
+
+static int mac_hid_create_emumouse(void)
+{
+	static struct lock_class_key mac_hid_emumouse_dev_event_class;
+	static struct lock_class_key mac_hid_emumouse_dev_mutex_class;
+	int err;
+
+	mac_hid_emumouse_dev = input_allocate_device();
+	if (!mac_hid_emumouse_dev)
+		return -ENOMEM;
+
+	lockdep_set_class(&mac_hid_emumouse_dev->event_lock,
+			  &mac_hid_emumouse_dev_event_class);
+	lockdep_set_class(&mac_hid_emumouse_dev->mutex,
+			  &mac_hid_emumouse_dev_mutex_class);
+
+	mac_hid_emumouse_dev->name = "Macintosh mouse button emulation";
+	mac_hid_emumouse_dev->id.bustype = BUS_ADB;
+	mac_hid_emumouse_dev->id.vendor = 0x0001;
+	mac_hid_emumouse_dev->id.product = 0x0001;
+	mac_hid_emumouse_dev->id.version = 0x0100;
+
+	mac_hid_emumouse_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_REL);
+	mac_hid_emumouse_dev->keybit[BIT_WORD(BTN_MOUSE)] =
+		BIT_MASK(BTN_LEFT) | BIT_MASK(BTN_MIDDLE) | BIT_MASK(BTN_RIGHT);
+	mac_hid_emumouse_dev->relbit[0] = BIT_MASK(REL_X) | BIT_MASK(REL_Y);
+
+	err = input_register_device(mac_hid_emumouse_dev);
+	if (err) {
+		input_free_device(mac_hid_emumouse_dev);
+		mac_hid_emumouse_dev = NULL;
+		return err;
+	}
+
+	return 0;
+}
+
+static void mac_hid_destroy_emumouse(void)
+{
+	input_unregister_device(mac_hid_emumouse_dev);
+	mac_hid_emumouse_dev = NULL;
+}
+
+static bool mac_hid_emumouse_filter(struct input_handle *handle,
+				    unsigned int type, unsigned int code,
+				    int value)
+{
+	unsigned int btn;
+
+	if (type != EV_KEY)
+		return false;
+
+	if (code == mouse_button2_keycode)
+		btn = BTN_MIDDLE;
+	else if (code == mouse_button3_keycode)
+		btn = BTN_RIGHT;
+	else
+		return false;
+
+	input_report_key(mac_hid_emumouse_dev, btn, value);
+	input_sync(mac_hid_emumouse_dev);
+
+	return true;
+}
+
+static int mac_hid_emumouse_connect(struct input_handler *handler,
+				    struct input_dev *dev,
+				    const struct input_device_id *id)
+{
+	struct input_handle *handle;
+	int error;
+
+	/* Don't bind to ourselves */
+	if (dev == mac_hid_emumouse_dev)
+		return -ENODEV;
+
+	handle = kzalloc_obj(struct input_handle);
+	if (!handle)
+		return -ENOMEM;
+
+	handle->dev = dev;
+	handle->handler = handler;
+	handle->name = "mac-button-emul";
+
+	error = input_register_handle(handle);
+	if (error) {
+		printk(KERN_ERR
+			"mac_hid: Failed to register button emulation handle, "
+			"error %d\n", error);
+		goto err_free;
+	}
+
+	error = input_open_device(handle);
+	if (error) {
+		printk(KERN_ERR
+			"mac_hid: Failed to open input device, error %d\n",
+			error);
+		goto err_unregister;
+	}
+
+	return 0;
+
+ err_unregister:
+	input_unregister_handle(handle);
+ err_free:
+	kfree(handle);
+	return error;
+}
+
+static void mac_hid_emumouse_disconnect(struct input_handle *handle)
+{
+	input_close_device(handle);
+	input_unregister_handle(handle);
+	kfree(handle);
+}
+
+static const struct input_device_id mac_hid_emumouse_ids[] = {
+	{
+		.flags = INPUT_DEVICE_ID_MATCH_EVBIT,
+		.evbit = { BIT_MASK(EV_KEY) },
+	},
+	{ },
+};
+
+MODULE_DEVICE_TABLE(input, mac_hid_emumouse_ids);
+
+static struct input_handler mac_hid_emumouse_handler = {
+	.filter		= mac_hid_emumouse_filter,
+	.connect	= mac_hid_emumouse_connect,
+	.disconnect	= mac_hid_emumouse_disconnect,
+	.name		= "mac-button-emul",
+	.id_table	= mac_hid_emumouse_ids,
+};
+
+static int mac_hid_start_emulation(void)
+{
+	int err;
+
+	err = mac_hid_create_emumouse();
+	if (err)
+		return err;
+
+	err = input_register_handler(&mac_hid_emumouse_handler);
+	if (err) {
+		mac_hid_destroy_emumouse();
+		return err;
+	}
+
+	return 0;
+}
+
+static void mac_hid_stop_emulation(void)
+{
+	input_unregister_handler(&mac_hid_emumouse_handler);
+	mac_hid_destroy_emumouse();
+}
+
+static int mac_hid_toggle_emumouse(const struct ctl_table *table, int write,
+				   void *buffer, size_t *lenp, loff_t *ppos)
+{
+	int *valp = table->data;
+	int old_val;
+	int rc;
+
+	rc = mutex_lock_killable(&mac_hid_emumouse_mutex);
+	if (rc)
+		return rc;
+
+	old_val = *valp;
+	rc = proc_dointvec(table, write, buffer, lenp, ppos);
+
+	if (rc == 0 && write && *valp != old_val) {
+		if (*valp == 1)
+			rc = mac_hid_start_emulation();
+		else if (*valp == 0)
+			mac_hid_stop_emulation();
+		else
+			rc = -EINVAL;
+	}
+
+	/* Restore the old value in case of error */
+	if (rc)
+		*valp = old_val;
+
+	mutex_unlock(&mac_hid_emumouse_mutex);
+
+	return rc;
+}
+
+/* file(s) in /proc/sys/dev/mac_hid */
+static const struct ctl_table mac_hid_files[] = {
+	{
+		.procname	= "mouse_button_emulation",
+		.data		= &mouse_emulate_buttons,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= mac_hid_toggle_emumouse,
+	},
+	{
+		.procname	= "mouse_button2_keycode",
+		.data		= &mouse_button2_keycode,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec,
+	},
+	{
+		.procname	= "mouse_button3_keycode",
+		.data		= &mouse_button3_keycode,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec,
+	},
+};
+
+static struct ctl_table_header *mac_hid_sysctl_header;
+
+static int __init mac_hid_init(void)
+{
+	mac_hid_sysctl_header = register_sysctl("dev/mac_hid", mac_hid_files);
+	if (!mac_hid_sysctl_header)
+		return -ENOMEM;
+
+	return 0;
+}
+module_init(mac_hid_init);
+
+static void __exit mac_hid_exit(void)
+{
+	unregister_sysctl_table(mac_hid_sysctl_header);
+
+	if (mouse_emulate_buttons)
+		mac_hid_stop_emulation();
+}
+module_exit(mac_hid_exit);