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, 152 insertions, 0 deletions

diff --git a/drivers/input/keyboard/xtkbd.c b/drivers/input/keyboard/xtkbd.c
new file mode 100644
index 000000000..c0b4978a8
--- /dev/null
+++ b/drivers/input/keyboard/xtkbd.c
@@ -0,0 +1,152 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  Copyright (c) 1999-2001 Vojtech Pavlik
+ */
+
+/*
+ * XT keyboard driver for Linux
+ */
+
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/input.h>
+#include <linux/serio.h>
+
+#define DRIVER_DESC	"XT keyboard driver"
+
+MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
+MODULE_DESCRIPTION(DRIVER_DESC);
+MODULE_LICENSE("GPL");
+
+#define XTKBD_EMUL0	0xe0
+#define XTKBD_EMUL1	0xe1
+#define XTKBD_KEY	0x7f
+#define XTKBD_RELEASE	0x80
+
+static unsigned char xtkbd_keycode[256] = {
+	  0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14, 15,
+	 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31,
+	 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47,
+	 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63,
+	 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79,
+	 80, 81, 82, 83,  0,  0,  0, 87, 88,  0,  0,  0,  0,  0,  0,  0,
+	  0,  0,  0,  0,  0, 87, 88,  0,  0,  0,  0,110,111,103,108,105,
+	106
+};
+
+struct xtkbd {
+	unsigned char keycode[256];
+	struct input_dev *dev;
+	struct serio *serio;
+	char phys[32];
+};
+
+static irqreturn_t xtkbd_interrupt(struct serio *serio,
+	unsigned char data, unsigned int flags)
+{
+	struct xtkbd *xtkbd = serio_get_drvdata(serio);
+
+	switch (data) {
+		case XTKBD_EMUL0:
+		case XTKBD_EMUL1:
+			break;
+		default:
+
+			if (xtkbd->keycode[data & XTKBD_KEY]) {
+				input_report_key(xtkbd->dev, xtkbd->keycode[data & XTKBD_KEY], !(data & XTKBD_RELEASE));
+				input_sync(xtkbd->dev);
+			} else {
+				printk(KERN_WARNING "xtkbd.c: Unknown key (scancode %#x) %s.\n",
+					data & XTKBD_KEY, data & XTKBD_RELEASE ? "released" : "pressed");
+			}
+	}
+	return IRQ_HANDLED;
+}
+
+static int xtkbd_connect(struct serio *serio, struct serio_driver *drv)
+{
+	struct xtkbd *xtkbd;
+	struct input_dev *input_dev;
+	int err = -ENOMEM;
+	int i;
+
+	xtkbd = kmalloc_obj(*xtkbd);
+	input_dev = input_allocate_device();
+	if (!xtkbd || !input_dev)
+		goto fail1;
+
+	xtkbd->serio = serio;
+	xtkbd->dev = input_dev;
+	snprintf(xtkbd->phys, sizeof(xtkbd->phys), "%s/input0", serio->phys);
+	memcpy(xtkbd->keycode, xtkbd_keycode, sizeof(xtkbd->keycode));
+
+	input_dev->name = "XT Keyboard";
+	input_dev->phys = xtkbd->phys;
+	input_dev->id.bustype = BUS_XTKBD;
+	input_dev->id.vendor  = 0x0001;
+	input_dev->id.product = 0x0001;
+	input_dev->id.version = 0x0100;
+	input_dev->dev.parent = &serio->dev;
+
+	input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_REP);
+	input_dev->keycode = xtkbd->keycode;
+	input_dev->keycodesize = sizeof(unsigned char);
+	input_dev->keycodemax = ARRAY_SIZE(xtkbd_keycode);
+
+	for (i = 0; i < 255; i++)
+		set_bit(xtkbd->keycode[i], input_dev->keybit);
+	clear_bit(0, input_dev->keybit);
+
+	serio_set_drvdata(serio, xtkbd);
+
+	err = serio_open(serio, drv);
+	if (err)
+		goto fail2;
+
+	err = input_register_device(xtkbd->dev);
+	if (err)
+		goto fail3;
+
+	return 0;
+
+ fail3:	serio_close(serio);
+ fail2:	serio_set_drvdata(serio, NULL);
+ fail1:	input_free_device(input_dev);
+	kfree(xtkbd);
+	return err;
+}
+
+static void xtkbd_disconnect(struct serio *serio)
+{
+	struct xtkbd *xtkbd = serio_get_drvdata(serio);
+
+	serio_close(serio);
+	serio_set_drvdata(serio, NULL);
+	input_unregister_device(xtkbd->dev);
+	kfree(xtkbd);
+}
+
+static const struct serio_device_id xtkbd_serio_ids[] = {
+	{
+		.type	= SERIO_XT,
+		.proto	= SERIO_ANY,
+		.id	= SERIO_ANY,
+		.extra	= SERIO_ANY,
+	},
+	{ 0 }
+};
+
+MODULE_DEVICE_TABLE(serio, xtkbd_serio_ids);
+
+static struct serio_driver xtkbd_drv = {
+	.driver		= {
+		.name	= "xtkbd",
+	},
+	.description	= DRIVER_DESC,
+	.id_table	= xtkbd_serio_ids,
+	.interrupt	= xtkbd_interrupt,
+	.connect	= xtkbd_connect,
+	.disconnect	= xtkbd_disconnect,
+};
+
+module_serio_driver(xtkbd_drv);