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, 40 insertions, 0 deletions

diff --git a/drivers/accessibility/speakup/serialio.h b/drivers/accessibility/speakup/serialio.h
new file mode 100644
index 000000000..b4f9a1925
--- /dev/null
+++ b/drivers/accessibility/speakup/serialio.h
@@ -0,0 +1,40 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _SPEAKUP_SERIAL_H
+#define _SPEAKUP_SERIAL_H
+
+#include <linux/serial.h>	/* for rs_table, serial constants */
+#include <linux/serial_reg.h>	/* for more serial constants */
+#include <linux/serial_core.h>
+
+#include "spk_priv.h"
+
+/*
+ * this is cut&paste from 8250.h. Get rid of the structure, the definitions
+ * and this whole broken driver.
+ */
+struct old_serial_port {
+	unsigned int uart; /* unused */
+	unsigned int baud_base;
+	unsigned int port;
+	unsigned int irq;
+	upf_t flags; /* unused */
+};
+
+/* countdown values for serial timeouts in us */
+#define SPK_SERIAL_TIMEOUT SPK_SYNTH_TIMEOUT
+/* countdown values transmitter/dsr timeouts in us */
+#define SPK_XMITR_TIMEOUT 100000
+/* countdown values cts timeouts in us */
+#define SPK_CTS_TIMEOUT 100000
+/* check ttyS0 ... ttyS3 */
+#define SPK_LO_TTY 0
+#define SPK_HI_TTY 3
+/* # of timeouts permitted before disable */
+#define NUM_DISABLE_TIMEOUTS 3
+/* buffer timeout in ms */
+#define SPK_TIMEOUT 100
+
+#define spk_serial_tx_busy() \
+	(!uart_lsr_tx_empty(inb(speakup_info.port_tts + UART_LSR)))
+
+#endif