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/char/nwbutton.h b/drivers/char/nwbutton.h
new file mode 100644
index 000000000..f2b9fdc1f
--- /dev/null
+++ b/drivers/char/nwbutton.h
@@ -0,0 +1,40 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __NWBUTTON_H
+#define __NWBUTTON_H
+
+/*
+ * 	NetWinder Button Driver-
+ *	Copyright (C) Alex Holden <alex@linuxhacker.org> 1998, 1999.
+ */
+
+#ifdef __NWBUTTON_C	/* Actually compiling the driver itself */
+
+/* Various defines: */
+
+#define NUM_PRESSES_REBOOT 2	/* How many presses to activate shutdown */
+#define BUTTON_DELAY 30 	/* How many jiffies for sequence to end */
+#define VERSION "0.3"		/* Driver version number */
+
+/* Structure definitions: */
+
+struct button_callback {
+	void (*callback) (void);
+	int count;
+};
+
+/* Function prototypes: */
+
+static void button_sequence_finished(struct timer_list *unused);
+static irqreturn_t button_handler (int irq, void *dev_id);
+int button_init (void);
+int button_add_callback (void (*callback) (void), int count);
+int button_del_callback (void (*callback) (void));
+static void button_consume_callbacks (int bpcount);
+
+#else /* Not compiling the driver itself */
+
+extern int button_add_callback (void (*callback) (void), int count);
+extern int button_del_callback (void (*callback) (void));
+
+#endif /* __NWBUTTON_C */
+#endif /* __NWBUTTON_H */