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, 46 insertions, 0 deletions

diff --git a/include/net/ax88796.h b/include/net/ax88796.h
new file mode 100644
index 000000000..303100f08
--- /dev/null
+++ b/include/net/ax88796.h
@@ -0,0 +1,46 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/* include/net/ax88796.h
+ *
+ * Copyright 2005 Simtec Electronics
+ *	Ben Dooks <ben@simtec.co.uk>
+*/
+
+#ifndef __NET_AX88796_PLAT_H
+#define __NET_AX88796_PLAT_H
+
+#include <linux/types.h>
+
+struct sk_buff;
+struct net_device;
+struct platform_device;
+
+#define AXFLG_HAS_EEPROM		(1<<0)
+#define AXFLG_MAC_FROMDEV		(1<<1)	/* device already has MAC */
+#define AXFLG_HAS_93CX6			(1<<2)	/* use eeprom_93cx6 driver */
+#define AXFLG_MAC_FROMPLATFORM		(1<<3)	/* MAC given by platform data */
+
+struct ax_plat_data {
+	unsigned int	 flags;
+	unsigned char	 wordlength;	/* 1 or 2 */
+	unsigned char	 dcr_val;	/* default value for DCR */
+	unsigned char	 rcr_val;	/* default value for RCR */
+	unsigned char	 gpoc_val;	/* default value for GPOC */
+	u32		*reg_offsets;	/* register offsets */
+	u8		*mac_addr;	/* MAC addr (only used when
+					   AXFLG_MAC_FROMPLATFORM is used */
+
+	/* uses default ax88796 buffer if set to NULL */
+	void (*block_output)(struct net_device *dev, int count,
+			const unsigned char *buf, int star_page);
+	void (*block_input)(struct net_device *dev, int count,
+			struct sk_buff *skb, int ring_offset);
+	/* returns nonzero if a pending interrupt request might be caused by
+	 * the ax88796. Handles all interrupts if set to NULL
+	 */
+	int (*check_irq)(struct platform_device *pdev);
+};
+
+/* exported from ax88796.c for xsurf100.c  */
+extern void ax_NS8390_reinit(struct net_device *dev);
+
+#endif /* __NET_AX88796_PLAT_H */