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, 41 insertions, 0 deletions

diff --git a/include/net/mip6.h b/include/net/mip6.h
new file mode 100644
index 000000000..67cd7e508
--- /dev/null
+++ b/include/net/mip6.h
@@ -0,0 +1,41 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C)2003-2006 Helsinki University of Technology
+ * Copyright (C)2003-2006 USAGI/WIDE Project
+ */
+/*
+ * Authors:
+ *	Noriaki TAKAMIYA @USAGI
+ *	Masahide NAKAMURA @USAGI
+ *	YOSHIFUJI Hideaki @USAGI
+ */
+#ifndef _NET_MIP6_H
+#define _NET_MIP6_H
+
+#include <linux/skbuff.h>
+#include <net/sock.h>
+
+/*
+ * Mobility Header
+ */
+struct ip6_mh {
+	__u8	ip6mh_proto;
+	__u8	ip6mh_hdrlen;
+	__u8	ip6mh_type;
+	__u8	ip6mh_reserved;
+	__u16	ip6mh_cksum;
+	/* Followed by type specific messages */
+	__u8	data[];
+} __packed;
+
+#define IP6_MH_TYPE_BRR		0   /* Binding Refresh Request */
+#define IP6_MH_TYPE_HOTI	1   /* HOTI Message   */
+#define IP6_MH_TYPE_COTI	2   /* COTI Message  */
+#define IP6_MH_TYPE_HOT		3   /* HOT Message   */
+#define IP6_MH_TYPE_COT		4   /* COT Message  */
+#define IP6_MH_TYPE_BU		5   /* Binding Update */
+#define IP6_MH_TYPE_BACK	6   /* Binding ACK */
+#define IP6_MH_TYPE_BERROR	7   /* Binding Error */
+#define IP6_MH_TYPE_MAX		IP6_MH_TYPE_BERROR
+
+#endif