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, 55 insertions, 0 deletions

diff --git a/net/mac80211/trace_msg.h b/net/mac80211/trace_msg.h
new file mode 100644
index 000000000..aea4ce55c
--- /dev/null
+++ b/net/mac80211/trace_msg.h
@@ -0,0 +1,55 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Portions of this file
+ * Copyright (C) 2019 Intel Corporation
+ */
+
+#ifdef CONFIG_MAC80211_MESSAGE_TRACING
+
+#if !defined(__MAC80211_MSG_DRIVER_TRACE) || defined(TRACE_HEADER_MULTI_READ)
+#define __MAC80211_MSG_DRIVER_TRACE
+
+#include <linux/tracepoint.h>
+#include <net/mac80211.h>
+#include "ieee80211_i.h"
+
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM mac80211_msg
+
+DECLARE_EVENT_CLASS(mac80211_msg_event,
+	TP_PROTO(struct va_format *vaf),
+
+	TP_ARGS(vaf),
+
+	TP_STRUCT__entry(
+		__vstring(msg, vaf->fmt, vaf->va)
+	),
+
+	TP_fast_assign(
+		__assign_vstr(msg, vaf->fmt, vaf->va);
+	),
+
+	TP_printk("%s", __get_str(msg))
+);
+
+DEFINE_EVENT(mac80211_msg_event, mac80211_info,
+	TP_PROTO(struct va_format *vaf),
+	TP_ARGS(vaf)
+);
+DEFINE_EVENT(mac80211_msg_event, mac80211_dbg,
+	TP_PROTO(struct va_format *vaf),
+	TP_ARGS(vaf)
+);
+DEFINE_EVENT(mac80211_msg_event, mac80211_err,
+	TP_PROTO(struct va_format *vaf),
+	TP_ARGS(vaf)
+);
+#endif /* !__MAC80211_MSG_DRIVER_TRACE || TRACE_HEADER_MULTI_READ */
+
+#undef TRACE_INCLUDE_PATH
+#define TRACE_INCLUDE_PATH .
+#undef TRACE_INCLUDE_FILE
+#define TRACE_INCLUDE_FILE trace_msg
+#include <trace/define_trace.h>
+
+#endif