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, 98 insertions, 0 deletions

diff --git a/include/trace/events/skb.h b/include/trace/events/skb.h
new file mode 100644
index 000000000..2945aa7fe
--- /dev/null
+++ b/include/trace/events/skb.h
@@ -0,0 +1,98 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM skb
+
+#if !defined(_TRACE_SKB_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_SKB_H
+
+#include <linux/skbuff.h>
+#include <linux/netdevice.h>
+#include <linux/tracepoint.h>
+
+#undef FN
+#define FN(reason)	TRACE_DEFINE_ENUM(SKB_DROP_REASON_##reason);
+DEFINE_DROP_REASON(FN, FN)
+
+#undef FN
+#undef FNe
+#define FN(reason)	{ SKB_DROP_REASON_##reason, #reason },
+#define FNe(reason)	{ SKB_DROP_REASON_##reason, #reason }
+
+/*
+ * Tracepoint for free an sk_buff:
+ */
+TRACE_EVENT(kfree_skb,
+
+	TP_PROTO(struct sk_buff *skb, void *location,
+		 enum skb_drop_reason reason, const struct sock *rx_sk),
+
+	TP_ARGS(skb, location, reason, rx_sk),
+
+	TP_STRUCT__entry(
+		__field(void *,		skbaddr)
+		__field(void *,		location)
+		__field(const void *,	rx_sk)
+		__field(unsigned short,	protocol)
+		__field(enum skb_drop_reason,	reason)
+	),
+
+	TP_fast_assign(
+		__entry->skbaddr = skb;
+		__entry->location = location;
+		__entry->rx_sk = rx_sk;
+		__entry->protocol = ntohs(skb->protocol);
+		__entry->reason = reason;
+	),
+
+	TP_printk("skbaddr=%p rx_sk=%p protocol=%u location=%pS reason: %s",
+		  __entry->skbaddr, __entry->rx_sk, __entry->protocol,
+		  __entry->location,
+		  __print_symbolic(__entry->reason,
+				   DEFINE_DROP_REASON(FN, FNe)))
+);
+
+#undef FN
+#undef FNe
+
+TRACE_EVENT(consume_skb,
+
+	TP_PROTO(struct sk_buff *skb, void *location),
+
+	TP_ARGS(skb, location),
+
+	TP_STRUCT__entry(
+		__field(	void *,	skbaddr)
+		__field(	void *,	location)
+	),
+
+	TP_fast_assign(
+		__entry->skbaddr = skb;
+		__entry->location = location;
+	),
+
+	TP_printk("skbaddr=%p location=%pS", __entry->skbaddr, __entry->location)
+);
+
+TRACE_EVENT(skb_copy_datagram_iovec,
+
+	TP_PROTO(const struct sk_buff *skb, int len),
+
+	TP_ARGS(skb, len),
+
+	TP_STRUCT__entry(
+		__field(	const void *,		skbaddr		)
+		__field(	int,			len		)
+	),
+
+	TP_fast_assign(
+		__entry->skbaddr = skb;
+		__entry->len = len;
+	),
+
+	TP_printk("skbaddr=%p len=%d", __entry->skbaddr, __entry->len)
+);
+
+#endif /* _TRACE_SKB_H */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>