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, 74 insertions, 0 deletions

diff --git a/net/rxrpc/skbuff.c b/net/rxrpc/skbuff.c
new file mode 100644
index 000000000..e2169d1a1
--- /dev/null
+++ b/net/rxrpc/skbuff.c
@@ -0,0 +1,74 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* Socket buffer accounting
+ *
+ * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/net.h>
+#include <linux/skbuff.h>
+#include <net/sock.h>
+#include <net/af_rxrpc.h>
+#include "ar-internal.h"
+
+#define select_skb_count(skb) (&rxrpc_n_rx_skbs)
+
+/*
+ * Note the allocation or reception of a socket buffer.
+ */
+void rxrpc_new_skb(struct sk_buff *skb, enum rxrpc_skb_trace why)
+{
+	int n = atomic_inc_return(select_skb_count(skb));
+	trace_rxrpc_skb(skb, refcount_read(&skb->users), n, why);
+}
+
+/*
+ * Note the re-emergence of a socket buffer from a queue or buffer.
+ */
+void rxrpc_see_skb(struct sk_buff *skb, enum rxrpc_skb_trace why)
+{
+	if (skb) {
+		int n = atomic_read(select_skb_count(skb));
+		trace_rxrpc_skb(skb, refcount_read(&skb->users), n, why);
+	}
+}
+
+/*
+ * Note the addition of a ref on a socket buffer.
+ */
+void rxrpc_get_skb(struct sk_buff *skb, enum rxrpc_skb_trace why)
+{
+	int n = atomic_inc_return(select_skb_count(skb));
+	trace_rxrpc_skb(skb, refcount_read(&skb->users), n, why);
+	skb_get(skb);
+}
+
+/*
+ * Note the destruction of a socket buffer.
+ */
+void rxrpc_free_skb(struct sk_buff *skb, enum rxrpc_skb_trace why)
+{
+	if (skb) {
+		int n = atomic_dec_return(select_skb_count(skb));
+		trace_rxrpc_skb(skb, refcount_read(&skb->users), n, why);
+		consume_skb(skb);
+	}
+}
+
+/*
+ * Clear a queue of socket buffers.
+ */
+void rxrpc_purge_queue(struct sk_buff_head *list)
+{
+	struct sk_buff *skb;
+
+	while ((skb = skb_dequeue((list))) != NULL) {
+		int n = atomic_dec_return(select_skb_count(skb));
+		trace_rxrpc_skb(skb, refcount_read(&skb->users), n,
+				rxrpc_skb_put_purge);
+		consume_skb(skb);
+	}
+}