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, 63 insertions, 0 deletions

diff --git a/include/net/llc_if.h b/include/net/llc_if.h
new file mode 100644
index 000000000..a33325961
--- /dev/null
+++ b/include/net/llc_if.h
@@ -0,0 +1,63 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef LLC_IF_H
+#define LLC_IF_H
+/*
+ * Copyright (c) 1997 by Procom Technology,Inc.
+ * 		 2001 by Arnaldo Carvalho de Melo <acme@conectiva.com.br>
+ */
+/* Defines LLC interface to network layer */
+/* Available primitives */
+#include <linux/if.h>
+#include <linux/if_arp.h>
+#include <linux/llc.h>
+#include <linux/etherdevice.h>
+#include <net/llc.h>
+
+#define LLC_DATAUNIT_PRIM	1
+#define LLC_CONN_PRIM		2
+#define LLC_DATA_PRIM		3
+#define LLC_DISC_PRIM		4
+#define LLC_RESET_PRIM		5
+#define LLC_FLOWCONTROL_PRIM	6 /* Not supported at this time */
+#define LLC_DISABLE_PRIM	7
+#define LLC_XID_PRIM		8
+#define LLC_TEST_PRIM		9
+#define LLC_SAP_ACTIVATION     10
+#define LLC_SAP_DEACTIVATION   11
+
+#define LLC_NBR_PRIMITIVES     11
+
+#define LLC_IND			1
+#define LLC_CONFIRM		2
+
+/* Primitive type */
+#define LLC_PRIM_TYPE_REQ	1
+#define LLC_PRIM_TYPE_IND	2
+#define LLC_PRIM_TYPE_RESP	3
+#define LLC_PRIM_TYPE_CONFIRM	4
+
+/* Reset reasons, remote entity or local LLC */
+#define LLC_RESET_REASON_REMOTE	1
+#define LLC_RESET_REASON_LOCAL	2
+
+/* Disconnect reasons */
+#define LLC_DISC_REASON_RX_DM_RSP_PDU	0
+#define LLC_DISC_REASON_RX_DISC_CMD_PDU	1
+#define LLC_DISC_REASON_ACK_TMR_EXP	2
+
+/* Confirm reasons */
+#define LLC_STATUS_CONN		0 /* connect confirm & reset confirm */
+#define LLC_STATUS_DISC		1 /* connect confirm & reset confirm */
+#define LLC_STATUS_FAILED	2 /* connect confirm & reset confirm */
+#define LLC_STATUS_IMPOSSIBLE	3 /* connect confirm */
+#define LLC_STATUS_RECEIVED	4 /* data conn */
+#define LLC_STATUS_REMOTE_BUSY	5 /* data conn */
+#define LLC_STATUS_REFUSE	6 /* data conn */
+#define LLC_STATUS_CONFLICT	7 /* disconnect conn */
+#define LLC_STATUS_RESET_DONE	8 /*  */
+
+int llc_establish_connection(struct sock *sk, const u8 *lmac, u8 *dmac,
+			     u8 dsap);
+int llc_build_and_send_pkt(struct sock *sk, struct sk_buff *skb);
+int llc_send_disc(struct sock *sk);
+#endif /* LLC_IF_H */