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, 159 insertions, 0 deletions

diff --git a/include/net/llc.h b/include/net/llc.h
new file mode 100644
index 000000000..029ba8a22
--- /dev/null
+++ b/include/net/llc.h
@@ -0,0 +1,159 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef LLC_H
+#define LLC_H
+/*
+ * Copyright (c) 1997 by Procom Technology, Inc.
+ * 		 2001-2003 by Arnaldo Carvalho de Melo <acme@conectiva.com.br>
+ */
+
+#include <linux/if.h>
+#include <linux/if_ether.h>
+#include <linux/list.h>
+#include <linux/spinlock.h>
+#include <linux/rculist_nulls.h>
+#include <linux/hash.h>
+#include <linux/jhash.h>
+
+#include <linux/atomic.h>
+
+struct net_device;
+struct packet_type;
+struct sk_buff;
+
+struct llc_addr {
+	unsigned char lsap;
+	unsigned char mac[IFHWADDRLEN];
+};
+
+#define LLC_SAP_STATE_INACTIVE	1
+#define LLC_SAP_STATE_ACTIVE	2
+
+#define LLC_SK_DEV_HASH_BITS 6
+#define LLC_SK_DEV_HASH_ENTRIES (1<<LLC_SK_DEV_HASH_BITS)
+
+#define LLC_SK_LADDR_HASH_BITS 6
+#define LLC_SK_LADDR_HASH_ENTRIES (1<<LLC_SK_LADDR_HASH_BITS)
+
+/**
+ * struct llc_sap - Defines the SAP component
+ *
+ * @station - station this sap belongs to
+ * @state - sap state
+ * @p_bit - only lowest-order bit used
+ * @f_bit - only lowest-order bit used
+ * @laddr - SAP value in this 'lsap'
+ * @node - entry in station sap_list
+ * @sk_list - LLC sockets this one manages
+ */
+struct llc_sap {
+	unsigned char	 state;
+	unsigned char	 p_bit;
+	unsigned char	 f_bit;
+	refcount_t		 refcnt;
+	int		 (*rcv_func)(struct sk_buff *skb,
+				     struct net_device *dev,
+				     struct packet_type *pt,
+				     struct net_device *orig_dev);
+	struct llc_addr	 laddr;
+	struct list_head node;
+	spinlock_t sk_lock;
+	int sk_count;
+	struct hlist_nulls_head sk_laddr_hash[LLC_SK_LADDR_HASH_ENTRIES];
+	struct hlist_head sk_dev_hash[LLC_SK_DEV_HASH_ENTRIES];
+	struct rcu_head rcu;
+};
+
+static inline
+struct hlist_head *llc_sk_dev_hash(struct llc_sap *sap, int ifindex)
+{
+	u32 bucket = hash_32(ifindex, LLC_SK_DEV_HASH_BITS);
+
+	return &sap->sk_dev_hash[bucket];
+}
+
+static inline
+u32 llc_sk_laddr_hashfn(struct llc_sap *sap, const struct llc_addr *laddr)
+{
+	return hash_32(jhash(laddr->mac, sizeof(laddr->mac), 0),
+		       LLC_SK_LADDR_HASH_BITS);
+}
+
+static inline
+struct hlist_nulls_head *llc_sk_laddr_hash(struct llc_sap *sap,
+					   const struct llc_addr *laddr)
+{
+	return &sap->sk_laddr_hash[llc_sk_laddr_hashfn(sap, laddr)];
+}
+
+#define LLC_DEST_INVALID         0      /* Invalid LLC PDU type */
+#define LLC_DEST_SAP             1      /* Type 1 goes here */
+#define LLC_DEST_CONN            2      /* Type 2 goes here */
+
+extern struct list_head llc_sap_list;
+
+int llc_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt,
+	    struct net_device *orig_dev);
+
+int llc_mac_hdr_init(struct sk_buff *skb, const unsigned char *sa,
+		     const unsigned char *da);
+
+void llc_add_pack(int type,
+		  void (*handler)(struct llc_sap *sap, struct sk_buff *skb));
+void llc_remove_pack(int type);
+
+void llc_set_station_handler(void (*handler)(struct sk_buff *skb));
+
+struct llc_sap *llc_sap_open(unsigned char lsap,
+			     int (*rcv)(struct sk_buff *skb,
+					struct net_device *dev,
+					struct packet_type *pt,
+					struct net_device *orig_dev));
+static inline void llc_sap_hold(struct llc_sap *sap)
+{
+	refcount_inc(&sap->refcnt);
+}
+
+static inline bool llc_sap_hold_safe(struct llc_sap *sap)
+{
+	return refcount_inc_not_zero(&sap->refcnt);
+}
+
+void llc_sap_close(struct llc_sap *sap);
+
+static inline void llc_sap_put(struct llc_sap *sap)
+{
+	if (refcount_dec_and_test(&sap->refcnt))
+		llc_sap_close(sap);
+}
+
+struct llc_sap *llc_sap_find(unsigned char sap_value);
+
+int llc_build_and_send_ui_pkt(struct llc_sap *sap, struct sk_buff *skb,
+			      const unsigned char *dmac, unsigned char dsap);
+
+void llc_sap_handler(struct llc_sap *sap, struct sk_buff *skb);
+void llc_conn_handler(struct llc_sap *sap, struct sk_buff *skb);
+
+void llc_station_init(void);
+void llc_station_exit(void);
+
+#ifdef CONFIG_PROC_FS
+int llc_proc_init(void);
+void llc_proc_exit(void);
+#else
+#define llc_proc_init()	(0)
+#define llc_proc_exit()	do { } while(0)
+#endif /* CONFIG_PROC_FS */
+#ifdef CONFIG_SYSCTL
+int llc_sysctl_init(void);
+void llc_sysctl_exit(void);
+
+extern int sysctl_llc2_ack_timeout;
+extern int sysctl_llc2_busy_timeout;
+extern int sysctl_llc2_p_timeout;
+extern int sysctl_llc2_rej_timeout;
+#else
+#define llc_sysctl_init() (0)
+#define llc_sysctl_exit() do { } while(0)
+#endif /* CONFIG_SYSCTL */
+#endif /* LLC_H */