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/net/packet/internal.h b/net/packet/internal.h
new file mode 100644
index 000000000..b76e645cd
--- /dev/null
+++ b/net/packet/internal.h
@@ -0,0 +1,159 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __PACKET_INTERNAL_H__
+#define __PACKET_INTERNAL_H__
+
+#include <linux/refcount.h>
+
+struct packet_mclist {
+	struct packet_mclist	*next;
+	int			ifindex;
+	int			count;
+	unsigned short		type;
+	unsigned short		alen;
+	unsigned char		addr[MAX_ADDR_LEN];
+	struct list_head	remove_list;
+};
+
+/* kbdq - kernel block descriptor queue */
+struct tpacket_kbdq_core {
+	struct pgv	*pkbdq;
+	unsigned int	feature_req_word;
+	unsigned int	hdrlen;
+	unsigned char	reset_pending_on_curr_blk;
+	unsigned short	kactive_blk_num;
+	unsigned short	blk_sizeof_priv;
+
+	unsigned short  version;
+
+	char		*pkblk_start;
+	char		*pkblk_end;
+	int		kblk_size;
+	unsigned int	max_frame_len;
+	unsigned int	knum_blocks;
+	uint64_t	knxt_seq_num;
+	char		*prev;
+	char		*nxt_offset;
+
+	struct sk_buff	*skb;
+
+	rwlock_t	blk_fill_in_prog_lock;
+
+	/* Default is set to 8ms */
+#define DEFAULT_PRB_RETIRE_TOV	(8)
+
+	ktime_t		interval_ktime;
+
+	/* timer to retire an outstanding block */
+	struct hrtimer  retire_blk_timer;
+};
+
+struct pgv {
+	char *buffer;
+};
+
+struct packet_ring_buffer {
+	struct pgv		*pg_vec;
+
+	unsigned int		head;
+	unsigned int		frames_per_block;
+	unsigned int		frame_size;
+	unsigned int		frame_max;
+
+	unsigned int		pg_vec_order;
+	unsigned int		pg_vec_pages;
+	unsigned int		pg_vec_len;
+
+	unsigned int __percpu	*pending_refcnt;
+
+	union {
+		unsigned long			*rx_owner_map;
+		struct tpacket_kbdq_core	prb_bdqc;
+	};
+};
+
+extern struct mutex fanout_mutex;
+#define PACKET_FANOUT_MAX	(1 << 16)
+
+struct packet_fanout {
+	possible_net_t		net;
+	unsigned int		num_members;
+	u32			max_num_members;
+	u16			id;
+	u8			type;
+	u8			flags;
+	union {
+		atomic_t		rr_cur;
+		struct bpf_prog __rcu	*bpf_prog;
+	};
+	struct list_head	list;
+	spinlock_t		lock;
+	refcount_t		sk_ref;
+	struct packet_type	prot_hook ____cacheline_aligned_in_smp;
+	struct sock	__rcu	*arr[] __counted_by(max_num_members);
+};
+
+struct packet_rollover {
+	int			sock;
+	atomic_long_t		num;
+	atomic_long_t		num_huge;
+	atomic_long_t		num_failed;
+#define ROLLOVER_HLEN	(L1_CACHE_BYTES / sizeof(u32))
+	u32			history[ROLLOVER_HLEN] ____cacheline_aligned;
+} ____cacheline_aligned_in_smp;
+
+struct packet_sock {
+	/* struct sock has to be the first member of packet_sock */
+	struct sock		sk;
+	struct packet_fanout	*fanout;
+	union  tpacket_stats_u	stats;
+	struct packet_ring_buffer	rx_ring;
+	struct packet_ring_buffer	tx_ring;
+	int			copy_thresh;
+	spinlock_t		bind_lock;
+	struct mutex		pg_vec_lock;
+	unsigned long		flags;
+	int			ifindex;	/* bound device		*/
+	u8			vnet_hdr_sz;
+	__be16			num;
+	struct packet_rollover	*rollover;
+	struct packet_mclist	*mclist;
+	atomic_long_t		mapped;
+	enum tpacket_versions	tp_version;
+	unsigned int		tp_hdrlen;
+	unsigned int		tp_reserve;
+	unsigned int		tp_tstamp;
+	struct completion	skb_completion;
+	struct net_device __rcu	*cached_dev;
+	struct packet_type	prot_hook ____cacheline_aligned_in_smp;
+	atomic_t		tp_drops ____cacheline_aligned_in_smp;
+};
+
+#define pkt_sk(ptr) container_of_const(ptr, struct packet_sock, sk)
+
+enum packet_sock_flags {
+	PACKET_SOCK_ORIGDEV,
+	PACKET_SOCK_AUXDATA,
+	PACKET_SOCK_TX_HAS_OFF,
+	PACKET_SOCK_TP_LOSS,
+	PACKET_SOCK_RUNNING,
+	PACKET_SOCK_PRESSURE,
+	PACKET_SOCK_QDISC_BYPASS,
+};
+
+static inline void packet_sock_flag_set(struct packet_sock *po,
+					enum packet_sock_flags flag,
+					bool val)
+{
+	if (val)
+		set_bit(flag, &po->flags);
+	else
+		clear_bit(flag, &po->flags);
+}
+
+static inline bool packet_sock_flag(const struct packet_sock *po,
+				    enum packet_sock_flags flag)
+{
+	return test_bit(flag, &po->flags);
+}
+
+#endif