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, 59 insertions, 0 deletions

diff --git a/drivers/net/wireguard/cookie.h b/drivers/net/wireguard/cookie.h
new file mode 100644
index 000000000..c4bd61ca0
--- /dev/null
+++ b/drivers/net/wireguard/cookie.h
@@ -0,0 +1,59 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2015-2019 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
+ */
+
+#ifndef _WG_COOKIE_H
+#define _WG_COOKIE_H
+
+#include "messages.h"
+#include <linux/rwsem.h>
+
+struct wg_peer;
+
+struct cookie_checker {
+	u8 secret[NOISE_HASH_LEN];
+	u8 cookie_encryption_key[NOISE_SYMMETRIC_KEY_LEN];
+	u8 message_mac1_key[NOISE_SYMMETRIC_KEY_LEN];
+	u64 secret_birthdate;
+	struct rw_semaphore secret_lock;
+	struct wg_device *device;
+};
+
+struct cookie {
+	u64 birthdate;
+	bool is_valid;
+	u8 cookie[COOKIE_LEN];
+	bool have_sent_mac1;
+	u8 last_mac1_sent[COOKIE_LEN];
+	u8 cookie_decryption_key[NOISE_SYMMETRIC_KEY_LEN];
+	u8 message_mac1_key[NOISE_SYMMETRIC_KEY_LEN];
+	struct rw_semaphore lock;
+};
+
+enum cookie_mac_state {
+	INVALID_MAC,
+	VALID_MAC_BUT_NO_COOKIE,
+	VALID_MAC_WITH_COOKIE_BUT_RATELIMITED,
+	VALID_MAC_WITH_COOKIE
+};
+
+void wg_cookie_checker_init(struct cookie_checker *checker,
+			    struct wg_device *wg);
+void wg_cookie_checker_precompute_device_keys(struct cookie_checker *checker);
+void wg_cookie_checker_precompute_peer_keys(struct wg_peer *peer);
+void wg_cookie_init(struct cookie *cookie);
+
+enum cookie_mac_state wg_cookie_validate_packet(struct cookie_checker *checker,
+						struct sk_buff *skb,
+						bool check_cookie);
+void wg_cookie_add_mac_to_packet(void *message, size_t len,
+				 struct wg_peer *peer);
+
+void wg_cookie_message_create(struct message_handshake_cookie *src,
+			      struct sk_buff *skb, __le32 index,
+			      struct cookie_checker *checker);
+void wg_cookie_message_consume(struct message_handshake_cookie *src,
+			       struct wg_device *wg);
+
+#endif /* _WG_COOKIE_H */