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, 69 insertions, 0 deletions

diff --git a/scripts/crypto/gen-aead-testvecs.py b/scripts/crypto/gen-aead-testvecs.py
new file mode 100755
index 000000000..d77d646f7
--- /dev/null
+++ b/scripts/crypto/gen-aead-testvecs.py
@@ -0,0 +1,69 @@
+#!/usr/bin/env python3
+# SPDX-License-Identifier: GPL-2.0-or-later
+#
+# Script that generates known-good data used in the AEAD tests.
+#
+# Requires that python-cryptography be installed.
+#
+# Copyright 2026 Google LLC
+
+import hashlib
+import sys
+import cryptography.hazmat.primitives.ciphers.aead
+
+
+# Deterministically generate 'length' random bytes.
+def rand_bytes(length):
+    seed = length
+    out = []
+    for _ in range(length):
+        seed = (seed * 25214903917 + 11) % 2**48
+        out.append((seed >> 16) % 256)
+    return bytes(out)
+
+
+# Deterministically generate many different AEAD inputs using exactly the same
+# method that the test uses; encrypt them using an independent implementation of
+# the algorithm; compute the checksum of all the resulting (ciphertext, authtag)
+# pairs concatenated to each other; and print the checksum as a C struct.
+def gen_monte_carlo_checksum(alg):
+    blake2s = hashlib.blake2s()
+    for data_len in range(1025):
+        ad_len = data_len % 293
+        pt = rand_bytes(data_len)
+        ad = rand_bytes(ad_len)
+        if alg == "aes-ccm":
+            key_len = [16, 24, 32][data_len % 3]
+            key = rand_bytes(key_len)
+            nonce = rand_bytes([7, 8, 9, 10, 11, 12, 13][data_len % 7])
+            tag_len = [4, 6, 8, 10, 12, 14, 16][data_len % 7]
+            ccm = cryptography.hazmat.primitives.ciphers.aead.AESCCM(
+                key, tag_length=tag_len
+            )
+            ct_and_tag = ccm.encrypt(nonce, pt, ad)
+        elif alg == "aes-gcm":
+            key_len = [16, 24, 32][data_len % 3]
+            key = rand_bytes(key_len)
+            nonce = rand_bytes(12)
+            tag_len = [4, 8, 12, 13, 14, 15, 16][data_len % 7]
+            gcm = cryptography.hazmat.primitives.ciphers.aead.AESGCM(key)
+            # python-cryptography supports only 16-byte GCM tags.  However, in
+            # GCM, shorter tags are simply truncated.  Do that below.
+            ct_and_tag = gcm.encrypt(nonce, pt, ad)[: data_len + tag_len]
+
+        blake2s.update(ct_and_tag)
+
+    name = f"{alg.replace('-', '_')}_monte_carlo_checksum"
+    value = blake2s.digest()
+    print(f"static const u8 {name}[BLAKE2S_HASH_SIZE] = {{")
+    for i in range(0, len(value), 11):
+        line = "\t" + "".join(f"0x{b:02x}, " for b in value[i : i + 11])
+        print(f"{line.rstrip()}")
+    print("};")
+
+
+if len(sys.argv) != 2 or sys.argv[1] not in ("aes-ccm", "aes-gcm"):
+    sys.stderr.write("Usage: gen-aead-testvecs.py [aes-ccm|aes-gcm]\n")
+    sys.exit(1)
+
+gen_monte_carlo_checksum(sys.argv[1])