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, 62 insertions, 0 deletions

diff --git a/include/crypto/mldsa.h b/include/crypto/mldsa.h
new file mode 100644
index 000000000..3ef267678
--- /dev/null
+++ b/include/crypto/mldsa.h
@@ -0,0 +1,62 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Support for verifying ML-DSA signatures
+ *
+ * Copyright 2025 Google LLC
+ */
+#ifndef _CRYPTO_MLDSA_H
+#define _CRYPTO_MLDSA_H
+
+#include <linux/types.h>
+
+/* Identifier for an ML-DSA parameter set */
+enum mldsa_alg {
+	MLDSA44, /* ML-DSA-44 */
+	MLDSA65, /* ML-DSA-65 */
+	MLDSA87, /* ML-DSA-87 */
+};
+
+/* Lengths of ML-DSA public keys and signatures in bytes */
+#define MLDSA44_PUBLIC_KEY_SIZE 1312
+#define MLDSA65_PUBLIC_KEY_SIZE 1952
+#define MLDSA87_PUBLIC_KEY_SIZE 2592
+#define MLDSA44_SIGNATURE_SIZE 2420
+#define MLDSA65_SIGNATURE_SIZE 3309
+#define MLDSA87_SIGNATURE_SIZE 4627
+
+/**
+ * mldsa_verify() - Verify an ML-DSA signature
+ * @alg: The ML-DSA parameter set to use
+ * @sig: The signature
+ * @sig_len: Length of the signature in bytes.  Should match the
+ *	     MLDSA*_SIGNATURE_SIZE constant associated with @alg,
+ *	     otherwise -EBADMSG will be returned.
+ * @msg: The message
+ * @msg_len: Length of the message in bytes
+ * @pk: The public key
+ * @pk_len: Length of the public key in bytes.  Should match the
+ *	    MLDSA*_PUBLIC_KEY_SIZE constant associated with @alg,
+ *	    otherwise -EBADMSG will be returned.
+ *
+ * This verifies a signature using pure ML-DSA with the specified parameter set.
+ * The context string is assumed to be empty.  This corresponds to FIPS 204
+ * Algorithm 3 "ML-DSA.Verify" with the ctx parameter set to the empty string
+ * and the lengths of the signature and key given explicitly by the caller.
+ *
+ * Context: Might sleep
+ *
+ * Return:
+ * * 0 if the signature is valid
+ * * -EBADMSG if the signature and/or public key is malformed
+ * * -EKEYREJECTED if the signature is invalid but otherwise well-formed
+ * * -ENOMEM if out of memory so the validity of the signature is unknown
+ */
+int mldsa_verify(enum mldsa_alg alg, const u8 *sig, size_t sig_len,
+		 const u8 *msg, size_t msg_len, const u8 *pk, size_t pk_len);
+
+#if IS_ENABLED(CONFIG_CRYPTO_LIB_MLDSA_KUNIT_TEST)
+/* Internal function, exposed only for unit testing */
+s32 mldsa_use_hint(u8 h, s32 r, s32 gamma2);
+#endif
+
+#endif /* _CRYPTO_MLDSA_H */