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, 50 insertions, 0 deletions

diff --git a/include/crypto/xts.h b/include/crypto/xts.h
new file mode 100644
index 000000000..16aef89f0
--- /dev/null
+++ b/include/crypto/xts.h
@@ -0,0 +1,50 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _CRYPTO_XTS_H
+#define _CRYPTO_XTS_H
+
+#include <crypto/b128ops.h>
+#include <crypto/internal/skcipher.h>
+#include <linux/fips.h>
+
+#define XTS_BLOCK_SIZE 16
+#define XTS_FORBID_WEAK_KEYS (1 << 0)
+
+static inline int __xts_verify_key(const u8 *key, size_t keylen, int flags)
+{
+	/*
+	 * key consists of keys of equal size concatenated, therefore
+	 * the length must be even.
+	 */
+	if (keylen % 2)
+		return -EINVAL;
+
+	/*
+	 * In FIPS mode only a combined key length of either 256 or
+	 * 512 bits is allowed, c.f. FIPS 140-3 IG C.I.
+	 */
+	if (fips_enabled && keylen != 32 && keylen != 64)
+		return -EINVAL;
+
+	/*
+	 * Ensure that the AES and tweak key are not identical when
+	 * in FIPS mode or the FORBID_WEAK_KEYS flag is set.
+	 */
+	if ((fips_enabled || (flags & XTS_FORBID_WEAK_KEYS)) &&
+	    !crypto_memneq(key, key + (keylen / 2), keylen / 2))
+		return -EINVAL;
+
+	return 0;
+}
+
+static inline int xts_verify_key(struct crypto_skcipher *tfm, const u8 *key,
+				 unsigned int keylen)
+{
+	int flags = (crypto_skcipher_get_flags(tfm) &
+		     CRYPTO_TFM_REQ_FORBID_WEAK_KEYS) ?
+			    XTS_FORBID_WEAK_KEYS :
+			    0;
+
+	return __xts_verify_key(key, keylen, flags);
+}
+
+#endif  /* _CRYPTO_XTS_H */