usb: gadget: f_uac1_legacy: validate bRequest index in generic_{set,get}_cmdgrafted

generic_set_cmd() and generic_get_cmd() use the low nibble of
ctrl->bRequest as an index into con->data[]:

    u8 cmd = (ctrl->bRequest & 0x0F);  /* 0 .. 15 */
    ...
    con->data[cmd] = value;            /* OOB when cmd >= 5 */

struct usb_audio_control (include/linux/usb/audio.h) declares data as
a 5-element array, so indices 5 through 15 write (or read) up to 44
bytes past the end of the array on the heap.

A malicious USB host can craft a class-specific SET_CUR / GET_CUR
request with an arbitrary bRequest value, triggering the out-of-bounds
access from an IRQ completion handler with no further preconditions.

Add an ARRAY_SIZE() guard to both functions.

Fixes: c47d7b09891a ("USB: audio: add USB audio class definitions")
Cc: stable <stable@kernel.org>
Reviewed-by: Weibin Liu <liuwb@xiaopeng.com>
Signed-off-by: Liu Chao <liuc63@xiaopeng.com>
Reviewed-by: Ivy Lopez <skunkolee@gmail.com>
Link: https://patch.msgid.link/20260921072551.3708191-1-liuc63@xiaopeng.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 91 insertions, 0 deletions

diff --git a/crypto/cipher.c b/crypto/cipher.c
new file mode 100644
index 000000000..c9dab656a
--- /dev/null
+++ b/crypto/cipher.c
@@ -0,0 +1,91 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Cryptographic API.
+ *
+ * Single-block cipher operations.
+ *
+ * Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
+ * Copyright (c) 2005 Herbert Xu <herbert@gondor.apana.org.au>
+ */
+
+#include <crypto/algapi.h>
+#include <crypto/internal/cipher.h>
+#include <linux/kernel.h>
+#include <linux/crypto.h>
+#include <linux/errno.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include "internal.h"
+
+static int setkey_unaligned(struct crypto_cipher *tfm, const u8 *key,
+			    unsigned int keylen)
+{
+	struct cipher_alg *cia = crypto_cipher_alg(tfm);
+	unsigned long alignmask = crypto_cipher_alignmask(tfm);
+	int ret;
+	u8 *buffer, *alignbuffer;
+	unsigned long absize;
+
+	absize = keylen + alignmask;
+	buffer = kmalloc(absize, GFP_ATOMIC);
+	if (!buffer)
+		return -ENOMEM;
+
+	alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
+	memcpy(alignbuffer, key, keylen);
+	ret = cia->cia_setkey(crypto_cipher_tfm(tfm), alignbuffer, keylen);
+	kfree_sensitive(buffer);
+	return ret;
+
+}
+
+int crypto_cipher_setkey(struct crypto_cipher *tfm,
+			 const u8 *key, unsigned int keylen)
+{
+	struct cipher_alg *cia = crypto_cipher_alg(tfm);
+	unsigned long alignmask = crypto_cipher_alignmask(tfm);
+
+	if (keylen < cia->cia_min_keysize || keylen > cia->cia_max_keysize)
+		return -EINVAL;
+
+	if ((unsigned long)key & alignmask)
+		return setkey_unaligned(tfm, key, keylen);
+
+	return cia->cia_setkey(crypto_cipher_tfm(tfm), key, keylen);
+}
+EXPORT_SYMBOL_NS_GPL(crypto_cipher_setkey, "CRYPTO_INTERNAL");
+
+static inline void cipher_crypt_one(struct crypto_cipher *tfm,
+				    u8 *dst, const u8 *src, bool enc)
+{
+	unsigned long alignmask = crypto_cipher_alignmask(tfm);
+	struct cipher_alg *cia = crypto_cipher_alg(tfm);
+	void (*fn)(struct crypto_tfm *, u8 *, const u8 *) =
+		enc ? cia->cia_encrypt : cia->cia_decrypt;
+
+	if (unlikely(((unsigned long)dst | (unsigned long)src) & alignmask)) {
+		unsigned int bs = crypto_cipher_blocksize(tfm);
+		u8 buffer[MAX_CIPHER_BLOCKSIZE + MAX_CIPHER_ALIGNMASK];
+		u8 *tmp = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
+
+		memcpy(tmp, src, bs);
+		fn(crypto_cipher_tfm(tfm), tmp, tmp);
+		memcpy(dst, tmp, bs);
+	} else {
+		fn(crypto_cipher_tfm(tfm), dst, src);
+	}
+}
+
+void crypto_cipher_encrypt_one(struct crypto_cipher *tfm,
+			       u8 *dst, const u8 *src)
+{
+	cipher_crypt_one(tfm, dst, src, true);
+}
+EXPORT_SYMBOL_NS_GPL(crypto_cipher_encrypt_one, "CRYPTO_INTERNAL");
+
+void crypto_cipher_decrypt_one(struct crypto_cipher *tfm,
+			       u8 *dst, const u8 *src)
+{
+	cipher_crypt_one(tfm, dst, src, false);
+}
+EXPORT_SYMBOL_NS_GPL(crypto_cipher_decrypt_one, "CRYPTO_INTERNAL");