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, 28 insertions, 0 deletions

diff --git a/include/crypto/serpent.h b/include/crypto/serpent.h
new file mode 100644
index 000000000..75c7eaa20
--- /dev/null
+++ b/include/crypto/serpent.h
@@ -0,0 +1,28 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Common values for serpent algorithms
+ */
+
+#ifndef _CRYPTO_SERPENT_H
+#define _CRYPTO_SERPENT_H
+
+#include <linux/types.h>
+#include <linux/crypto.h>
+
+#define SERPENT_MIN_KEY_SIZE		  0
+#define SERPENT_MAX_KEY_SIZE		 32
+#define SERPENT_EXPKEY_WORDS		132
+#define SERPENT_BLOCK_SIZE		 16
+
+struct serpent_ctx {
+	u32 expkey[SERPENT_EXPKEY_WORDS];
+};
+
+int __serpent_setkey(struct serpent_ctx *ctx, const u8 *key,
+		     unsigned int keylen);
+int serpent_setkey(struct crypto_tfm *tfm, const u8 *key, unsigned int keylen);
+
+void __serpent_encrypt(const void *ctx, u8 *dst, const u8 *src);
+void __serpent_decrypt(const void *ctx, u8 *dst, const u8 *src);
+
+#endif