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, 39 insertions, 0 deletions

diff --git a/include/crypto/pcrypt.h b/include/crypto/pcrypt.h
new file mode 100644
index 000000000..234d7cf3c
--- /dev/null
+++ b/include/crypto/pcrypt.h
@@ -0,0 +1,39 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * pcrypt - Parallel crypto engine.
+ *
+ * Copyright (C) 2009 secunet Security Networks AG
+ * Copyright (C) 2009 Steffen Klassert <steffen.klassert@secunet.com>
+ */
+
+#ifndef _CRYPTO_PCRYPT_H
+#define _CRYPTO_PCRYPT_H
+
+#include <linux/container_of.h>
+#include <linux/crypto.h>
+#include <linux/padata.h>
+
+struct pcrypt_request {
+	struct padata_priv	padata;
+	void			*data;
+	void			*__ctx[] CRYPTO_MINALIGN_ATTR;
+};
+
+static inline void *pcrypt_request_ctx(struct pcrypt_request *req)
+{
+	return req->__ctx;
+}
+
+static inline
+struct padata_priv *pcrypt_request_padata(struct pcrypt_request *req)
+{
+	return &req->padata;
+}
+
+static inline
+struct pcrypt_request *pcrypt_padata_request(struct padata_priv *padata)
+{
+	return container_of(padata, struct pcrypt_request, padata);
+}
+
+#endif