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, 22 insertions, 0 deletions

diff --git a/arch/powerpc/tools/checkpatch.sh b/arch/powerpc/tools/checkpatch.sh
new file mode 100755
index 000000000..91c04802e
--- /dev/null
+++ b/arch/powerpc/tools/checkpatch.sh
@@ -0,0 +1,22 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0+
+# Copyright 2018, Michael Ellerman, IBM Corporation.
+#
+# Wrapper around checkpatch that uses our preferred settings
+
+script_base=$(realpath $(dirname $0))
+
+exec $script_base/../../../scripts/checkpatch.pl \
+	--subjective \
+	--no-summary \
+	--show-types \
+	--ignore ARCH_INCLUDE_LINUX \
+	--ignore BIT_MACRO \
+	--ignore COMPARISON_TO_NULL \
+	--ignore EMAIL_SUBJECT \
+	--ignore FILE_PATH_CHANGES \
+	--ignore GLOBAL_INITIALISERS \
+	--ignore LINE_SPACING \
+	--ignore MULTIPLE_ASSIGNMENTS \
+	--ignore DT_SPLIT_BINDING_PATCH \
+	$@