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, 27 insertions, 0 deletions

diff --git a/scripts/mkcompile_h b/scripts/mkcompile_h
new file mode 100755
index 000000000..2596f78e5
--- /dev/null
+++ b/scripts/mkcompile_h
@@ -0,0 +1,27 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+
+UTS_MACHINE=$1
+CC_VERSION="$2"
+LD=$3
+
+if test -z "$KBUILD_BUILD_USER"; then
+	LINUX_COMPILE_BY=$(whoami | sed 's/\\/\\\\/')
+else
+	LINUX_COMPILE_BY=$KBUILD_BUILD_USER
+fi
+if test -z "$KBUILD_BUILD_HOST"; then
+	LINUX_COMPILE_HOST=`uname -n`
+else
+	LINUX_COMPILE_HOST=$KBUILD_BUILD_HOST
+fi
+
+LD_VERSION=$(LC_ALL=C $LD -v | head -n1 |
+		sed -e 's/(compatible with [^)]*)//' -e 's/[[:space:]]*$//')
+
+cat <<EOF
+#define UTS_MACHINE		"${UTS_MACHINE}"
+#define LINUX_COMPILE_BY	"${LINUX_COMPILE_BY}"
+#define LINUX_COMPILE_HOST	"${LINUX_COMPILE_HOST}"
+#define LINUX_COMPILER		"${CC_VERSION}, ${LD_VERSION}"
+EOF