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, 49 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/pps/pps-gpio.yaml b/Documentation/devicetree/bindings/pps/pps-gpio.yaml
new file mode 100644
index 000000000..383a83874
--- /dev/null
+++ b/Documentation/devicetree/bindings/pps/pps-gpio.yaml
@@ -0,0 +1,49 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/pps/pps-gpio.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: PPS Signal via GPIO
+
+maintainers:
+  - Fabio Estevam <festevam@gmail.com>
+
+properties:
+  compatible:
+    const: pps-gpio
+
+  gpios:
+    description: The GPIO that provides the PPS signal.
+    maxItems: 1
+
+  echo-gpios:
+    description: The GPIO that provides the PPS ECHO signal.
+    maxItems: 1
+
+  echo-active-ms:
+    description: Duration in ms of the active portion of the echo pulse.
+
+  assert-falling-edge:
+    description: Indicates a falling edge assert, when present. Rising edge if absent.
+    type: boolean
+
+required:
+  - compatible
+  - gpios
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/gpio/gpio.h>
+
+    pps {
+        compatible = "pps-gpio";
+        pinctrl-names = "default";
+        pinctrl-0 = <&pinctrl_pps>;
+        gpios = <&gpio1 26 GPIO_ACTIVE_HIGH>;
+        assert-falling-edge;
+        echo-gpios = <&gpio1 27 GPIO_ACTIVE_HIGH>;
+        echo-active-ms = <100>;
+    };