---
id: CVE-2026-98769
title: 'usb: gadget: f_uac1_legacy: validate bRequest index in generic_{set,get}_cmd'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  usb: gadget: f_uac1_legacy: validate bRequest index in generic_{set,get}_cmd

  generic_set_cmd() and generic_get_cmd() use the low nibble of
  ctrl->bRequest as an index i…
severity: none
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= c47d7b09891abb4f8b222317c89c7469bed8db3a <
    36f3f009049bc91e14dc856007932473318d12f8
  - >-
    Linux >= c47d7b09891abb4f8b222317c89c7469bed8db3a <
    8c611876c002d712ae5f246af5188432c708f79d
  - >-
    Linux >= c47d7b09891abb4f8b222317c89c7469bed8db3a <
    697cfe6e53b66cda196d6f8833b0ee97fefd0a8a
  - >-
    Linux >= c47d7b09891abb4f8b222317c89c7469bed8db3a <
    9062d50e75c24dc7911be05c9b1719b3b256af15
  - Linux 2.6.31
published: '2026-10-18'
updated: '2026-10-18'
sourceUpdated: '2026-10-18T15:48:04.800Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-98769'
references:
  - url: 'https://git.kernel.org/stable/c/36f3f009049bc91e14dc856007932473318d12f8'
  - url: 'https://git.kernel.org/stable/c/8c611876c002d712ae5f246af5188432c708f79d'
  - url: 'https://git.kernel.org/stable/c/697cfe6e53b66cda196d6f8833b0ee97fefd0a8a'
  - url: 'https://git.kernel.org/stable/c/9062d50e75c24dc7911be05c9b1719b3b256af15'
tags:
  - cve.org
ingestedAt: '2026-10-18T16:47:32.493Z'
---

## Overview

In the Linux kernel, the following vulnerability has been resolved:

usb: gadget: f_uac1_legacy: validate bRequest index in generic_{set,get}_cmd

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.

## Affected

- `Linux >= c47d7b09891abb4f8b222317c89c7469bed8db3a < 36f3f009049bc91e14dc856007932473318d12f8`
- `Linux >= c47d7b09891abb4f8b222317c89c7469bed8db3a < 8c611876c002d712ae5f246af5188432c708f79d`
- `Linux >= c47d7b09891abb4f8b222317c89c7469bed8db3a < 697cfe6e53b66cda196d6f8833b0ee97fefd0a8a`
- `Linux >= c47d7b09891abb4f8b222317c89c7469bed8db3a < 9062d50e75c24dc7911be05c9b1719b3b256af15`
- `Linux 2.6.31`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.