---
id: CVE-2026-98765
title: 'USB: gadget: dummy-hcd: Fix wait for outstanding request completions'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  USB: gadget: dummy-hcd: Fix wait for outstanding request completions

  The dummy-hcd driver emulates synchronize_irq() by waiting until its
  private callback_usage counte…
severity: none
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 7dbd8f4cabd96db5a50513de9d83a8105a5ffc81 <
    7ce4dca0d53b1c3cb2b7e7bb2e42bf5db860caf2
  - >-
    Linux >= 7dbd8f4cabd96db5a50513de9d83a8105a5ffc81 <
    5298c96bf0068f3160969f7ddad81976d01a9b66
  - >-
    Linux >= 7dbd8f4cabd96db5a50513de9d83a8105a5ffc81 <
    3070806a7bc7bb36ed04a21022c09dafcc5619f4
  - >-
    Linux >= 7dbd8f4cabd96db5a50513de9d83a8105a5ffc81 <
    b263ff9b0fc5c1f371d65c4eb196b31263d039ff
  - Linux 7b416b9dac6ede26d4ca0c1a88b448b543623ff3
  - Linux 8590bc1da625dd4a589eac0fc3aa3cf4f400424d
  - Linux a867d5b932ac4911d3f8a1e63505061b0c81f889
  - Linux e84b4a008365b7edbd842a063ae28d040a98db25
  - Linux e39b17143a5b5aac81f066d455e5d3a9877eb3ae
  - Linux 4f8ae1fcb0dfbb72a7678f81bf01fb7fc85c6715
  - Linux >= 3.2.97 < 3.3
  - Linux >= 3.16.52 < 3.17
  - Linux >= 4.1.46 < 4.2
  - Linux >= 4.4.92 < 4.5
  - Linux >= 4.9.55 < 4.10
  - Linux >= 4.13.6 < 4.14
  - Linux 4.14
published: '2026-10-18'
updated: '2026-10-18'
sourceUpdated: '2026-10-18T15:47:57.358Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-98765'
references:
  - url: 'https://git.kernel.org/stable/c/7ce4dca0d53b1c3cb2b7e7bb2e42bf5db860caf2'
  - url: 'https://git.kernel.org/stable/c/5298c96bf0068f3160969f7ddad81976d01a9b66'
  - url: 'https://git.kernel.org/stable/c/3070806a7bc7bb36ed04a21022c09dafcc5619f4'
  - url: 'https://git.kernel.org/stable/c/b263ff9b0fc5c1f371d65c4eb196b31263d039ff'
tags:
  - cve.org
ingestedAt: '2026-10-18T16:47:32.496Z'
---

## Overview

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

USB: gadget: dummy-hcd: Fix wait for outstanding request completions

The dummy-hcd driver emulates synchronize_irq() by waiting until its
private callback_usage counter drops to 0 (with the private lock not
held).  This counter is incremented whenever a gadget driver callback
occurs (which requires the private lock to be dropped), but not when a
request completion handler is called.

This is an oversight.  Request completion is triggered by timer
interrupts (emulating device IRQs in a real UDC), and the interrupt
handlers are supposed to have completed when the synchronize_irq()
emulation routine returns -- they aren't supposed to be in the middle
of a completion callback.  If this happens it can lead to a gadget
driver's unbind routine running before all outstanding request
completions have finished, maybe even allowing the gadget driver's
module to be unloaded while a completion handler is still running.

Fix the oversight by incrementing the callback_usage value across
request completion callbacks.

## Affected

- `Linux >= 7dbd8f4cabd96db5a50513de9d83a8105a5ffc81 < 7ce4dca0d53b1c3cb2b7e7bb2e42bf5db860caf2`
- `Linux >= 7dbd8f4cabd96db5a50513de9d83a8105a5ffc81 < 5298c96bf0068f3160969f7ddad81976d01a9b66`
- `Linux >= 7dbd8f4cabd96db5a50513de9d83a8105a5ffc81 < 3070806a7bc7bb36ed04a21022c09dafcc5619f4`
- `Linux >= 7dbd8f4cabd96db5a50513de9d83a8105a5ffc81 < b263ff9b0fc5c1f371d65c4eb196b31263d039ff`
- `Linux 7b416b9dac6ede26d4ca0c1a88b448b543623ff3`
- `Linux 8590bc1da625dd4a589eac0fc3aa3cf4f400424d`
- `Linux a867d5b932ac4911d3f8a1e63505061b0c81f889`
- `Linux e84b4a008365b7edbd842a063ae28d040a98db25`
- `Linux e39b17143a5b5aac81f066d455e5d3a9877eb3ae`
- `Linux 4f8ae1fcb0dfbb72a7678f81bf01fb7fc85c6715`
- `Linux >= 3.2.97 < 3.3`
- `Linux >= 3.16.52 < 3.17`
- `Linux >= 4.1.46 < 4.2`
- `Linux >= 4.4.92 < 4.5`
- `Linux >= 4.9.55 < 4.10`
- `Linux >= 4.13.6 < 4.14`
- `Linux 4.14`

## Remediation

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