# CVE-2024-50100: USB: gadget: dummy-hcd: Fix "task hung" problem

> A logic error in the Linux kernel's dummy-hcd USB driver causes tasks to hang, leading to a denial of service.

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 5 Nov 2024
- **Updated:** 11 May 2026
- **Also known as:** BELL-CVE-2024-50100, DEBIAN-CVE-2024-50100, GHSA-66q2-ffpq-62mp, UBUNTU-CVE-2024-50100

## What is CVE-2024-50100?

CVE-2024-50100 is a medium-severity denial of service vulnerability in Linux kernel, published on 5 Nov 2024. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

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

USB: gadget: dummy-hcd: Fix "task hung" problem

The syzbot fuzzer has been encountering "task hung" problems ever
since the dummy-hcd driver was changed to use hrtimers instead of
regular timers.  It turns out that the problems are caused by a subtle
difference between the timer_pending() and hrtimer_active() APIs.

The changeover blindly replaced the first by the second.  However,
timer_pending() returns True when the timer is queued but not when its
callback is running, whereas hrtimer_active() returns True when the
hrtimer is queued _or_ its callback is running.  This difference
occasionally caused dummy_urb_enqueue() to think that the callback
routine had not yet started when in fact it was almost finished.  As a
result the hrtimer was not restarted, which made it impossible for the
driver to dequeue later the URB that was just enqueued.  This caused
usb_kill_urb() to hang, and things got worse from there.

Since hrtimers have no API for telling when they are queued and the
callback isn't running, the driver must keep track of this for itself.
That's what this patch does, adding a new "timer_pending" flag and
setting or clearing it at the appropriate times.

## Which versions are affected by CVE-2024-50100?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2024-50100?

Apply the vendor's patch.

## Is CVE-2024-50100 being exploited?

There is no known exploitation of CVE-2024-50100 in the wild and no public exploit code.

## Other vulnerabilities in Linux kernel

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2024-50100 and fix it if it is affected.

What it is: CVE-2024-50100 is a medium-severity denial of service vulnerability in Linux kernel, published on 5 Nov 2024. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2024-50100 in the wild and no public exploit code.

Affected product: Linux kernel. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2024-50100/ (Markdown: https://insights.sbomify.com/CVE-2024-50100/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-50100
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-50100
- OSV: https://osv.dev/vulnerability/CVE-2024-50100

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-50100/
Summaries are generated and may contain mistakes; the official description above is the record.