# CVE-2023-54277: fbdev: udlfb: Fix endpoint check

> A missing endpoint type check in the udlfb driver allows a malicious USB device to trigger a kernel warning and potential denial of service.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 30 Dec 2025
- **Updated:** 23 May 2026
- **Also known as:** BELL-CVE-2023-54277, DEBIAN-CVE-2023-54277, GHSA-gqhr-h84m-5956, UBUNTU-CVE-2023-54277

## What is CVE-2023-54277?

CVE-2023-54277 is a denial of service vulnerability in Linux, published on 30 Dec 2025. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

### Official description

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

fbdev: udlfb: Fix endpoint check

The syzbot fuzzer detected a problem in the udlfb driver, caused by an
endpoint not having the expected type:

usb 1-1: Read EDID byte 0 failed: -71
usb 1-1: Unable to get valid EDID from device/display
------------[ cut here ]------------
usb 1-1: BOGUS urb xfer, pipe 3 != type 1
WARNING: CPU: 0 PID: 9 at drivers/usb/core/urb.c:504 usb_submit_urb+0xed6/0x1880
drivers/usb/core/urb.c:504
Modules linked in:
CPU: 0 PID: 9 Comm: kworker/0:1 Not tainted
6.4.0-rc1-syzkaller-00016-ga4422ff22142 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google
04/28/2023
Workqueue: usb_hub_wq hub_event
RIP: 0010:usb_submit_urb+0xed6/0x1880 drivers/usb/core/urb.c:504
...
Call Trace:
 <TASK>
 dlfb_submit_urb+0x92/0x180 drivers/video/fbdev/udlfb.c:1980
 dlfb_set_video_mode+0x21f0/0x2950 drivers/video/fbdev/udlfb.c:315
 dlfb_ops_set_par+0x2a7/0x8d0 drivers/video/fbdev/udlfb.c:1111
 dlfb_usb_probe+0x149a/0x2710 drivers/video/fbdev/udlfb.c:1743

The current approach for this issue failed to catch the problem
because it only checks for the existence of a bulk-OUT endpoint; it
doesn't check whether this endpoint is the one that the driver will
actually use.

We can fix the problem by instead checking that the endpoint used by
the driver does exist and is bulk-OUT.

## Which versions are affected by CVE-2023-54277?


## How do I fix CVE-2023-54277?

Apply the vendor's patch.

## Is CVE-2023-54277 being exploited?

There is no known exploitation of CVE-2023-54277 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-54277 and fix it if it is affected.

What it is: CVE-2023-54277 is a denial of service vulnerability in Linux, published on 30 Dec 2025. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2023-54277 in the wild and no public exploit code.

Affected product: Linux. 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-2023-54277/ (Markdown: https://insights.sbomify.com/CVE-2023-54277/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-54277
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-54277
- OSV: https://osv.dev/vulnerability/CVE-2023-54277

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-54277/
Summaries are generated and may contain mistakes; the official description above is the record.