# CVE-2023-53777: erofs: kill hooked chains to avoid loops on deduplicated compressed images

> A race condition in the Linux kernel EROFS filesystem can cause a deadlock and denial of service when processing specific deduplicated compressed images.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 9 Dec 2025
- **Updated:** 11 May 2026
- **Also known as:** BELL-CVE-2023-53777, DEBIAN-CVE-2023-53777, GHSA-v9mq-q8m3-5r3r, UBUNTU-CVE-2023-53777

## What is CVE-2023-53777?

CVE-2023-53777 is a denial of service vulnerability in Linux, published on 9 Dec 2025. 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:

erofs: kill hooked chains to avoid loops on deduplicated compressed images

After heavily stressing EROFS with several images which include a
hand-crafted image of repeated patterns for more than 46 days, I found
two chains could be linked with each other almost simultaneously and
form a loop so that the entire loop won't be submitted.  As a
consequence, the corresponding file pages will remain locked forever.

It can be _only_ observed on data-deduplicated compressed images.
For example, consider two chains with five pclusters in total:
	Chain 1:  2->3->4->5    -- The tail pcluster is 5;
        Chain 2:  5->1->2       -- The tail pcluster is 2.

Chain 2 could link to Chain 1 with pcluster 5; and Chain 1 could link
to Chain 2 at the same time with pcluster 2.

Since hooked chains are all linked locklessly now, I have no idea how
to simply avoid the race.  Instead, let's avoid hooked chains completely
until I could work out a proper way to fix this and end users finally
tell us that it's needed to add it back.

Actually, this optimization can be found with multi-threaded workloads
(especially even more often on deduplicated compressed images), yet I'm
not sure about the overall system impacts of not having this compared
with implementation complexity.

## Which versions are affected by CVE-2023-53777?


## How do I fix CVE-2023-53777?

Apply the vendor's patch.

## Is CVE-2023-53777 being exploited?

There is no known exploitation of CVE-2023-53777 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-53777 and fix it if it is affected.

What it is: CVE-2023-53777 is a denial of service vulnerability in Linux, published on 9 Dec 2025. 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-2023-53777 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-2023-53777/ (Markdown: https://insights.sbomify.com/CVE-2023-53777/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-53777
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-53777
- OSV: https://osv.dev/vulnerability/CVE-2023-53777

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-53777/
Summaries are generated and may contain mistakes; the official description above is the record.