# CVE-2022-49408: ext4: fix memory leak in parse_apply_sb_mount_options()

> A memory leak in the Linux kernel ext4 filesystem allows attackers to cause denial of service by mounting a crafted filesystem.

- **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:** 26 Feb 2025
- **Updated:** 11 May 2026
- **Also known as:** DEBIAN-CVE-2022-49408, GHSA-j793-r5pf-7w34, UBUNTU-CVE-2022-49408

## What is CVE-2022-49408?

CVE-2022-49408 is a medium-severity denial of service vulnerability in Linux kernel, published on 26 Feb 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:

ext4: fix memory leak in parse_apply_sb_mount_options()

If processing the on-disk mount options fails after any memory was
allocated in the ext4_fs_context, e.g. s_qf_names, then this memory is
leaked.  Fix this by calling ext4_fc_free() instead of kfree() directly.

Reproducer:

    mkfs.ext4 -F /dev/vdc
    tune2fs /dev/vdc -E mount_opts=usrjquota=file
    echo clear > /sys/kernel/debug/kmemleak
    mount /dev/vdc /vdc
    echo scan > /sys/kernel/debug/kmemleak
    sleep 5
    echo scan > /sys/kernel/debug/kmemleak
    cat /sys/kernel/debug/kmemleak

Weakness: CWE-401 (Missing Release of Memory after Effective Lifetime)

## Which versions are affected by CVE-2022-49408?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2022-49408?

Apply the vendor's patch.

## Is CVE-2022-49408 being exploited?

There is no known exploitation of CVE-2022-49408 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-2022-49408 and fix it if it is affected.

What it is: CVE-2022-49408 is a medium-severity denial of service vulnerability in Linux kernel, published on 26 Feb 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-2022-49408 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-2022-49408/ (Markdown: https://insights.sbomify.com/CVE-2022-49408/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2022-49408
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2022-49408
- OSV: https://osv.dev/vulnerability/CVE-2022-49408

---
From sbomify Insights: https://insights.sbomify.com/CVE-2022-49408/
Summaries are generated and may contain mistakes; the official description above is the record.