# CVE-2026-98443: xfs: fix cursor and pointer handling when recovering iunlink buckets

> A use-after-free vulnerability in the Linux kernel XFS filesystem allows local attackers to potentially execute arbitrary code or escalate privileges.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H`)
- **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:** 18 Oct 2026
- **Updated:** 24 Oct 2026
- **Also known as:** AZL-108929, BELL-CVE-2026-98443, DEBIAN-CVE-2026-98443, GHSA-27hr-pwp4-53ph, UBUNTU-CVE-2026-98443

## What is CVE-2026-98443?

CVE-2026-98443 is a high-severity use after free vulnerability in Linux, published on 18 Oct 2026. 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:

xfs: fix cursor and pointer handling when recovering iunlink buckets

LOLLM pointed out a bug in xlog_recover_iunlink_bucket:

1. We don't null out prev_ip after releasing it, which can lead to UAF
   problems if the inodegc flush call in the loop fails.

at which point I noticed even more bugs:

2. If the inodegc flush inside the loop fails, we also leak @ip.

3. We set prev_agino to agino having already advanced agino, which
   results in inodes with i_prev_unlinked set to itself.

4. If we exit the bottom of the loop with prev_ip set, then prev_ip
   aliases ip and we also set its i_prev_unlinked to itself.

Bugs 3 and 4 introduce loops into the unlinked list, though these loops
don't surface because we immediately flush each unlinked inode after
loading it.

Fix all of these issues.

## Which versions are affected by CVE-2026-98443?


## How do I fix CVE-2026-98443?

Apply the vendor's patch.

## Is CVE-2026-98443 being exploited?

There is no known exploitation of CVE-2026-98443 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-98443 and fix it if it is affected.

What it is: CVE-2026-98443 is a high-severity use after free vulnerability in Linux, published on 18 Oct 2026. 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-2026-98443 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-2026-98443/ (Markdown: https://insights.sbomify.com/CVE-2026-98443/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-98443
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-98443
- OSV: https://osv.dev/vulnerability/CVE-2026-98443

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-98443/
Summaries are generated and may contain mistakes; the official description above is the record.