# CVE-2026-89854: scsi: qla2xxx: Fix cs84xx use-after-free on host teardown

> A use-after-free in the qla2xxx SCSI driver allows local attackers to execute arbitrary code or escalate privileges via concurrent sysfs access during host teardown.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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:** 16 Sep 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-101412, BELL-CVE-2026-89854, DEBIAN-CVE-2026-89854, GHSA-9v3f-qp8w-f486, UBUNTU-CVE-2026-89854

## What is CVE-2026-89854?

CVE-2026-89854 is a high-severity use after free vulnerability in Linux, published on 16 Sep 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:

scsi: qla2xxx: Fix cs84xx use-after-free on host teardown

qla84xx_put_chip() drops the last reference to ha->cs84xx and frees it via
__qla84xx_chip_release() without clearing ha->cs84xx. During teardown it ran
before scsi_remove_host(), which is what removes the 84xx_fw_version host
sysfs attribute. A concurrent read of that attribute in the window between
the two calls executes qla24xx_84xx_fw_version_show(), which dereferences
the freed ha->cs84xx, resulting in a use-after-free.

Move qla84xx_put_chip() to after scsi_remove_host() in both
qla2x00_remove_one() and qla2x00_disable_board_on_pci_error(). Once
scsi_remove_host() returns, the sysfs attribute is gone and kernfs has
drained any in-flight show(), so no reader can touch cs84xx; the put still
runs before the host and ha are freed.

## Which versions are affected by CVE-2026-89854?


## How do I fix CVE-2026-89854?

Apply the vendor's patch.

## Is CVE-2026-89854 being exploited?

There is no known exploitation of CVE-2026-89854 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-89854 and fix it if it is affected.

What it is: CVE-2026-89854 is a high-severity use after free vulnerability in Linux, published on 16 Sep 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-2026-89854 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-2026-89854/ (Markdown: https://insights.sbomify.com/CVE-2026-89854/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-89854
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-89854
- OSV: https://osv.dev/vulnerability/CVE-2026-89854

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-89854/
Summaries are generated and may contain mistakes; the official description above is the record.