# lockd: fix NULL dereference on lockowner allocation failure

CVE record · `CVE-2026-89484`

- **Identifiers:** `CVE-2026-89484`
- **State:** Confirmed
- **Severity:** No CVSS score
- **Critical:** No
- **CNA:** Linux
- **Technologies:** [Linux kernel](https://agentprime.io/advisories/technology/linux-kernel.md)
- **Published:** 11 Sept 2026
- **Updated:** 30 Oct 2026
- **Reviewed by a person:** No

Published by the CVE Program (CNA: Linux) at 11 Sept 2026, 19:43 UTC. agentprime has not analysed this yet, so whether it affects any app is not known. This CVE names a vendor and product rather than a package, so the lockfile check doesn’t match it.

## Affected products, as the CNA wrote them

- Vendor: Linux. Product: Linux.
  - affected: `1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before b61053a3795c2913a7af3ab6218acfdaf52fcafe` (git)
  - affected: `1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before 6db5af172ccc3223c8f730a9a4212f6427feee3e` (git)
  - affected: `1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before 07adfbb3de7529f58ca708a97ead7fa4fdb71056` (git)
  - affected: `1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before d662f7fc04fde305a27f304b3cd19b614d366839` (git)
  - affected: `1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before 51af080ca4e553256c59a75a877b9b4fff828311` (git)
  - affected: `1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before 4c7fc129db061c7daab841c4f3c342d894832362` (git)
  - Other versions: unaffected
- Vendor: Linux. Product: Linux.
  - affected: `2.6.12`
  - unaffected: `before 2.6.12` (semver)
  - unaffected: `6.1.191 to 6.1.*, inclusive` (semver)
  - unaffected: `6.6.160 to 6.6.*, inclusive` (semver)
  - unaffected: `6.12.109 to 6.12.*, inclusive` (semver)
  - unaffected: `6.18.50 to 6.18.*, inclusive` (semver)
  - unaffected: `7.2.4 to 7.2.*, inclusive` (semver)
  - unaffected: `7.3 to *, inclusive` (original_commit_for_fix)
  - Other versions: affected

## Machine-written summary

Summary written by Claude Haiku from the source advisory. Not reviewed by a person.

> This Linux kernel advisory covers the NLM (lockd) client code, which handles NFS file locking. When a lockowner allocation fails, the kernel can later dereference an uninstalled owner pointer and crash. The source does not describe the conditions under which an attacker could trigger the allocation failure, so the attack requirements are unclear. The fix is in the upstream kernel; upgrade to a fixed kernel version for your branch, such as 6.1.191 or later in the 6.1 series.

Written 12 Nov 2026.

## Not analysed yet

We haven’t published our own analysis of this CVE. If a person reviews it, this page will say what’s affected and what has to be true for it to matter.

## Severity and exploitation

No source has published a CVSS score for this record yet.

- **CISA KEV:** Not listed.
- **EPSS:** 0.0021, the 11th percentile, on 14 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

This record came from the full history of the CVE Program, published 11 Sept 2026. New records show when each source confirmed them.

## Sources

- [CVE List: CVE-2026-89484](https://www.cve.org/CVERecord?id=CVE-2026-89484)
- [NVD: CVE-2026-89484](https://nvd.nist.gov/vuln/detail/CVE-2026-89484)

### References from the CNA

- <https://git.kernel.org/stable/c/b61053a3795c2913a7af3ab6218acfdaf52fcafe>
- <https://git.kernel.org/stable/c/6db5af172ccc3223c8f730a9a4212f6427feee3e>
- <https://git.kernel.org/stable/c/07adfbb3de7529f58ca708a97ead7fa4fdb71056>
- <https://git.kernel.org/stable/c/d662f7fc04fde305a27f304b3cd19b614d366839>
- <https://git.kernel.org/stable/c/51af080ca4e553256c59a75a877b9b4fff828311>
- <https://git.kernel.org/stable/c/4c7fc129db061c7daab841c4f3c342d894832362>

Facts on this page come from the CVE List as the CNA published them, with CVSS from the sources named above, CISA KEV and FIRST EPSS. Vendors, products and versions are shown as the CNA wrote them. We don’t reproduce the CVE’s description.

## Check whether this affects you

This CVE names a vendor and product rather than a package, so the lockfile check doesn’t match it. Compare the affected versions above with what you run.

- With the agentprime MCP server (<https://api.agentprime.io/mcp>), `get_advisory` returns this record and `search_advisories` finds related ones. Setup: <https://agentprime.io/mcp.md>
- As JSON: <https://api.agentprime.io/v1/advisories/CVE-2026-89484>
- Everything that needs attention now: <https://agentprime.io/advisories/critical.md>

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The web page: <https://agentprime.io/advisories/CVE-2026-89484/>. Everything for agents: <https://agentprime.io/llms.txt>.