# CVE-2026-90126: rtc: pcf8563: fix clock provider leak on unbind

> A memory leak in the PCF8563 RTC driver allows local attackers to exhaust kernel memory via repeated device unbinding, causing denial of service.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 17 Sep 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-102510, BELL-CVE-2026-90126, DEBIAN-CVE-2026-90126, GHSA-7jrh-4gfg-rh69, UBUNTU-CVE-2026-90126

## What is CVE-2026-90126?

CVE-2026-90126 is a memory corruption vulnerability in Linux, published on 17 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:

rtc: pcf8563: fix clock provider leak on unbind

pcf8563_clkout_register_clk() registers the CLKOUT clock provider with
of_clk_add_provider(), but nothing ever unwinds it: there is no
of_clk_del_provider() call and the driver has no remove callback. Each
of_clk_add_provider() allocates a struct of_clk_provider, takes a
reference on the OF node and adds an entry to the global of_clk_providers
list, none of which is released when the device is unbound. Every
bind/unbind (or module reload) therefore leaks a provider structure and
an of_node reference.

The clock itself is already device-managed (devm_clk_register()); only
the provider registration was not. Use devm_of_clk_add_hw_provider() so
the provider is removed automatically on unbind. Tie it to the parent
i2c device, whose OF node carries the #clock-cells and clock-output-names
properties (the RTC class device has no OF node of its own).

## Which versions are affected by CVE-2026-90126?


## How do I fix CVE-2026-90126?

Apply the vendor's patch.

## Is CVE-2026-90126 being exploited?

There is no known exploitation of CVE-2026-90126 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-90126 and fix it if it is affected.

What it is: CVE-2026-90126 is a memory corruption vulnerability in Linux, published on 17 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-2026-90126 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-2026-90126/ (Markdown: https://insights.sbomify.com/CVE-2026-90126/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-90126
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-90126
- OSV: https://osv.dev/vulnerability/CVE-2026-90126

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-90126/
Summaries are generated and may contain mistakes; the official description above is the record.