# CVE-2026-90422: clk: mediatek: pllfh: Fix IO remapping leak in register_pllfhs error path

CVE-2026-90422 is fixed in linux on 1 platform, first by DEBIAN-CVE-2026-90422, released September 23, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-90422
- Priority: Routine
- CVSS: 5.5 (Moderate)
- EPSS: 0.0021
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Sep 17, 2026
- Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-90422

## Description

In the Linux kernel, the following vulnerability has been resolved:  clk: mediatek: pllfh: Fix IO remapping leak in register_pllfhs error path  When mtk_clk_register_pllfhs function fails to register a PLL, it unregisters all PLLs and cleans up itself in its error path before returning, so the function callers don't need to do it.  But contrary to mtk_clk_unregister_pllfhs function, that does almost the same sequence, it does not free the IO memory mapped on fhctl node, leading to a leak.  Fix this leak by factorizing the cleanup sequence in a new private function and use it both mtk_clk_register_pllfhs and mtk_clk_unregister_pllfhs functions.  Also, change the loop index start value to avoid the -1 operation on index at each loop.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | linux Debian 13.5 (trixie) | 6.12.115-2 | [DEBIAN-CVE-2026-90422](https://patchblox.com/security/data/fix/linux/debian-cve-2026-90422.md) | Sep 23, 2026 |
| Linux | linux Debian 14 | 7.2.6-1 | [DEBIAN-CVE-2026-90422](https://patchblox.com/security/data/fix/linux/debian-cve-2026-90422.md) | Sep 23, 2026 |

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Data as of 2026-11-09T01:18:40Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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