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

Official 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.

Affected packages & fixed versions

Affected products (as reported)

References

• https://git.kernel.org/stable/c/6e3e93bc718c4fea556d7ca5fba07ab3511c9918
• https://git.kernel.org/stable/c/111235106099019b8a8d1947dc5c2674e0329ffa
• https://git.kernel.org/stable/c/d35e45e5bad4fabcf122126402b6c6dcb4379672
• https://git.kernel.org/stable/c/fea0b4fd891a2af77b55e05b950e7ea55b5d234e
• https://git.kernel.org/stable/c/540d91480bcb1b28a62d7023aa70947ea44c55b9