CVE-2021-47205: clk: sunxi-ng: Unregister clocks/resets when unbinding

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-04-10 · updated 2026-06-17
Weakness: CWE-401

Description

In the Linux kernel, the following vulnerability has been resolved: clk: sunxi-ng: Unregister clocks/resets when unbinding Currently, unbinding a CCU driver unmaps the device's MMIO region, while leaving its clocks/resets and their providers registered. This can cause a page fault later when some clock operation tries to perform MMIO. Fix this by separating the CCU initialization from the memory allocation, and then using a devres callback to unregister the clocks and resets. This also fixes a memory leak of the `struct ccu_reset`, and uses the correct owner (the specific platform driver) for the clocks and resets. Early OF clock providers are never unregistered, and limited error handling is possible, so they are mostly unchanged. The error reporting is made more consistent by moving the message inside of_sunxi_ccu_probe.

Affected products

Linux kernel: before 5.15.5 — fixed in 5.15.5

How to fix

Upgrade to a fixed version: Linux kernel 5.15.5. Check the vendor advisory for mitigations.

References

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