CVE-2021-47058: regmap: set debugfs_name to NULL after it is freed

Severity: high (CVSS 7.8 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: 2024-02-29 · updated 2026-06-17
Weakness: CWE-416

Description

In the Linux kernel, the following vulnerability has been resolved: regmap: set debugfs_name to NULL after it is freed There is a upstream commit cffa4b2122f5("regmap:debugfs: Fix a memory leak when calling regmap_attach_dev") that adds a if condition when create name for debugfs_name. With below function invoking logical, debugfs_name is freed in regmap_debugfs_exit(), but it is not created again because of the if condition introduced by above commit. regmap_reinit_cache() regmap_debugfs_exit() ... regmap_debugfs_init() So, set debugfs_name to NULL after it is freed.

Affected products

Linux kernel: from 4.19.168 before 4.19.191; from 5.4.90 before 5.4.119; from 5.10.8 before 5.10.37; from 5.11 before 5.11.21; from 5.12 before 5.12.4 — fixed in 4.19.191, 5.10.37, 5.11.21, 5.12.4, 5.4.119

How to fix

Upgrade to a fixed version: Linux kernel 4.19.191, 5.10.37, 5.11.21, 5.12.4. Check the vendor advisory for mitigations.

References

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