Persistent regulator enablement via unbalanced reference counts
Published Sep 16, 2026 · Updated Sep 16, 2026
Reference-count imbalance in the Linux kernel M62332 DAC driver allows local users to leave the Vcc regulator enabled indefinitely. m62332_set_value enables Vcc for every nonzero write but disables it only once when zero is written, so nonzero-to-nonzero transitions accumulate references. Access to the raw channel write interface and attached M62332 hardware is required; the documented consequence is persistent power enablement, not a crash or code execution.
Summary
What happened
Reference-count imbalance in the Linux kernel M62332 DAC driver allows local users to leave the Vcc regulator enabled indefinitely. m62332_set_value enables Vcc for every nonzero write but disables it only once when zero is written, so nonzero-to-nonzero transitions accumulate references. Access to the raw channel write interface and attached M62332 hardware is required; the documented consequence is persistent power enablement, not a crash or code execution.
The record
- CVE
- CVE-2026-89936
- Published
- Sep 16, 2026
- Updated
- Sep 16, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- Unavailable
- Attack vector
- local
- Privileges
- Unavailable
Timeline
How it unfolded
- Sep 16, 2026CVE publishedPublication date reported by the CVE source.
- Sep 16, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
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- Affected versionversion=4.2
- Affected versionversion=b87b0c0f81e8d11c881b726b886b7502ab67d884 <08ac8d2976d57aa943d64e351c4d0bd8bb0c6de9
- Affected versionversion=b87b0c0f81e8d11c881b726b886b7502ab67d884 <1d3a7d7dd3adee19e00be2b2237140f0fe169484
- Affected versionversion=b87b0c0f81e8d11c881b726b886b7502ab67d884 <9263b9ad968a563337a60e0eb66e35186e1faf9a
- Affected versionversion=b87b0c0f81e8d11c881b726b886b7502ab67d884 <9fe22f563b2a0fdb11fd3711a8c39c023629c08a
- Affected versionversion=b87b0c0f81e8d11c881b726b886b7502ab67d884 <a130404ce0b69ca1438126bd81c1985d3b4d2e6f
- Affected versionversion=b87b0c0f81e8d11c881b726b886b7502ab67d884 <ae18d2d2ef27a4d04fda6e30c23774513dc9be1e
- Affected versionversion=b87b0c0f81e8d11c881b726b886b7502ab67d884 <bac0ed8bee651aa841375edf72c6ab1d10ac80c6
- Affected versionversion=b87b0c0f81e8d11c881b726b886b7502ab67d884 <f5acb824277a97a5210c454872202bf7f08c75d4
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
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Technologies
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