Local denial of service via PM reference leak
Published Feb 28, 2024 · Updated May 11, 2026
A reference leak in the Cadence I2C driver in Linux allows local users to exhaust power-management references and interrupt service. cdns_i2c_master_xfer and cdns_reg_slave call pm_runtime_get_sync, which increments the usage counter even when runtime resume fails, but the error paths omit the balancing put operation. Reachability requires low-privilege local access and a Cadence I2C controller path where runtime resume fails; the resulting leak affects availability only.
Summary
What happened
A reference leak in the Cadence I2C driver in Linux allows local users to exhaust power-management references and interrupt service. cdns_i2c_master_xfer and cdns_reg_slave call pm_runtime_get_sync, which increments the usage counter even when runtime resume fails, but the error paths omit the balancing put operation. Reachability requires low-privilege local access and a Cadence I2C controller path where runtime resume fails; the resulting leak affects availability only.
The record
- CVE
- CVE-2020-36784
- Published
- Feb 28, 2024
- Updated
- May 11, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- CWE-772, T1499.001
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Feb 28, 2024CVE publishedPublication date reported by the CVE source.
- May 11, 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=4.5
- Affected versionversion=7fa32329ca03148fb2c07b4ef3247b8fc0488d6a <23ceb8462dc6f4b4decdb5536a7e5fc477cdf0b6
- Affected versionversion=7fa32329ca03148fb2c07b4ef3247b8fc0488d6a <30410519328c94367e561fd878e5f0d3a0303585
- Affected versionversion=7fa32329ca03148fb2c07b4ef3247b8fc0488d6a <a45fc41beed8e0fe31864619c34aa00797fb60c1
- Affected versionversion=7fa32329ca03148fb2c07b4ef3247b8fc0488d6a <d57ff04e0ed6f3be1682ae861ead33f879225e07
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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