Crash or privilege escalation via action-buffer underflow
Published Sep 1, 2022 · Updated Aug 3, 2024
An integer coercion error in the Linux Kernel 5.18 Open vSwitch module allows local users to crash the system or escalate privileges. The reserve_sfa_size() check subtracts an oversized next_offset from MAX_ACTIONS_BUFSIZE, so unsigned underflow bypasses size rejection before later actions are copied out of bounds. Exploitation requires local access and a sufficiently large flow-action set; a kernel crash is demonstrated, while privilege escalation is reported but not publicly demonstrated.
Summary
What happened
An integer coercion error in the Linux Kernel 5.18 Open vSwitch module allows local users to crash the system or escalate privileges. The reserve_sfa_size() check subtracts an oversized next_offset from MAX_ACTIONS_BUFSIZE, so unsigned underflow bypasses size rejection before later actions are copied out of bounds. Exploitation requires local access and a sufficiently large flow-action set; a kernel crash is demonstrated, while privilege escalation is reported but not publicly demonstrated.
The record
- CVE
- CVE-2022-2639
- Published
- Sep 1, 2022
- Updated
- Aug 3, 2024
- Vendor
- The Linux Kernel Organization
- Product
- Linux Kernel
- Classifications
- CWE-681, CWE-192, T1068, T1499.004
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Sep 1, 2022CVE publishedPublication date reported by the CVE source.
- Aug 3, 2024Record 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=kernel 5.18
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
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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