Kernel-pointer exposure via released-resource type confusion
Published May 1, 2025 · Updated May 11, 2026
Incorrect type conversion in the Linux eBPF verifier allows local users to expose a kernel pointer through an eBPF map. release_references() applies __mark_reg_unknown() to registers associated with a released resource, incorrectly retyping a runtime pointer as SCALAR_VALUE instead of making it uninitialized. Exploitation requires local low-privileged access and an eBPF-loading path; published material establishes kernel-address exposure but no broader data read, write, or code execution.
Summary
What happened
Incorrect type conversion in the Linux eBPF verifier allows local users to expose a kernel pointer through an eBPF map. release_references() applies __mark_reg_unknown() to registers associated with a released resource, incorrectly retyping a runtime pointer as SCALAR_VALUE instead of making it uninitialized. Exploitation requires local low-privileged access and an eBPF-loading path; published material establishes kernel-address exposure but no broader data read, write, or code execution.
The record
- CVE
- CVE-2022-49873
- Published
- May 1, 2025
- Updated
- May 11, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- CWE-704
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- May 1, 2025CVE 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?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=4.20
- Affected versionversion=fd978bf7fd312581a7ca454a991f0ffb34c4204b <466ce46f251dfb259a8cbaa895ab9edd6fb56240
- Affected versionversion=fd978bf7fd312581a7ca454a991f0ffb34c4204b <ae5ccad6c711db0f2ca1231be051935dd128b8f5
- Affected versionversion=fd978bf7fd312581a7ca454a991f0ffb34c4204b <cedd4f01f67be94735f15123158f485028571037
- Affected versionversion=fd978bf7fd312581a7ca454a991f0ffb34c4204b <f1db20814af532f85e091231223e5e4818e8464b
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
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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