Kernel information disclosure via uninitialized ioctl padding
Published Dec 24, 2025 · Updated Dec 24, 2025
Information disclosure in Linux kernel 6.2 through 6.2.2 allows local users to read kernel stack padding through an iommufd ioctl. iommufd_vfio_iommu_get_info copies a vfio_iommu_type1_info structure to user space after copy_from_user leaves its final eight padding bytes uninitialized. Reachability requires permission to invoke the VFIO compatibility GET_INFO operation; disclosure is limited to stale data in those eight bytes.
Summary
What happened
Information disclosure in Linux kernel 6.2 through 6.2.2 allows local users to read kernel stack padding through an iommufd ioctl. iommufd_vfio_iommu_get_info copies a vfio_iommu_type1_info structure to user space after copy_from_user leaves its final eight padding bytes uninitialized. Reachability requires permission to invoke the VFIO compatibility GET_INFO operation; disclosure is limited to stale data in those eight bytes.
The record
- CVE
- CVE-2023-54034
- Published
- Dec 24, 2025
- Updated
- Dec 24, 2025
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- Unavailable
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Dec 24, 2025CVE publishedPublication date reported by the CVE source.
- Dec 24, 2025Record 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=6.2
- Affected versionversion=d624d6652a65ad4f47a58b8651a1ec1163bb81d3 <7adcec686e4d699c169d34c722132b2bce5232cb
- Affected versionversion=d624d6652a65ad4f47a58b8651a1ec1163bb81d3 <b3551ead616318ea155558cdbe7e91495b8d9b33
What conditions does exploitation require?
What is affected?
Published CVSS scores
No CVSS assessment is available in this record.
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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
No sourced classifications are available.
Public exploit references
- syzbot KMSAN iommufd_vfio_ioctl reproducerproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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