Kernel stack disclosure via byte-count confusion
Published Feb 26, 2025 · Updated May 11, 2026
An out-of-bounds read in affected Linux User-Mode Linux kernels allows local users to read kernel stack data during LDT setup. The write_ldt_entry function passes a 16-byte LDT descriptor size as a byte count to syscall_stub_data, which treats the value as a count of longs and copies 128 bytes from the stack object. The affected code is confined to x86 User-Mode Linux, and the observed fault occurs while a new memory context initializes its LDT.
Summary
What happened
An out-of-bounds read in affected Linux User-Mode Linux kernels allows local users to read kernel stack data during LDT setup. The write_ldt_entry function passes a 16-byte LDT descriptor size as a byte count to syscall_stub_data, which treats the value as a count of longs and copies 128 bytes from the stack object. The affected code is confined to x86 User-Mode Linux, and the observed fault occurs while a new memory context initializes its LDT.
The record
- CVE
- CVE-2022-49395
- Published
- Feb 26, 2025
- Updated
- May 11, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- CWE-125
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Feb 26, 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?
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- Affected versionversion=2.6.15
- Affected versionversion=858259cf7d1c443c836a2022b78cb281f0a9b95e <10995a382271254bd276627ec74136da4a23c4a6
- Affected versionversion=858259cf7d1c443c836a2022b78cb281f0a9b95e <24ca648bf5f72ed8878cf09b5d4431935779681e
- Affected versionversion=858259cf7d1c443c836a2022b78cb281f0a9b95e <2a4a62a14be1947fa945c5c11ebf67326381a568
- Affected versionversion=858259cf7d1c443c836a2022b78cb281f0a9b95e <3549ab4b962cf619e8c55484a0d870a34b3f845f
- Affected versionversion=858259cf7d1c443c836a2022b78cb281f0a9b95e <668ca34a428d6ffc0f99a1a6a9b661a288d4183b
- Affected versionversion=858259cf7d1c443c836a2022b78cb281f0a9b95e <91e5ba2af2d729d5126aefd5aa3eadc69b8426e5
- Affected versionversion=858259cf7d1c443c836a2022b78cb281f0a9b95e <9caad70819aef3431abaf73ba5163b55b161aba0
- Affected versionversion=858259cf7d1c443c836a2022b78cb281f0a9b95e <cf0dabc37446c5ee538ae7b4c467ab0e53fa5463
- Affected versionversion=858259cf7d1c443c836a2022b78cb281f0a9b95e <ef1dc929a1e5fa1b2d842256db9fb8710d3be910
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
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Your stack
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