Kernel compromise via conflated PMD reference counts
Published Jan 15, 2025 · Updated Aug 5, 2026
Use-after-free in affected Linux kernel releases allows local users to read and write kernel memory through crafted HugeTLB mappings. The huge_pmd_unshare path treats the folio reference count as the PMD sharing count, so transient try_get_folio pins misclassify a private table and leave live mappings tied to freed or leaked pages. An unprivileged local user needs provisioned, accessible huge pages and can race mapping changes against repeated GUP-fast operations; success grants physical-memory access, kernel control-flow compromise, resource exhaustion, or a crash.
Summary
What happened
Use-after-free in affected Linux kernel releases allows local users to read and write kernel memory through crafted HugeTLB mappings. The huge_pmd_unshare path treats the folio reference count as the PMD sharing count, so transient try_get_folio pins misclassify a private table and leave live mappings tied to freed or leaked pages. An unprivileged local user needs provisioned, accessible huge pages and can race mapping changes against repeated GUP-fast operations; success grants physical-memory access, kernel control-flow compromise, resource exhaustion, or a crash.
The record
- CVE
- CVE-2024-57883
- Published
- Jan 15, 2025
- Updated
- Aug 5, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- T1068
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Jan 15, 2025CVE publishedPublication date reported by the CVE source.
- Aug 5, 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=2.6.20
- Affected versionversion=39dde65c9940c97fcd178a3d2b1c57ed8b7b68aa <02333ac1c35370517a19a4a131332a9690c6a5c7
- Affected versionversion=39dde65c9940c97fcd178a3d2b1c57ed8b7b68aa <2e31443a0d18ae43b9d29e02bf0563f07772193d
- Affected versionversion=39dde65c9940c97fcd178a3d2b1c57ed8b7b68aa <56b274473d6e7e7375f2d0a2b4aca11d67c6b52f
- Affected versionversion=39dde65c9940c97fcd178a3d2b1c57ed8b7b68aa <59d9094df3d79443937add8700b2ef1a866b1081
- Affected versionversion=39dde65c9940c97fcd178a3d2b1c57ed8b7b68aa <8410996eb6fea116fe1483ed977aacf580eee7b4
- Affected versionversion=39dde65c9940c97fcd178a3d2b1c57ed8b7b68aa <94b4b41d0cdf5cfd4d4325bc0e6e9e0d0e996133
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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