Local kernel compromise via AMD IOMMU race
Published Oct 9, 2025 · Updated Oct 9, 2025
Race condition in the AMD IOMMU page-table code in Linux allows local users to read or overwrite host kernel memory. iommu_v1_unmap_pages() calls fetch_pte(), which reads pgtable->root and pgtable->mode without synchronization while increase_address_space() updates them, so a torn pair can leave a stale DMA translation. The path requires an AMD x86_64 host using v1 IOMMU page tables and concurrent high-IOVA mapping and unmapping; successful exploitation can escape device isolation or crash the kernel.
Summary
What happened
Race condition in the AMD IOMMU page-table code in Linux allows local users to read or overwrite host kernel memory. iommu_v1_unmap_pages() calls fetch_pte(), which reads pgtable->root and pgtable->mode without synchronization while increase_address_space() updates them, so a torn pair can leave a stale DMA translation. The path requires an AMD x86_64 host using v1 IOMMU page tables and concurrent high-IOVA mapping and unmapping; successful exploitation can escape device isolation or crash the kernel.
The record
- CVE
- CVE-2025-39961
- Published
- Oct 9, 2025
- Updated
- Oct 9, 2025
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- T1068
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Oct 9, 2025CVE publishedPublication date reported by the CVE source.
- Oct 9, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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- Affected versionversion=0d50f7b1e8c80a8c20db5049e269468c059b0378
- Affected versionversion=5.3
- Affected versionversion=6fb92f18555a7b8e085267d513612dc0ff9a5360
- Affected versionversion=754265bcab78a9014f0f99cd35e0d610fcd7dfa7 <075abf0b1a958acfbea2435003d228e738e90346
- Affected versionversion=754265bcab78a9014f0f99cd35e0d610fcd7dfa7 <1e56310b40fd2e7e0b9493da9ff488af145bdd0c
- Affected versionversion=754265bcab78a9014f0f99cd35e0d610fcd7dfa7 <7d462bdecb7d9c32934dab44aaeb7ea7d73a27a2
- Affected versionversion=754265bcab78a9014f0f99cd35e0d610fcd7dfa7 <cd92c8ab336c3a633d46e6f35ebcd3509ae7db3b
- Affected versionversion=785ca708a908b9c596ede852470ba28b8dc3e40b
- Affected versionversion=b15bf74405faa1a65025eb8a6eb337e140e5250a
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
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Technologies
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