iommu/amd/pgtbl: Fix possible race while increase page table level
In the Linux kernel, the following vulnerability has been resolved: iommu/amd/pgtbl: Fix possible race while increase page table level The AMD IOMMU host page table implementation supports dynamic page table levels (up to 6 levels), starting with a 3-level configuration that expands based on IOVA address. The kernel maintains a root pointer and current page table level to enable proper page table walks in alloc_pte()/fetch_pte() operations. The IOMMU IOVA allocator initially starts with 32-bit address and onces its exhuasted it switches to 64-bit address (max address is determined based on IOMMU and device DMA capability). To support larger IOVA, AMD IOMMU driver increases page table level. But in unmap path (iommu_v1_unmap_pages()), fetch_pte() reads pgtable->[root/mode] without lock. So its possible that in exteme corner case, when increase_address_space() is updating pgtable->[root/mode], fetch_pte() reads wrong page table level (pgtable->mode). It does compare the value with level encoded in page table and returns NULL. This will result is iommu_unmap ops to fail and upper layer may retry/log WARN_ON. CPU 0 CPU 1 ------ ------ map pages unmap pages alloc_pte() -> increase_address_space() iommu_v1_unmap_pages() -> fetch_pte() pgtable->root = pte (new root value) READ pgtable->[mode/root] Reads new root, old mode Updates mode (pgtable->mode += 1) Since Page table level updates are infrequent and already synchronized with a spinlock, implement seqcount to enable lock-free re
CVE-2025-39961
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2025-39961
Linux
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Linux
Source reference: /containers/cna/affected/1/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "754265bcab78a9014f0f99cd35e0d610fcd7dfa7",
"lessThan": "075abf0b1a958acfbea2435003d228e738e90346",
"versionType": "git"
},
{
"status": "affected",
"version": "754265bcab78a9014f0f99cd35e0d610fcd7dfa7",
"lessThan": "cd92c8ab336c3a633d46e6f35ebcd3509ae7db3b",
"versionType": "git"
},
{
"status": "affected",
"version": "754265bcab78a9014f0f99cd35e0d610fcd7dfa7",
"lessThan": "7d462bdecb7d9c32934dab44aaeb7ea7d73a27a2",
"versionType": "git"
},
{
"status": "affected",
"version": "754265bcab78a9014f0f99cd35e0d610fcd7dfa7",
"lessThan": "1e56310b40fd2e7e0b9493da9ff488af145bdd0c",
"versionType": "git"
},
{
"status": "affected",
"version": "6fb92f18555a7b8e085267d513612dc0ff9a5360",
"versionType": "git"
},
{
"status": "affected",
"version": "b15bf74405faa1a65025eb8a6eb337e140e5250a",
"versionType": "git"
},
{
"status": "affected",
"version": "0d50f7b1e8c80a8c20db5049e269468c059b0378",
"versionType": "git"
},
{
"status": "affected",
"version": "785ca708a908b9c596ede852470ba28b8dc3e40b",
"versionType": "git"
},
{
"status": "affected",
"version": "4.9.194",
"lessThan": "4.10",
"versionType": "semver"
},
{
"status": "affected",
"version": "4.14.146",
"lessThan": "4.15",
"versionType": "semver"
},
{
"status": "affected",
"version": "4.19.75",
"lessThan": "4.20",
"versionType": "semver"
},
{
"status": "affected",
"version": "5.2.17",
"lessThan": "5.3",
"versionType": "semver"
}
],
"programFiles": [
"drivers/iommu/amd/amd_iommu_types.h",
"drivers/iommu/amd/io_pgtable.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "5.3"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "5.3",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.6.108",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.49",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.16.9",
"versionType": "semver",
"lessThanOrEqual": "6.16.*"
},
{
"status": "unaffected",
"version": "6.17",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"drivers/iommu/amd/amd_iommu_types.h",
"drivers/iommu/amd/io_pgtable.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2025-39961
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #30645 · Revision 1
- Added to Heist Feed
- Publisher date