{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2025-39961","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2025-04-16T07:20:57.149Z","datePublished":"2025-10-09T12:13:22.029Z","dateUpdated":"2026-05-11T21:39:46.466Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-05-11T21:39:46.466Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\niommu/amd/pgtbl: Fix possible race while increase page table level\n\nThe AMD IOMMU host page table implementation supports dynamic page table levels\n(up to 6 levels), starting with a 3-level configuration that expands based on\nIOVA address. The kernel maintains a root pointer and current page table level\nto enable proper page table walks in alloc_pte()/fetch_pte() operations.\n\nThe IOMMU IOVA allocator initially starts with 32-bit address and onces its\nexhuasted it switches to 64-bit address (max address is determined based\non IOMMU and device DMA capability). To support larger IOVA, AMD IOMMU\ndriver increases page table level.\n\nBut in unmap path (iommu_v1_unmap_pages()), fetch_pte() reads\npgtable->[root/mode] without lock. So its possible that in exteme corner case,\nwhen increase_address_space() is updating pgtable->[root/mode], fetch_pte()\nreads wrong page table level (pgtable->mode). It does compare the value with\nlevel encoded in page table and returns NULL. This will result is\niommu_unmap ops to fail and upper layer may retry/log WARN_ON.\n\nCPU 0                                         CPU 1\n------                                       ------\nmap pages                                    unmap pages\nalloc_pte() -> increase_address_space()      iommu_v1_unmap_pages() -> fetch_pte()\n  pgtable->root = pte (new root value)\n                                             READ pgtable->[mode/root]\n\t\t\t\t\t       Reads new root, old mode\n  Updates mode (pgtable->mode += 1)\n\nSince Page table level updates are infrequent and already synchronized with a\nspinlock, implement seqcount to enable lock-free read operations on the read path."}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/iommu/amd/amd_iommu_types.h","drivers/iommu/amd/io_pgtable.c"],"versions":[{"version":"754265bcab78a9014f0f99cd35e0d610fcd7dfa7","lessThan":"075abf0b1a958acfbea2435003d228e738e90346","status":"affected","versionType":"git"},{"version":"754265bcab78a9014f0f99cd35e0d610fcd7dfa7","lessThan":"cd92c8ab336c3a633d46e6f35ebcd3509ae7db3b","status":"affected","versionType":"git"},{"version":"754265bcab78a9014f0f99cd35e0d610fcd7dfa7","lessThan":"7d462bdecb7d9c32934dab44aaeb7ea7d73a27a2","status":"affected","versionType":"git"},{"version":"754265bcab78a9014f0f99cd35e0d610fcd7dfa7","lessThan":"1e56310b40fd2e7e0b9493da9ff488af145bdd0c","status":"affected","versionType":"git"},{"version":"6fb92f18555a7b8e085267d513612dc0ff9a5360","status":"affected","versionType":"git"},{"version":"b15bf74405faa1a65025eb8a6eb337e140e5250a","status":"affected","versionType":"git"},{"version":"0d50f7b1e8c80a8c20db5049e269468c059b0378","status":"affected","versionType":"git"},{"version":"785ca708a908b9c596ede852470ba28b8dc3e40b","status":"affected","versionType":"git"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/iommu/amd/amd_iommu_types.h","drivers/iommu/amd/io_pgtable.c"],"versions":[{"version":"5.3","status":"affected"},{"version":"0","lessThan":"5.3","status":"unaffected","versionType":"semver"},{"version":"6.6.108","lessThanOrEqual":"6.6.*","status":"unaffected","versionType":"semver"},{"version":"6.12.49","lessThanOrEqual":"6.12.*","status":"unaffected","versionType":"semver"},{"version":"6.16.9","lessThanOrEqual":"6.16.*","status":"unaffected","versionType":"semver"},{"version":"6.17","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.3","versionEndExcluding":"6.6.108"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.3","versionEndExcluding":"6.12.49"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.3","versionEndExcluding":"6.16.9"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.3","versionEndExcluding":"6.17"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.9.194"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.14.146"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.19.75"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.2.17"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/075abf0b1a958acfbea2435003d228e738e90346"},{"url":"https://git.kernel.org/stable/c/cd92c8ab336c3a633d46e6f35ebcd3509ae7db3b"},{"url":"https://git.kernel.org/stable/c/7d462bdecb7d9c32934dab44aaeb7ea7d73a27a2"},{"url":"https://git.kernel.org/stable/c/1e56310b40fd2e7e0b9493da9ff488af145bdd0c"}],"title":"iommu/amd/pgtbl: Fix possible race while increase page table level","x_generator":{"engine":"bippy-1.2.0"}}}}