{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2025-40058", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-04-16T07:20:57.158Z", "datePublished": "2025-10-28T11:48:31.567Z", "dateUpdated": "2026-08-05T12:07:25.986Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:07:25.986Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\niommu/vt-d: Disallow dirty tracking if incoherent page walk\n\nDirty page tracking relies on the IOMMU atomically updating the dirty bit\nin the paging-structure entry. For this operation to succeed, the paging-\nstructure memory must be coherent between the IOMMU and the CPU. In\nanother word, if the iommu page walk is incoherent, dirty page tracking\ndoesn't work.\n\nThe Intel VT-d specification, Section 3.10 \"Snoop Behavior\" states:\n\n\"Remapping hardware encountering the need to atomically update A/EA/D bits\n in a paging-structure entry that is not snooped will result in a non-\n recoverable fault.\"\n\nTo prevent an IOMMU from being incorrectly configured for dirty page\ntracking when it is operating in an incoherent mode, mark SSADS as\nsupported only when both ecap_slads and ecap_smpwc are supported." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H", "baseScore": 8.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The vulnerable configuration is reached only through local ioctls on /dev/iommu (IOMMU_HWPT_ALLOC with IOMMU_HWPT_ALLOC_DIRTY_TRACKING, then IOMMU_HWPT_SET_DIRTY_TRACKING) against a bound VFIO device fd. There is no network-facing path into the VT-d dirty-tracking code.\nAC:L - On an affected IOMMU the attacker deterministically allocates the dirty-tracking hwpt and enables SSADE with two ioctls — no race to win and no memory layout to groom. Where the IOMMU is emulated for a guest, the ecap_slads=1/ecap_smpwc=0 combination is itself under attacker or hypervisor control.\nPR:L - Access to /dev/iommu plus a VFIO device fd is required, which in standard device-assignment deployments is delegated to the unprivileged VMM user (qemu/libvirt) rather than requiring real root. A compromised VMM process or a user in a device-assignment group can drive the entire sequence.\nUI:N - The full sequence — hwpt allocation, dirty-tracking enable, and the subsequent device DMA — is driven entirely by the attacker's own process and the device it already controls. No victim action is needed.\nS:C - The defect is in the IOMMU's own DMA-isolation enforcement: SSADE is programmed on hardware that cannot coherently update paging-structure entries, and the unflushed cached RMW in intel_iommu_read_and_clear_dirty() can resurrect stale second-stage PTEs. An assigned device's DMA then reaches memory outside its authorized translation, crossing the IOMMU security boundary.\nC:H - Stale or incorrectly-updated second-stage paging entries leave a device-visible mapping to host pages that have been unmapped and potentially reassigned, giving the controlled device DMA reads of arbitrary host memory. Dirty-bitmap results are also unreliable, leaking incorrect state across a migration boundary.\nI:H - The same stale-translation window gives the assigned device DMA writes into host memory outside its mapping — an arbitrary write primitive from the device side that defeats IOMMU containment. Silently missed dirty pages additionally corrupt guest memory state on live migration.\nA:H - The VT-d specification mandates a non-recoverable fault whenever the hardware must atomically update A/EA/D bits in a non-snooped paging-structure entry, so the assigned device's DMA is blocked outright and the DMAR fault handler is driven repeatedly. The device and any VM depending on it are rendered inoperable." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/iommu/intel/iommu.h" ], "versions": [ { "version": "f35f22cc760eb2c7034bf53251399685d611e03f", "lessThan": "ebe16d245a00626bb87163862a1b07daf5475a3e", "status": "affected", "versionType": "git" }, { "version": "f35f22cc760eb2c7034bf53251399685d611e03f", "lessThan": "8d096ce0e87bdc361f0b25d7943543bc53aa0b9e", "status": "affected", "versionType": "git" }, { "version": "f35f22cc760eb2c7034bf53251399685d611e03f", "lessThan": "57f55048e564dedd8a4546d018e29d6bbfff0a7e", "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/intel/iommu.h" ], "versions": [ { "version": "6.7", "status": "affected" }, { "version": "0", "lessThan": "6.7", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.53", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.17.3", "lessThanOrEqual": "6.17.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18", "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": "6.7", "versionEndExcluding": "6.12.53" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.7", "versionEndExcluding": "6.17.3" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.7", "versionEndExcluding": "6.18" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/ebe16d245a00626bb87163862a1b07daf5475a3e" }, { "url": "https://git.kernel.org/stable/c/8d096ce0e87bdc361f0b25d7943543bc53aa0b9e" }, { "url": "https://git.kernel.org/stable/c/57f55048e564dedd8a4546d018e29d6bbfff0a7e" } ], "title": "iommu/vt-d: Disallow dirty tracking if incoherent page walk", "x_generator": { "engine": "bippy-1.2.0" } } } }