{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-64151",
        "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "state": "PUBLISHED",
        "assignerShortName": "Linux",
        "dateReserved": "2026-07-19T07:54:57.037Z",
        "datePublished": "2026-07-19T15:40:40.643Z",
        "dateUpdated": "2026-08-05T12:39:45.883Z"
    },
    "containers": {
        "cna": {
            "providerMetadata": {
                "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
                "shortName": "Linux",
                "dateUpdated": "2026-08-05T12:39:45.883Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "In the Linux kernel, the following vulnerability has been resolved:\n\niommupt: Check for missing PAGE_SIZE in the pgsize_bitmap\n\nSashiko pointed out that the driver could drop PAGE_SIZE from the\npgsize_bitmap. That is technically allowed but nothing does it, and\nsuch an iommu_domain would not be used with the DMA API today.\n\nStill, it is against the design and it is trivial to fix up. Lift\nthe PT_WARN_ON to the if branch and just skip the fast path."
                }
            ],
            "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:N",
                        "baseScore": 8.4,
                        "baseSeverity": "HIGH"
                    },
                    "scenarios": [
                        {
                            "lang": "en",
                            "value": "AV:L - The bug is in `map_range()` inside the generic IOMMU page-table path, reached only via local kernel interfaces (`iommu_map()` → `iommu_map_nosync()` → `pt->ops->map_range()`), primarily through `/dev/iommufd` or `/dev/vfio/*` ioctls during device passthrough mapping setup. There is no network-facing entry point.\nAC:L - Once an IOMMU paging domain exists with `PAGE_SIZE` cleared from `pgsize_bitmap`, any `iommu_map()`/`IOMMU_IOAS_MAP` call mapping a single page reliably takes the buggy fast path; the attacker controls mapping requests and needs no races or special memory layout.\nPR:L - Exploitation requires local ability to create IOMMU mappings for a passthrough device (IOMMUFD/VFIO ioctl access and device group permissions), which is available to unprivileged tenants on cloud GPU/NIC passthrough hosts without host root, even though opening `/dev/iommufd` alone is insufficient.\nUI:N - Triggering the flaw is entirely programmatic through IOMMU mapping ioctls; no victim interaction such as mounting a filesystem or opening a file is required.\nS:C - Incorrect leaf PTE installation on an IOMMU domain can break DMA isolation, allowing a device to read/write host physical memory outside its authorized mappings—an IOMMU/DMA security-boundary bypass per kernel CVSS guidance.\nC:H - Malformed or policy-violating IOMMU page-table entries can cause a DMA-capable device to read arbitrary host physical memory beyond the intended IOVA window, constituting arbitrary memory disclosure through the IOMMU bypass primitive.\nI:H - The fast path installs `PAGE_SHIFT` leaf entries even when `PAGE_SIZE` is excluded from `pgsize_bitmap`, corrupting IOMMU translation state and enabling a DMA device to write to unauthorized host physical pages.\nA:N - The flaw corrupts IOMMU translation entries rather than causing a kernel oops, panic, or hang; availability impact is not a primary or reliable outcome of triggering this bug."
                        }
                    ]
                }
            ],
            "affected": [
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "unaffected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "drivers/iommu/generic_pt/iommu_pt.h"
                    ],
                    "versions": [
                        {
                            "version": "dcd6a011a8d523a114af2360a8753de5bd60c139",
                            "lessThan": "00850f41da24423587abd6124a790dd4f12bcef3",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "dcd6a011a8d523a114af2360a8753de5bd60c139",
                            "lessThan": "8ef3f77c440005c7f04229a75976bfc078364247",
                            "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/generic_pt/iommu_pt.h"
                    ],
                    "versions": [
                        {
                            "version": "6.19",
                            "status": "affected"
                        },
                        {
                            "version": "0",
                            "lessThan": "6.19",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.0.11",
                            "lessThanOrEqual": "7.0.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.1",
                            "lessThanOrEqual": "*",
                            "status": "unaffected",
                            "versionType": "original_commit_for_fix"
                        }
                    ]
                }
            ],
            "cpeApplicability": [
                {
                    "nodes": [
                        {
                            "operator": "OR",
                            "negate": false,
                            "cpeMatch": [
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                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "6.19",
                                    "versionEndExcluding": "7.0.11"
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                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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            "references": [
                {
                    "url": "https://git.kernel.org/stable/c/00850f41da24423587abd6124a790dd4f12bcef3"
                },
                {
                    "url": "https://git.kernel.org/stable/c/8ef3f77c440005c7f04229a75976bfc078364247"
                }
            ],
            "title": "iommupt: Check for missing PAGE_SIZE in the pgsize_bitmap",
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