{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-45945", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-05-13T15:03:33.088Z", "datePublished": "2026-05-27T12:18:01.345Z", "dateUpdated": "2026-08-05T12:28:52.094Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:28:52.094Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\niommu/vt-d: Fix race condition during PASID entry replacement\n\nThe Intel VT-d PASID table entry is 512 bits (64 bytes). When replacing\nan active PASID entry (e.g., during domain replacement), the current\nimplementation calculates a new entry on the stack and copies it to the\ntable using a single structure assignment.\n\n struct pasid_entry *pte, new_pte;\n\n pte = intel_pasid_get_entry(dev, pasid);\n pasid_pte_config_first_level(iommu, &new_pte, ...);\n *pte = new_pte;\n\nBecause the hardware may fetch the 512-bit PASID entry in multiple\n128-bit chunks, updating the entire entry while it is active (Present\nbit set) risks a \"torn\" read. In this scenario, the IOMMU hardware\ncould observe an inconsistent state — partially new data and partially\nold data — leading to unpredictable behavior or spurious faults.\n\nFix this by removing the unsafe \"replace\" helpers and following the\n\"clear-then-update\" flow, which ensures the Present bit is cleared and\nthe required invalidation handshake is completed before the new\nconfiguration is applied." } ], "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 replace path is reached only through local IOMMUFD/VFIO ioctls (`/dev/iommu` device PASID domain replacement); there is no network or remote-peer path to this code.\nAC:L - Although it is a hardware/software race on the 128-bit-chunked entry fetch, the attacker controls both sides — driving continuous device DMA (forcing frequent entry fetches) while repeatedly issuing the replacement ioctl — so the torn-entry window is reliably reachable through repetition.\nPR:L - Triggering domain replacement requires IOMMUFD/VFIO access to an assigned device, which is gated by device-file permissions rather than an init-namespace root capability check; a confined VMM/user granted passthrough suffices.\nUI:N - The replacement and concurrent DMA are entirely attacker-driven; no action by another user is needed.\nS:C - The flaw is in the IOMMU DMA-isolation structure, and a torn PASID entry can let a device's DMA escape its assigned domain — an IOMMU/DMA boundary bypass that crosses the security authority of the affected component.\nC:H - A torn page-table-pointer field can cause the IOMMU to translate device DMA through stale/corrupt tables, allowing the device to read host or other-domain physical memory across the isolation boundary.\nI:H - The same mistranslation gives the device a write primitive into memory outside its domain, enabling corruption of host/other-domain memory.\nA:H - The commit explicitly notes the torn entry causes \"unpredictable behavior or spurious faults,\" which can manifest as IOMMU faults, device failures, or kernel crashes." } ] } ], "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.c", "drivers/iommu/intel/nested.c", "drivers/iommu/intel/pasid.c", "drivers/iommu/intel/pasid.h" ], "versions": [ { "version": "7543ee63e8113aa34b07df3b16b3b9d2c5f73939", "lessThan": "4718007870547e1efebbdd6745d9fce58f008fef", "status": "affected", "versionType": "git" }, { "version": "7543ee63e8113aa34b07df3b16b3b9d2c5f73939", "lessThan": "66a7aff480a82b8642b3991fed5fdc9780022157", "status": "affected", "versionType": "git" }, { "version": "7543ee63e8113aa34b07df3b16b3b9d2c5f73939", "lessThan": "c3b1edea3791fa91ab7032faa90355913ad9451b", "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.c", "drivers/iommu/intel/nested.c", "drivers/iommu/intel/pasid.c", "drivers/iommu/intel/pasid.h" ], "versions": [ { "version": "6.13", "status": "affected" }, { "version": "0", "lessThan": "6.13", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.39", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.19.4", "lessThanOrEqual": "6.19.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.0", "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": "6.13", "versionEndExcluding": "6.18.39" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.13", "versionEndExcluding": "6.19.4" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.13", "versionEndExcluding": "7.0" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/4718007870547e1efebbdd6745d9fce58f008fef" }, { "url": "https://git.kernel.org/stable/c/66a7aff480a82b8642b3991fed5fdc9780022157" }, { "url": "https://git.kernel.org/stable/c/c3b1edea3791fa91ab7032faa90355913ad9451b" } ], "title": "iommu/vt-d: Fix race condition during PASID entry replacement", "x_generator": { "engine": "bippy-1.2.0" } } } }