{"id":"CVE-2026-45945","revision":"d197ed3251d44c97ac2eba133bf677bb","records":[{"revision":"d197ed3251d44c97ac2eba133bf677bb","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-45945","aliases":[],"title":"iommu/vt-d: Fix race condition during PASID entry replacement","description":"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.","state":0,"publishedAt":"2026-05-27T12:18:01.345+00:00","modifiedAt":"2026-10-19T19:26:40.294+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"unaffected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"drivers/iommu/intel/iommu.c\",\n                        \"drivers/iommu/intel/nested.c\",\n                        \"drivers/iommu/intel/pasid.c\",\n                        \"drivers/iommu/intel/pasid.h\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"7543ee63e8113aa34b07df3b16b3b9d2c5f73939\",\n                            \"lessThan\": \"4718007870547e1efebbdd6745d9fce58f008fef\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"7543ee63e8113aa34b07df3b16b3b9d2c5f73939\",\n                            \"lessThan\": \"66a7aff480a82b8642b3991fed5fdc9780022157\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"7543ee63e8113aa34b07df3b16b3b9d2c5f73939\",\n                            \"lessThan\": \"c3b1edea3791fa91ab7032faa90355913ad9451b\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        }\n                    ]\n                }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"affected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"drivers/iommu/intel/iommu.c\",\n                        \"drivers/iommu/intel/nested.c\",\n                        \"drivers/iommu/intel/pasid.c\",\n                        \"drivers/iommu/intel/pasid.h\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"6.13\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"6.13\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.39\",\n                            \"lessThanOrEqual\": \"6.18.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.19.4\",\n                            \"lessThanOrEqual\": \"6.19.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.0\",\n                            \"lessThanOrEqual\": \"*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"original_commit_for_fix\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H","score":8.8,"severity":"HIGH"}],"references":["https://git.kernel.org/stable/c/4718007870547e1efebbdd6745d9fce58f008fef","https://git.kernel.org/stable/c/66a7aff480a82b8642b3991fed5fdc9780022157","https://git.kernel.org/stable/c/c3b1edea3791fa91ab7032faa90355913ad9451b"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-45945","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-45945","identifiers":["CVE-2026-45945"]},"retained":false,"historicalAffected":[]}],"coverage":[]}