{"id":"CVE-2026-89593","revision":"da1d419fda0e4d8d99a18a60759dcbb4","records":[{"revision":"da1d419fda0e4d8d99a18a60759dcbb4","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-89593","aliases":[],"title":"hugetlb: only adjust reservation during unmapping if mapcount is 0","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nhugetlb: only adjust reservation during unmapping if mapcount is 0\n\nSince df7a6d1f6405, __unmap_hugepage_range can adjust reservations.  In\nthe case of folio mapped in both a parent and a child, if the parent\nunmaps the range first, the reservation adjustment will result in an\nunderflow of the reserved count.  Once the child unmaps the range, the\ncount is restored.  Change __unmap_hugepage_range() to check the mapcount\nbefore adjusting the reservation.","state":0,"publishedAt":"2026-09-11T19:44:56.557+00:00","modifiedAt":"2026-10-19T08:49:25.74+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                        \"mm/hugetlb.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"df7a6d1f64056aec572162c5d35ed9ff86ece6f3\",\n                            \"lessThan\": \"b0b1b9ca80b795ed2223e76dd787db7067121fb9\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"df7a6d1f64056aec572162c5d35ed9ff86ece6f3\",\n                            \"lessThan\": \"a3c65af20cceb7f997847727636b4017326f845d\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"df7a6d1f64056aec572162c5d35ed9ff86ece6f3\",\n                            \"lessThan\": \"0f001491e5a2ec69aa9d5dd6b799e5742245f9ea\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"df7a6d1f64056aec572162c5d35ed9ff86ece6f3\",\n                            \"lessThan\": \"5120b1e048d48596ffaec1a8412012a91adba73b\",\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                        \"mm/hugetlb.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"6.9\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"6.9\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.12.110\",\n                            \"lessThanOrEqual\": \"6.12.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.50\",\n                            \"lessThanOrEqual\": \"6.18.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.2.4\",\n                            \"lessThanOrEqual\": \"7.2.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.3\",\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:U/C:N/I:H/A:H","score":7.1,"severity":"HIGH"}],"references":["https://git.kernel.org/stable/c/b0b1b9ca80b795ed2223e76dd787db7067121fb9","https://git.kernel.org/stable/c/a3c65af20cceb7f997847727636b4017326f845d","https://git.kernel.org/stable/c/0f001491e5a2ec69aa9d5dd6b799e5742245f9ea","https://git.kernel.org/stable/c/5120b1e048d48596ffaec1a8412012a91adba73b"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-89593","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-89593","identifiers":["CVE-2026-89593"]},"retained":false,"historicalAffected":[]}],"coverage":[]}