{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-31589", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-03-09T15:48:24.120Z", "datePublished": "2026-04-24T14:42:16.955Z", "dateUpdated": "2026-08-05T12:23:40.286Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:23:40.286Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmm: call ->free_folio() directly in folio_unmap_invalidate()\n\nWe can only call filemap_free_folio() if we have a reference to (or hold a\nlock on) the mapping. Otherwise, we've already removed the folio from the\nmapping so it no longer pins the mapping and the mapping can be removed,\ncausing a use-after-free when accessing mapping->a_ops.\n\nFollow the same pattern as __remove_mapping() and load the free_folio\nfunction pointer before dropping the lock on the mapping. That lets us\nmake filemap_free_folio() static as this was the only caller outside\nfilemap.c." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "baseScore": 9.8, "baseSeverity": "CRITICAL" }, "scenarios": [ { "lang": "en", "value": "AV:N - The vulnerable path can be reached by remote NFS clients when nfsd is configured for NFSD_IO_DONTCACHE on a filesystem advertising FOP_DONTCACHE, causing remote READ/WRITE handling to set IOCB_DONTCACHE and enter the dropbehind invalidation path. This is a network-facing kernel service.\nAC:L - Once the affected DONTCACHE path is available, an attacker can repeatedly drive writeback/dropbehind and inode lifetime pressure with ordinary I/O operations. The race is attacker-influenced rather than dependent on an uncontrollable system state.\nPR:N - A remote NFS client can reach nfsd request processing without local shell access or kernel capabilities on the target; permissive or anonymous exports make the relevant file operations reachable without prior target privileges. When uncertain between N and L, N is the higher-severity defensible choice.\nUI:N - No victim user action is needed after the service and export are available. The attacker triggers the path by sending I/O requests.\nS:U - The vulnerability corrupts/uses freed memory inside the same kernel security authority that processes the request. It is not a VM escape, IOMMU bypass, or cross-authority boundary violation.\nC:H - The bug is a use-after-free of the address_space/inode-backed mapping when dereferencing mapping->a_ops after the folio no longer pins the mapping. Kernel UAFs are defensibly scored as high confidentiality impact because they can be shaped into kernel memory disclosure primitives.\nI:H - The stale mapping dereference includes an indirect free_folio function pointer lookup and potential call, making control-flow or memory corruption exploitation defensible. Kernel UAFs are scored high for integrity under the provided guidance.\nA:H - At minimum, dereferencing mapping->a_ops after the mapping has been freed can crash or oops the kernel. The attacker can trigger the vulnerable path repeatedly, so availability impact is high." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "mm/filemap.c", "mm/internal.h", "mm/truncate.c" ], "versions": [ { "version": "fb7d3bc4149395c1ae99029c852eab6c28fc3c88", "lessThan": "efc52947247a21bbf79059539bbbd40f4ea76f00", "status": "affected", "versionType": "git" }, { "version": "fb7d3bc4149395c1ae99029c852eab6c28fc3c88", "lessThan": "b667df39d98a7a24be7c2a40ff0863dac1ad2cd7", "status": "affected", "versionType": "git" }, { "version": "fb7d3bc4149395c1ae99029c852eab6c28fc3c88", "lessThan": "c330e65ea59c4805d6ab6757c4ddfe8c63acef31", "status": "affected", "versionType": "git" }, { "version": "fb7d3bc4149395c1ae99029c852eab6c28fc3c88", "lessThan": "615d9bb2ccad42f9e21d837431e401db2e471195", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "mm/filemap.c", "mm/internal.h", "mm/truncate.c" ], "versions": [ { "version": "6.14", "status": "affected" }, { "version": "0", "lessThan": "6.14", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.27", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.19.14", "lessThanOrEqual": "6.19.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.0.1", "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": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.14", "versionEndExcluding": "6.18.27" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.14", "versionEndExcluding": "6.19.14" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.14", "versionEndExcluding": "7.0.1" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.14", "versionEndExcluding": "7.1" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/efc52947247a21bbf79059539bbbd40f4ea76f00" }, { "url": "https://git.kernel.org/stable/c/b667df39d98a7a24be7c2a40ff0863dac1ad2cd7" }, { "url": "https://git.kernel.org/stable/c/c330e65ea59c4805d6ab6757c4ddfe8c63acef31" }, { "url": "https://git.kernel.org/stable/c/615d9bb2ccad42f9e21d837431e401db2e471195" } ], "title": "mm: call ->free_folio() directly in folio_unmap_invalidate()", "x_generator": { "engine": "bippy-1.2.0" } } } }