{"api_version":"1","generated_at":"2026-10-27T07:13:07+00:00","cve":"CVE-2026-89840","urls":{"html":"https://cve.report/CVE-2026-89840","api":"https://cve.report/api/cve/CVE-2026-89840.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-89840","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-89840"},"summary":{"title":"f2fs: validate MOVE_RANGE destination size","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nf2fs: validate MOVE_RANGE destination size\n\nF2FS_IOC_MOVE_RANGE checks the source range, but not the destination end\nbefore updating i_size. A source hole can expose this: __clone_blkaddrs()\nskips NULL_ADDR entries and returns success, so the caller can still extend\nthe destination inode with unchecked pos_out + len.\n\nReject destination overflow and use inode_newsize_ok() before extending\nthe destination inode.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-09-16 11:16:50","updated_at":"2026-10-21 13:20:31"},"problem_types":[],"metrics":[{"version":"3.1","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","score":"7.1","severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H","data":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H","baseScore":7.1,"baseSeverity":"HIGH","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"HIGH","availabilityImpact":"HIGH"}},{"version":"3.1","source":"CNA","type":"DECLARED","score":"7.1","severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H","data":{"baseScore":7.1,"baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H","version":"3.1"}}],"references":[{"url":"https://git.kernel.org/stable/c/54c587f3f95ce2d6932a16566db83f73cc4313e1","name":"https://git.kernel.org/stable/c/54c587f3f95ce2d6932a16566db83f73cc4313e1","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/bca61ee5192ea47003722486ae9588a2a4bb47b6","name":"https://git.kernel.org/stable/c/bca61ee5192ea47003722486ae9588a2a4bb47b6","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/db13064669526494cd78ba3a4394063b740e940c","name":"https://git.kernel.org/stable/c/db13064669526494cd78ba3a4394063b740e940c","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/dcae1eeda53149f219dd6af93b3083b7271c1c63","name":"https://git.kernel.org/stable/c/dcae1eeda53149f219dd6af93b3083b7271c1c63","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/e533889fc26aea0cd83c90327063f272061dd820","name":"https://git.kernel.org/stable/c/e533889fc26aea0cd83c90327063f272061dd820","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-89840","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89840","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 4dd6f977fc778e5a0da604e5f8cb2f36d163d27b 54c587f3f95ce2d6932a16566db83f73cc4313e1 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 4dd6f977fc778e5a0da604e5f8cb2f36d163d27b bca61ee5192ea47003722486ae9588a2a4bb47b6 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 4dd6f977fc778e5a0da604e5f8cb2f36d163d27b db13064669526494cd78ba3a4394063b740e940c git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 4dd6f977fc778e5a0da604e5f8cb2f36d163d27b dcae1eeda53149f219dd6af93b3083b7271c1c63 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 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original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"89840","cve":"CVE-2026-89840","epss":"0.001710000","percentile":"0.058200000","score_date":"2026-10-05","updated_at":"2026-10-06 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the Linux kernel, the following vulnerability has been resolved:\n\nf2fs: validate MOVE_RANGE destination size\n\nF2FS_IOC_MOVE_RANGE checks the source range, but not the destination end\nbefore updating i_size. A source hole can expose this: __clone_blkaddrs()\nskips NULL_ADDR entries and returns success, so the caller can still extend\nthe destination inode with unchecked pos_out + len.\n\nReject destination overflow and use inode_newsize_ok() before extending\nthe destination inode."}],"metrics":[{"cvssV3_1":{"baseScore":7.1,"baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H","version":"3.1"},"scenarios":[{"lang":"en","value":"AV:L - F2FS_IOC_MOVE_RANGE is a local ioctl (f2fs_ioctl → f2fs_ioc_move_range → f2fs_move_file_range) on f2fs file descriptors. f2fs has no remap_file_range, so nfsd/ksmbd copy_file_range cannot reach this path.\nAC:L - The attacker fully controls pos_out and len and can ftruncate a sparse source so __clone_blkaddrs skips NULL_ADDR holes and returns success, making the unchecked destination i_size update deterministic with no race or uncontrollable layout.\nPR:L - f2fs_ioc_move_range has no capable() check; it only needs FMODE_READ|FMODE_WRITE on the source and FMODE_WRITE on the destination. Any unprivileged user with files on mounted f2fs (Android /data, embedded userdata) can trigger it.\nUI:N - The attacker opens their own files on an already-mounted f2fs volume and issues F2FS_IOC_MOVE_RANGE; no separate victim action such as mounting a filesystem or opening a crafted file is required.\nS:U - Impact is corruption of f2fs inode size metadata and subsequent filesystem/kernel state on the local host, a standard kernel compromise within the same security authority with no VM escape or IOMMU bypass.\nC:N - The bug writes an oversized or overflowed i_size; reads of the resulting sparse file return zeros or EOF (negative i_size makes pos >= i_size), and lookups beyond max_file_blocks fail with -E2BIG, so there is no kernel-memory or cross-file disclosure primitive.\nI:H - Missing overflow and inode_newsize_ok() checks let the attacker set destination i_size past s_maxbytes or wrap size_t into a negative loff_t, persisting corrupt on-disk inode size and poisoning later paths (fallocate COLLAPSE nrpages, __exchange_data_block ALLOC_NODE) that trust i_size for block-tree updates.\nA:H - A poisoned i_size enables unbounded node-tree walks and block-exchange loops (SEEK_DATA/HOLE, fallocate COLLAPSE via DIV_ROUND_UP(i_size)), can hang the kernel or exhaust node space, and leaves durable filesystem corruption on shared f2fs userdata."}]}],"providerMetadata":{"dateUpdated":"2026-10-21T12:49:02.980Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/54c587f3f95ce2d6932a16566db83f73cc4313e1"},{"url":"https://git.kernel.org/stable/c/bca61ee5192ea47003722486ae9588a2a4bb47b6"},{"url":"https://git.kernel.org/stable/c/db13064669526494cd78ba3a4394063b740e940c"},{"url":"https://git.kernel.org/stable/c/dcae1eeda53149f219dd6af93b3083b7271c1c63"},{"url":"https://git.kernel.org/stable/c/e533889fc26aea0cd83c90327063f272061dd820"}],"title":"f2fs: validate MOVE_RANGE destination size","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-89840","datePublished":"2026-09-16T10:31:14.646Z","dateReserved":"2026-09-11T19:38:34.769Z","dateUpdated":"2026-10-21T12:49:02.980Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-09-16 11:16:50","lastModifiedDate":"2026-10-21 13:20:31","problem_types":[],"metrics":{"cvssMetricV31":[{"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H","baseScore":7.1,"baseSeverity":"HIGH","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"HIGH","availabilityImpact":"HIGH"},"exploitabilityScore":1.8,"impactScore":5.2}]},"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"89840","Ordinal":"1","Title":"f2fs: validate MOVE_RANGE destination size","CVE":"CVE-2026-89840","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"89840","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nf2fs: validate MOVE_RANGE destination size\n\nF2FS_IOC_MOVE_RANGE checks the source range, but not the destination end\nbefore updating i_size. A source hole can expose this: __clone_blkaddrs()\nskips NULL_ADDR entries and returns success, so the caller can still extend\nthe destination inode with unchecked pos_out + len.\n\nReject destination overflow and use inode_newsize_ok() before extending\nthe destination inode.","Type":"Description","Title":"f2fs: validate MOVE_RANGE destination size"}]}}}