{"api_version":"1","generated_at":"2026-09-14T04:31:50+00:00","cve":"CVE-2026-89574","urls":{"html":"https://cve.report/CVE-2026-89574","api":"https://cve.report/api/cve/CVE-2026-89574.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-89574","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-89574"},"summary":{"title":"dm array: validate array block headers on read","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ndm array: validate array block headers on read\n\narray_block_check() validates blocknr and csum and nothing else, while\nnode_check(), next to it, has bounded the structural fields since both\nwere written. dm_array_cursor_next() takes its loop bound from the\non-disk nr_entries and element_at() is unguarded pointer arithmetic, so\na count larger than the block holds keeps the cursor in one block while\nthe index grows past it and the read walks off the dm-bufio buffer --\ndm_cache_load_mappings() drives it once per cache block at activation.\n\nCheck the header against itself: reject a zero value_size, require\nmax_entries to equal calc_max_entries() for that value_size and block\nsize, and require nr_entries to fit. Equality rather than an upper bound,\nsince a count below the real capacity trips BUG_ON() in fill_ablock() and\ntrim_ablock(). Metadata dm-array writes satisfies all three.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-09-11 20:19:41","updated_at":"2026-09-13 07:17:23"},"problem_types":[],"metrics":[{"version":"3.1","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","score":"7.8","severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","data":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH"}},{"version":"3.1","source":"CNA","type":"DECLARED","score":"7.8","severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","data":{"baseScore":7.8,"baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","version":"3.1"}}],"references":[{"url":"https://git.kernel.org/stable/c/b33f76d33aaeacf3baf3370d8d64985169b36600","name":"https://git.kernel.org/stable/c/b33f76d33aaeacf3baf3370d8d64985169b36600","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/9808ddffb4bc659352df3020cd84d9d864820ee5","name":"https://git.kernel.org/stable/c/9808ddffb4bc659352df3020cd84d9d864820ee5","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/67adda7ed5da3e3b64f5b9021a02c21fb374fd9c","name":"https://git.kernel.org/stable/c/67adda7ed5da3e3b64f5b9021a02c21fb374fd9c","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/2965787723084835b18dfe993cd450ebf5bd4540","name":"https://git.kernel.org/stable/c/2965787723084835b18dfe993cd450ebf5bd4540","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-89574","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89574","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6513c29f44f2cc970c0e9fecfe5a6526c3e73025 67adda7ed5da3e3b64f5b9021a02c21fb374fd9c git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6513c29f44f2cc970c0e9fecfe5a6526c3e73025 b33f76d33aaeacf3baf3370d8d64985169b36600 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6513c29f44f2cc970c0e9fecfe5a6526c3e73025 9808ddffb4bc659352df3020cd84d9d864820ee5 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6513c29f44f2cc970c0e9fecfe5a6526c3e73025 2965787723084835b18dfe993cd450ebf5bd4540 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 3.9","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 3.9 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.109 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.50 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2.4 7.2.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.3-rc1 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"89574","cve":"CVE-2026-89574","epss":"0.001630000","percentile":"0.058460000","score_date":"2026-09-13","updated_at":"2026-09-14 00:18:01"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["drivers/md/persistent-data/dm-array.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"67adda7ed5da3e3b64f5b9021a02c21fb374fd9c","status":"affected","version":"6513c29f44f2cc970c0e9fecfe5a6526c3e73025","versionType":"git"},{"lessThan":"b33f76d33aaeacf3baf3370d8d64985169b36600","status":"affected","version":"6513c29f44f2cc970c0e9fecfe5a6526c3e73025","versionType":"git"},{"lessThan":"9808ddffb4bc659352df3020cd84d9d864820ee5","status":"affected","version":"6513c29f44f2cc970c0e9fecfe5a6526c3e73025","versionType":"git"},{"lessThan":"2965787723084835b18dfe993cd450ebf5bd4540","status":"affected","version":"6513c29f44f2cc970c0e9fecfe5a6526c3e73025","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["drivers/md/persistent-data/dm-array.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"3.9"},{"lessThan":"3.9","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.109","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.50","versionType":"semver"},{"lessThanOrEqual":"7.2.*","status":"unaffected","version":"7.2.4","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.3-rc1","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.109","versionStartIncluding":"3.9","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.50","versionStartIncluding":"3.9","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2.4","versionStartIncluding":"3.9","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.3-rc1","versionStartIncluding":"3.9","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\ndm array: validate array block headers on read\n\narray_block_check() validates blocknr and csum and nothing else, while\nnode_check(), next to it, has bounded the structural fields since both\nwere written. dm_array_cursor_next() takes its loop bound from the\non-disk nr_entries and element_at() is unguarded pointer arithmetic, so\na count larger than the block holds keeps the cursor in one block while\nthe index grows past it and the read walks off the dm-bufio buffer --\ndm_cache_load_mappings() drives it once per cache block at activation.\n\nCheck the header against itself: reject a zero value_size, require\nmax_entries to equal calc_max_entries() for that value_size and block\nsize, and require nr_entries to fit. Equality rather than an upper bound,\nsince a count below the real capacity trips BUG_ON() in fill_ablock() and\ntrim_ablock(). Metadata dm-array writes satisfies all three."}],"metrics":[{"cvssV3_1":{"baseScore":7.8,"baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","version":"3.1"},"scenarios":[{"lang":"en","value":"AV:L - The bug is reached when the kernel reads attacker-crafted dm-array metadata from a local block device during device-mapper activation (dm-cache dm_cache_load_mappings, dm-clone bitset load, or dm-era array resize), not via a network protocol.\nAC:L - The attacker fully controls the on-disk array-block header (nr_entries, max_entries, value_size) and can compute a matching checksum, so activation deterministically walks off the dm-bufio buffer; there is no race or attacker-uncontrollable memory layout.\nPR:L - Device-mapper ioctls require init-namespace CAP_SYS_ADMIN and are not reachable via user namespaces, but the malformed data is on-disk metadata, so the attacker only needs write access to the backing store (loop file, VM/container disk, iSCSI/NBD LUN) that a dm-cache/dm-era/dm-clone stack is built on.\nUI:N - Once corrupt metadata is on the backing store, LVM/udev autoactivation, boot, or reattachment of the volume loads mappings without a separate victim action such as mounting a filesystem or opening a file.\nS:U - The out-of-bounds access is confined to kernel dm-bufio metadata buffers on the same host; this is ordinary kernel memory corruption, not a VM escape, IOMMU bypass, or sandbox boundary crossing.\nC:H - dm_array_cursor_next() takes its loop bound from on-disk nr_entries while element_at() is unguarded pointer arithmetic, so a too-large count keeps the cursor in one block and reads past the dm-bufio data buffer (typically a 4K slab/page) for every cache block at activation, an unbounded kernel out-of-bounds read.\nI:H - Unchecked headers let fill_ablock()/trim_ablock() hit BUG_ON on resize, and out-of-bounds mapping, hint, and bitset values from adjacent kernel memory are installed into the cache policy and then used for origin/cache I/O, giving a memory-corruption integrity primitive.\nA:H - Walking off the dm-bufio buffer causes a kernel oops or KASAN panic, and an undersized on-disk max_entries hits BUG_ON in fill_ablock() and trim_ablock() during array resize at activation."}]}],"providerMetadata":{"dateUpdated":"2026-09-13T06:31:11.485Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/67adda7ed5da3e3b64f5b9021a02c21fb374fd9c"},{"url":"https://git.kernel.org/stable/c/b33f76d33aaeacf3baf3370d8d64985169b36600"},{"url":"https://git.kernel.org/stable/c/9808ddffb4bc659352df3020cd84d9d864820ee5"},{"url":"https://git.kernel.org/stable/c/2965787723084835b18dfe993cd450ebf5bd4540"}],"title":"dm array: validate array block headers on read","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-89574","datePublished":"2026-09-11T19:44:42.494Z","dateReserved":"2026-09-11T19:38:34.727Z","dateUpdated":"2026-09-13T06:31:11.485Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-09-11 20:19:41","lastModifiedDate":"2026-09-13 07:17:23","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:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH"},"exploitabilityScore":1.8,"impactScore":5.9}]},"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"89574","Ordinal":"1","Title":"dm array: validate array block headers on read","CVE":"CVE-2026-89574","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"89574","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\ndm array: validate array block headers on read\n\narray_block_check() validates blocknr and csum and nothing else, while\nnode_check(), next to it, has bounded the structural fields since both\nwere written. dm_array_cursor_next() takes its loop bound from the\non-disk nr_entries and element_at() is unguarded pointer arithmetic, so\na count larger than the block holds keeps the cursor in one block while\nthe index grows past it and the read walks off the dm-bufio buffer --\ndm_cache_load_mappings() drives it once per cache block at activation.\n\nCheck the header against itself: reject a zero value_size, require\nmax_entries to equal calc_max_entries() for that value_size and block\nsize, and require nr_entries to fit. Equality rather than an upper bound,\nsince a count below the real capacity trips BUG_ON() in fill_ablock() and\ntrim_ablock(). Metadata dm-array writes satisfies all three.","Type":"Description","Title":"dm array: validate array block headers on read"}]}}}