{"id":"CVE-2026-89574","summary":"dm array: validate array block headers on read","details":"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.","modified":"2026-09-14T03:46:15.803793838Z","published":"2026-09-11T19:44:42.494Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89574.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/2965787723084835b18dfe993cd450ebf5bd4540"},{"type":"WEB","url":"https://git.kernel.org/stable/c/67adda7ed5da3e3b64f5b9021a02c21fb374fd9c"},{"type":"WEB","url":"https://git.kernel.org/stable/c/9808ddffb4bc659352df3020cd84d9d864820ee5"},{"type":"WEB","url":"https://git.kernel.org/stable/c/b33f76d33aaeacf3baf3370d8d64985169b36600"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89574.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89574"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"6513c29f44f2cc970c0e9fecfe5a6526c3e73025"},{"fixed":"67adda7ed5da3e3b64f5b9021a02c21fb374fd9c"},{"fixed":"b33f76d33aaeacf3baf3370d8d64985169b36600"},{"fixed":"9808ddffb4bc659352df3020cd84d9d864820ee5"},{"fixed":"2965787723084835b18dfe993cd450ebf5bd4540"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-89574.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"3.9.0"},{"fixed":"6.12.109"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.50"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.2.4"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-89574.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"}]}