{"id":"CVE-2026-89492","title":"In the Linux kernel, the following vulnerability has been resolved:\n\nocfs2: validate directory-index entry counts when reading metadata\n\nocfs2_validate_dx_leaf() and ocfs2_validate_dx_root() check the ECC and\nsignature of an indexed-dire…","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nocfs2: validate directory-index entry counts when reading metadata\n\nocfs2_validate_dx_leaf() and ocfs2_validate_dx_root() check the ECC and\nsignature of an indexed-dire…","severity":"critical","cvss":9.8,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","cwe":["CWE-125"],"vendor":"Linux","product":"Linux","affected":["Linux >= 9b7895efac906d66d19856194e1ba61f37e231a4 < 5e661f55ca8568471fce558effe81cca112f5cb2","Linux >= 9b7895efac906d66d19856194e1ba61f37e231a4 < fcfcba8fe17dbf2c8805690b8cc25e32d81249a4","Linux >= 9b7895efac906d66d19856194e1ba61f37e231a4 < b8a5c0c32df2c5b685ceef76ac77e37c7e1dc3ed","Linux >= 9b7895efac906d66d19856194e1ba61f37e231a4 < bc70726ddad53c7e9a9a85915bf2415b0d4f42f9","Linux 2.6.30"],"published":"2026-09-11","updated":"2026-09-21","sourceUpdated":"2026-09-21T14:17:22.547","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-89492","references":[{"url":"https://git.kernel.org/stable/c/5e661f55ca8568471fce558effe81cca112f5cb2","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/b8a5c0c32df2c5b685ceef76ac77e37c7e1dc3ed","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/bc70726ddad53c7e9a9a85915bf2415b0d4f42f9","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/fcfcba8fe17dbf2c8805690b8cc25e32d81249a4","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89492.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-89492"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2532489"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-89492"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89492"},{"url":"https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89492.mbox"}],"tags":["nvd","cve.org","csaf","vex","red-hat","score-dispute"],"epss":0.00605,"epssPercentile":0.47356,"scores":{"nvd":9.8,"cna":9.8,"vendor":5.5},"ingestedAt":"2026-09-14T15:23:07.475Z","slug":"CVE-2026-89492","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nocfs2: validate directory-index entry counts when reading metadata\n\nocfs2_validate_dx_leaf() and ocfs2_validate_dx_root() check the ECC and\nsignature of an indexed-directory block before it reaches higher-level\ncallers, but neither validator bounds the ocfs2_dx_entry_list counts\nagainst the capacity of the block that holds them.\n\nocfs2_dx_dir_search() then walks\n\n\tfor (i = 0; i < le16_to_cpu(entry_list->de_num_used); i++)\n\t\tdx_entry = &entry_list->de_entries[i];\n\nover de_num_used entries with no bounds check.  entry_list is either\ndx_leaf->dl_list (from ocfs2_read_dx_leaf) or, for an inline root,\ndx_root->dr_entries.  A crafted on-disk image can set de_num_used (and\nde_count, which is the __counted_by_le() bound of de_entries) to 0xffff\nand make the walk read far past the end of the 4KB metadata block, giving\na slab out-of-bounds read reachable from any path lookup, stat() or open()\non an indexed directory once the image is mounted.\n\nCommit 775c17386a6f (\"ocfs2: validate dx_root extent list fields during\nblock read\") already bounds dr_list for the non-inline dx_root, but left\nthe inline dr_entries path and the dx_leaf dl_list unchecked.  Add the\nsame read-time validation for both entry lists: de_count must equal the\ncapacity of the block (ocfs2_dx_entries_per_leaf()/per_root()) and\nde_num_used must not exceed de_count, rejecting corrupted metadata with\n-EFSCORRUPTED before ocfs2_dx_dir_search() can walk an out-of-range entry\narray.\n\nde_count is always written as exactly the block capacity when a leaf or\ninline root is formatted, so the equality check does not reject any valid\nimage.\n\nFound by 0sec automated security-research tooling (https://0sec.ai).\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Vendor advisories\n\n- **Red Hat VEX** · Moderate · updated 2026-09-15 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89492.json)","depth":"midnight","depthScore":54,"depthScoreParts":{"impact":53.9,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[{"seq":208396,"id":"CVE-2026-89492","ts":1789997916777,"field":"cvss","old":"5.5","new":"9.8"},{"seq":208395,"id":"CVE-2026-89492","ts":1789997916777,"field":"severity","old":"medium","new":"critical"},{"seq":203883,"id":"CVE-2026-89492","ts":1789490210664,"field":"cvss","old":"4.1","new":"5.5"},{"seq":202903,"id":"CVE-2026-89492","ts":1789403732878,"field":"cvss","old":"9.8","new":"4.1"},{"seq":202902,"id":"CVE-2026-89492","ts":1789403732878,"field":"severity","old":"critical","new":"medium"},{"seq":198012,"id":"CVE-2026-89492","ts":1789384321379,"field":"cvss","old":"4.1","new":"9.8"},{"seq":198011,"id":"CVE-2026-89492","ts":1789384321379,"field":"severity","old":"medium","new":"critical"},{"seq":183518,"id":"CVE-2026-89492","ts":1789356675695,"field":"cvss","old":"9.8","new":"4.1"},{"seq":183517,"id":"CVE-2026-89492","ts":1789356675695,"field":"severity","old":"critical","new":"medium"},{"seq":153278,"id":"CVE-2026-89492","ts":1789285349855,"field":"cvss","old":null,"new":"9.8"},{"seq":153277,"id":"CVE-2026-89492","ts":1789285349855,"field":"severity","old":"none","new":"critical"},{"seq":147131,"id":"CVE-2026-89492","ts":1789270195816,"field":"cvss","old":null,"new":"4.1"},{"seq":147130,"id":"CVE-2026-89492","ts":1789270195816,"field":"severity","old":"none","new":"medium"},{"seq":108884,"id":"CVE-2026-89492","ts":1789183729399,"field":"cvss","old":null,"new":"4.1"},{"seq":108883,"id":"CVE-2026-89492","ts":1789183729399,"field":"severity","old":"none","new":"medium"}]}