{"id":"CVE-2026-72225","summary":"jbd2: fix integer underflow in jbd2_journal_initialize_fast_commit()","details":"In the Linux kernel, the following vulnerability has been resolved:\n\njbd2: fix integer underflow in jbd2_journal_initialize_fast_commit()\n\njbd2_journal_initialize_fast_commit() validates journal capacity by\nchecking (journal-\u003ej_last - num_fc_blks \u003c JBD2_MIN_JOURNAL_BLOCKS).\nBoth j_last and num_fc_blks are unsigned, so when num_fc_blks exceeds\nj_last the subtraction wraps to a large value, bypassing the bounds\ncheck.\n\nThe resulting underflow corrupts j_last, j_fc_first, and j_free,\nleading to journal abort.\n\nFix by checking num_fc_blks against j_last before the subtraction,\nreturning -EFSCORRUPTED.","modified":"2026-08-25T03:51:27.629255052Z","published":"2026-08-15T05:54:17.541Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/72xxx/CVE-2026-72225.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/289a2ca0c9b7eae74f93fc213b0b971669b8683d"},{"type":"WEB","url":"https://git.kernel.org/stable/c/4450dcaadf7d4aae8b6e4223b5d6ee4eb77097a9"},{"type":"WEB","url":"https://git.kernel.org/stable/c/4b48dcb88bb9117e3d3f051175a9a8b7cff7f8b6"},{"type":"WEB","url":"https://git.kernel.org/stable/c/78955fdce8ff654e6d33a2fa90882a1e7eb26330"},{"type":"WEB","url":"https://git.kernel.org/stable/c/a58fc10adf503969fec2007b5afe8987258046c4"},{"type":"WEB","url":"https://git.kernel.org/stable/c/aa90f00932bf572d6ef284c977c2a60b39c13bd6"},{"type":"WEB","url":"https://git.kernel.org/stable/c/e144ad0250f77e23e28949587b8b57e40dc3b512"},{"type":"WEB","url":"https://git.kernel.org/stable/c/fb9b49618ed7296ebfad62a3835da8945f727001"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/72xxx/CVE-2026-72225.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-72225"},{"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":"6866d7b3f2bb4f011041ba54c98b1584497fe2fd"},{"fixed":"aa90f00932bf572d6ef284c977c2a60b39c13bd6"},{"fixed":"e144ad0250f77e23e28949587b8b57e40dc3b512"},{"fixed":"4b48dcb88bb9117e3d3f051175a9a8b7cff7f8b6"},{"fixed":"fb9b49618ed7296ebfad62a3835da8945f727001"},{"fixed":"4450dcaadf7d4aae8b6e4223b5d6ee4eb77097a9"},{"fixed":"78955fdce8ff654e6d33a2fa90882a1e7eb26330"},{"fixed":"a58fc10adf503969fec2007b5afe8987258046c4"},{"fixed":"289a2ca0c9b7eae74f93fc213b0b971669b8683d"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-72225.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"5.10.0"},{"fixed":"5.10.266"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.11.0"},{"fixed":"5.15.212"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.1.178"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.145"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.97"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.40"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.1.5"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-72225.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"}]}