{"id":"CVE-2026-89786","summary":"ext4: fix out-of-bounds read in ext4_read_inline_dir()","details":"In the Linux kernel, the following vulnerability has been resolved:\n\next4: fix out-of-bounds read in ext4_read_inline_dir()\n\next4_read_inline_dir() can read a dirent header past the end of its inline\nbuffer, triggering a slab-out-of-bounds read during getdents64():\n\n  BUG: KASAN: slab-out-of-bounds in __ext4_check_dir_entry\n  Read of size 2 at addr ffff88800f3dd23c by task exploit/148\n   ...\n   __ext4_check_dir_entry\n   ext4_read_inline_dir\n   iterate_dir\n\nThe dirent payload lives in a buffer of exactly inline_size bytes:\n\n\tdir_buf = kmalloc(inline_size, GFP_NOFS);\n\nbut iteration runs in a position space extra_offset bytes larger\n(extra_size = extra_offset + inline_size) so the synthetic \".\" and \"..\"\nland at their block-dir offsets. A dirent is formed at \"dir_buf + pos -\nextra_offset\", yet the ext4_check_dir_entry() length argument uses the\nlarger extra_size. A position whose dirent header would extend past\nextra_size is therefore accepted, and the rescan loop's rec_len probe and\next4_check_dir_entry() dereference de-\u003erec_len before the entry is rejected.\n\nReject a position whose minimum-size dirent header would not fit within\nextra_size before forming de, in both the rescan and main loops, and pass\ninline_size rather than extra_size to ext4_check_dir_entry() so the length\ncheck matches the physical buffer.","modified":"2026-09-18T03:48:32.388428811Z","published":"2026-09-16T08:48:23.730Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89786.json","cna_assigner":"Linux"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/1a1dea633b724a1c042dbcdb1fed27f410916688"},{"type":"WEB","url":"https://git.kernel.org/stable/c/36bf17bb90cdf7a623499b624b05acde4d2feef5"},{"type":"WEB","url":"https://git.kernel.org/stable/c/5fd20d4e50dd6e460b3ea8e4396f8553d4526f8f"},{"type":"WEB","url":"https://git.kernel.org/stable/c/6702c7da86d8cdb88d0fc57166286e115ffeb8c0"},{"type":"WEB","url":"https://git.kernel.org/stable/c/9333cc809f0a89e001b814155a6cb8903a6274df"},{"type":"WEB","url":"https://git.kernel.org/stable/c/b060861f662d4826dc700a1c3584243bb3474cfe"},{"type":"WEB","url":"https://git.kernel.org/stable/c/d1e7c186555ad65554fd2f2b02f5a539aa35ae48"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89786.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89786"},{"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":"c4d8b0235aa98f8c26bf94d308be3fdd24154572"},{"fixed":"d1e7c186555ad65554fd2f2b02f5a539aa35ae48"},{"fixed":"5fd20d4e50dd6e460b3ea8e4396f8553d4526f8f"},{"fixed":"1a1dea633b724a1c042dbcdb1fed27f410916688"},{"fixed":"b060861f662d4826dc700a1c3584243bb3474cfe"},{"fixed":"6702c7da86d8cdb88d0fc57166286e115ffeb8c0"},{"fixed":"36bf17bb90cdf7a623499b624b05acde4d2feef5"},{"fixed":"9333cc809f0a89e001b814155a6cb8903a6274df"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-89786.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"3.10.0"},{"fixed":"5.15.221"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.1.188"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.157"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.110"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.52"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.2.6"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-89786.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H"}]}