{"id":"CVE-2026-63817","summary":"f2fs: validate compress cache inode only when enabled","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nf2fs: validate compress cache inode only when enabled\n\nF2FS_COMPRESS_INO() uses NM_I(sbi)-\u003emax_nid as the synthetic inode\nnumber for the compressed page cache inode. That inode only exists when\nthe compress_cache mount option is enabled.\n\nWhen compress_cache is disabled, max_nid is outside the valid inode\nrange. A corrupted directory entry that points to ino == max_nid should\ntherefore be rejected by f2fs_check_nid_range(). However, is_meta_ino()\ncurrently treats F2FS_COMPRESS_INO() as a meta inode unconditionally,\nso f2fs_iget() bypasses do_read_inode() and its nid range check, and\ninstantiates a fake internal inode instead.\n\nGate the compressed cache inode case on COMPRESS_CACHE, matching\nf2fs_init_compress_inode(). With compress_cache disabled, ino ==\nmax_nid now follows the normal inode path and is rejected as an\nout-of-range nid.","modified":"2026-10-08T02:51:28.839184386Z","published":"2026-07-19T12:02:16.441Z","related":["openSUSE-SU-2026:11339-1"],"database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/63xxx/CVE-2026-63817.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/0969926d987bbde9a1aa49da317582ba37095805"},{"type":"WEB","url":"https://git.kernel.org/stable/c/13e4b59d3a9413f66f116fa6c4828519b960a5ea"},{"type":"WEB","url":"https://git.kernel.org/stable/c/16161444c30d8dff9428abbae42b72ce4e32a932"},{"type":"WEB","url":"https://git.kernel.org/stable/c/29115b8c9172d34e67ab26cc4f6c209b7a236d7a"},{"type":"WEB","url":"https://git.kernel.org/stable/c/5073c66a96a9c23c0c2533ed4ed06e42f9021208"},{"type":"WEB","url":"https://git.kernel.org/stable/c/77f216ff9ce5cde8eed9f6d12707e906dffdc9f7"},{"type":"WEB","url":"https://git.kernel.org/stable/c/fcc051d377a9701a452e7663a1a8223c26225df9"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/63xxx/CVE-2026-63817.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-63817"},{"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":"6ce19aff0b8cd386860855185c6cd79337fc4d2b"},{"fixed":"fcc051d377a9701a452e7663a1a8223c26225df9"},{"fixed":"29115b8c9172d34e67ab26cc4f6c209b7a236d7a"},{"fixed":"13e4b59d3a9413f66f116fa6c4828519b960a5ea"},{"fixed":"16161444c30d8dff9428abbae42b72ce4e32a932"},{"fixed":"77f216ff9ce5cde8eed9f6d12707e906dffdc9f7"},{"fixed":"0969926d987bbde9a1aa49da317582ba37095805"},{"fixed":"5073c66a96a9c23c0c2533ed4ed06e42f9021208"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"5.13.19"},{"fixed":"5.14"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"a23706426da9b611be5beae0f3faa260fb453b4e"}]}],"versions":["v5.13.19"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-63817.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"5.14.0"},{"fixed":"5.15.212"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.1.177"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.144"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.95"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.38"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.1.3"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-63817.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"}]}