{"id":"CVE-2026-74350","summary":"ocfs2: validate fast symlink target during inode read","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nocfs2: validate fast symlink target during inode read\n\nocfs2_validate_inode_block() already rejects several inconsistent\nself-contained dinodes before they are exposed to the rest of the\nfilesystem.  Fast symlinks need the same treatment.\n\nA zero-cluster symlink is treated as a fast symlink and later read through\npage_get_link() and ocfs2_fast_symlink_read_folio().  That path uses\nstrnlen() on the inline payload and then copies len + 1 bytes into the\nfolio.  If a corrupt dinode stores an i_size that does not fit the inline\narea or omits the terminating NUL at i_size, that copy reads past the end\nof the inode block buffer.\n\nReject zero-cluster symlink dinodes whose i_size exceeds the inline\nfast-symlink capacity or whose inline payload is not NUL-terminated\nexactly at i_size when the inode block is validated.  This keeps malformed\nfast symlinks from reaching the read path.\n\nValidation reproduced this kernel report:\nKASAN use-after-free in ocfs2_fast_symlink_read_folio+0x12c/0x1f0\nRIP: 0033:0x7f5c6d859aa7\nRead of size 3905\nCall trace:\n  dump_stack_lvl+0x66/0xa0 (?:?)\n  print_report+0xce/0x630 (?:?)\n  ocfs2_fast_symlink_read_folio+0x12c/0x1f0 (fs/ocfs2/inode.c:?)\n  srso_alias_return_thunk+0x5/0xfbef5 (?:?)\n  __virt_addr_valid+0x19f/0x330 (?:?)\n  kasan_report+0xe0/0x110 (?:?)\n  kasan_check_range+0x105/0x1b0 (?:?)\n  __asan_memcpy+0x23/0x60 (?:?)\n  filemap_read_folio+0x27/0xe0 (?:?)\n  filemap_read_folio+0x35/0xe0 (?:?)\n  do_read_cache_folio+0x138/0x230 (?:?)\n  __page_get_link+0x26/0x110 (?:?)\n  page_get_link+0x2e/0x70 (?:?)\n  vfs_readlink+0x15e/0x250 (?:?)\n  touch_atime+0x4d/0x370 (?:?)\n  do_readlinkat+0x186/0x200 (?:?)\n  do_user_addr_fault+0x65a/0x890 (?:?)\n  __x64_sys_readlink+0x46/0x60 (?:?)\n  do_syscall_64+0x115/0x6a0 (arch/x86/entry/syscall_64.c:87)\n  entry_SYSCALL_64_after_hwframe+0x77/0x7f (?:?)","modified":"2026-08-18T04:17:30.620642983Z","published":"2026-08-15T05:58:37.298Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/74xxx/CVE-2026-74350.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/e234973f286ed2e8961a24561ec91594ec3e3ff8"},{"type":"WEB","url":"https://git.kernel.org/stable/c/f9e2cb692b77a679b1f4cc2b7b277fa908586533"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/74xxx/CVE-2026-74350.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-74350"},{"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":"ea022dfb3c2a4680483b00eb2fecc9fc4f6091d1"},{"fixed":"f9e2cb692b77a679b1f4cc2b7b277fa908586533"},{"fixed":"e234973f286ed2e8961a24561ec91594ec3e3ff8"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-74350.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"3.5.0"},{"fixed":"7.1.5"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-74350.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:H/A:H"}]}