{"cve":"CVE-2026-63814","nvd":{"published":"2026-07-19T12:16:54.390","modified":"2026-08-17T05:17:18.567","status":"Awaiting Analysis","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nf2fs: validate ACL entry sizes in f2fs_acl_from_disk()\n\nf2fs_acl_count() only validates the aggregate ACL xattr length. A\nmalformed ACL can still place ACL_USER or ACL_GROUP in a slot that only\ncontains struct f2fs_acl_entry_short bytes, and f2fs_acl_from_disk()\nthen reads entry->e_id before verifying that a full entry fits.\n\nRequire a short entry before reading e_tag and e_perm, and require a\nfull entry before reading e_id for ACL_USER and ACL_GROUP. Return\n-EFSCORRUPTED from these new truncated-entry checks, while keeping the\npre-existing -EINVAL paths unchanged.\n\nValidation reproduced this kernel report:\nKASAN slab-out-of-bounds in __f2fs_get_acl+0x6fb/0x7e0\nRIP: 0033:0x7f4b835ea7aa\nThe buggy address belongs to the object at ffff888114589960 which belongs\nto the cache kmalloc-8 of size 8\nThe buggy address is located 0 bytes to the right of allocated 8-byte\nregion [ffff888114589960, ffff888114589968)\nRead of size 4\nCall trace:\n  dump_stack_lvl+0x66/0xa0 (?:?)\n  print_report+0xce/0x630 (?:?)\n  __f2fs_get_acl+0x6fb/0x7e0 (fs/f2fs/acl.c:169)\n  srso_alias_return_thunk+0x5/0xfbef5 (?:?)\n  __virt_addr_valid+0x224/0x430 (?:?)\n  kasan_report+0xe0/0x110 (?:?)\n  __f2fs_get_acl+0x5/0x7e0 (fs/f2fs/acl.c:169)\n  __get_acl+0x281/0x380 (?:?)\n  vfs_get_acl+0x10b/0x190 (?:?)\n  do_get_acl+0x2a/0x410 (?:?)\n  do_get_acl+0x9/0x410 (?:?)\n  do_getxattr+0xe8/0x260 (?:?)\n  filename_getxattr+0xd1/0x140 (?:?)\n  do_getname+0x2d/0x2d0 (?:?)\n  path_getxattrat+0x16c/0x200 (?:?)\n  lock_release+0xc8/0x290 (?:?)\n  cgroup_update_frozen+0x9d/0x320 (?:?)\n  lockdep_hardirqs_on_prepare+0xea/0x1a0 (?:?)\n  trace_hardirqs_on+0x1a/0x170 (?:?)\n  _raw_spin_unlock_irq+0x28/0x50 (?:?)\n  do_syscall_64+0x115/0x6a0 (arch/x86/entry/syscall_64.c:87)\n  entry_SYSCALL_64_after_hwframe+0x77/0x7f (?:?)","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":7.8},"cwes":[],"references":["https://git.kernel.org/stable/c/1ddf3fd21c4c652f9cab5552515c04a166662306","https://git.kernel.org/stable/c/442ca20c54038e2400cf28aaa944cf1de2c8e65d","https://git.kernel.org/stable/c/4e2a96ec7236e248e706850568e0a925fd21b588","https://git.kernel.org/stable/c/5d8a39649947a4e86c8fbc682d7fc0041b8d109a","https://git.kernel.org/stable/c/733cd8474e6d763d75ed96f3f2b98a25480cf2b9"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:45:36.895656543+00:00"},"epss":{"cve":"CVE-2026-63814","score":0.00127,"percentile":0.02358,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}