{"id":"CVE-2026-63814","title":"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","summary":"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_…","severity":"none","published":"2026-07-19","updated":"2026-07-19","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-63814","references":[{"url":"https://git.kernel.org/stable/c/1ddf3fd21c4c652f9cab5552515c04a166662306","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/442ca20c54038e2400cf28aaa944cf1de2c8e65d","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/4e2a96ec7236e248e706850568e0a925fd21b588","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/5d8a39649947a4e86c8fbc682d7fc0041b8d109a","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/733cd8474e6d763d75ed96f3f2b98a25480cf2b9","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/aba4f94ac1832c7299c33e1b4fe5f87eef6dc8f1","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/c4810ada31e80cbe4011467c4f3b1e93f94134f3","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/ff83de56882cb8466184d322abece2589258ca56","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"tags":["nvd"],"ingestedAt":"2026-07-20T11:37:38.792Z","epss":0.00127,"epssPercentile":0.01981,"slug":"CVE-2026-63814","body":"## Overview\n\nIn 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 (?:?)\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}