CVE-2026-89617

In the Linux kernel, the following vulnerability has been resolved:

fs/ntfs3: validate dirty page table on log replay

Each DIR_PAGE_ENTRY ends in a page_lcns[] array whose length is the on-disk

lcns_follow field. check_rstbl() validates the table bookkeeping but never

checks that this array fits in the entry, so a crafted lcns_follow lets the

v0->v1 conversion memmove and later replay passes run off the entry.

Add check_dp_table() to reject, right after check_rstbl(), any entry larger

than its size claims via struct_size() (the same expression used to allocate

these entries, so the check is overflow-safe by construction). All consumers

can then trust lcns_follow as the real capacity. This covers every

page_lcns[] access whose index is bounded by the entry itself (the

conversion memmove, the HotFix store via find_dp(), and the self-bounded

scan loops). Accesses whose index comes from the log record need a separate

bound and are handled in a follow-up patch.