CVE-2026-89617

/// Technical description

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.

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References