CVE-2026-89615

/// Technical description

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

fs/ntfs3: bound page_lcns[] index by the log record

The copy_lcns loop and the redo shorten loop index page_lcns[] at j + i,

where i runs up to the log record's lcns_follow. That count is checked only

against the record's own length, not the target entry, so check_dp_table()

(which validates the entry's lcns_follow) does not cover it: the copy_lcns

entry may even be freshly allocated after that check, and find_dp() bounds j

but not i. A crafted record thus overflows page_lcns[] of an otherwise valid

entry.

Add dp_range_ok() and reject, before each loop, any record whose run does

not fit the entry. These are the only two page_lcns[] accesses indexed by

the record rather than the entry, so together with the entry validation

every access is now bounded.

[[email protected]: original patch contained changes to the problem already handled, applied partly]

/// 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