CVE-2026-72196

Technical Description

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

fs/ntfs3: bound copy_lcns dp->page_lcns[] index in analysis pass

In log_replay()'s analysis pass, after find_dp() returns a

valid DIR_PAGE_ENTRY for the (target_attr, target_vcn) tuple,

the copy_lcns block walks lrh->lcns_follow further entries:

t16 = le16_to_cpu(lrh->lcns_follow);

for (i = 0; i < t16; i++) {

size_t j = (size_t)(le64_to_cpu(lrh->target_vcn) -

le64_to_cpu(dp->vcn));

dp->page_lcns[j + i] = lrh->page_lcns[i];

}

find_dp() only validates that target_vcn falls within

[dp->vcn, dp->vcn + dp->lcns_follow), i.e., that the FIRST

cluster is covered. The walk through the further entries is

not bounded against dp->lcns_follow. For a malformed LRH

where target_vcn = dp->vcn + dp->lcns_follow - 1 and

lrh->lcns_follow > 1, the i > 0 writes overflow the dp's

allocated page_lcns[] array.

Add the missing j + lrh->lcns_follow <= dp->lcns_follow guard.

Reproduced under UML+KASA

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