CVE-2026-43187

Technical Description

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

xfs: delete attr leaf freemap entries when empty

Back in commit 2a2b5932db6758 ("xfs: fix attr leaf header freemap.size

underflow"), Brian Foster observed that it's possible for a small

freemap at the end of the end of the xattr entries array to experience

a size underflow when subtracting the space consumed by an expansion of

the entries array. There are only three freemap entries, which means

that it is not a complete index of all free space in the leaf block.

This code can leave behind a zero-length freemap entry with a nonzero

base. Subsequent setxattr operations can increase the base up to the

point that it overlaps with another freemap entry. This isn't in and of

itself a problem because the code in _leaf_add that finds free space

ignores any freemap entry with zero size.

However, there's another bug in the freemap update code in _leaf_add,

which is that it fails to update a freemap entry that begins midwa

Remediation

Check the references section for vendor advisories and patches from linux. Update linux_kernel to the latest patched version. 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.

Affected Products

References