CVE-2026-90259

/// Technical description

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

btrfs: qgroup: fix a wrong length calculation in qgroup_free_reserved_data()

In that function, we round down the start position and round up the

ending position.

But during the calculation of @len, we use "round_up(start + len,

sectorsize)", which is the rounded up end position, not the rounded up

length.

Which results a much larger length, and later we are still using

"start + len", which is completely incorrect.

Fix it by declaring a local @aligned_start and @aligned_len and use them

instead.

/// 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