CVE-2026-64357: xfs: fix exchmaps reservation limit check
In the Linux kernel, the following vulnerability has been resolved:
xfs: fix exchmaps reservation limit check
xfsexchmapsestimateoverhead() adds the bmbt and rmapbt overhead to a local resblks variable, but the final UINTMAX check still tests req->resblks. That is the reservation value from before the overhead was added.
The computed value is stored back in req->resblks and later passed to xfstransalloc(), whose block reservation argument is unsigned int. Check the computed reservation so the existing limit applies to the value that will be used.
Affected Software
Remediation
Event History
Frequently Asked Questions
What level of access is required to exploit this issue?
Exploitation requires local access and low privileges. No user interaction is required.
What is the expected security impact?
The reported impact is high availability impact, with no confidentiality or integrity impact indicated by the CVSS vector.
Is a fix available?
Yes. A patch is available, with fixes referenced in the Linux stable kernel repository.