CVE-2026-90384

/// Technical description

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

iomap: release the folio batch on iomap callback failures

A sashiko review of an unrelated patch points out that the folio

batch mechanism used for iomap zero range fails to release the batch

in a couple error scenarios. If either calls to ->iomap_end() or

->iomap_begin() fail, the direct return paths bypass the batch

cleanup.

The ->iomap_end() case is not a practical issue at the moment

because there is no user of the mechanism that returns an error from

this path. The ->iomap_begin() case is theoretically possible

because XFS can invoke the fill helper and error out at various

points thereafter. This subtly complicates things because XFS does

not transfer iomap_flags to the iomap data structure in the error

path.

To deal with both of these issues, first make sure to invoke the

cleanup helper in the error path for either fs callback. Second,

update the helper to clear the flag unconditionally and release the

batch

/// 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