In the Linux kernel, the following vulnerability has been resolved: netfs: zero gaps in read-gaps folio to avoid writing back stale data… (CVE-2026-98843)

The vulnerability in the Linux kernel's netfs subsystem was caused by netfs_read_gaps() leaving gaps around a streaming write's dirty region unread on the server side. This resulted in stale folio content being written back when a short or EOF response was received. The remediation changes the zeroing of these gaps to occur after the read completes, using an iterator over the same bvec array to zero only the actual shortfall, avoiding touching the dirty region. This prevents stale data from being written back to storage.

The vulnerability could lead to stale data being written back to storage, potentially causing data corruption or integrity issues. There is no information about active exploitation or broader impact beyond the stale data write-back behavior.

A fix has been implemented in the Linux kernel to address this issue by zeroing the gaps after the read completes rather than before. Users should apply the official kernel update that includes this fix. No additional mitigations are specified.