The Linux kernel contained a vulnerability in the xsk zero-copy transmit path where TX metadata was validated initially but then read again later during hardware request preparation. This allowed user space to change the metadata between these operations, effectively bypassing the original validation. The patch addresses this by validating metadata once in xsk_tx_metadata_request() and using the resulting flags snapshot for all feature checks, ensuring consistent and secure processing of metadata by zero-copy drivers.

The vulnerability could allow user space to bypass metadata validation in the zero-copy transmit path, potentially leading to inconsistent or unauthorized hardware requests. No specific exploitation details or impacts such as privilege escalation or denial of service are provided.

A fix has been implemented in the Linux kernel to validate metadata once and use a consistent snapshot for all processing steps. Users should apply the official kernel update that includes this patch. Patch status is not explicitly confirmed in the provided data; check the vendor advisory or Linux kernel mailing lists for the exact fixed versions and update accordingly.