Zerocopy Send Vulnerability in Linux Kernel Affecting Networking Functions

CVE-2026-43502

What is CVE-2026-43502?

A vulnerability in the Linux kernel's networking functionality can lead to improper cleanup of zerocopy sends. This occurs when a zerocopy send operation fails after user pages are pinned but before the message is queued to the sending socket. The existing cleanup mechanism incorrectly assumes the state of zerocopy ownership based on an incomplete check. This vulnerability has been addressed by refining the cleanup process, ensuring that early send failures are handled consistently with the zerocopy lifecycle rules without altering the completion path for queued messages.

References