CVE-2026-43502

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

net/rds: handle zerocopy send cleanup before the message is queued

A zerocopy send can fail after user pages have been pinned but before the message is attached to the sending socket.

The purge path currently infers zerocopy state from rm->mrs, so an unqueued message can be cleaned up as if it owned normal payload pages. However, zerocopy ownership is really determined by the presence of opmmp_znotifier, regardless of whether the message has reached the socket queue.

Capture opmmpznotifier up front in rdsmessagepurge() and use it as the cleanup discriminator. If the message is already associated with a socket, keep the existing completion path. Otherwise, drop the pinned page accounting directly and release the notifier before putting the payload pages.

This keeps early send failure cleanup consistent with the zerocopy lifetime rules without changing the normal queued completion path.