Linux kernel (net/tls): The async decrypt completion released pages that the decrypt path never took a reference on, so

Impact

The async decrypt completion released pages that the decrypt path never took a reference on, so a partially-read record left the receive list pointing at freed pages. The next read walks freed memory - a network-driven use-after-free in the kTLS receive path.

Who can reach it

Remote: a peer sends records to a kTLS RX socket while the local reader does partial reads (a short recv() buffer is enough). Any kTLS connection on the node qualifies; no local privilege or device node required. Async decrypt must be in play, i.e. an async-capable AEAD driver such as cryptd-backed AES-NI.

What to do

Boot a kernel carrying the linked stable commits, along with the rest of the tls async-decrypt series. Interim: disable async crypto offload for kTLS.

References