Linux kernel (net/tls): When the crypto queue is full the AEAD call returns -EBUSY instead of -EINPROGRESS and the

Impact

When the crypto queue is full the AEAD call returns -EBUSY instead of -EINPROGRESS and the async callback fires twice. kTLS treated that as an error and unwound buffers the callback still owns, giving a double-release of record memory on a node under crypto load.

Who can reach it

Remote peers supply the record volume; the trigger is a saturated cryptd queue, which a co-tenant driving heavy kTLS or dm-crypt traffic produces on the same node. Any kTLS socket is in scope, no privilege needed. Requires a backlog-capable async AEAD (cryptd/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, or raise cryptd queue limits so the backlog path is not hit.

References