> We're disabling a cryptographic performance enhancement feature entirely because there was a security bug in them that one time? It's a rather weird default to use.

The need for this feature/functionality in the fist place is questioned by some:

> As someone who works on the Linux kernel's cryptography code, the regularly occurring AF_ALG exploits are really frustrating. AF_ALG, which was added to the kernel many years ago without sufficient review, should not exist. It's very complex, and it exposes a massive attack surface to unprivileged userspace programs. And it's almost completely unnecessary, as userspace already has its own cryptography code to use. The kernel's cryptography code is just for in-kernel users (for example, dm-crypt).

> The algorithm being used in this [specific] exploit, "authencesn", is even an IPsec implementation detail, which never should have been exposed to userspace as a general-purpose en/decryption API. […]

* https://news.ycombinator.com/item?id=47952181#unv_47956312