Re: [PATCH] crypto: af_alg - Document the deprecation of AF_ALG

From: Eric Biggers

Date: Tue Jun 23 2026 - 15:22:44 EST


On Tue, Jun 23, 2026 at 11:56:10AM -0700, Linus Torvalds wrote:
> On Tue, 23 Jun 2026 at 09:51, Eric Biggers <ebiggers@xxxxxxxxxx> wrote:
> >
> > We're aware of that and are taking it into account in the allowlist:
>
> Note that if we can just unconditionally make it depend on
> CAP_NET_ADMIN, that would be good - independently of any allowlist.
>
> Because if iwd and abluetoothd are the main two users, and both of
> those already require CAP_NET_ADMIN anyway...

There's also cryptsetup, including unprivileged benchmarking and also
(in theory) formatting support, and pre-7.0 versions of iproute2 which
used it for computing SHA-1 hashes of BPF programs.

If we broke unprivileged 'cryptsetup benchmark', some people would
definitely notice. However, since it's just a manually-run benchmark
anyway, users could just run it with sudo.

I don't know about the iproute2 case.

It depends how aggressive we want to be. My current proposal
(https://lore.kernel.org/linux-crypto/20260622234803.6982-1-ebiggers@xxxxxxxxxx/)
has the entries in the allowlist marked as either privileged or
unprivileged. There are just a few unprivileged ones, for cryptsetup
and iproute2 as mentioned. But we could try doing away with the
unprivileged ones entirely and see who complains.

- Eric