From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.hallyn.com (mail.hallyn.com [178.63.66.53]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 26A0C2116F4; Fri, 5 Jun 2026 13:45:15 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=178.63.66.53 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780667118; cv=none; b=H8/nJC+2f4foDUW29G2oXcXp2GWjR7GQFqUTXrUe8pi5MhAOpsBezhyEvMCKfz9pTVkDHuAHlfPak/QGeNJaGv6JdICWHtlzExgnEmkhp56cd3CHZ0nfxuxhEzna2tEdZKEmftoK9kmsoQ7a5knHu7S8fwJnnkeOs9Hmg5Bg0oE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780667118; c=relaxed/simple; bh=56LzANDXLeGt3Cb3NBq35BfCpKLrBNw7dddTSmki2EU=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=ipNACXukckHZlZrapc1lTAc+5kZfC3FFRsleYFyTuzv6Zc3XP6PtgMlBh6cT8+holpr4yBkr0+7nNyF7yjGOCk4y3/MMmM1Lhcif8jLSlOvKtN41H6QY2CZdiEalU5TGfIlH7FkQETQ7edIOB3UJprXZbKtP635nXr9uKNNRwZQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=hallyn.com; spf=pass smtp.mailfrom=mail.hallyn.com; dkim=pass (2048-bit key) header.d=hallyn.com header.i=@hallyn.com header.b=n0ZpP+Te; arc=none smtp.client-ip=178.63.66.53 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=hallyn.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=mail.hallyn.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=hallyn.com header.i=@hallyn.com header.b="n0ZpP+Te" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=hallyn.com; s=mail; t=1780667108; bh=56LzANDXLeGt3Cb3NBq35BfCpKLrBNw7dddTSmki2EU=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=n0ZpP+Te0X9SSmdWCcprwUqZWAkVwIqSTx3ZKwkDyKkvpcRN7+apUNjlqMLp7PsT+ mfFmEqr8YIjYvxF1rpOMZXjuv6seUp77+IstHYHv3IWYzJgAHOon3TEF3YhGn8XWP/ XcL4L7thXDOq4Yh5TeGEJjeFkX+zx4ApvuXHHeW11oRCykTFVv301Xs7WgDrGMQPJ3 2Q8wgQI5QIXO1CuZ+BI1kpv5QbgByeFz66jCMaM+WWm4c9KXMwYrVCpgh3YGct71Al B2HDVOnOmc2cGfmnqKWPmAwxwUrWidE8KStjWqWQ9XBE4jhFwx7tH6ubOQhxeziHU9 K0GPkbyr4E0qg== Received: by mail.hallyn.com (Postfix, from userid 1001) id 069C1432; Fri, 5 Jun 2026 08:45:07 -0500 (CDT) Date: Fri, 5 Jun 2026 08:45:07 -0500 From: "Serge E. Hallyn" To: Linus Torvalds Cc: Paul Moore , linux-security-module@vger.kernel.org, Mark Brown , Blaise Boscaccy , Alexei Starovoitov , linux-next@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: -next status as at v7.1-rc6 Message-ID: References: <83f77b2b-8c00-424d-b6f9-b044e7ea1ee7@sirena.org.uk> Precedence: bulk X-Mailing-List: linux-security-module@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Thu, Jun 04, 2026 at 04:18:46PM -0700, Linus Torvalds wrote: > On Thu, 4 Jun 2026 at 15:23, Paul Moore wrote: > > > > While you didn't reply to any of my comments explaining how Hornet > > works, specifically how it ties into the kernel, I'm assuming you've > > read the overview. Can you help those of us in the LSM space > > understand why a BPF dev's NACK on code that lives strictly under > > security/ is sufficient grounds to reject an LSM patch? > > Honestly, I'm not competent to make a judgment call between two > different models for hash chain verification, so I basically *have* to > go by maintainer opinions. > > And the discussions I have been cc'd on have not been what I'd call > enlightening. > > But people have pointed out that the LSM code mucks around with bpf > internals, and those NAK's have had reasons for them. > > And honestly, I don't understand *why* Hornet does what it does - and > does it in ways that obviously annoy the bpf people. There is no > *reason* to look at the bpf maps that I can see, and from my > understanding of Alexei's arguments (which may be lacking), the fact > that Hornet does that is the main reason for the NAK. The two most useful threads I believe were from a year ago, 20250502184421.1424368-1-bboscaccy@linux.microsoft.com and 20250528215037.2081066-1-bboscaccy@linux.microsoft.com which includes the proposal by the BPF side: https://lore.kernel.org/linux-security-module/CACYkzJ6VQUExfyt0=-FmXz46GHJh3d=FXh5j4KfexcEFbHV-vg@mail.gmail.com/ There were 2 or three objections from each side iiuc, but the main ones that stuck in my mind were 1. whether it is ok to rely on a signed userspace bpf verifier program to verify the signature. 2. objection by James Bottomley (2f71d6c03698eb17d51f7247efde777627ee578a.camel@HansenPartnership.com) about the verifiability of the hash chain link. > But instead of working with the bpf people on coming up with some > model that does *not* do that, it all seems to have become a "we'll do > it anyway, despite maintainer complaints". > > And I *did* see the bpf people pointing to "this would be an > acceptable alternative" with KP Singh outlining something that *had* > been discussed. > > But I never actually saw anybody say "ok, we'll try that instead". > > Maybe I missed it. > > But from what I saw, it really looked like "I see NAK's from three > different bpf maintainers, with suggested alternate approaches". None > of which resulted in anything that looked like "ok, we'll try to > follow your guidance", only more of the same. > > Why would *my* input then make any difference? > > The bpf people's arguments resonated more with me. For example, the > whole "we need to know if it passed the bpf signature" seems to be > complate pointless silliness, and the bpf peoples responses to that > resonated with me. There's *no* point in any LSM check whether the > signature passed or not, since if it didn't pass, it's not getting > loaded. > > So that's basically where I stand - I've seen disagreement, and I've > seen what looks to me like reasonable push-back, and I've not really > seen the LSM response as taking it into account. > > Linus