From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794755739; b=yrwgL+FyfjfCgFhHZORxqPQ2X0wUNUltSDowK/QuDH+siNASFuJDv5IMKUlZwNCnSgUU KJDHZIo8LX9pKptoDkJPtL6h2geg+iVCbFPEzV1jkbp5o9c9Jfq+Fu+dlTlTxy4Ys8Z4C 3Ez7M0ZmUXDewn0bVIZHudimaT8BmIclZsorpJgU67vUgjreKHK+fpRXQ8iknoumHCxAk DqZ+oHJtRoKUnSAyhf4yAO31+riEo9nlWLOKitTtPZlarGU9dQCOCD3rGP1hvApmhmJ+0 AW9igpxuI5CCWWE1JfpwTEgdBocZkY6vydT49xEqg3kNBR+txURuSOMPmRgitxvNYWg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794755739; h=Received:DKIM-Signature:Date:From:To:Cc:Subject:Message-ID: References:MIME-Version:Content-Type:Content-Disposition:In-Reply-To; bh=ZMJp4/fulOCGDmJoG0GQAtDWGPmAgWD+3y7C5zmC73o=; b=E1ikWI3LEuBSSUxbLi8/fpbUtNtUQ3tI7xXOifDvXYk6spFeNeAMxDpR4N8vxoN3iqvn O2QvDHW6xNLovMlA4LFXiQCY9QWZSz2RPixj3VXkCnvbPS6XGHOaGSqk12Xh79jbYsUGV BReBBo1Po04TBvbpdChtBIcqPbrV6LwWzYOEtj4LNJAhKZcTVXzWW8edPL0Mz+whCrEjg uB1of66pWpp3O+O+yqjN9vrTaVGe9BYl+mn//zHndStKXLb6oN+DhWXG+Ac0aFvR4VTHp 17Wu1DubEehnjVYpehmsOqZTbfYOfY2W2AeE1Wa2ncYF3yqGBOexrF6W3DiY5HE/XaQ== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=aPRY9RWp; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with UTF8SMTPS id 1177B606A31A; Sun, 15 Nov 2026 15:15:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=aPRY9RWp Received: by smtp.kernel.org (Postfix) with UTF8SMTPSA id 3E3441F000C4; Sun, 15 Nov 2026 15:15:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794755738; bh=ZMJp4/fulOCGDmJoG0GQAtDWGPmAgWD+3y7C5zmC73o=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=aPRY9RWpolvNu0ag3CuefduZM1tVexeZetcAmcbNFYRetdmAMXdX7fEMloTnd6wYi 1cON5uNR5P4Ovloj8oBK9c3iutcAZsvRmrwgWhBBmL9gjy3Th1zffytgqbboASJ7gJ PJOTqPfZbfuBEtf53QhTXWeDrxhwakxuIJUQb7ip/PUOEn/Iab9EK9KJJxAehkJvbg 8Gm41Me2v8ZXwi3WrWfPMyYGcdIVL2XK7YsLtlJFR5GsZjEJQgsr6nApb2/DN9nr3l kh85fCmUYRLMjf5ZX5Ia/aO43VdVshLb8hjrdZz+VlQX68N/ocgJdEbyF72woI8vrX YltI13ozcILdg== Date: Sun, 15 Nov 2026 17:15:35 +0200 From: Jarkko Sakkinen To: Matthew Garrett Cc: James Bottomley , Matthew Garrett , keyrings@vger.kernel.org, linux-integrity@vger.kernel.org, rafael@kernel.org, linux-pm@vger.kernel.org, linux-efi@vger.kernel.org Subject: Re: [PATCH 01/17] tpm: Define a kernel-owned TPM NV index that can't be modified by userland Message-ID: References: <20261008132532.1155166-1-matthewg@nvidia.com> <20261008132532.1155166-2-matthewg@nvidia.com> <435907614242e82ecde1767a967a3110fca6fb37.camel@HansenPartnership.com> <059384e86fd256618498b9a7214b6421d38fdf1f.camel@HansenPartnership.com> X-Mailing-List: linux-pm@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Sun, Oct 11, 2026 at 04:28:33AM -0700, Matthew Garrett wrote: > On Sun, Oct 11, 2026 at 12:27:58PM +0200, James Bottomley wrote: > > On Sun, 2026-10-11 at 03:23 -0700, Matthew Garrett wrote: > > > Hmm. Well, that's irritating. Which year's XPS is this? > > > > It's an XPS-13 9380 Core i7 ... circa 2019 I think. > > Yes, that's definitely later than I hoped. Bother. I think this patchset > is probably still worthwhile because it does unblock us on at least some > machines, and the implementation is intended to be opaque (other than > the change in PCR 5 measurements, but we should still get log replay) > and can be replaced with something else if we want. The other approach > that springs to mind is tying this to having distros switch to a new > kernel signing key before enabling this and so having PCR 7 be > associated with the feature, but that sounds like an incredibly tedious > thing to get right in a reliable way. What prevents blocking PCR 5 access from /dev/tpm*? If firmware already, does it, this can only add defense-in-depth. This feels way too obvious question to ask so I presume I'm missing something. Br, Jarkko