From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wm2-f13.google.com (mail-wm2-f13.google.com [74.125.225.141]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7C61D33A9FE for ; Mon, 5 Oct 2026 06:20:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=74.125.225.141 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791181219; cv=none; b=pG0GrQN73jueYiVs42OOHatf+PGoee67Y+VGW/uzviPENwQhS/UKwqnqNMpM2RCZkfV/tcMKeVk23bjAW56JAJPkPslhywatpiCs5BGpmxEuJad9+YV7N1HYcX+WialDJp3MegLQ+CHJcrBDQDZR0HzHxY7eDvIeqRJlU5AxfNg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791181219; c=relaxed/simple; bh=0ExWA1l1yPQaHfCJdCeIV2uvEiOA/vQlQ+Irax5DPyI=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=dostawjwZBNKGR812H6u+34nTGjKsc5/c+GphZRbmFC4XE1Hr8JUSOluWxgFth73n+0AAJGxoBFWr8ctU93K6oQ5EZ+z6YBlQpoPN5BeBlEGrmzaXDU6cRWohbJVC7+UiXe4WxAUJTw524v+7tKkRrAfO8bTOFnFkvpMXMXnOks= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=q9KBmsWh; arc=none smtp.client-ip=74.125.225.141 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="q9KBmsWh" Received: by mail-wm2-f13.google.com with SMTP id 5b1f17b1804b1-49ccf3ca626so8883855e9.0 for ; Sun, 04 Oct 2026 23:20:17 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1791181216; x=1791786016; darn=vger.kernel.org; h=content-transfer-encoding:content-type:in-reply-to:autocrypt:from :content-language:references:cc:to:subject:user-agent:mime-version :date:message-id:from:to:cc:subject:date:message-id:reply-to :content-type; bh=l0FuaBTKJktE8SOUhXZCNhOW7/MvZW2r4riGHbubmm4=; b=q9KBmsWhfZMVyRclrbFV8f7IbGpLSWluuU/gbU3jxm8cOtIjRVFba2WSHKwaRrkqcb 1fhHLrT5EgPRFh5riFLIzyoNsDN1UqKStbwOjTMNTe4EggulZPSZfaNwGtj3oi+EzGak jE239znaCP7800R0O6f3/nB1goV1SDFU6ZPEXbgZ/i4qB65caC7YCOIqfmkZWUPW17Ey i89SREcmNpZev12POteSKn1kMaCRGbUsPHEGWWtdYzsodAHIspHZ/br+QeoGnZ+6O3kY z3PfqvcR1oc2PG+7TgHYW4wSYll+zTPBU9RFMia80L+kMkvBoph3GxadP3gxefx2LrG5 eJKg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1791181216; x=1791786016; h=content-transfer-encoding:content-type:in-reply-to:autocrypt:from :content-language:references:cc:to:subject:user-agent:mime-version :date:message-id:x-gm-gg:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to:content-type; bh=l0FuaBTKJktE8SOUhXZCNhOW7/MvZW2r4riGHbubmm4=; b=AbX+F82hV1RH7SkXuH73Ilg9tVakpnjWGFJUfpDkUxwbe0E7qDAOhFPabwBRoQw1oU PlGJw9V9OCk8CkfpXF/Nhfzof7gEGF8tpsHoKHBXKOl+dwvnhxcOgjOIUkNvNRXmriaU Tm99LY/HAeB0s14UY6i05WJtLR4S8N3SgfQFxuOovSgT6Ak0/RB6GVm+7NTVC0LnkLkq SzqJI4LmHU6Vy3KXcMaQ2O+tadUbmu0lVbvbKcURl/SuRqxPS1IqPAvwgeHCywAPRqXb +jtxKuRnsuNG3aDW+fuHny6QgFnR8829LCeGEeE+RAu7mI/yAw7psyeWV3U+/SofKiWC ZtGQ== X-Forwarded-Encrypted: i=1; AKwUvBzyyoEJ9pXIlAD7FiBUvjeA2MwhLenBY1kGD/kPwj+/G46kXVaRlvoEK2CY0wb07z8wz0Om8ETVZRbjSPQ=@vger.kernel.org X-Gm-Message-State: AFuF++kQENakBDUnMHXZpZMmoL/cbElmTH7d0gJpIXkbAwmXYNDBEvw8 myYIoE9u6pBPWAZclfpSFJeOZ7vA/ofAztZi095BfsTGY9WkbX14kEYQ X-Gm-Gg: AYBFou0A1fxlhSbvKQS5WTFPM3QHzCaXSYyfFAjWXlwUX8NieP/NqEiQiubRZmC99iB 8xuuptkT0tjFSkMcNGYwClPqJ74Cdn6CmOQ/YBRp+rDAgEKNkEqunDDy1sWmnlSNOXhqJo10DJF tZSKzykiCk0bNyZ0RollU2bexq7KuUQG6Wb7aOSasfLHn6R/gDJGuHJ05XXvZECuYmDAAQuuqDz fmUlRNm7InXW/5H7z/NmABMS39Ta90tm8kO4UZ/sj4rP+GxIFjP6uD4nDJJ9F965mPt5rxbF4E2 sRkv1A2TWzjhW/5KKRNtsDB3N8M8XjW8I3tUxUeaVOKzzr2sS8impLtX845gFZmRgTrVO9SfnNH WgZLCQRnxOkkDMx8TAWkKvR++q/Xo54/k14WQVJAnj6CRsAwRp57giwubeO2bJfwF7iak2cOt7H U133bXxs0OEMuzv589jgn4FH8FzH9OuduEuQHbA3mELvhutyD/Hw0cE5yAiqzDeizX8WE7sIk= X-Received: by 2002:a05:600c:1e0f:b0:49e:6249:268b with SMTP id 5b1f17b1804b1-4a027697ef2mr157549445e9.32.1791181215479; Sun, 04 Oct 2026 23:20:15 -0700 (PDT) Received: from [192.168.1.109] ([178.17.7.30]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-48c622704a5sm3189409f8f.15.2026.10.04.23.20.14 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sun, 04 Oct 2026 23:20:15 -0700 (PDT) Message-ID: Date: Mon, 5 Oct 2026 08:20:14 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [RFC PATCH 1/1] dm-integrity: support keys in the kernel keyring To: Eric Biggers Cc: Mikulas Patocka , Lorenz Kofler , Mike Snitzer , Benjamin Marzinski , Alasdair Kergon , dm-devel@lists.linux.dev, linux-kernel@vger.kernel.org, upstream+dm@sigma-star.at, David Howells , Jarkko Sakkinen , keyrings@vger.kernel.org References: <20260928062734.3805458-1-lorenz@sigma-star.at> <20260928062734.3805458-2-lorenz@sigma-star.at> <6e7bd72b-6f1a-211d-16a8-a35a530af408@redhat.com> <1e53661e-42f4-72b2-3331-33af21e9fe0f@redhat.com> <20261002201419.GA205250@google.com> <20261004172934.GC1906@quark> Content-Language: en-US From: Milan Broz Autocrypt: addr=gmazyland@gmail.com; keydata= xsFNBE94p38BEADZRET8y1gVxlfDk44/XwBbFjC7eM6EanyCuivUPMmPwYDo9qRey0JdOGhW hAZeutGGxsKliozmeTL25Z6wWICu2oeY+ZfbgJQYHFeQ01NVwoYy57hhytZw/6IMLFRcIaWS Hd7oNdneQg6mVJcGdA/BOX68uo3RKSHj6Q8GoQ54F/NpCotzVcP1ORpVJ5ptyG0x6OZm5Esn 61pKE979wcHsz7EzcDYl+3MS63gZm+O3D1u80bUMmBUlxyEiC5jo5ksTFheA8m/5CAPQtxzY vgezYlLLS3nkxaq2ERK5DhvMv0NktXSutfWQsOI5WLjG7UWStwAnO2W+CVZLcnZV0K6OKDaF bCj4ovg5HV0FyQZknN2O5QbxesNlNWkMOJAnnX6c/zowO7jq8GCpa3oJl3xxmwFbCZtH4z3f EVw0wAFc2JlnufR4dhaax9fhNoUJ4OSVTi9zqstxhEyywkazakEvAYwOlC5+1FKoc9UIvApA GvgcTJGTOp7MuHptHGwWvGZEaJqcsqoy7rsYPxtDQ7bJuJJblzGIUxWAl8qsUsF8M4ISxBkf fcUYiR0wh1luUhXFo2rRTKT+Ic/nJDE66Ee4Ecn9+BPlNODhlEG1vk62rhiYSnyzy5MAUhUl stDxuEjYK+NGd2aYH0VANZalqlUZFTEdOdA6NYROxkYZVsVtXQARAQABzSBNaWxhbiBCcm96 IDxnbWF6eWxhbmRAZ21haWwuY29tPsLBlQQTAQgAPwIbAwYLCQgHAwIGFQgCCQoLBBYCAwEC HgECF4AWIQQqKRgkP95GZI0GhvnZsFd72T6Y/AUCYaUUZgUJJPhv5wAKCRDZsFd72T6Y/D5N D/438pkYd5NyycQ2Gu8YAjF57Od2GfeiftCDBOMXzh1XxIx7gLosLHvzCZ0SaRYPVF/Nr/X9 sreJVrMkwd1ILNdCQB1rLBhhKzwYFztmOYvdCG9LRrBVJPgtaYqO/0493CzXwQ7FfkEc4OVB uhBs4YwFu+kmhh0NngcP4jaaaIziHw/rQ9vLiAi28p1WeVTzOjtBt8QisTidS2VkZ+/iAgqB 9zz2UPkE1UXBAPU4iEsGCVXGWRz99IULsTNjP4K3p8ZpdZ6ovy7X6EN3lYhbpmXYLzZ3RXst PEojSvqpkSQsjUksR5VBE0GnaY4B8ZlM3Ng2o7vcxbToQOsOkbVGn+59rpBKgiRadRFuT+2D x80VrwWBccaph+VOfll9/4FVv+SBQ1wSPOUHl11TWVpdMFKtQgA5/HHldVqrcEssWJb9/tew 9pqxTDn6RHV/pfzKCspiiLVkI66BF802cpyboLBBSvcDuLHbOBHrpC+IXCZ7mgkCrgMlZMql wFWBjAu8Zlc5tQJPgE9eeQAQrfZRcLgux88PtxhVihA1OsMNoqYapgMzMTubLUMYCCsjrHZe nzw5uTcjig0RHz9ilMJlvVbhwVVLmmmf4p/R37QYaqm1RycLpvkUZUzSz2NCyTcZp9nM6ooR GhpDQWmUdH1Jz9T6E9//KIhI6xt4//P15ZfiIs7BTQRPeKd/ARAA3oR1fJ/D3GvnoInVqydD U9LGnMQaVSwQe+fjBy5/ILwo3pUZSVHdaKeVoa84gLO9g6JLToTo+ooMSBtsCkGHb//oiGTU 7KdLTLiFh6kmL6my11eiK53o1BI1CVwWMJ8jxbMBPet6exUubBzceBFbmqq3lVz4RZ2D1zKV njxB0/KjdbI53anIv7Ko1k+MwaKMTzO/O6vBmI71oGQkKO6WpcyzVjLIip9PEpDUYJRCrhKg hBeMPwe+AntP9Om4N/3AWF6icarGImnFvTYswR2Q+C6AoiAbqI4WmXOuzJLKiImwZrSYnSfQ 7qtdDGXWYr/N1+C+bgI8O6NuAg2cjFHE96xwJVhyaMzyROUZgm4qngaBvBvCQIhKzit61oBe I/drZ/d5JolzlKdZZrcmofmiCQRa+57OM3Fbl8ykFazN1ASyCex2UrftX5oHmhaeeRlGVaTV iEbAvU4PP4RnNKwaWQivsFhqQrfFFhvFV9CRSvsR6qu5eiFI6c8CjB49gBcKKAJ9a8gkyWs8 sg4PYY7L15XdRn8kOf/tg98UCM1vSBV2moEJA0f98/Z48LQXNb7dgvVRtH6owARspsV6nJyD vktsLTyMW5BW9q4NC1rgQC8GQXjrQ+iyQLNwy5ESe2MzGKkHogxKg4Pvi1wZh9Snr+RyB0Rq rIrzbXhyi47+7wcAEQEAAcLBfAQYAQgAJgIbDBYhBCopGCQ/3kZkjQaG+dmwV3vZPpj8BQJh pRSXBQkk+HAYAAoJENmwV3vZPpj8BPMP/iZV+XROOhs/MsKd7ngQeFgETkmt8YVhb2Rg3Vgp AQe9cn6aw9jk3CnB0ecNBdoyyt33t3vGNau6iCwlRfaTdXg9qtIyctuCQSewY2YMk5AS8Mmb XoGvjH1Z/irrVsoSz+N7HFPKIlAy8D/aRwS1CHm9saPQiGoeR/zThciVYncRG/U9J6sV8XH9 OEPnQQR4w/V1bYI9Sk+suGcSFN7pMRMsSslOma429A3bEbZ7Ikt9WTJnUY9XfL5ZqQnjLeRl 8243OTfuHSth26upjZIQ2esccZMYpQg0/MOlHvuFuFu6MFL/gZDNzH8jAcBrNd/6ABKsecYT nBInKH2TONc0kC65oAhrSSBNLudTuPHce/YBCsUCAEMwgJTybdpMQh9NkS68WxQtXxU6neoQ U7kEJGGFsc7/yXiQXuVvJUkK/Xs04X6j0l1f/6KLoNQ9ep/2In596B0BcvvaKv7gdDt1Trgg vlB+GpT+iFRLvhCBe5kAERREfRfmWJq1bHod/ulrp/VLGAaZlOBTgsCzufWF5SOLbZkmV2b5 xy2F/AU3oQUZncCvFMTWpBC+gO/o3kZCyyGCaQdQe4jS/FUJqR1suVwNMzcOJOP/LMQwujE/ Ch7XLM35VICo9qqhih4OvLHUAWzC5dNSipL+rSGHvWBdfXDhbezJIl6sp7/1rJfS8qPs In-Reply-To: <20261004172934.GC1906@quark> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 10/4/26 7:29 PM, Eric Biggers wrote: > On Sun, Oct 04, 2026 at 09:44:57AM +0200, Milan Broz wrote: >> On 10/2/26 10:14 PM, Eric Biggers wrote: >> ... >>> From what I understand, the point of the keyring support in >>> dm-{crypt,inlinecrypt,integrity} is: >>> >>> - To support "trusted" keys. But that is not what was actually >>> implemented in dm-inlinecrypt. >>> >>> - To avoid having the key be readable with STATUSTYPE_TABLE. But that >>> is not what was actually implemented in dm-inlinecrypt. Keyrings are >>> also unnecesary to solve that problem. >> >> There is more to that >> >> - to avoid key cached in dm-crypt (or other target) >> (dmsetup must be able to retrieve mapping table in the form directly >> reusable for recreating DM mapping, so raw key must be available) > > It's of course still there anyway, so that the data can be encrypted or > decrypted. crypt_config::cipher_tfm for dm-crypt, inlinecrypt_ctx::key > for dm-inlinecrypt, or dm_integrity_c::internal_shash for dm-integrity. Raw key is then not part of internal dm-crypt structures, that was the point. Crypto API needs key, obviously. I did not check recent dm-inline crypt, though. >> - to avoid inclusion of key in DM ioctl calls (mapping table again) > > Unless the "trusted" key type is being used it just makes the raw key be > passed to the kernel using a different syscall: add_key() instead of > ioctl(). It doesn't seem fundamentally different. Technically, yes. Just the key is now sent through ioctl that (should) be designed for it, not in DM-ioctls that are used extensively for all other parameters. We had to add wiping of all buffers there exactly for this reason. And I think the split is better also for tracing calls etc. And while all these subsystems are not perfect, they are compatible for many years. IMO this is very important. We are not in Google monorepo environment where anything can be changed anytime as you know all users. Milan