From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 86742C5DF66 for ; Sun, 16 Aug 2026 12:13:46 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 513BD6B081E; Sun, 16 Aug 2026 08:13:45 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 4EB0C6B081F; Sun, 16 Aug 2026 08:13:45 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 428596B0820; Sun, 16 Aug 2026 08:13:45 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id 12DBF6B081E for ; Sun, 16 Aug 2026 08:13:45 -0400 (EDT) Received: from smtpin06.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay07.hostedemail.com (Postfix) with ESMTP id 18B6016050D for ; Sun, 16 Aug 2026 12:13:43 +0000 (UTC) X-FDA: 85107023526.06.E666D32 Received: from mailout1.hostsharing.net (mailout1.hostsharing.net [83.223.95.204]) by imf08.hostedemail.com (Postfix) with ESMTP id 8991F160006 for ; Sun, 16 Aug 2026 12:13:40 +0000 (UTC) Authentication-Results: imf08.hostedemail.com; spf=pass (imf08.hostedemail.com: domain of lukas@wunner.de designates 83.223.95.204 as permitted sender) smtp.mailfrom=lukas@wunner.de ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1786882421; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=Cn0zUN/hrMLQAPmuNzHmIPISGC8g6oolk9qIb89TBIU=; b=tWV9CZPRxVoDl+gV8letDZvoBMRk7B8eDYHLyhJpGvUJGgZnd4HXsA66W54mNPcp4fRB52 RKlVaOF+gyGC2eFBncIxhHxOUjffAJNAI98nuRNIn3rEzxJe8MAKhs00MzCBU/4cZcgPVl rLsonJe939FmPg0yXUFb3N377PlJfQA= ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1786882421; b=C7aPuSY53wOoglzVxyxxtYOCD6savX3qkiN8xdceYDLisivciGvFEcW27uk2U2xy7GMn87 TORWHwVxAYwUZuXyj0rgXsFUGSKaXExhi2oZl/PeguvkoFLkpwJc4Z8wx0rTRi3JLVW2oO KfHIWJFmjKJS5VghdAHT7stqe0qtOv4= ARC-Authentication-Results: i=1; imf08.hostedemail.com; dkim=none; dmarc=none; spf=pass (imf08.hostedemail.com: domain of lukas@wunner.de designates 83.223.95.204 as permitted sender) smtp.mailfrom=lukas@wunner.de Received: from h08.hostsharing.net (h08.hostsharing.net [83.223.95.28]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange x25519 server-signature ECDSA (secp384r1) server-digest SHA384 client-signature ECDSA (secp384r1) client-digest SHA384) (Client CN "*.hostsharing.net", Issuer "GlobalSign GCC R6 AlphaSSL CA 2025" (verified OK)) by mailout1.hostsharing.net (Postfix) with ESMTPS id 83A3F3BC; Sun, 16 Aug 2026 14:13:37 +0200 (CEST) Received: by h08.hostsharing.net (Postfix, from userid 100393) id 61BAE629CE27; Sun, 16 Aug 2026 14:13:37 +0200 (CEST) Date: Sun, 16 Aug 2026 14:13:37 +0200 From: Lukas Wunner To: Jan Sebastian =?iso-8859-1?Q?G=F6tte?= Cc: Baoquan He , Jan Sebastian =?iso-8859-1?Q?G=F6tte?= , Andrew Morton , Mike Rapoport , Pasha Tatashin , Pratyush Yadav , Dave Young , Catalin Marinas , Will Deacon , David Howells , Jarkko Sakkinen , Jonathan Corbet , Shuah Khan , Paul Moore , James Morris , "Serge E. Hallyn" , Ignat Korchagin , Herbert Xu , "David S. Miller" , Keith Busch , Jens Axboe , Christoph Hellwig , Sagi Grimberg , Trond Myklebust , Anna Schumaker , Mimi Zohar , James Bottomley , Marc Dionne , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Simon Horman , Eric Biggers , "Theodore Y. Ts'o" , Jaegeuk Kim , Alexander Viro , Christian Brauner , Jan Kara , Alasdair Kergon , Mike Snitzer , Mikulas Patocka , Benjamin Marzinski , kexec@lists.infradead.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org, keyrings@vger.kernel.org, linux-doc@vger.kernel.org, linux-security-module@vger.kernel.org, linux-crypto@vger.kernel.org, linux-nvme@lists.infradead.org, linux-nfs@vger.kernel.org, linux-integrity@vger.kernel.org, linux-afs@lists.infradead.org, netdev@vger.kernel.org, linux-fscrypt@vger.kernel.org, linux-fsdevel@vger.kernel.org, dm-devel@lists.linux.dev Subject: Re: [PATCH v2 01/13] kexec: add CRASH_WIPE_SECRETS to wipe secrets before kdump Message-ID: References: <20260811-crash-zeroize-rework-v2-0-9561d13c2340@jaseg.de> <20260811-crash-zeroize-rework-v2-1-9561d13c2340@jaseg.de> <9765f7ea-36bb-4c7b-a19b-7facec97b762@jaseg.de> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <9765f7ea-36bb-4c7b-a19b-7facec97b762@jaseg.de> X-Rspam-User: X-Stat-Signature: 7y83j9neyk6bj7whfrnj4wsys36qjwr7 X-Rspamd-Server: rspam08 X-Rspamd-Queue-Id: 8991F160006 X-HE-Tag: 1786882420-456980 X-HE-Meta: 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 sME7zURG Ns4GQ7U4t5HlB6fNUnNGnuuubzxOgbr5smEkDSoS2RU8Bim4zXlhhdpvysoQ90747fekY7dVvCxdW3kY2HbTIBuWdIvSUZ6rpcPBOFl524STVO1l+TlkuWdm4rC7V6k4jh4gITybs2f64vIoRgy63FbIPs2qV01ifX2QJHW01vb78thzZhHKkAMaN/TuVHZOwxoK/9UCBXNFZPYpO5Y7sbrUib0Vx7ghDy0oE Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Wed, Aug 12, 2026 at 12:08:39PM +0200, Jan Sebastian Götte wrote: > I can imagine one alternative way to approach this, tell me what you think: > Instead of registering wipe handlers that memzero places on panic, I could > put an optional registry of (addr, len) descriptors into crashkernel memory > that the original kernel populates with the PAs of buffers to clear ahead of > time. Then the kdump kernel could do the actual memzero. This would remove > all code from the actual kdump path here. The registry could be made > per-core to avoid locks. Or create a dedicated mempool from which all sensitive data is allocated, then call mempool_free_bulk() on kexec to poison everything in that pool? Thanks, Lukas