From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mta0.migadu.com (out-221.mta0.migadu.com [91.218.175.221]) (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 567323B442B for ; Mon, 17 Aug 2026 07:39:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.221 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786952342; cv=none; b=uNhjrhb3WKck91t8K/SvocklgysHWCFrCccP8rEeE0cb9MikMqhHuDkeRcaEbPacLjYl2UeBHdlKnu41S3R1IIJ+IqH3DGB4tyMUGQ5/ylUQoVplwcVoNAD+oXm6fuXT1zLPym2YmLai/w1J4tY+qVFhPZkib0uVOgQpVlx4sZE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786952342; c=relaxed/simple; bh=4YGgPm1wRAd8vr5pINF7lmz4ylld4f9QdvgoaXgstqU=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=je6ICXD1RtLuVNLiiMRII0hHuS8wmgJsMxI0YLD3NncRqqwAk14IMD2bxXyFj/0eEL+iiT4V0CN/SrAyjOkYmnlkyVhFWGJzWlOSvuV2bsN2p1r2TlnizBvZo3NKGYMReZPsKOOJrgS5dZaRH4IF7SJU09R2oWYnkRyU8DuiH44= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=fAvcBpgW; arc=none smtp.client-ip=91.218.175.221 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="fAvcBpgW" X-Envelope-To: linux-kernel@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=4YGgPm1wRAd8vr5pINF7lmz4ylld4f9QdvgoaXgstqU=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1786952337; v=1; x=1787557137; b=fAvcBpgWs9Qhdx7zHtKnZUXvfc/e05DuB4q15Xv1X+jwe+C46Lm3EPm4tKh4HbiLhY0WPHZz fCRoZh0TZ8AIvHNOq9yFFoW01YnLM0RpKwrFqMBgf9Q4bAB8p76tY9E9jjwbc/H6patvuooZwSY X96L28T3cpxqUz2paePTR0c0= X-Envelope-To: linux-kernel@vger.kernel.org Received: from localhost (3.112.29.171) by mta12.migadu.com with ESMTPS id 17e9312474d067d5; Mon, 17 Aug 2026 07:38:57 +0000 X-Migadu-Flow: FLOW_OUT Date: Mon, 17 Aug 2026 15:38:53 +0800 From: Baoquan He To: Lukas Wunner , Jan Sebastian =?iso-8859-1?Q?G=F6tte?= Cc: 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> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: On 08/16/26 at 02:13pm, Lukas Wunner wrote: > 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. Since there are a lot of security expert in CC, I am wondering what's the risk if we wipe secrets during dumping. System is located in user's place, and vmcore is dumped and collected in user's place. If we filter out secrets memory when we dumping, what could be leaked out? > > 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