From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from sipsolutions.net (s3.sipsolutions.net [168.119.38.16]) (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 BBF09219ED; Wed, 12 Feb 2025 14:09:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=168.119.38.16 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739369353; cv=none; b=QNSoBcaOHWEiG/Bk/vqcgjATCkZxPUAHl20x3BbDPTh24qmIbixRf9VgaQfAY9EBijDKXkvNoKe4SSMLORUXQOkJGB8bd1SF32aAnPwgE/QnMoj6bhfzv9L12bX+r+r2kIp6bqL0tfg730+jNg64l5siQKl4+Pl+RtKxfb0yloY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739369353; c=relaxed/simple; bh=Elf/FaTDK9fVRFnIY3VNHEhn1eL3NZf69mLnjaztmRU=; h=Message-ID:Subject:From:To:Cc:Date:In-Reply-To:References: Content-Type:MIME-Version; b=h8ReXykzIjxaUhyNGwcD3jj+w3ittrVt47yipBvF9QkM/YlLep4fMFMXeJYHYK5H2Cu40YYAQ2E29edBRHqXwuXWRZsRNR8kVQ9ePIQ4HXqgJrSVQK11hRfIa81s0TS/+8eov4BmVTOQ9AUF51YeeixZN571q5Zv6Kk/iPXNb1E= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=sipsolutions.net; spf=pass smtp.mailfrom=sipsolutions.net; dkim=pass (2048-bit key) header.d=sipsolutions.net header.i=@sipsolutions.net header.b=UliI5jNo; arc=none smtp.client-ip=168.119.38.16 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=sipsolutions.net Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=sipsolutions.net Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=sipsolutions.net header.i=@sipsolutions.net header.b="UliI5jNo" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sipsolutions.net; s=mail; h=MIME-Version:Content-Transfer-Encoding: Content-Type:References:In-Reply-To:Date:Cc:To:From:Subject:Message-ID:Sender :Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From:Resent-To: Resent-Cc:Resent-Message-ID; bh=Elf/FaTDK9fVRFnIY3VNHEhn1eL3NZf69mLnjaztmRU=; t=1739369351; x=1740578951; b=UliI5jNoVYFHhCXfjiO9AmxmC9CrjGR9PRKwx5E07lBs2Ge Ve0YrTSGxl6USPkgKpVNltFr2s6VFh2Vao/Z6xHfusKKS1+8Tosq7z+qD3emuhXWQPslEbBVYNyjf 9lEhsHkUpbtsE/7r9nXNJrq0aXRJ5AXRDfxESyPeUH0bwliuRjUeX+NGq/cfOEHZPOZeA0U0+JSYQ ACVGcOOwO4Rk8hUXBSnmtx9GxIDTS3iEO1cA5pXSKmMBEOclYT5Wl7r7VCRzdiSmV9ZbYl+7N8R3b v5MYHlfDV0jlxioaJZP6wru4o90w8bdhs91QJZCrwmrciQtmKhkhwBYThNPd431A==; Received: by sipsolutions.net with esmtpsa (TLS1.3:ECDHE_X25519__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim 4.98) (envelope-from ) id 1tiDQ5-0000000CFTu-2Jhk; Wed, 12 Feb 2025 15:08:54 +0100 Message-ID: Subject: Re: [RFC PATCH v5 0/7] mseal system mappings From: Johannes Berg To: Lorenzo Stoakes , Pedro Falcato Cc: jeffxu@chromium.org, akpm@linux-foundation.org, keescook@chromium.org, jannh@google.com, torvalds@linux-foundation.org, vbabka@suse.cz, Liam.Howlett@oracle.com, adhemerval.zanella@linaro.org, oleg@redhat.com, avagin@gmail.com, benjamin@sipsolutions.net, linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org, linux-mm@kvack.org, jorgelo@chromium.org, sroettger@google.com, hch@lst.de, ojeda@kernel.org, thomas.weissschuh@linutronix.de, adobriyan@gmail.com, hca@linux.ibm.com, willy@infradead.org, anna-maria@linutronix.de, mark.rutland@arm.com, linus.walleij@linaro.org, Jason@zx2c4.com, deller@gmx.de, rdunlap@infradead.org, davem@davemloft.net, peterx@redhat.com, f.fainelli@gmail.com, gerg@kernel.org, dave.hansen@linux.intel.com, mingo@kernel.org, ardb@kernel.org, mhocko@suse.com, 42.hyeyoo@gmail.com, peterz@infradead.org, ardb@google.com, enh@google.com, rientjes@google.com, groeck@chromium.org, mpe@ellerman.id.au, aleksandr.mikhalitsyn@canonical.com, mike.rapoport@gmail.com Date: Wed, 12 Feb 2025 15:08:51 +0100 In-Reply-To: <7545d5eb-a16e-4cc8-a9e3-5431be01aade@lucifer.local> References: <20250212032155.1276806-1-jeffxu@google.com> <7545d5eb-a16e-4cc8-a9e3-5431be01aade@lucifer.local> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.54.3 (3.54.3-1.fc41) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-malware-bazaar: not-scanned On Wed, 2025-02-12 at 14:01 +0000, Lorenzo Stoakes wrote: > Thanks, yeah that's a good point, it would have to be implemented as a > personality or something similar otherwise you're essentially relying on > 'unsealing' which can't be permitted. >=20 > I'm not sure how useful that'd be for the likes of rr though. But I suppo= se > if it makes everything exec'd by a child inherit it then maybe that works > for a debugging session etc.? For whatever that's worth, ARCH=3Dum should not need 'unsealing' or 'not sealing' it for *itself*, but rather only for the *children* it starts, which are for the userspace processes inside of it. Which I suppose could actually start without a VDSO in the first place, but I don't think that's possible now? Which I'll note should not have access to the host, so in a way this outer security feature (sealing) breaks the inner ARCH=3Dum security, I think. johannes