Path: csiph.com!news.dns-netz.com!news.freedyn.net!aioe.org!bofh.it!news.nic.it!robomod From: Noah Meyerhans Newsgroups: linux.debian.bugs.dist,linux.debian.kernel Subject: Bug#948519: insufficient boot-time entropy on arm64 virtual machines Date: Thu, 09 Jan 2020 20:30:01 +0100 Message-ID: X-Mailbox-Line: From debian-bugs-dist-request@lists.debian.org Thu Jan 9 19:27:09 2020 Old-Return-Path: X-Spam-Flag: NO X-Spam-Score: 0.2 Reply-To: Noah Meyerhans , 948519@bugs.debian.org Resent-To: debian-bugs-dist@lists.debian.org Resent-Cc: Debian Kernel Team X-Debian-Pr-Message: report 948519 X-Debian-Pr-Package: src:linux X-Debian-Pr-Source: linux X-Spam-Bayes: score:0.0000 Tokens: new, 15; hammy, 143; neutral, 45; spammy, 0. spammytokens: hammytokens:0.000-+--H*u:1.10.1, 0.000-+--H*UA:1.10.1, 0.000-+--H*u:2018-07-13, 0.000-+--H*UA:2018-07-13, 0.000-+--H*F:U*noahm Dkim-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=morgul.net; s=20141010; h=Content-Type:MIME-Version:Message-ID:Subject:To:From:Date: Sender:Reply-To:Cc:Content-Transfer-Encoding:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: In-Reply-To:References:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=eOvabp4uvOYcXmLmbdMoQroOXUUZ6ZpTQLVllKXXRds=; b=cSvKLfJcUxic6gKBrKkTrn6+jH Q0cW4re2gs4gc2suCKHjwsk9NVn76tN0Js7rw807oiCeM7RxFGG3E+70bC+n42VAYxtaKEicab0AF vfQr63lJfZRdRT8G6smfD0THUAfqF3iHWbuKZTLjqEVjMPCRadRS0x1HtGCHo+C/I2Rs=; MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.10.1 (2018-07-13) X-Greylist: delayed 1323 seconds by postgrey-1.36 at buxtehude; Thu, 09 Jan 2020 19:22:08 UTC X-Debian-Message: from BTS X-Mailing-List: archive/latest/1578225 List-ID: List-URL: Approved: robomod@news.nic.it Lines: 26 Organization: linux.* mail to news gateway Sender: robomod@news.nic.it X-Original-Date: Thu, 9 Jan 2020 14:00:01 -0500 X-Original-Message-ID: <20200109190001.GC15186@morgul.net> Xref: csiph.com linux.debian.bugs.dist:990572 linux.debian.kernel:66043 Package: src:linux Version: 4.19.67-2+deb10u2 Severity: important See the thread at https://lists.debian.org/debian-cloud/2020/01/threads.html#00013 for some context. When launching arm64 VMs on Amazon EC2, a lack of entropy at boot results in the full boot process taking several minutes, when the expectation is that it take a small number of seconds (<10). Analysis of the boot process shows the ssh key generation is the culprit, taking nearly 3 minutes. admin@ip-10-0-1-87:~$ cloud-init analyze blame -- Boot Record 01 -- 165.77300s (init-network/config-ssh) The 5.4 kernel currently in sid does not experience this lack of entropy. It has been suggested that upstream commit 50ee7529ec45 ("random: try to actively add entropy rather than passively wait for it") may be the difference here, but I have not confirmed this. A suggested workaround has been to install haveged in the image, but this tends to make crypto people frown.