From patchwork Wed Apr 5 20:15:54 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Howells X-Patchwork-Id: 9665689 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id A316360352 for ; Wed, 5 Apr 2017 20:20:24 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 95DAD2859F for ; Wed, 5 Apr 2017 20:20:24 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 89118285A4; Wed, 5 Apr 2017 20:20:24 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 1BA0B2859F for ; Wed, 5 Apr 2017 20:20:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933881AbdDEUUW (ORCPT ); Wed, 5 Apr 2017 16:20:22 -0400 Received: from mx1.redhat.com ([209.132.183.28]:45619 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932371AbdDEUP6 (ORCPT ); Wed, 5 Apr 2017 16:15:58 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id E4A347E9C0; Wed, 5 Apr 2017 20:15:56 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com E4A347E9C0 Authentication-Results: ext-mx02.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx02.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=dhowells@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com E4A347E9C0 Received: from warthog.procyon.org.uk (ovpn-120-211.rdu2.redhat.com [10.10.120.211]) by smtp.corp.redhat.com (Postfix) with ESMTP id 2224E5C895; Wed, 5 Apr 2017 20:15:54 +0000 (UTC) Organization: Red Hat UK Ltd. Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 Subject: [PATCH 09/24] kexec_file: Disable at runtime if securelevel has been set From: David Howells To: linux-kernel@vger.kernel.org Cc: Matthew Garrett , dhowells@redhat.com, linux-efi@vger.kernel.org, gnomes@lxorguk.ukuu.org.uk, gregkh@linuxfoundation.org, kexec@lists.infradead.org, Chun-Yi Lee , linux-security-module@vger.kernel.org, keyrings@vger.kernel.org, matthew.garrett@nebula.com Date: Wed, 05 Apr 2017 21:15:54 +0100 Message-ID: <149142335441.5101.2294976563846442575.stgit@warthog.procyon.org.uk> In-Reply-To: <149142326734.5101.4596394505987813763.stgit@warthog.procyon.org.uk> References: <149142326734.5101.4596394505987813763.stgit@warthog.procyon.org.uk> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.26]); Wed, 05 Apr 2017 20:15:57 +0000 (UTC) Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: X-Virus-Scanned: ClamAV using ClamSMTP From: Chun-Yi Lee When KEXEC_VERIFY_SIG is not enabled, kernel should not loads image through kexec_file systemcall if securelevel has been set. This code was showed in Matthew's patch but not in git: https://lkml.org/lkml/2015/3/13/778 Cc: Matthew Garrett Signed-off-by: Chun-Yi Lee Signed-off-by: David Howells cc: kexec@lists.infradead.org Acked-by: Dave Young --- kernel/kexec_file.c | 6 ++++++ 1 file changed, 6 insertions(+) -- To unsubscribe from this list: send the line "unsubscribe linux-security-module" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c index b118735fea9d..f6937eecd1eb 100644 --- a/kernel/kexec_file.c +++ b/kernel/kexec_file.c @@ -268,6 +268,12 @@ SYSCALL_DEFINE5(kexec_file_load, int, kernel_fd, int, initrd_fd, if (!capable(CAP_SYS_BOOT) || kexec_load_disabled) return -EPERM; + /* Don't permit images to be loaded into trusted kernels if we're not + * going to verify the signature on them + */ + if (!IS_ENABLED(CONFIG_KEXEC_VERIFY_SIG) && kernel_is_locked_down()) + return -EPERM; + /* Make sure we have a legal set of flags */ if (flags != (flags & KEXEC_FILE_FLAGS)) return -EINVAL;