From patchwork Tue Mar 26 18:27:25 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthew Garrett X-Patchwork-Id: 10871937 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id C0EEE13B5 for ; Tue, 26 Mar 2019 18:28:20 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id AE2BB28DD7 for ; Tue, 26 Mar 2019 18:28:20 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id A1F8E28DF9; Tue, 26 Mar 2019 18:28:20 +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=-15.5 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI, USER_IN_DEF_DKIM_WL 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 4AD3C28DD7 for ; Tue, 26 Mar 2019 18:28:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732642AbfCZS2T (ORCPT ); Tue, 26 Mar 2019 14:28:19 -0400 Received: from mail-qt1-f202.google.com ([209.85.160.202]:50373 "EHLO mail-qt1-f202.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732664AbfCZS2T (ORCPT ); Tue, 26 Mar 2019 14:28:19 -0400 Received: by mail-qt1-f202.google.com with SMTP id g17so14394285qte.17 for ; Tue, 26 Mar 2019 11:28:18 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=UWUYbOZniscPzPib57I8cPwH1j1zNPSziYufzU02lOY=; b=Oz9kzY7d3lv55fVkI6Kb0Gzd3zJwJVSAVP1ulUaw9XyfUgwUTFQ69SW1TpPJkSkz4I 8NUL2BguYiSmd8NFIwTgZKd7UB7lU8F2hm+SV82c1BpjE00Nve3eEAV5dCvYM6U0Adft 8cHrLisTQIpYkEfVr7pSsB7vKPAWYQArSJSuLNv7EWxW+QmxHN7LZdgApdkQI107/Ow2 GZ3GQday6ZqELcHEK3ZUIq2VgMJhr6I6/cma2bxfcIUaCW826/CfZVTmkThJ3vczr5og R+xZyn2RY8eloJabWhb+3U23suPmtoBLFDiFAW2oz2cFDyDctnrk/MCbULdQ+P4rFbUa 32UQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=UWUYbOZniscPzPib57I8cPwH1j1zNPSziYufzU02lOY=; b=P2ZqNmkhQLwKksG4/ufHaXPF020YAYbxZU8YzkTUdskg41s7UR1R863qDBKdnfqjhY yxwHcxHG3MhbIp9BGIYnENOCCRz0FeiChBp5f0vGzcNpQLOKjhmnxVPyPsc2gxuoPKgZ hAM8lHggJ+cBIEpEu42Cw+QCJVlLRAczD363uDYJcqLcZXxpJ/J7cUS1nxzamTa1pRsj 59/vxWj/ANJm6ViwLg8l0D6MMYM4h4dsVeaEqkU6SQeMOAhXmWQOcoBXWBT+jaI0yYY8 Mzjb113JcP6qiwGaEYsrNIvqZWG5tmQ57oW3VeFKGVBKD7sSsMXFFucvsIuLR2UrR6ww UDJg== X-Gm-Message-State: APjAAAU109z9pb1xMWc/U4AtCkmtBkZeiS6w5bjJzcGouv0k3ygkInNu A6cdjYQEOrOlGIph/aSS8IWyYYH9Q04BVr84sIEqGw== X-Google-Smtp-Source: APXvYqy8T5iMSU8bRAJDeiOYdZ+vf7wI+oEKQds8Wx9UYe7VIOiL7DRxsniEJLG6jiM0ADBnIZ62Ujuch6uEFVoBA5UeiQ== X-Received: by 2002:ac8:1091:: with SMTP id a17mr25977158qtj.135.1553624898035; Tue, 26 Mar 2019 11:28:18 -0700 (PDT) Date: Tue, 26 Mar 2019 11:27:25 -0700 In-Reply-To: <20190326182742.16950-1-matthewgarrett@google.com> Message-Id: <20190326182742.16950-10-matthewgarrett@google.com> Mime-Version: 1.0 References: <20190326182742.16950-1-matthewgarrett@google.com> X-Mailer: git-send-email 2.21.0.392.gf8f6787159e-goog Subject: [PATCH V31 09/25] uswsusp: Disable when the kernel is locked down From: Matthew Garrett To: jmorris@namei.org Cc: linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org, dhowells@redhat.com, linux-api@vger.kernel.org, luto@kernel.org, Matthew Garrett , Matthew Garrett , linux-pm@vger.kernel.org, pavel@ucw.cz, rjw@rjwysocki.net Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Matthew Garrett uswsusp allows a user process to dump and then restore kernel state, which makes it possible to modify the running kernel. Disable this if the kernel is locked down. Signed-off-by: David Howells Signed-off-by: Matthew Garrett cc: linux-pm@vger.kernel.org Cc: pavel@ucw.cz Cc: rjw@rjwysocki.net --- kernel/power/user.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/kernel/power/user.c b/kernel/power/user.c index 2d8b60a3c86b..99e13fd13237 100644 --- a/kernel/power/user.c +++ b/kernel/power/user.c @@ -52,6 +52,9 @@ static int snapshot_open(struct inode *inode, struct file *filp) if (!hibernation_available()) return -EPERM; + if (kernel_is_locked_down("/dev/snapshot", LOCKDOWN_INTEGRITY)) + return -EPERM; + lock_system_sleep(); if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {