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[209.132.180.67]) by mx.google.com with ESMTP id z20si14424564pgu.43.2019.04.03.17.37.30; Wed, 03 Apr 2019 17:37:46 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=pass header.i=@google.com header.s=20161025 header.b=A2EFYZwE; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=REJECT sp=REJECT dis=NONE) header.from=google.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728483AbfDDAfK (ORCPT + 99 others); Wed, 3 Apr 2019 20:35:10 -0400 Received: from mail-ot1-f73.google.com ([209.85.210.73]:42765 "EHLO mail-ot1-f73.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726783AbfDDAdS (ORCPT ); Wed, 3 Apr 2019 20:33:18 -0400 Received: by mail-ot1-f73.google.com with SMTP id j17so298836otp.9 for ; Wed, 03 Apr 2019 17:33:18 -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=A2EFYZwEC5y58dctC8LWHsqA6qoE5h0LFuFYwP6Uwqnal/NFUhQVsKZ/0Ysr8bH//x FT17CqgqigWaJaw5c+416HEm1SOJ5orG1jO9WJ4kVGBoTxfe2sFF3NgIGiHr1ETJUCoC AGe5N/8cJDz2uObdp0e8WjGFpC8mGvo4d5ebbKSY9TuIQ8SyXWnil8fW2KzUZCt/aofk 8biDkpWIJeJyZnldpFA5lFAbH8dXFWs7Ho0n0l1twAexbAB/330nKb/6uAkKYGyTrW0N OJepi47SLo9FwbAlZUvw24949yhqGJ+zGZV7oTsTvqOH+6+6k01sIrImWHkw9JwsgDIu 28oA== 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=YN19RBL+egzT7/4Ugb3aO6chLBjrlEmqw6rbG+qTDxVwZLWyaHLOd0mrZom+L7QG5O kwbfF2FEdcSnnxDwnDuFCn4by4dLZlPf65ccV3lF2oDdoOkXasUCLzXLMxC8xICi+/sO 6ymrHOOt9ZiYHUxyYe3T304EGZnNmNYM9duo9BegUE3jgl81XEsYQ7YKFl7BadJCLQNg XTWtF7mfdkNP6arQVgmHBTwsFba7fZMeB5GCmi2HQUk+/iWgl9lWFnVerShXdg1djWm8 OlNv/TLt6+qHBnaiM2423oOxhiKjLWHwmcOhsyxgwxtJpWVYY/cGKkAeJDcW/CY9/xUM KhQA== X-Gm-Message-State: APjAAAWrrwADNnpXesYcZlQM8xdUFzuBBT7vH8YjFlb/SbjIytaoet+z PxMZaUKEMaQksLeuMvBB21WUa6Y+08BBoXVjGBd7mg== X-Received: by 2002:a9d:6343:: with SMTP id y3mr301853otk.38.1554337997827; Wed, 03 Apr 2019 17:33:17 -0700 (PDT) Date: Wed, 3 Apr 2019 17:32:31 -0700 In-Reply-To: <20190404003249.14356-1-matthewgarrett@google.com> Message-Id: <20190404003249.14356-10-matthewgarrett@google.com> Mime-Version: 1.0 References: <20190404003249.14356-1-matthewgarrett@google.com> X-Mailer: git-send-email 2.21.0.392.gf8f6787159e-goog Subject: [PATCH V32 09/27] 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 Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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)) { -- 2.21.0.392.gf8f6787159e-goog