From patchwork Thu Apr 4 00:32:45 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthew Garrett X-Patchwork-Id: 10884649 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 C39A717E1 for ; Thu, 4 Apr 2019 00:33:59 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id AE3A928913 for ; Thu, 4 Apr 2019 00:33:59 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id A2ABA2897F; Thu, 4 Apr 2019 00:33:59 +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=-14.5 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 4E77A28913 for ; Thu, 4 Apr 2019 00:33:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728591AbfDDAd6 (ORCPT ); Wed, 3 Apr 2019 20:33:58 -0400 Received: from mail-io1-f74.google.com ([209.85.166.74]:33233 "EHLO mail-io1-f74.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728589AbfDDAdy (ORCPT ); Wed, 3 Apr 2019 20:33:54 -0400 Received: by mail-io1-f74.google.com with SMTP id n15so602522ioc.0 for ; Wed, 03 Apr 2019 17:33:54 -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=H3HRoHYDWMArQkaxv1MNV9sbVAN4QTLQDsX3m+S9eoU=; b=EuvZBJXktt6F0ubAptUi55XvRrS0bKkJnnv1U/zgt6sGHkb46NdO1QZ+G9sI+ZkhfA JelD4bF/2Pj/hihb+SKHwlJ8aIjjC7e63Pu3qmQ3SlJe54ayQ6S9xdyfaTuT1jP09UZQ p5n1e8v2LdA/LRCQEeXI2QKFxaPLp8FNAWrgShmJIxnE1H6AkZMQwuPTyOGlFYMSR0nh NoyORJSv21az9frVzup98ATuqYeUtUG0Av2bSGPCU2zcN9wclGUw3JzELE6GzV1KxhFy l5/lV4gzrWlUE08BglDw/kUo6esP+LKLYEMhsER7SVRCEC7kdasgVUQWuHjLBMDqKmDc 8qtg== 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=H3HRoHYDWMArQkaxv1MNV9sbVAN4QTLQDsX3m+S9eoU=; b=C5pcN7UT4uGioZmUeyUXNqEOefMhHJA3/EdbV3m59GWaJqqiwjiBo+y7EmAodiQXfp MRMZLT0PA/rY3p5FLPoPAj72W0EVumvjyUC1xNIVcBFRPuBQ75ZvVEa+o+Wtgw3fdHBL DZneEJNGI6yN0NDl1ecGot8aBLnyw3yUQmeK8Ux2UyQRobheMGX/ebGPrIqc89ab0sjP ccnSCMVqWdMxmtQ+FIFvWXXwoLRdYkO5OWq5Rj9EwlZ7okoNmb5Cz+lKNBlDBvb1q8Et GRiylBj53wjWNsywIpueNFCnBURUALiRRNM9/io1/MBofS2kjjR6x1ghz3EyrvO4Vs6R uiZg== X-Gm-Message-State: APjAAAXrtt5qooT9+22sfOzQcSYNQpoIkO8p+3dDeqoApNk5Wl8VqDEX K2amdkON/oa439nShftu8uKCDSPYwiGfycVl2gl6zA== X-Google-Smtp-Source: APXvYqx2eKKhEOnybJeNgu76/wWUtSGW35RuZ+QQ32lRZx5l58gboRDh908+pCXmRC8kk88E8Ad7UHpBCodo1958l2JfVg== X-Received: by 2002:a24:7f52:: with SMTP id r79mr581420itc.33.1554338033807; Wed, 03 Apr 2019 17:33:53 -0700 (PDT) Date: Wed, 3 Apr 2019 17:32:45 -0700 In-Reply-To: <20190404003249.14356-1-matthewgarrett@google.com> Message-Id: <20190404003249.14356-24-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 23/27] Lock down perf when in confidentiality mode 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 , Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: X-Virus-Scanned: ClamAV using ClamSMTP From: David Howells Disallow the use of certain perf facilities that might allow userspace to access kernel data. Signed-off-by: David Howells Signed-off-by: Matthew Garrett Cc: Peter Zijlstra Cc: Ingo Molnar Cc: Arnaldo Carvalho de Melo --- kernel/events/core.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/kernel/events/core.c b/kernel/events/core.c index 3cd13a30f732..6ad3d83c091c 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -10461,6 +10461,12 @@ SYSCALL_DEFINE5(perf_event_open, return -EINVAL; } + if ((attr.sample_type & PERF_SAMPLE_REGS_INTR) && + kernel_is_locked_down("PERF_SAMPLE_REGS_INTR", + LOCKDOWN_CONFIDENTIALITY)) + /* REGS_INTR can leak data, lockdown must prevent this */ + return -EPERM; + /* Only privileged users can get physical addresses */ if ((attr.sample_type & PERF_SAMPLE_PHYS_ADDR) && perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN))