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[209.132.180.67]) by mx.google.com with ESMTP id o61si15353964pld.280.2019.04.03.17.35.37; Wed, 03 Apr 2019 17:35:52 -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=EuvZBJXk; 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 S1728710AbfDDAeY (ORCPT + 99 others); Wed, 3 Apr 2019 20:34:24 -0400 Received: from mail-it1-f202.google.com ([209.85.166.202]:43553 "EHLO mail-it1-f202.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728570AbfDDAdy (ORCPT ); Wed, 3 Apr 2019 20:33:54 -0400 Received: by mail-it1-f202.google.com with SMTP id m192so683025ita.8 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=XN1BZLOi27A77JDN6EwuCAzNzANdVhPbXnFLq61oLpDlgcBeBnPNzGhUvK6TrLbm48 N5gN8Hn/nu/4Fxo3J0a+ciTj/GiqnBEQSz55oHRWXXW5vDffuYpSFc754dDZQ3vtU3HU pzJi5p/1Yc64+NVQj3GNy8O/VOjt11ZkWg1JWhUElmo1Et0dLXo/aKqMaNreTTh69tsi bZYoi3RPUC1CTR6QNjmAKV4M9rLUzJmV1vugfDzsS8XYGyw/fjUORROI0SAN8ypjzwn1 Ys6YGDZEGa4HtBSwvmlYmGe9TDMys510E9tojdUKZYVqQ6gMxJKezLVtg9Yn/drqaQJD 2X7w== X-Gm-Message-State: APjAAAW1vB+zicUVO8A8/jdNzM98z6zYQli1eD+dZELQURB8i2D2xoGu 7Sznbf4OJRUjE95bXK4H+8hO4T++Xis5kR50i66MkQ== 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 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: 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)) -- 2.21.0.392.gf8f6787159e-goog