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[209.132.180.67]) by mx.google.com with ESMTP id 33si15167879pgm.385.2019.04.03.17.34.52; Wed, 03 Apr 2019 17:35:07 -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=WD2fqHr0; 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 S1728548AbfDDAdu (ORCPT + 99 others); Wed, 3 Apr 2019 20:33:50 -0400 Received: from mail-vk1-f202.google.com ([209.85.221.202]:51579 "EHLO mail-vk1-f202.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728442AbfDDAdr (ORCPT ); Wed, 3 Apr 2019 20:33:47 -0400 Received: by mail-vk1-f202.google.com with SMTP id r14so423746vkd.18 for ; Wed, 03 Apr 2019 17:33:47 -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=i92ao4UQPXz3UyfztS9poQmhL/y3JHZOqS1ytGgJ0IM=; b=WD2fqHr0nDM4EQFGLbdjZzJ4OnQw5Ddxx68yzwL66IurjJUsv0Yb+gxKTO9lDeytxP nSWlzoRoFeHqKw66bCCz3HdUH6+GXH/g812nh8i+kEgTpnZSGeOIZqg3RbAEy5GXEWFV JfyHzIWeiBYbK+iKm01BQA7ViUxVDYh96kcMJtkOzrqaPm0bzYclshYaW/xjvX2JOFq/ at7lM3kTiHHrRFWmjc61Vjk2X71jdUlkZ+EWTKvY2LdmCdxdqei30RkDY5CIDJGXgJYB X/UF7Ujc1cDOAOhHBLFtdAPOTxrR2CnKzowQMumOkT2uXSo3kKGchcsuxFGsWDG9tue4 XjLQ== 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=i92ao4UQPXz3UyfztS9poQmhL/y3JHZOqS1ytGgJ0IM=; b=nGywm2PtLj8YSYhIR+wVhB6ybpPCqSgi0xmGc1ENND4yo0JuMrpJG8vhd6AVnsyJEz hI7ts3y+LcTx2mbdMZWan2au1Kdwk8nm79xhrMXU3DcRlk0n5268wCn6HntG0WcjBGHI bK4l9VdHdOVECl3vfSK+v3Iy/piEjIDPBIwnuKi93VtGdRN3KgPMEjaSnuFS+gV343Q/ p+ZwtxFdVs0qnHZ7Cl1KfZDW/ccnqs2a1nkDXISuF+wCOW97uZ+hArTy2Y2yvrF3bVR/ QKr0pjEfsqZtLo7S5cXkO98hxXK/lT85qCG/4nfgBXucGGeye98DpQaGja1w8ICS1VXH IVvg== X-Gm-Message-State: APjAAAVFJTMxONNgU3i0UZG1/5xWj/7f1LAy2hFAzqELhJPl5Y2yUGS/ 32P7mtJ1mVHmqvf7CeK7Ey/iY0/ubeG7hUee7b2WVQ== X-Received: by 2002:a67:fdd1:: with SMTP id l17mr379136vsq.19.1554338026502; Wed, 03 Apr 2019 17:33:46 -0700 (PDT) Date: Wed, 3 Apr 2019 17:32:42 -0700 In-Reply-To: <20190404003249.14356-1-matthewgarrett@google.com> Message-Id: <20190404003249.14356-21-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 20/27] Lock down /proc/kcore 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 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 access to /proc/kcore when the kernel is locked down to prevent access to cryptographic data. This is limited to lockdown confidentiality mode and is still permitted in integrity mode. Signed-off-by: David Howells Signed-off-by: Matthew Garrett --- fs/proc/kcore.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/fs/proc/kcore.c b/fs/proc/kcore.c index bbcc185062bb..1c556a453569 100644 --- a/fs/proc/kcore.c +++ b/fs/proc/kcore.c @@ -518,6 +518,8 @@ read_kcore(struct file *file, char __user *buffer, size_t buflen, loff_t *fpos) static int open_kcore(struct inode *inode, struct file *filp) { + if (kernel_is_locked_down("/proc/kcore", LOCKDOWN_CONFIDENTIALITY)) + return -EPERM; if (!capable(CAP_SYS_RAWIO)) return -EPERM; -- 2.21.0.392.gf8f6787159e-goog