From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.9 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_GIT autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 21E71C32771 for ; Mon, 20 Jan 2020 04:54:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DD3552073A for ; Mon, 20 Jan 2020 04:54:31 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=axtens.net header.i=@axtens.net header.b="W0L2jdRQ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729123AbgATEyb (ORCPT ); Sun, 19 Jan 2020 23:54:31 -0500 Received: from mail-pf1-f195.google.com ([209.85.210.195]:45603 "EHLO mail-pf1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729043AbgATEya (ORCPT ); Sun, 19 Jan 2020 23:54:30 -0500 Received: by mail-pf1-f195.google.com with SMTP id 2so15193066pfg.12 for ; Sun, 19 Jan 2020 20:54:30 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=axtens.net; s=google; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=xN3Z4EtUvjD28efJ92xKpoRYufScEeM5MB1/Qfws810=; b=W0L2jdRQ6MREKzDtBfeqsFqnHKSHfF7Sb0eeF/NO+1tO1ak2JirozIT8ho0P748UC9 v4qHLYd83CfoETl2RH3lHI86fgn7phaWJtD2sN+sibKTOv/Q5NMU8XhsujL/2ad6Z4y/ dfI+HuzKHI86RmSdmNVVEy0X3+DDCG3/jSsa0= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=xN3Z4EtUvjD28efJ92xKpoRYufScEeM5MB1/Qfws810=; b=p5GKa2KoxvVB4LFYpnCxH5o/uWQidoXQOj5pl7dPrIG3nq+YS14n8ZYw1LjtXrjDpU QuMH+gd+2gZ3xg7ygkt+1ooxdkPD4UcaoD2JcWGkTNztklNTEbEG7Fm1a3Ev1YeNMRw1 qn4gFxthcO2IQZqG6NO0GDeEJ4gKNFAk2bIkn7VnBPjUwuTURMX83O0dJwGIxdSI3KER vZWMq+MwCkbCzDyAgeFsvLVwNve7+ntk4WrQBdnmqVwxZlxtqrtERnxlo6t+kXV/mQM2 siaygdct9RfbXCzf5LINtGN4vUe3ZNIioD1mrDVTPD25i/nhEQ5KpU1u2MQtMlrgy6hE KAfA== X-Gm-Message-State: APjAAAVFLaB+qpdS+V9DOJBeauQqB7ok1xSyP50nxJsZ5M2X/mpjS/L5 72NJo3dKfWwJqLD0Ze3LoNhkCQ== X-Google-Smtp-Source: APXvYqxbURRFxgJ90M08NbktU6NV4cTwTLt4WEZcRDxlNQeK+6mOpbIca82m89cBJLFfn4kJ+VH1eA== X-Received: by 2002:a63:642:: with SMTP id 63mr56653726pgg.73.1579496069997; Sun, 19 Jan 2020 20:54:29 -0800 (PST) Received: from localhost (2001-44b8-1113-6700-4064-d910-a710-f29a.static.ipv6.internode.on.net. [2001:44b8:1113:6700:4064:d910:a710:f29a]) by smtp.gmail.com with ESMTPSA id i2sm35693066pgi.94.2020.01.19.20.54.28 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 19 Jan 2020 20:54:29 -0800 (PST) From: Daniel Axtens To: kernel-hardening@lists.openwall.com, akpm@linux-foundation.org, keescook@chromium.org Cc: linux-kernel@vger.kernel.org, Daniel Axtens Subject: [PATCH v2 0/2] FORTIFY_SOURCE: detect intra-object overflow in string functions Date: Mon, 20 Jan 2020 15:54:22 +1100 Message-Id: <20200120045424.16147-1-dja@axtens.net> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When the fortify feature was first introduced in commit 6974f0c4555e ("include/linux/string.h: add the option of fortified string.h functions"), Daniel Micay observed: * It should be possible to optionally use __builtin_object_size(x, 1) for some functions (C strings) to detect intra-object overflows (like glibc's _FORTIFY_SOURCE=2), but for now this takes the conservative approach to avoid likely compatibility issues. This patch set: - converts a number of string functions to use __builtin_object_size(x, 1) - adds LKDTM tests for both types of fortified function. This change passes an allyesconfig on powerpc and x86, and an x86 kernel built with it survives running with syz-stress from syzkaller, so it seems safe so far. Daniel Axtens (2): string.h: detect intra-object overflow in fortified string functions lkdtm: tests for FORTIFY_SOURCE drivers/misc/lkdtm/bugs.c | 51 ++++++++++++++++++++++++++++++++++++++ drivers/misc/lkdtm/core.c | 2 ++ drivers/misc/lkdtm/lkdtm.h | 2 ++ include/linux/string.h | 27 ++++++++++++-------- 4 files changed, 71 insertions(+), 11 deletions(-) -- 2.20.1