From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751318AbdKUH6U (ORCPT ); Tue, 21 Nov 2017 02:58:20 -0500 Received: from mail-io0-f196.google.com ([209.85.223.196]:45755 "EHLO mail-io0-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751228AbdKUH6S (ORCPT ); Tue, 21 Nov 2017 02:58:18 -0500 X-Google-Smtp-Source: AGs4zMYN9x/2Fw67JIQf5weCrULlBTy26y1NMBvjpsSmvGIaWsVJDf5qQW9CEd+NwkPAoB3eo/XzaA== Message-ID: <1511251094.25970.18.camel@gmail.com> Subject: [PATCH v1] scripts: leaking_addresses.pl: add support for 32-bit kernel addresses From: kaiwan.billimoria@gmail.com To: me@tobin.cc Cc: linux-kernel@vger.kernel.org, kernel-hardening@lists.openwall.com Date: Tue, 21 Nov 2017 13:28:14 +0530 Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.26.2 (3.26.2-1.fc27) Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The current leaking_addresses.pl script only supports showing "leaked" 64-bit kernel virtual addresses. This patch adds support for showing "leaked" 32-bit kernel virtual addresses. The way it currently works- once it detects we're running on an i'x'86 platform (where x=3|4|5|6), it takes this arch into account for checking: the essential rationale: virt-addr >= PAGE_OFFSET => it's a kernel virtual address. Note- 1. It's a work in progress; some pending TODOs: - support for ARM-32 - programatically query and set the PAGE_OFFSET based on arch (it's currently hard-coded) 2. Minor edit: the '--raw', '--suppress-dmesg', '--squash-by-path' and '--squash-by-filename' option switches are only meaningful when the '----input-raw=' option is used. So, indent the 'Help' screen lines to reflect the fact. Feedback welcome.. Signed-off-by: Kaiwan N Billimoria --- diff --git a/scripts/leaking_addresses.pl b/scripts/leaking_addresses.pl index bc5788000018..e139de445ad1 100755 --- a/scripts/leaking_addresses.pl +++ b/scripts/leaking_addresses.pl @@ -12,7 +12,10 @@ # # You may like to set kptr_restrict=2 before running script # (see Documentation/sysctl/kernel.txt). - +# +# 32-bit kernel address support : Kaiwan N Billimoria +# +# use warnings; use strict; use POSIX; @@ -35,7 +38,7 @@ my $TIMEOUT = 10; # Script can only grep for kernel addresses on the following architectures. If # your architecture is not listed here and has a grep'able kernel address please # consider submitting a patch. -my @SUPPORTED_ARCHITECTURES = ('x86_64', 'ppc64'); +my @SUPPORTED_ARCHITECTURES = ('x86_64', 'ppc64', 'i[3456]86'); # Command line options. my $help = 0; @@ -48,6 +51,9 @@ my $suppress_dmesg = 0; # Don't show dmesg in output. my $squash_by_path = 0; # Summary report grouped by absolute path. my $squash_by_filename = 0; # Summary report grouped by filename. +my $bit_size = 64; # Check 64-bit kernel addresses by default +my $PAGE_OFFSET_32BIT = 0xc0000000; + # Do not parse these files (absolute path). my @skip_parse_files_abs = ('/proc/kmsg', '/proc/kcore', @@ -97,10 +103,10 @@ Options: -o, --output-raw= Save results for future processing. -i, --input-raw= Read results from file instead of scanning. - --raw Show raw results (default). - --suppress-dmesg Do not show dmesg results. - --squash-by-path Show one result per unique path. - --squash-by-filename Show one result per unique filename. + --raw Show raw results (default). + --suppress-dmesg Do not show dmesg results. + --squash-by-path Show one result per unique path. + --squash-by-filename Show one result per unique filename. -d, --debug Display debugging output. -h, --help, --version Display this help and exit. @@ -177,7 +183,7 @@ sub dprint sub is_supported_architecture { - return (is_x86_64() or is_ppc64()); + return (is_x86_64() or is_ppc64() or is_ix86_32()); } sub is_x86_64 @@ -185,6 +191,7 @@ sub is_x86_64 my $archname = $Config{archname}; if ($archname =~ m/x86_64/) { + $bit_size=64; return 1; } return 0; @@ -195,6 +202,19 @@ sub is_ppc64 my $archname = $Config{archname}; if ($archname =~ m/powerpc/ and $archname =~ m/64/) { + $bit_size=64; + return 1; + } + return 0; +} + +# 32-bit x86: is_i'x'86_32() ; where x is [3 or 4 or 5 or 6] +sub is_ix86_32 +{ + my $archname = $Config{archname}; + + if ($archname =~ m/i[3456]86-linux/) { + $bit_size=32; return 1; } return 0; @@ -215,6 +235,15 @@ sub is_false_positive $match =~ '\bf{10}601000\b') { return 1; } + } elsif ($bit_size == 32) { + my $addr32 = eval hex($match); + if ($addr32 < $PAGE_OFFSET_32BIT ) { + return 1; + } + if ($match =~ '\b(0x)?(f|F){8}\b') { + return 1; + } } return 0; @@ -243,6 +272,8 @@ sub may_leak_address $address_re = '\b(0x)?ffff[[:xdigit:]]{12}\b'; } elsif (is_ppc64()) { $address_re = '\b(0x)?[89abcdef]00[[:xdigit:]]{13}\b'; + } elsif (is_ix86_32()) { + $address_re = '\b(0x)?[[:xdigit:]]{8}\b'; } while (/($address_re)/g) {