Adding upstream version 4.19.249.upstream/4.19.249upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 648 insertions, 0 deletions

diff --git a/scripts/leaking_addresses.pl b/scripts/leaking_addresses.pl
new file mode 100755
index 000000000..6e4b0f7ae
--- /dev/null
+++ b/scripts/leaking_addresses.pl
@@ -0,0 +1,648 @@
+#!/usr/bin/env perl
+#
+# (c) 2017 Tobin C. Harding <me@tobin.cc>
+# Licensed under the terms of the GNU GPL License version 2
+#
+# leaking_addresses.pl: Scan the kernel for potential leaking addresses.
+#  - Scans dmesg output.
+#  - Walks directory tree and parses each file (for each directory in @DIRS).
+#
+# Use --debug to output path before parsing, this is useful to find files that
+# cause the script to choke.
+
+#
+# When the system is idle it is likely that most files under /proc/PID will be
+# identical for various processes.  Scanning _all_ the PIDs under /proc is
+# unnecessary and implies that we are thoroughly scanning /proc.  This is _not_
+# the case because there may be ways userspace can trigger creation of /proc
+# files that leak addresses but were not present during a scan.  For these two
+# reasons we exclude all PID directories under /proc except '1/'
+
+use warnings;
+use strict;
+use POSIX;
+use File::Basename;
+use File::Spec;
+use Cwd 'abs_path';
+use Term::ANSIColor qw(:constants);
+use Getopt::Long qw(:config no_auto_abbrev);
+use Config;
+use bigint qw/hex/;
+use feature 'state';
+
+my $P = $0;
+
+# Directories to scan.
+my @DIRS = ('/proc', '/sys');
+
+# Timer for parsing each file, in seconds.
+my $TIMEOUT = 10;
+
+# Kernel addresses vary by architecture.  We can only auto-detect the following
+# architectures (using `uname -m`).  (flag --32-bit overrides auto-detection.)
+my @SUPPORTED_ARCHITECTURES = ('x86_64', 'ppc64', 'x86');
+
+# Command line options.
+my $help = 0;
+my $debug = 0;
+my $raw = 0;
+my $output_raw = "";	# Write raw results to file.
+my $input_raw = "";	# Read raw results from file instead of scanning.
+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 $kernel_config_file = "";	# Kernel configuration file.
+my $opt_32bit = 0;		# Scan 32-bit kernel.
+my $page_offset_32bit = 0;	# Page offset for 32-bit kernel.
+
+# Skip these absolute paths.
+my @skip_abs = (
+	'/proc/kmsg',
+	'/proc/device-tree',
+	'/proc/1/syscall',
+	'/sys/firmware/devicetree',
+	'/sys/kernel/debug/tracing/trace_pipe',
+	'/sys/kernel/security/apparmor/revision');
+
+# Skip these under any subdirectory.
+my @skip_any = (
+	'pagemap',
+	'events',
+	'access',
+	'registers',
+	'snapshot_raw',
+	'trace_pipe_raw',
+	'ptmx',
+	'trace_pipe',
+	'fd',
+	'usbmon');
+
+sub help
+{
+	my ($exitcode) = @_;
+
+	print << "EOM";
+
+Usage: $P [OPTIONS]
+
+Options:
+
+	-o, --output-raw=<file>		Save results for future processing.
+	-i, --input-raw=<file>		Read results from file instead of scanning.
+	      --raw			Show raw results (default).
+	      --suppress-dmesg		Do not show dmesg results.
+	      --squash-by-path		Show one result per unique path.
+	      --squash-by-filename	Show one result per unique filename.
+	--kernel-config-file=<file>     Kernel configuration file (e.g /boot/config)
+	--32-bit			Scan 32-bit kernel.
+	--page-offset-32-bit=o		Page offset (for 32-bit kernel 0xABCD1234).
+	-d, --debug			Display debugging output.
+	-h, --help, --version		Display this help and exit.
+
+Scans the running kernel for potential leaking addresses.
+
+EOM
+	exit($exitcode);
+}
+
+GetOptions(
+	'd|debug'		=> \$debug,
+	'h|help'		=> \$help,
+	'version'		=> \$help,
+	'o|output-raw=s'        => \$output_raw,
+	'i|input-raw=s'         => \$input_raw,
+	'suppress-dmesg'        => \$suppress_dmesg,
+	'squash-by-path'        => \$squash_by_path,
+	'squash-by-filename'    => \$squash_by_filename,
+	'raw'                   => \$raw,
+	'kernel-config-file=s'	=> \$kernel_config_file,
+	'32-bit'		=> \$opt_32bit,
+	'page-offset-32-bit=o'	=> \$page_offset_32bit,
+) or help(1);
+
+help(0) if ($help);
+
+if ($input_raw) {
+	format_output($input_raw);
+	exit(0);
+}
+
+if (!$input_raw and ($squash_by_path or $squash_by_filename)) {
+	printf "\nSummary reporting only available with --input-raw=<file>\n";
+	printf "(First run scan with --output-raw=<file>.)\n";
+	exit(128);
+}
+
+if (!(is_supported_architecture() or $opt_32bit or $page_offset_32bit)) {
+	printf "\nScript does not support your architecture, sorry.\n";
+	printf "\nCurrently we support: \n\n";
+	foreach(@SUPPORTED_ARCHITECTURES) {
+		printf "\t%s\n", $_;
+	}
+	printf("\n");
+
+	printf("If you are running a 32-bit architecture you may use:\n");
+	printf("\n\t--32-bit or --page-offset-32-bit=<page offset>\n\n");
+
+	my $archname = `uname -m`;
+	printf("Machine hardware name (`uname -m`): %s\n", $archname);
+
+	exit(129);
+}
+
+if ($output_raw) {
+	open my $fh, '>', $output_raw or die "$0: $output_raw: $!\n";
+	select $fh;
+}
+
+parse_dmesg();
+walk(@DIRS);
+
+exit 0;
+
+sub dprint
+{
+	printf(STDERR @_) if $debug;
+}
+
+sub is_supported_architecture
+{
+	return (is_x86_64() or is_ppc64() or is_ix86_32());
+}
+
+sub is_32bit
+{
+	# Allow --32-bit or --page-offset-32-bit to override
+	if ($opt_32bit or $page_offset_32bit) {
+		return 1;
+	}
+
+	return is_ix86_32();
+}
+
+sub is_ix86_32
+{
+       state $arch = `uname -m`;
+
+       chomp $arch;
+       if ($arch =~ m/i[3456]86/) {
+               return 1;
+       }
+       return 0;
+}
+
+sub is_arch
+{
+       my ($desc) = @_;
+       my $arch = `uname -m`;
+
+       chomp $arch;
+       if ($arch eq $desc) {
+               return 1;
+       }
+       return 0;
+}
+
+sub is_x86_64
+{
+	state $is = is_arch('x86_64');
+	return $is;
+}
+
+sub is_ppc64
+{
+	state $is = is_arch('ppc64');
+	return $is;
+}
+
+# Gets config option value from kernel config file.
+# Returns "" on error or if config option not found.
+sub get_kernel_config_option
+{
+	my ($option) = @_;
+	my $value = "";
+	my $tmp_file = "";
+	my @config_files;
+
+	# Allow --kernel-config-file to override.
+	if ($kernel_config_file ne "") {
+		@config_files = ($kernel_config_file);
+	} elsif (-R "/proc/config.gz") {
+		my $tmp_file = "/tmp/tmpkconf";
+
+		if (system("gunzip < /proc/config.gz > $tmp_file")) {
+			dprint "$0: system(gunzip < /proc/config.gz) failed\n";
+			return "";
+		} else {
+			@config_files = ($tmp_file);
+		}
+	} else {
+		my $file = '/boot/config-' . `uname -r`;
+		chomp $file;
+		@config_files = ($file, '/boot/config');
+	}
+
+	foreach my $file (@config_files) {
+		dprint("parsing config file: %s\n", $file);
+		$value = option_from_file($option, $file);
+		if ($value ne "") {
+			last;
+		}
+	}
+
+	if ($tmp_file ne "") {
+		system("rm -f $tmp_file");
+	}
+
+	return $value;
+}
+
+# Parses $file and returns kernel configuration option value.
+sub option_from_file
+{
+	my ($option, $file) = @_;
+	my $str = "";
+	my $val = "";
+
+	open(my $fh, "<", $file) or return "";
+	while (my $line = <$fh> ) {
+		if ($line =~ /^$option/) {
+			($str, $val) = split /=/, $line;
+			chomp $val;
+			last;
+		}
+	}
+
+	close $fh;
+	return $val;
+}
+
+sub is_false_positive
+{
+	my ($match) = @_;
+
+	if (is_32bit()) {
+		return is_false_positive_32bit($match);
+	}
+
+	# 64 bit false positives.
+
+	if ($match =~ '\b(0x)?(f|F){16}\b' or
+	    $match =~ '\b(0x)?0{16}\b') {
+		return 1;
+	}
+
+	if (is_x86_64() and is_in_vsyscall_memory_region($match)) {
+		return 1;
+	}
+
+	return 0;
+}
+
+sub is_false_positive_32bit
+{
+       my ($match) = @_;
+       state $page_offset = get_page_offset();
+
+       if ($match =~ '\b(0x)?(f|F){8}\b') {
+               return 1;
+       }
+
+       if (hex($match) < $page_offset) {
+               return 1;
+       }
+
+       return 0;
+}
+
+# returns integer value
+sub get_page_offset
+{
+       my $page_offset;
+       my $default_offset = 0xc0000000;
+
+       # Allow --page-offset-32bit to override.
+       if ($page_offset_32bit != 0) {
+               return $page_offset_32bit;
+       }
+
+       $page_offset = get_kernel_config_option('CONFIG_PAGE_OFFSET');
+       if (!$page_offset) {
+	       return $default_offset;
+       }
+       return $page_offset;
+}
+
+sub is_in_vsyscall_memory_region
+{
+	my ($match) = @_;
+
+	my $hex = hex($match);
+	my $region_min = hex("0xffffffffff600000");
+	my $region_max = hex("0xffffffffff601000");
+
+	return ($hex >= $region_min and $hex <= $region_max);
+}
+
+# True if argument potentially contains a kernel address.
+sub may_leak_address
+{
+	my ($line) = @_;
+	my $address_re;
+
+	# Signal masks.
+	if ($line =~ '^SigBlk:' or
+	    $line =~ '^SigIgn:' or
+	    $line =~ '^SigCgt:') {
+		return 0;
+	}
+
+	if ($line =~ '\bKEY=[[:xdigit:]]{14} [[:xdigit:]]{16} [[:xdigit:]]{16}\b' or
+	    $line =~ '\b[[:xdigit:]]{14} [[:xdigit:]]{16} [[:xdigit:]]{16}\b') {
+		return 0;
+	}
+
+	$address_re = get_address_re();
+	while ($line =~ /($address_re)/g) {
+		if (!is_false_positive($1)) {
+			return 1;
+		}
+	}
+
+	return 0;
+}
+
+sub get_address_re
+{
+	if (is_ppc64()) {
+		return '\b(0x)?[89abcdef]00[[:xdigit:]]{13}\b';
+	} elsif (is_32bit()) {
+		return '\b(0x)?[[:xdigit:]]{8}\b';
+	}
+
+	return get_x86_64_re();
+}
+
+sub get_x86_64_re
+{
+	# We handle page table levels but only if explicitly configured using
+	# CONFIG_PGTABLE_LEVELS.  If config file parsing fails or config option
+	# is not found we default to using address regular expression suitable
+	# for 4 page table levels.
+	state $ptl = get_kernel_config_option('CONFIG_PGTABLE_LEVELS');
+
+	if ($ptl == 5) {
+		return '\b(0x)?ff[[:xdigit:]]{14}\b';
+	}
+	return '\b(0x)?ffff[[:xdigit:]]{12}\b';
+}
+
+sub parse_dmesg
+{
+	open my $cmd, '-|', 'dmesg';
+	while (<$cmd>) {
+		if (may_leak_address($_)) {
+			print 'dmesg: ' . $_;
+		}
+	}
+	close $cmd;
+}
+
+# True if we should skip this path.
+sub skip
+{
+	my ($path) = @_;
+
+	foreach (@skip_abs) {
+		return 1 if (/^$path$/);
+	}
+
+	my($filename, $dirs, $suffix) = fileparse($path);
+	foreach (@skip_any) {
+		return 1 if (/^$filename$/);
+	}
+
+	return 0;
+}
+
+sub timed_parse_file
+{
+	my ($file) = @_;
+
+	eval {
+		local $SIG{ALRM} = sub { die "alarm\n" }; # NB: \n required.
+		alarm $TIMEOUT;
+		parse_file($file);
+		alarm 0;
+	};
+
+	if ($@) {
+		die unless $@ eq "alarm\n";	# Propagate unexpected errors.
+		printf STDERR "timed out parsing: %s\n", $file;
+	}
+}
+
+sub parse_file
+{
+	my ($file) = @_;
+
+	if (! -R $file) {
+		return;
+	}
+
+	if (! -T $file) {
+		return;
+	}
+
+	open my $fh, "<", $file or return;
+	while ( <$fh> ) {
+		chomp;
+		if (may_leak_address($_)) {
+			printf("$file: $_\n");
+		}
+	}
+	close $fh;
+}
+
+# Checks if the actual path name is leaking a kernel address.
+sub check_path_for_leaks
+{
+	my ($path) = @_;
+
+	if (may_leak_address($path)) {
+		printf("Path name may contain address: $path\n");
+	}
+}
+
+# Recursively walk directory tree.
+sub walk
+{
+	my @dirs = @_;
+
+	while (my $pwd = shift @dirs) {
+		next if (!opendir(DIR, $pwd));
+		my @files = readdir(DIR);
+		closedir(DIR);
+
+		foreach my $file (@files) {
+			next if ($file eq '.' or $file eq '..');
+
+			my $path = "$pwd/$file";
+			next if (-l $path);
+
+			# skip /proc/PID except /proc/1
+			next if (($path =~ /^\/proc\/[0-9]+$/) &&
+				 ($path !~ /^\/proc\/1$/));
+
+			next if (skip($path));
+
+			check_path_for_leaks($path);
+
+			if (-d $path) {
+				push @dirs, $path;
+				next;
+			}
+
+			dprint "parsing: $path\n";
+			timed_parse_file($path);
+		}
+	}
+}
+
+sub format_output
+{
+	my ($file) = @_;
+
+	# Default is to show raw results.
+	if ($raw or (!$squash_by_path and !$squash_by_filename)) {
+		dump_raw_output($file);
+		return;
+	}
+
+	my ($total, $dmesg, $paths, $files) = parse_raw_file($file);
+
+	printf "\nTotal number of results from scan (incl dmesg): %d\n", $total;
+
+	if (!$suppress_dmesg) {
+		print_dmesg($dmesg);
+	}
+
+	if ($squash_by_filename) {
+		squash_by($files, 'filename');
+	}
+
+	if ($squash_by_path) {
+		squash_by($paths, 'path');
+	}
+}
+
+sub dump_raw_output
+{
+	my ($file) = @_;
+
+	open (my $fh, '<', $file) or die "$0: $file: $!\n";
+	while (<$fh>) {
+		if ($suppress_dmesg) {
+			if ("dmesg:" eq substr($_, 0, 6)) {
+				next;
+			}
+		}
+		print $_;
+	}
+	close $fh;
+}
+
+sub parse_raw_file
+{
+	my ($file) = @_;
+
+	my $total = 0;          # Total number of lines parsed.
+	my @dmesg;              # dmesg output.
+	my %files;              # Unique filenames containing leaks.
+	my %paths;              # Unique paths containing leaks.
+
+	open (my $fh, '<', $file) or die "$0: $file: $!\n";
+	while (my $line = <$fh>) {
+		$total++;
+
+		if ("dmesg:" eq substr($line, 0, 6)) {
+			push @dmesg, $line;
+			next;
+		}
+
+		cache_path(\%paths, $line);
+		cache_filename(\%files, $line);
+	}
+
+	return $total, \@dmesg, \%paths, \%files;
+}
+
+sub print_dmesg
+{
+	my ($dmesg) = @_;
+
+	print "\ndmesg output:\n";
+
+	if (@$dmesg == 0) {
+		print "<no results>\n";
+		return;
+	}
+
+	foreach(@$dmesg) {
+		my $index = index($_, ': ');
+		$index += 2;    # skid ': '
+		print substr($_, $index);
+	}
+}
+
+sub squash_by
+{
+	my ($ref, $desc) = @_;
+
+	print "\nResults squashed by $desc (excl dmesg). ";
+	print "Displaying [<number of results> <$desc>], <example result>\n";
+
+	if (keys %$ref == 0) {
+		print "<no results>\n";
+		return;
+	}
+
+	foreach(keys %$ref) {
+		my $lines = $ref->{$_};
+		my $length = @$lines;
+		printf "[%d %s] %s", $length, $_, @$lines[0];
+	}
+}
+
+sub cache_path
+{
+	my ($paths, $line) = @_;
+
+	my $index = index($line, ': ');
+	my $path = substr($line, 0, $index);
+
+	$index += 2;            # skip ': '
+	add_to_cache($paths, $path, substr($line, $index));
+}
+
+sub cache_filename
+{
+	my ($files, $line) = @_;
+
+	my $index = index($line, ': ');
+	my $path = substr($line, 0, $index);
+	my $filename = basename($path);
+
+	$index += 2;            # skip ': '
+	add_to_cache($files, $filename, substr($line, $index));
+}
+
+sub add_to_cache
+{
+	my ($cache, $key, $value) = @_;
+
+	if (!$cache->{$key}) {
+		$cache->{$key} = ();
+	}
+	push @{$cache->{$key}}, $value;
+}