File dpkg-CVE-2022-1664.patch of Package update-alternatives.24405
diff --git a/scripts/Dpkg/Source/Archive.pm b/scripts/Dpkg/Source/Archive.pm
index 33c181b20..2ddd04af8 100644
--- a/scripts/Dpkg/Source/Archive.pm
+++ b/scripts/Dpkg/Source/Archive.pm
@@ -21,9 +21,11 @@ use warnings;
our $VERSION = '0.01';
use Carp;
+use Errno qw(ENOENT);
use File::Temp qw(tempdir);
use File::Basename qw(basename);
use File::Spec;
+use File::Find;
use Cwd;
use Dpkg ();
@@ -110,19 +112,13 @@ sub extract {
my %spawn_opts = (wait_child => 1);
# Prepare destination
- my $tmp;
- if ($opts{in_place}) {
- $spawn_opts{chdir} = $dest;
- $tmp = $dest; # So that fixperms call works
- } else {
- my $template = basename($self->get_filename()) . '.tmp-extract.XXXXX';
- unless (-e $dest) {
- # Kludge so that realpath works
- mkdir($dest) or syserr(g_('cannot create directory %s'), $dest);
- }
- $tmp = tempdir($template, DIR => Cwd::realpath("$dest/.."), CLEANUP => 1);
- $spawn_opts{chdir} = $tmp;
+ my $template = basename($self->get_filename()) . '.tmp-extract.XXXXX';
+ unless (-e $dest) {
+ # Kludge so that realpath works
+ mkdir($dest) or syserr(g_('cannot create directory %s'), $dest);
}
+ my $tmp = tempdir($template, DIR => Cwd::realpath("$dest/.."), CLEANUP => 1);
+ $spawn_opts{chdir} = $tmp;
# Prepare stuff that handles the input of tar
$self->ensure_open('r', delete_sig => [ 'PIPE' ]);
@@ -145,22 +141,94 @@ sub extract {
# have to be calculated using mount options and other madness.
fixperms($tmp) unless $opts{no_fixperms};
- # Stop here if we extracted in-place as there's nothing to move around
- return if $opts{in_place};
-
- # Rename extracted directory
- opendir(my $dir_dh, $tmp) or syserr(g_('cannot opendir %s'), $tmp);
- my @entries = grep { $_ ne '.' && $_ ne '..' } readdir($dir_dh);
- closedir($dir_dh);
- my $done = 0;
- erasedir($dest);
- if (scalar(@entries) == 1 && ! -l "$tmp/$entries[0]" && -d _) {
- rename("$tmp/$entries[0]", $dest)
- or syserr(g_('unable to rename %s to %s'),
- "$tmp/$entries[0]", $dest);
+ # If we are extracting "in-place" do not remove the destination directory.
+ if ($opts{in_place}) {
+ my $canon_basedir = Cwd::realpath($dest);
+ # On Solaris /dev/null points to /devices/pseudo/mm@0:null.
+ my $canon_devnull = Cwd::realpath('/dev/null');
+ my $check_symlink = sub {
+ my $pathname = shift;
+ my $canon_pathname = Cwd::realpath($pathname);
+ if (not defined $canon_pathname) {
+ return if $! == ENOENT;
+
+ syserr(g_("pathname '%s' cannot be canonicalized"), $pathname);
+ }
+ return if $canon_pathname eq $canon_devnull;
+ return if $canon_pathname eq $canon_basedir;
+ return if $canon_pathname =~ m{^\Q$canon_basedir/\E};
+ warning(g_("pathname '%s' points outside source root (to '%s')"),
+ $pathname, $canon_pathname);
+ };
+
+ my $move_in_place = sub {
+ my $relpath = File::Spec->abs2rel($File::Find::name, $tmp);
+ my $destpath = File::Spec->catfile($dest, $relpath);
+
+ my ($mode, $atime, $mtime);
+ lstat $File::Find::name
+ or syserr(g_('cannot get source pathname %s metadata'), $File::Find::name);
+ ((undef) x 2, $mode, (undef) x 5, $atime, $mtime) = lstat _;
+ my $src_is_dir = -d _;
+
+ my $dest_exists = 1;
+ if (not lstat $destpath) {
+ if ($! == ENOENT) {
+ $dest_exists = 0;
+ } else {
+ syserr(g_('cannot get target pathname %s metadata'), $destpath);
+ }
+ }
+ my $dest_is_dir = -d _;
+ if ($dest_exists) {
+ if ($dest_is_dir && $src_is_dir) {
+ # Refresh the destination directory attributes with the
+ # ones from the tarball.
+ chmod $mode, $destpath
+ or syserr(g_('cannot change directory %s mode'), $File::Find::name);
+ utime $atime, $mtime, $destpath
+ or syserr(g_('cannot change directory %s times'), $File::Find::name);
+
+ # We should do nothing, and just walk further tree.
+ return;
+ } elsif ($dest_is_dir) {
+ rmdir $destpath
+ or syserr(g_('cannot remove destination directory %s'), $destpath);
+ } else {
+ $check_symlink->($destpath);
+ unlink $destpath
+ or syserr(g_('cannot remove destination file %s'), $destpath);
+ }
+ }
+ # If we are moving a directory, we do not need to walk it.
+ if ($src_is_dir) {
+ $File::Find::prune = 1;
+ }
+ rename $File::Find::name, $destpath
+ or syserr(g_('cannot move %s to %s'), $File::Find::name, $destpath);
+ };
+
+ find({
+ wanted => $move_in_place,
+ no_chdir => 1,
+ dangling_symlinks => 0,
+ }, $tmp);
} else {
- rename($tmp, $dest)
- or syserr(g_('unable to rename %s to %s'), $tmp, $dest);
+ # Rename extracted directory
+ opendir(my $dir_dh, $tmp) or syserr(g_('cannot opendir %s'), $tmp);
+ my @entries = grep { $_ ne '.' && $_ ne '..' } readdir($dir_dh);
+ closedir($dir_dh);
+
+ erasedir($dest);
+
+ if (scalar(@entries) == 1 && ! -l "$tmp/$entries[0]" && -d _) {
+ rename("$tmp/$entries[0]", $dest)
+ or syserr(g_('unable to rename %s to %s'),
+ "$tmp/$entries[0]", $dest);
+ } else {
+ rename($tmp, $dest)
+ or syserr(g_('unable to rename %s to %s'), $tmp, $dest);
+ }
}
erasedir($tmp);
}
diff --git a/scripts/t/Dpkg_Source_Archive.t b/scripts/t/Dpkg_Source_Archive.t
index 7b70da68e..09496aeea 100644
--- a/scripts/t/Dpkg_Source_Archive.t
+++ b/scripts/t/Dpkg_Source_Archive.t
@@ -16,12 +16,120 @@
use strict;
use warnings;
-use Test::More tests => 1;
+use Test::More tests => 4;
+use Test::Dpkg qw(:paths);
+
+use File::Spec;
+use File::Path qw(make_path rmtree);
BEGIN {
use_ok('Dpkg::Source::Archive');
}
+use Dpkg;
+
+my $tmpdir = 't.tmp/Dpkg_Source_Archive';
+
+rmtree($tmpdir);
+
+sub test_touch
+{
+ my ($name, $data) = @_;
+
+ open my $fh, '>', $name
+ or die "cannot touch file $name\n";
+ print { $fh } $data if $data;
+ close $fh;
+}
+
+sub test_path_escape
+{
+ my $name = shift;
+
+ my $treedir = File::Spec->rel2abs("$tmpdir/$name-tree");
+ my $overdir = File::Spec->rel2abs("$tmpdir/$name-overlay");
+ my $outdir = "$tmpdir/$name-out";
+ my $expdir = "$tmpdir/$name-exp";
+
+ # This is the base directory, where we are going to be extracting stuff
+ # into, which include traps.
+ make_path("$treedir/subdir-a");
+ test_touch("$treedir/subdir-a/file-a");
+ test_touch("$treedir/subdir-a/file-pre-a");
+ make_path("$treedir/subdir-b");
+ test_touch("$treedir/subdir-b/file-b");
+ test_touch("$treedir/subdir-b/file-pre-b");
+ symlink File::Spec->abs2rel($outdir, $treedir), "$treedir/symlink-escape";
+ symlink File::Spec->abs2rel("$outdir/nonexistent", $treedir), "$treedir/symlink-nonexistent";
+ symlink "$treedir/file", "$treedir/symlink-within";
+ test_touch("$treedir/supposed-dir");
+
+ # This is the overlay directory, which we'll pack and extract over the
+ # base directory.
+ make_path($overdir);
+ make_path("$overdir/subdir-a/aa");
+ test_touch("$overdir/subdir-a/aa/file-aa", 'aa');
+ test_touch("$overdir/subdir-a/file-a", 'a');
+ make_path("$overdir/subdir-b/bb");
+ test_touch("$overdir/subdir-b/bb/file-bb", 'bb');
+ test_touch("$overdir/subdir-b/file-b", 'b');
+ make_path("$overdir/symlink-escape");
+ test_touch("$overdir/symlink-escape/escaped-file", 'escaped');
+ test_touch("$overdir/symlink-nonexistent", 'nonexistent');
+ make_path("$overdir/symlink-within");
+ make_path("$overdir/supposed-dir");
+ test_touch("$overdir/supposed-dir/supposed-file", 'something');
+
+ # Generate overlay tar.
+ system($Dpkg::PROGTAR, '-cf', "$overdir.tar", '-C', $overdir, qw(
+ subdir-a subdir-b
+ symlink-escape/escaped-file symlink-nonexistent symlink-within
+ supposed-dir
+ )) == 0
+ or die "cannot create overlay tar archive\n";
+
+ # This is the expected directory, which we'll be comparing against.
+ make_path($expdir);
+ system('cp', '-a', $overdir, $expdir) == 0
+ or die "cannot copy overlay hierarchy into expected directory\n";
+
+ # Store the expected and out reference directories into a tar to compare
+ # its structure against the result reference.
+ system($Dpkg::PROGTAR, '-cf', "$expdir.tar", '-C', $overdir, qw(
+ subdir-a subdir-b
+ symlink-escape/escaped-file symlink-nonexistent symlink-within
+ supposed-dir
+ ), '-C', $treedir, qw(
+ subdir-a/file-pre-a
+ subdir-b/file-pre-b
+ )) == 0
+ or die "cannot create expected tar archive\n";
+
+ # This directory is supposed to remain empty, anything inside implies a
+ # directory traversal.
+ make_path($outdir);
+
+ my $warnseen;
+ local $SIG{__WARN__} = sub { $warnseen = $_[0] };
+
+ # Perform the extraction.
+ my $tar = Dpkg::Source::Archive->new(filename => "$overdir.tar");
+ $tar->extract($treedir, in_place => 1);
+
+ # Store the result into a tar to compare its structure against a reference.
+ system($Dpkg::PROGTAR, '-cf', "$treedir.tar", '-C', $treedir, '.');
+
+ # Check results
+ ok(length $warnseen && $warnseen =~ m/points outside source root/,
+ 'expected warning seen');
+ ok(system($Dpkg::PROGTAR, '--compare', '-f', "$expdir.tar", '-C', $treedir) == 0,
+ 'expected directory matches');
+ ok(! -e "$outdir/escaped-file",
+ 'expected output directory is empty, directory traversal');
+}
+
+test_path_escape('in-place');
+
# TODO: Add actual test cases.
1;
