store temporary files in /tmp inside the rootfs to avoid problems in unshare mode and TMPDIR set

This commit is contained in:
Johannes 'josch' Schauer 2020-03-07 23:40:55 +01:00
parent b9db466a26
commit 89e7dd6756
Signed by untrusted user: josch
GPG key ID: F2CBA5C78FBD83E1

View file

@ -1190,12 +1190,57 @@ sub setup {
warning "cannot read $options->{apttrustedparts}";
}
# We create the temporary apt.conf inside the rootfs as an easy way to make
# sure that the unshared process is able to create it even if the user has
# TMPDIR set to a directory that the unshared process does not directly
# have access to.
{
my @directories = (
'/etc/apt/apt.conf.d', '/etc/apt/sources.list.d',
'/etc/apt/preferences.d', '/var/cache/apt',
'/var/lib/apt/lists/partial', '/var/lib/dpkg',
'/etc/dpkg/dpkg.cfg.d/', '/tmp'
);
# if dpkg and apt operate from the outside we need some more
# directories because dpkg and apt might not even be installed inside
# the chroot
if ($options->{mode} eq 'chrootless') {
push @directories,
(
'/var/log/apt', '/var/lib/dpkg/triggers',
'/var/lib/dpkg/info', '/var/lib/dpkg/alternatives',
'/var/lib/dpkg/updates'
);
}
foreach my $dir (@directories) {
if (-e "$options->{root}/$dir") {
if (!-d "$options->{root}/$dir") {
error "$dir already exists but is not a directory";
}
} else {
my $num_created = make_path "$options->{root}/$dir",
{ error => \my $err };
if ($err && @$err) {
error(
join "; ",
(map { "cannot create " . (join ": ", %{$_}) } @$err));
} elsif ($num_created == 0) {
error "cannot create $options->{root}/$dir";
}
}
}
}
# The TMPDIR set by the user or even /tmp might be inaccessible by the
# unshared user. Thus, we place all temporary files in /tmp inside the new
# rootfs.
#
# This will affect calls to tempfile() as well as runs of "apt-get update"
# which will create temporary clearsigned.message.XXXXXX files to verify
# signatures.
{
## no critic (Variables::RequireLocalizedPunctuationVars)
$ENV{"TMPDIR"} = "$options->{root}/tmp";
}
my ($conf, $tmpfile)
= tempfile("mmdebstrap.apt.conf.XXXXXXXXXXXX", DIR => $options->{root})
= tempfile("mmdebstrap.apt.conf.XXXXXXXXXXXX", TMPDIR => 1)
or error "cannot open apt.conf: $!";
print $conf "Apt::Architecture \"$options->{nativearch}\";\n";
# the host system might have configured additional architectures
@ -1239,43 +1284,6 @@ sub setup {
}
close $conf;
{
my @directories = (
'/etc/apt/apt.conf.d', '/etc/apt/sources.list.d',
'/etc/apt/preferences.d', '/var/cache/apt',
'/var/lib/apt/lists/partial', '/var/lib/dpkg',
'/etc/dpkg/dpkg.cfg.d/'
);
# if dpkg and apt operate from the outside we need some more
# directories because dpkg and apt might not even be installed inside
# the chroot
if ($options->{mode} eq 'chrootless') {
push @directories,
(
'/var/log/apt', '/var/lib/dpkg/triggers',
'/var/lib/dpkg/info', '/var/lib/dpkg/alternatives',
'/var/lib/dpkg/updates'
);
}
foreach my $dir (@directories) {
if (-e "$options->{root}/$dir") {
if (!-d "$options->{root}/$dir") {
error "$dir already exists but is not a directory";
}
} else {
my $num_created = make_path "$options->{root}/$dir",
{ error => \my $err };
if ($err && @$err) {
error(
join "; ",
(map { "cannot create " . (join ": ", %{$_}) } @$err));
} elsif ($num_created == 0) {
error "cannot create $options->{root}/$dir";
}
}
}
}
# We put certain configuration items in their own configuration file
# because they have to be valid for apt invocation from outside as well as
# from inside the chroot.