lix/tests/setuid.nix
2022-06-07 14:27:10 +02:00

127 lines
3.5 KiB
Nix

# Verify that Linux builds cannot create setuid or setgid binaries.
{ nixpkgs, system, overlay }:
with import (nixpkgs + "/nixos/lib/testing-python.nix") {
inherit system;
extraConfigurations = [ { nixpkgs.overlays = [ overlay ]; } ];
};
makeTest {
name = "setuid";
nodes.machine =
{ config, lib, pkgs, ... }:
{ virtualisation.writableStore = true;
nix.binaryCaches = lib.mkForce [ ];
nix.nixPath = [ "nixpkgs=${lib.cleanSource pkgs.path}" ];
virtualisation.additionalPaths = [ pkgs.stdenv pkgs.pkgsi686Linux.stdenv ];
};
testScript = { nodes }: ''
# fmt: off
start_all()
# Copying to /tmp should succeed.
machine.succeed(r"""
nix-build --no-sandbox -E '(with import <nixpkgs> {}; runCommand "foo" {} "
mkdir -p $out
cp ${pkgs.coreutils}/bin/id /tmp/id
")'
""".strip())
machine.succeed('[[ $(stat -c %a /tmp/id) = 555 ]]')
machine.succeed("rm /tmp/id")
# Creating a setuid binary should fail.
machine.fail(r"""
nix-build --no-sandbox -E '(with import <nixpkgs> {}; runCommand "foo" {} "
mkdir -p $out
cp ${pkgs.coreutils}/bin/id /tmp/id
chmod 4755 /tmp/id
")'
""".strip())
machine.succeed('[[ $(stat -c %a /tmp/id) = 555 ]]')
machine.succeed("rm /tmp/id")
# Creating a setgid binary should fail.
machine.fail(r"""
nix-build --no-sandbox -E '(with import <nixpkgs> {}; runCommand "foo" {} "
mkdir -p $out
cp ${pkgs.coreutils}/bin/id /tmp/id
chmod 2755 /tmp/id
")'
""".strip())
machine.succeed('[[ $(stat -c %a /tmp/id) = 555 ]]')
machine.succeed("rm /tmp/id")
# The checks should also work on 32-bit binaries.
machine.fail(r"""
nix-build --no-sandbox -E '(with import <nixpkgs> { system = "i686-linux"; }; runCommand "foo" {} "
mkdir -p $out
cp ${pkgs.coreutils}/bin/id /tmp/id
chmod 2755 /tmp/id
")'
""".strip())
machine.succeed('[[ $(stat -c %a /tmp/id) = 555 ]]')
machine.succeed("rm /tmp/id")
# The tests above use fchmodat(). Test chmod() as well.
machine.succeed(r"""
nix-build --no-sandbox -E '(with import <nixpkgs> {}; runCommand "foo" { buildInputs = [ perl ]; } "
mkdir -p $out
cp ${pkgs.coreutils}/bin/id /tmp/id
perl -e \"chmod 0666, qw(/tmp/id) or die\"
")'
""".strip())
machine.succeed('[[ $(stat -c %a /tmp/id) = 666 ]]')
machine.succeed("rm /tmp/id")
machine.fail(r"""
nix-build --no-sandbox -E '(with import <nixpkgs> {}; runCommand "foo" { buildInputs = [ perl ]; } "
mkdir -p $out
cp ${pkgs.coreutils}/bin/id /tmp/id
perl -e \"chmod 04755, qw(/tmp/id) or die\"
")'
""".strip())
machine.succeed('[[ $(stat -c %a /tmp/id) = 555 ]]')
machine.succeed("rm /tmp/id")
# And test fchmod().
machine.succeed(r"""
nix-build --no-sandbox -E '(with import <nixpkgs> {}; runCommand "foo" { buildInputs = [ perl ]; } "
mkdir -p $out
cp ${pkgs.coreutils}/bin/id /tmp/id
perl -e \"my \\\$x; open \\\$x, qw(/tmp/id); chmod 01750, \\\$x or die\"
")'
""".strip())
machine.succeed('[[ $(stat -c %a /tmp/id) = 1750 ]]')
machine.succeed("rm /tmp/id")
machine.fail(r"""
nix-build --no-sandbox -E '(with import <nixpkgs> {}; runCommand "foo" { buildInputs = [ perl ]; } "
mkdir -p $out
cp ${pkgs.coreutils}/bin/id /tmp/id
perl -e \"my \\\$x; open \\\$x, qw(/tmp/id); chmod 04777, \\\$x or die\"
")'
""".strip())
machine.succeed('[[ $(stat -c %a /tmp/id) = 555 ]]')
machine.succeed("rm /tmp/id")
'';
}