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Merge pull request #95924 from helsinki-systems/port/hardened-test

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nixos/hardened: Port test to Python and fix it
This commit is contained in:
Florian Klink 2020-08-23 10:06:44 +02:00 committed by GitHub
commit c2a75a8041
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2 changed files with 63 additions and 56 deletions
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7
nixos/lib/test-driver/test-driver.py
View File

@ -424,15 +424,18 @@ class Machine:
output += out
return output
def fail(self, *commands: str) -> None:
def fail(self, *commands: str) -> str:
"""Execute each command and check that it fails."""
output = ""
for command in commands:
with self.nested("must fail: {}".format(command)):
status, output = self.execute(command)
(status, out) = self.execute(command)
if status == 0:
raise Exception(
"command `{}` unexpectedly succeeded".format(command)
)
output += out
return output
def wait_until_succeeds(self, command: str) -> str:
"""Wait until a command returns success and return its output.

112
nixos/tests/hardened.nix
View File

@ -1,4 +1,4 @@
import ./make-test.nix ({ pkgs, latestKernel ? false, ... } : {
import ./make-test-python.nix ({ pkgs, latestKernel ? false, ... } : {
name = "hardened";
meta = with pkgs.stdenv.lib.maintainers; {
maintainers = [ joachifm ];
@ -47,84 +47,88 @@ import ./make-test.nix ({ pkgs, latestKernel ? false, ... } : {
};
in
''
$machine->waitForUnit("multi-user.target");
machine.wait_for_unit("multi-user.target")
with subtest("AppArmor profiles are loaded"):
machine.succeed("systemctl status apparmor.service")
subtest "apparmor-loaded", sub {
$machine->succeed("systemctl status apparmor.service");
};
# AppArmor securityfs
subtest "apparmor-securityfs", sub {
$machine->succeed("mountpoint -q /sys/kernel/security");
$machine->succeed("cat /sys/kernel/security/apparmor/profiles");
};
with subtest("AppArmor securityfs is mounted"):
machine.succeed("mountpoint -q /sys/kernel/security")
machine.succeed("cat /sys/kernel/security/apparmor/profiles")
# Test loading out-of-tree modules
subtest "extra-module-packages", sub {
$machine->succeed("grep -Fq wireguard /proc/modules");
};
with subtest("Out-of-tree modules can be loaded"):
machine.succeed("grep -Fq wireguard /proc/modules")
# Test hidepid
subtest "hidepid", sub {
$machine->succeed("grep -Fq hidepid=2 /proc/mounts");
with subtest("hidepid=2 option is applied and works"):
machine.succeed("grep -Fq hidepid=2 /proc/mounts")
# cannot use pgrep -u here, it segfaults when access to process info is denied
$machine->succeed("[ `su - sybil -c 'ps --no-headers --user root | wc -l'` = 0 ]");
$machine->succeed("[ `su - alice -c 'ps --no-headers --user root | wc -l'` != 0 ]");
};
machine.succeed("[ `su - sybil -c 'ps --no-headers --user root | wc -l'` = 0 ]")
machine.succeed("[ `su - alice -c 'ps --no-headers --user root | wc -l'` != 0 ]")
# Test kernel module hardening
subtest "lock-modules", sub {
with subtest("No more kernel modules can be loaded"):
# note: this better a be module we normally wouldn't load ...
$machine->fail("modprobe dccp");
};
machine.fail("modprobe dccp")
# Test userns
subtest "userns", sub {
$machine->succeed("unshare --user true");
$machine->fail("su -l alice -c 'unshare --user true'");
};
with subtest("User namespaces are restricted"):
machine.succeed("unshare --user true")
machine.fail("su -l alice -c 'unshare --user true'")
# Test dmesg restriction
subtest "dmesg", sub {
$machine->fail("su -l alice -c dmesg");
};
with subtest("Regular users cannot access dmesg"):
machine.fail("su -l alice -c dmesg")
# Test access to kcore
subtest "kcore", sub {
$machine->fail("cat /proc/kcore");
};
with subtest("Kcore is inaccessible as root"):
machine.fail("cat /proc/kcore")
# Test deferred mount
subtest "mount", sub {
$machine->fail("mountpoint -q /efi"); # was deferred
$machine->execute("mkdir -p /efi");
$machine->succeed("mount /dev/disk/by-label/EFISYS /efi");
$machine->succeed("mountpoint -q /efi"); # now mounted
};
with subtest("Deferred mounts work"):
machine.fail("mountpoint -q /efi") # was deferred
machine.execute("mkdir -p /efi")
machine.succeed("mount /dev/disk/by-label/EFISYS /efi")
machine.succeed("mountpoint -q /efi") # now mounted
# Test Nix dæmon usage
subtest "nix-daemon", sub {
$machine->fail("su -l nobody -s /bin/sh -c 'nix ping-store'");
$machine->succeed("su -l alice -c 'nix ping-store'") =~ "OK";
};
with subtest("nix-daemon cannot be used by all users"):
machine.fail("su -l nobody -s /bin/sh -c 'nix ping-store'")
machine.succeed("su -l alice -c 'nix ping-store'")
# Test kernel image protection
subtest "kernelimage", sub {
$machine->fail("systemctl hibernate");
$machine->fail("systemctl kexec");
};
with subtest("The kernel image is protected"):
machine.fail("systemctl hibernate")
machine.fail("systemctl kexec")
# Test hardened memory allocator
sub runMallocTestProg {
my ($progName, $errorText) = @_;
my $text = "fatal allocator error: " . $errorText;
$machine->fail("${hardened-malloc-tests}/bin/" . $progName) =~ $text;
};
def runMallocTestProg(prog_name, error_text):
text = "fatal allocator error: " + error_text
if not text in machine.fail(
"${hardened-malloc-tests}/bin/"
+ prog_name
+ " 2>&1"
):
raise Exception("Hardened malloc does not work for {}".format(error_text))
subtest "hardenedmalloc", sub {
runMallocTestProg("double_free_large", "invalid free");
runMallocTestProg("unaligned_free_small", "invalid unaligned free");
runMallocTestProg("write_after_free_small", "detected write after free");
};
with subtest("The hardened memory allocator works"):
runMallocTestProg("double_free_large", "invalid free")
runMallocTestProg("unaligned_free_small", "invalid unaligned free")
runMallocTestProg("write_after_free_small", "detected write after free")
'';
})