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package seccomp
/* flatpak commit 4c3bf179e2e4a2a298cd1db1d045adaf3f564532 */
import (
. "syscall"
. "hakurei.app/container/std"
. "hakurei.app/ext"
)
func Preset(presets FilterPreset, flags ExportFlag) (rules []NativeRule) {
allowedPersonality := PersonaLinux
if presets&PresetLinux32 != 0 {
allowedPersonality = PersonaLinux32
}
presetDevelFinal := presetDevel(ScmpDatum(allowedPersonality))
l := len(presetCommon)
if presets&PresetDenyNS != 0 {
l += len(presetNamespace)
}
if presets&PresetDenyTTY != 0 {
l += len(presetTTY)
}
if presets&PresetDenyDevel != 0 {
l += len(presetDevelFinal)
}
if flags&AllowMultiarch == 0 {
l += len(presetEmu)
}
if presets&PresetExt != 0 {
l += len(presetCommonExt)
if presets&PresetDenyNS != 0 {
l += len(presetNamespaceExt)
}
if flags&AllowMultiarch == 0 {
l += len(presetEmuExt)
}
}
rules = make([]NativeRule, 0, l)
rules = append(rules, presetCommon...)
if presets&PresetDenyNS != 0 {
rules = append(rules, presetNamespace...)
}
if presets&PresetDenyTTY != 0 {
rules = append(rules, presetTTY...)
}
if presets&PresetDenyDevel != 0 {
rules = append(rules, presetDevelFinal...)
}
if flags&AllowMultiarch == 0 {
rules = append(rules, presetEmu...)
}
if presets&PresetExt != 0 {
rules = append(rules, presetCommonExt...)
if presets&PresetDenyNS != 0 {
rules = append(rules, presetNamespaceExt...)
}
if flags&AllowMultiarch == 0 {
rules = append(rules, presetEmuExt...)
}
}
return
}
var (
presetCommon = []NativeRule{
/* Block dmesg */
{Syscall: SNR_SYSLOG, Errno: ScmpErrno(EPERM), Arg: nil},
/* Useless old syscall */
{Syscall: SNR_USELIB, Errno: ScmpErrno(EPERM), Arg: nil},
/* Don't allow disabling accounting */
{Syscall: SNR_ACCT, Errno: ScmpErrno(EPERM), Arg: nil},
/* Don't allow reading current quota use */
{Syscall: SNR_QUOTACTL, Errno: ScmpErrno(EPERM), Arg: nil},
/* Don't allow access to the kernel keyring */
{Syscall: SNR_ADD_KEY, Errno: ScmpErrno(EPERM), Arg: nil},
{Syscall: SNR_KEYCTL, Errno: ScmpErrno(EPERM), Arg: nil},
{Syscall: SNR_REQUEST_KEY, Errno: ScmpErrno(EPERM), Arg: nil},
/* Scary VM/NUMA ops */
{Syscall: SNR_MOVE_PAGES, Errno: ScmpErrno(EPERM), Arg: nil},
{Syscall: SNR_MBIND, Errno: ScmpErrno(EPERM), Arg: nil},
{Syscall: SNR_GET_MEMPOLICY, Errno: ScmpErrno(EPERM), Arg: nil},
{Syscall: SNR_SET_MEMPOLICY, Errno: ScmpErrno(EPERM), Arg: nil},
{Syscall: SNR_MIGRATE_PAGES, Errno: ScmpErrno(EPERM), Arg: nil},
}
/* hakurei: project-specific extensions */
presetCommonExt = []NativeRule{
/* system calls for changing the system clock */
{Syscall: SNR_ADJTIMEX, Errno: ScmpErrno(EPERM), Arg: nil},
{Syscall: SNR_CLOCK_ADJTIME, Errno: ScmpErrno(EPERM), Arg: nil},
{Syscall: SNR_CLOCK_ADJTIME64, Errno: ScmpErrno(EPERM), Arg: nil},
{Syscall: SNR_CLOCK_SETTIME, Errno: ScmpErrno(EPERM), Arg: nil},
{Syscall: SNR_CLOCK_SETTIME64, Errno: ScmpErrno(EPERM), Arg: nil},
{Syscall: SNR_SETTIMEOFDAY, Errno: ScmpErrno(EPERM), Arg: nil},
/* loading and unloading of kernel modules */
{Syscall: SNR_DELETE_MODULE, Errno: ScmpErrno(EPERM), Arg: nil},
{Syscall: SNR_FINIT_MODULE, Errno: ScmpErrno(EPERM), Arg: nil},
{Syscall: SNR_INIT_MODULE, Errno: ScmpErrno(EPERM), Arg: nil},
/* system calls for rebooting and reboot preparation */
{Syscall: SNR_KEXEC_FILE_LOAD, Errno: ScmpErrno(EPERM), Arg: nil},
{Syscall: SNR_KEXEC_LOAD, Errno: ScmpErrno(EPERM), Arg: nil},
{Syscall: SNR_REBOOT, Errno: ScmpErrno(EPERM), Arg: nil},
/* system calls for enabling/disabling swap devices */
{Syscall: SNR_SWAPOFF, Errno: ScmpErrno(EPERM), Arg: nil},
{Syscall: SNR_SWAPON, Errno: ScmpErrno(EPERM), Arg: nil},
}
presetNamespace = []NativeRule{
/* Don't allow subnamespace setups: */
{Syscall: SNR_UNSHARE, Errno: ScmpErrno(EPERM), Arg: nil},
{Syscall: SNR_SETNS, Errno: ScmpErrno(EPERM), Arg: nil},
{Syscall: SNR_MOUNT, Errno: ScmpErrno(EPERM), Arg: nil},
{Syscall: SNR_UMOUNT, Errno: ScmpErrno(EPERM), Arg: nil},
{Syscall: SNR_UMOUNT2, Errno: ScmpErrno(EPERM), Arg: nil},
{Syscall: SNR_PIVOT_ROOT, Errno: ScmpErrno(EPERM), Arg: nil},
{Syscall: SNR_CHROOT, Errno: ScmpErrno(EPERM), Arg: nil},
{Syscall: SNR_CLONE, Errno: ScmpErrno(EPERM),
Arg: &ScmpArgCmp{Arg: cloneArg, Op: SCMP_CMP_MASKED_EQ, DatumA: CLONE_NEWUSER, DatumB: CLONE_NEWUSER}},
/* seccomp can't look into clone3()'s struct clone_args to check whether
* the flags are OK, so we have no choice but to block clone3().
* Return ENOSYS so user-space will fall back to clone().
* (CVE-2021-41133; see also https://github.com/moby/moby/commit/9f6b562d)
*/
{Syscall: SNR_CLONE3, Errno: ScmpErrno(ENOSYS), Arg: nil},
/* New mount manipulation APIs can also change our VFS. There's no
* legitimate reason to do these in the sandbox, so block all of them
* rather than thinking about which ones might be dangerous.
* (CVE-2021-41133) */
{Syscall: SNR_OPEN_TREE, Errno: ScmpErrno(ENOSYS), Arg: nil},
{Syscall: SNR_MOVE_MOUNT, Errno: ScmpErrno(ENOSYS), Arg: nil},
{Syscall: SNR_FSOPEN, Errno: ScmpErrno(ENOSYS), Arg: nil},
{Syscall: SNR_FSCONFIG, Errno: ScmpErrno(ENOSYS), Arg: nil},
{Syscall: SNR_FSMOUNT, Errno: ScmpErrno(ENOSYS), Arg: nil},
{Syscall: SNR_FSPICK, Errno: ScmpErrno(ENOSYS), Arg: nil},
{Syscall: SNR_MOUNT_SETATTR, Errno: ScmpErrno(ENOSYS), Arg: nil},
}
/* hakurei: project-specific extensions */
presetNamespaceExt = []NativeRule{
/* changing file ownership */
{Syscall: SNR_CHOWN, Errno: ScmpErrno(EPERM), Arg: nil},
{Syscall: SNR_CHOWN32, Errno: ScmpErrno(EPERM), Arg: nil},
{Syscall: SNR_FCHOWN, Errno: ScmpErrno(EPERM), Arg: nil},
{Syscall: SNR_FCHOWN32, Errno: ScmpErrno(EPERM), Arg: nil},
{Syscall: SNR_FCHOWNAT, Errno: ScmpErrno(EPERM), Arg: nil},
{Syscall: SNR_LCHOWN, Errno: ScmpErrno(EPERM), Arg: nil},
{Syscall: SNR_LCHOWN32, Errno: ScmpErrno(EPERM), Arg: nil},
/* system calls for changing user ID and group ID credentials */
{Syscall: SNR_SETGID, Errno: ScmpErrno(EPERM), Arg: nil},
{Syscall: SNR_SETGID32, Errno: ScmpErrno(EPERM), Arg: nil},
{Syscall: SNR_SETGROUPS, Errno: ScmpErrno(EPERM), Arg: nil},
{Syscall: SNR_SETGROUPS32, Errno: ScmpErrno(EPERM), Arg: nil},
{Syscall: SNR_SETREGID, Errno: ScmpErrno(EPERM), Arg: nil},
{Syscall: SNR_SETREGID32, Errno: ScmpErrno(EPERM), Arg: nil},
{Syscall: SNR_SETRESGID, Errno: ScmpErrno(EPERM), Arg: nil},
{Syscall: SNR_SETRESGID32, Errno: ScmpErrno(EPERM), Arg: nil},
{Syscall: SNR_SETRESUID, Errno: ScmpErrno(EPERM), Arg: nil},
{Syscall: SNR_SETRESUID32, Errno: ScmpErrno(EPERM), Arg: nil},
{Syscall: SNR_SETREUID, Errno: ScmpErrno(EPERM), Arg: nil},
{Syscall: SNR_SETREUID32, Errno: ScmpErrno(EPERM), Arg: nil},
{Syscall: SNR_SETUID, Errno: ScmpErrno(EPERM), Arg: nil},
{Syscall: SNR_SETUID32, Errno: ScmpErrno(EPERM), Arg: nil},
}
presetTTY = []NativeRule{
/* Don't allow faking input to the controlling tty (CVE-2017-5226) */
{Syscall: SNR_IOCTL, Errno: ScmpErrno(EPERM),
Arg: &ScmpArgCmp{Arg: 1, Op: SCMP_CMP_MASKED_EQ, DatumA: 0xFFFFFFFF, DatumB: TIOCSTI}},
/* In the unlikely event that the controlling tty is a Linux virtual
* console (/dev/tty2 or similar), copy/paste operations have an effect
* similar to TIOCSTI (CVE-2023-28100) */
{Syscall: SNR_IOCTL, Errno: ScmpErrno(EPERM),
Arg: &ScmpArgCmp{Arg: 1, Op: SCMP_CMP_MASKED_EQ, DatumA: 0xFFFFFFFF, DatumB: TIOCLINUX}},
}
presetEmu = []NativeRule{
/* modify_ldt is a historic source of interesting information leaks,
* so it's disabled as a hardening measure.
* However, it is required to run old 16-bit applications
* as well as some Wine patches, so it's allowed in multiarch. */
{Syscall: SNR_MODIFY_LDT, Errno: ScmpErrno(EPERM), Arg: nil},
}
/* hakurei: project-specific extensions */
presetEmuExt = []NativeRule{
{Syscall: SNR_SUBPAGE_PROT, Errno: ScmpErrno(ENOSYS), Arg: nil},
{Syscall: SNR_SWITCH_ENDIAN, Errno: ScmpErrno(ENOSYS), Arg: nil},
{Syscall: SNR_VM86, Errno: ScmpErrno(ENOSYS), Arg: nil},
{Syscall: SNR_VM86OLD, Errno: ScmpErrno(ENOSYS), Arg: nil},
}
)
func presetDevel(allowedPersonality ScmpDatum) []NativeRule {
return []NativeRule{
/* Profiling operations; we expect these to be done by tools from outside
* the sandbox. In particular perf has been the source of many CVEs. */
{Syscall: SNR_PERF_EVENT_OPEN, Errno: ScmpErrno(EPERM), Arg: nil},
/* Don't allow you to switch to bsd emulation or whatnot */
{Syscall: SNR_PERSONALITY, Errno: ScmpErrno(EPERM),
Arg: &ScmpArgCmp{Arg: 0, Op: SCMP_CMP_NE, DatumA: allowedPersonality}},
{Syscall: SNR_PTRACE, Errno: ScmpErrno(EPERM), Arg: nil},
}
}
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