cloud-hypervisor/vmm/src/seccomp_filters.rs
Sebastien Boeuf bdef54ead6 vmm: Add brk syscall to the API thread
The brk syscall is not always called as the system might not need it.
But when it's needed from the API thread, this causes the thread to
terminate as it is not part of the authorized list of syscalls.

This should fix some sporadic failures on the CI with the musl build.

Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
2020-08-11 15:04:21 +01:00

415 lines
17 KiB
Rust

// Copyright 2018 Amazon.com, Inc. or its affiliates. All Rights Reserved.
//
// Copyright © 2020 Intel Corporation
//
// SPDX-License-Identifier: Apache-2.0
use seccomp::{
allow_syscall, allow_syscall_if, BpfProgram, Error, SeccompAction, SeccompCmpArgLen as ArgLen,
SeccompCmpOp::Eq, SeccompCondition as Cond, SeccompError, SeccompFilter, SeccompRule,
SyscallRuleSet,
};
use std::convert::TryInto;
pub enum Thread {
Vmm,
Api,
}
/// Shorthand for chaining `SeccompCondition`s with the `and` operator in a `SeccompRule`.
/// The rule will take the `Allow` action if _all_ the conditions are true.
///
/// [`Allow`]: enum.SeccompAction.html
/// [`SeccompCondition`]: struct.SeccompCondition.html
/// [`SeccompRule`]: struct.SeccompRule.html
macro_rules! and {
($($x:expr,)*) => (SeccompRule::new(vec![$($x),*], SeccompAction::Allow));
($($x:expr),*) => (SeccompRule::new(vec![$($x),*], SeccompAction::Allow))
}
/// Shorthand for chaining `SeccompRule`s with the `or` operator in a `SeccompFilter`.
///
/// [`SeccompFilter`]: struct.SeccompFilter.html
/// [`SeccompRule`]: struct.SeccompRule.html
macro_rules! or {
($($x:expr,)*) => (vec![$($x),*]);
($($x:expr),*) => (vec![$($x),*])
}
// Define io_uring syscalls as they are not yet part of libc.
const SYS_IO_URING_SETUP: i64 = 425;
const SYS_IO_URING_ENTER: i64 = 426;
const SYS_IO_URING_REGISTER: i64 = 427;
// See include/uapi/asm-generic/ioctls.h in the kernel code.
const TCGETS: u64 = 0x5401;
const TCSETS: u64 = 0x5402;
const TIOCGWINSZ: u64 = 0x5413;
const FIOCLEX: u64 = 0x5451;
const FIONBIO: u64 = 0x5421;
// See include/uapi/linux/if_tun.h in the kernel code.
const TUNSETIFF: u64 = 0x4004_54ca;
const TUNSETOFFLOAD: u64 = 0x4004_54d0;
const TUNSETVNETHDRSZ: u64 = 0x4004_54d8;
const TUNGETFEATURES: u64 = 0x8004_54cf;
// See include/uapi/linux/sockios.h in the kernel code.
const SIOCGIFFLAGS: u64 = 0x8913;
const SIOCGIFHWADDR: u64 = 0x8927;
const SIOCSIFFLAGS: u64 = 0x8914;
const SIOCSIFADDR: u64 = 0x8916;
const SIOCSIFHWADDR: u64 = 0x8924;
const SIOCSIFNETMASK: u64 = 0x891c;
// See include/uapi/linux/vfio.h in the kernel code.
const VFIO_GET_API_VERSION: u64 = 0x3b64;
const VFIO_CHECK_EXTENSION: u64 = 0x3b65;
const VFIO_SET_IOMMU: u64 = 0x3b66;
const VFIO_GROUP_GET_STATUS: u64 = 0x3b67;
const VFIO_GROUP_SET_CONTAINER: u64 = 0x3b68;
const VFIO_GROUP_UNSET_CONTAINER: u64 = 0x3b69;
const VFIO_GROUP_GET_DEVICE_FD: u64 = 0x3b6a;
const VFIO_DEVICE_GET_INFO: u64 = 0x3b6b;
const VFIO_DEVICE_GET_REGION_INFO: u64 = 0x3b6c;
const VFIO_DEVICE_GET_IRQ_INFO: u64 = 0x3b6d;
const VFIO_DEVICE_SET_IRQS: u64 = 0x3b6e;
const VFIO_DEVICE_RESET: u64 = 0x3b6f;
const VFIO_IOMMU_MAP_DMA: u64 = 0x3b71;
const VFIO_IOMMU_UNMAP_DMA: u64 = 0x3b72;
const VFIO_DEVICE_IOEVENTFD: u64 = 0x3b74;
fn create_vmm_ioctl_seccomp_rule_common() -> Result<Vec<SeccompRule>, Error> {
// See include/uapi/linux/kvm.h in the kernel code.
const KVM_GET_API_VERSION: u64 = 0xae00;
const KVM_CREATE_VM: u64 = 0xae01;
const KVM_CHECK_EXTENSION: u64 = 0xae03;
const KVM_GET_VCPU_MMAP_SIZE: u64 = 0xae04;
const KVM_CREATE_VCPU: u64 = 0xae41;
const KVM_CREATE_IRQCHIP: u64 = 0xae60;
const KVM_RUN: u64 = 0xae80;
const KVM_SET_MP_STATE: u64 = 0x4004_ae99;
const KVM_SET_GSI_ROUTING: u64 = 0x4008_ae6a;
const KVM_SET_DEVICE_ATTR: u64 = 0x4018_aee1;
const KVM_SET_ONE_REG: u64 = 0x4010_aeac;
const KVM_SET_USER_MEMORY_REGION: u64 = 0x4020_ae46;
const KVM_IRQFD: u64 = 0x4020_ae76;
const KVM_IOEVENTFD: u64 = 0x4040_ae79;
const KVM_SET_VCPU_EVENTS: u64 = 0x4040_aea0;
const KVM_ENABLE_CAP: u64 = 0x4068_aea3;
const KVM_SET_REGS: u64 = 0x4090_ae82;
const KVM_GET_MP_STATE: u64 = 0x8004_ae98;
const KVM_GET_DEVICE_ATTR: u64 = 0x4018_aee2;
const KVM_GET_VCPU_EVENTS: u64 = 0x8040_ae9f;
const KVM_GET_ONE_REG: u64 = 0x4010_aeab;
const KVM_GET_REGS: u64 = 0x8090_ae81;
const KVM_GET_SUPPORTED_CPUID: u64 = 0xc008_ae05;
const KVM_CREATE_DEVICE: u64 = 0xc00c_aee0;
Ok(or![
and![Cond::new(1, ArgLen::DWORD, Eq, FIOCLEX)?],
and![Cond::new(1, ArgLen::DWORD, Eq, FIONBIO)?],
and![Cond::new(1, ArgLen::DWORD, Eq, KVM_CHECK_EXTENSION,)?],
and![Cond::new(1, ArgLen::DWORD, Eq, KVM_CREATE_DEVICE,)?],
and![Cond::new(1, ArgLen::DWORD, Eq, KVM_CREATE_IRQCHIP,)?],
and![Cond::new(1, ArgLen::DWORD, Eq, KVM_CREATE_VCPU)?],
and![Cond::new(1, ArgLen::DWORD, Eq, KVM_CREATE_VM)?],
and![Cond::new(1, ArgLen::DWORD, Eq, KVM_ENABLE_CAP)?],
and![Cond::new(1, ArgLen::DWORD, Eq, KVM_GET_API_VERSION,)?],
and![Cond::new(1, ArgLen::DWORD, Eq, KVM_GET_DEVICE_ATTR,)?],
and![Cond::new(1, ArgLen::DWORD, Eq, KVM_GET_MP_STATE)?],
and![Cond::new(1, ArgLen::DWORD, Eq, KVM_GET_ONE_REG)?],
and![Cond::new(1, ArgLen::DWORD, Eq, KVM_GET_REGS)?],
and![Cond::new(1, ArgLen::DWORD, Eq, KVM_GET_SUPPORTED_CPUID,)?],
and![Cond::new(1, ArgLen::DWORD, Eq, KVM_GET_VCPU_EVENTS,)?],
and![Cond::new(1, ArgLen::DWORD, Eq, KVM_GET_VCPU_MMAP_SIZE,)?],
and![Cond::new(1, ArgLen::DWORD, Eq, KVM_IOEVENTFD)?],
and![Cond::new(1, ArgLen::DWORD, Eq, KVM_IRQFD)?],
and![Cond::new(1, ArgLen::DWORD, Eq, KVM_RUN)?],
and![Cond::new(1, ArgLen::DWORD, Eq, KVM_SET_DEVICE_ATTR,)?],
and![Cond::new(1, ArgLen::DWORD, Eq, KVM_SET_GSI_ROUTING)?],
and![Cond::new(1, ArgLen::DWORD, Eq, KVM_SET_MP_STATE)?],
and![Cond::new(1, ArgLen::DWORD, Eq, KVM_SET_ONE_REG)?],
and![Cond::new(1, ArgLen::DWORD, Eq, KVM_SET_REGS)?],
and![Cond::new(1, ArgLen::DWORD, Eq, KVM_SET_USER_MEMORY_REGION,)?],
and![Cond::new(1, ArgLen::DWORD, Eq, KVM_SET_VCPU_EVENTS,)?],
and![Cond::new(1, ArgLen::DWORD, Eq, SIOCGIFFLAGS)?],
and![Cond::new(1, ArgLen::DWORD, Eq, SIOCGIFHWADDR)?],
and![Cond::new(1, ArgLen::DWORD, Eq, SIOCSIFADDR)?],
and![Cond::new(1, ArgLen::DWORD, Eq, SIOCSIFFLAGS)?],
and![Cond::new(1, ArgLen::DWORD, Eq, SIOCSIFHWADDR)?],
and![Cond::new(1, ArgLen::DWORD, Eq, SIOCSIFNETMASK)?],
and![Cond::new(1, ArgLen::DWORD, Eq, TCSETS)?],
and![Cond::new(1, ArgLen::DWORD, Eq, TCGETS)?],
and![Cond::new(1, ArgLen::DWORD, Eq, TIOCGWINSZ)?],
and![Cond::new(1, ArgLen::DWORD, Eq, TUNGETFEATURES)?],
and![Cond::new(1, ArgLen::DWORD, Eq, TUNSETIFF)?],
and![Cond::new(1, ArgLen::DWORD, Eq, TUNSETOFFLOAD)?],
and![Cond::new(1, ArgLen::DWORD, Eq, TUNSETVNETHDRSZ)?],
and![Cond::new(1, ArgLen::DWORD, Eq, VFIO_GET_API_VERSION)?],
and![Cond::new(1, ArgLen::DWORD, Eq, VFIO_CHECK_EXTENSION)?],
and![Cond::new(1, ArgLen::DWORD, Eq, VFIO_SET_IOMMU)?],
and![Cond::new(1, ArgLen::DWORD, Eq, VFIO_GROUP_GET_STATUS)?],
and![Cond::new(1, ArgLen::DWORD, Eq, VFIO_GROUP_SET_CONTAINER)?],
and![Cond::new(1, ArgLen::DWORD, Eq, VFIO_GROUP_UNSET_CONTAINER)?],
and![Cond::new(1, ArgLen::DWORD, Eq, VFIO_GROUP_GET_DEVICE_FD)?],
and![Cond::new(1, ArgLen::DWORD, Eq, VFIO_DEVICE_GET_INFO)?],
and![Cond::new(
1,
ArgLen::DWORD,
Eq,
VFIO_DEVICE_GET_REGION_INFO
)?],
and![Cond::new(1, ArgLen::DWORD, Eq, VFIO_DEVICE_GET_IRQ_INFO)?],
and![Cond::new(1, ArgLen::DWORD, Eq, VFIO_DEVICE_SET_IRQS)?],
and![Cond::new(1, ArgLen::DWORD, Eq, VFIO_DEVICE_RESET)?],
and![Cond::new(1, ArgLen::DWORD, Eq, VFIO_IOMMU_MAP_DMA)?],
and![Cond::new(1, ArgLen::DWORD, Eq, VFIO_IOMMU_UNMAP_DMA)?],
and![Cond::new(1, ArgLen::DWORD, Eq, VFIO_DEVICE_IOEVENTFD)?],
])
}
#[cfg(target_arch = "x86_64")]
fn create_vmm_ioctl_seccomp_rule() -> Result<Vec<SeccompRule>, Error> {
const KVM_CREATE_PIT2: u64 = 0x4040_ae77;
const KVM_GET_CLOCK: u64 = 0x8030_ae7c;
const KVM_GET_FPU: u64 = 0x81a0_ae8c;
const KVM_GET_LAPIC: u64 = 0x8400_ae8e;
const KVM_GET_MSR_INDEX_LIST: u64 = 0xc004_ae02;
const KVM_GET_MSRS: u64 = 0xc008_ae88;
const KVM_GET_SREGS: u64 = 0x8138_ae83;
const KVM_GET_XCRS: u64 = 0x8188_aea6;
const KVM_GET_XSAVE: u64 = 0x9000_aea4;
const KVM_KVMCLOCK_CTRL: u64 = 0xaead;
const KVM_SET_CLOCK: u64 = 0x4030_ae7b;
const KVM_SET_CPUID2: u64 = 0x4008_ae90;
const KVM_SET_FPU: u64 = 0x41a0_ae8d;
const KVM_SET_LAPIC: u64 = 0x4400_ae8f;
const KVM_SET_MSRS: u64 = 0x4008_ae89;
const KVM_SET_SREGS: u64 = 0x4138_ae84;
const KVM_SET_TSS_ADDR: u64 = 0xae47;
const KVM_SET_XCRS: u64 = 0x4188_aea7;
const KVM_SET_XSAVE: u64 = 0x5000_aea5;
let common_rules = create_vmm_ioctl_seccomp_rule_common()?;
let mut arch_rules = or![
and![Cond::new(1, ArgLen::DWORD, Eq, KVM_CREATE_PIT2)?],
and![Cond::new(1, ArgLen::DWORD, Eq, KVM_GET_CLOCK,)?],
and![Cond::new(1, ArgLen::DWORD, Eq, KVM_GET_FPU)?],
and![Cond::new(1, ArgLen::DWORD, Eq, KVM_GET_LAPIC)?],
and![Cond::new(1, ArgLen::DWORD, Eq, KVM_GET_MSR_INDEX_LIST)?],
and![Cond::new(1, ArgLen::DWORD, Eq, KVM_GET_MSRS)?],
and![Cond::new(1, ArgLen::DWORD, Eq, KVM_GET_SREGS)?],
and![Cond::new(1, ArgLen::DWORD, Eq, KVM_GET_XCRS,)?],
and![Cond::new(1, ArgLen::DWORD, Eq, KVM_GET_XSAVE,)?],
and![Cond::new(1, ArgLen::DWORD, Eq, KVM_KVMCLOCK_CTRL)?],
and![Cond::new(1, ArgLen::DWORD, Eq, KVM_SET_CLOCK)?],
and![Cond::new(1, ArgLen::DWORD, Eq, KVM_SET_CPUID2)?],
and![Cond::new(1, ArgLen::DWORD, Eq, KVM_SET_FPU)?],
and![Cond::new(1, ArgLen::DWORD, Eq, KVM_SET_LAPIC)?],
and![Cond::new(1, ArgLen::DWORD, Eq, KVM_SET_SREGS)?],
and![Cond::new(1, ArgLen::DWORD, Eq, KVM_SET_TSS_ADDR,)?],
and![Cond::new(1, ArgLen::DWORD, Eq, KVM_SET_MSRS)?],
and![Cond::new(1, ArgLen::DWORD, Eq, KVM_SET_XCRS,)?],
and![Cond::new(1, ArgLen::DWORD, Eq, KVM_SET_XSAVE,)?],
];
arch_rules.extend(common_rules);
Ok(arch_rules)
}
#[cfg(target_arch = "aarch64")]
fn create_vmm_ioctl_seccomp_rule() -> Result<Vec<SeccompRule>, Error> {
const KVM_ARM_PREFERRED_TARGET: u64 = 0x8020_aeaf;
const KVM_ARM_VCPU_INIT: u64 = 0x4020_aeae;
let common_rules = create_vmm_ioctl_seccomp_rule_common()?;
let mut arch_rules = or![
and![Cond::new(1, ArgLen::DWORD, Eq, KVM_ARM_PREFERRED_TARGET,)?],
and![Cond::new(1, ArgLen::DWORD, Eq, KVM_ARM_VCPU_INIT,)?],
];
arch_rules.extend(common_rules);
Ok(arch_rules)
}
fn create_api_ioctl_seccomp_rule() -> Result<Vec<SeccompRule>, Error> {
Ok(or![and![Cond::new(1, ArgLen::DWORD, Eq, FIONBIO)?],])
}
// The filter containing the white listed syscall rules required by the VMM to
// function.
fn vmm_thread_rules() -> Result<Vec<SyscallRuleSet>, Error> {
Ok(vec![
allow_syscall(libc::SYS_accept4),
#[cfg(target_arch = "x86_64")]
allow_syscall(libc::SYS_access),
#[cfg(target_arch = "x86_64")]
allow_syscall(libc::SYS_arch_prctl),
allow_syscall(libc::SYS_bind),
allow_syscall(libc::SYS_brk),
allow_syscall(libc::SYS_clock_gettime),
allow_syscall(libc::SYS_clock_nanosleep),
allow_syscall(libc::SYS_clone),
allow_syscall(libc::SYS_close),
allow_syscall(libc::SYS_connect),
allow_syscall(libc::SYS_dup),
allow_syscall(libc::SYS_epoll_create1),
allow_syscall(libc::SYS_epoll_ctl),
allow_syscall(libc::SYS_epoll_pwait),
#[cfg(target_arch = "x86_64")]
allow_syscall(libc::SYS_epoll_wait),
allow_syscall(libc::SYS_eventfd2),
allow_syscall(libc::SYS_execve),
allow_syscall(libc::SYS_exit),
allow_syscall(libc::SYS_exit_group),
allow_syscall(libc::SYS_fallocate),
allow_syscall(libc::SYS_fcntl),
allow_syscall(libc::SYS_fdatasync),
#[cfg(target_arch = "x86_64")]
allow_syscall(libc::SYS_fork),
allow_syscall(libc::SYS_fstat),
allow_syscall(libc::SYS_fsync),
#[cfg(target_arch = "x86_64")]
allow_syscall(libc::SYS_ftruncate),
#[cfg(target_arch = "aarch64")]
// The definition of libc::SYS_ftruncate is missing on AArch64.
// Use a hard-code number instead.
allow_syscall(46),
allow_syscall(libc::SYS_futex),
allow_syscall(libc::SYS_getpid),
allow_syscall(libc::SYS_getrandom),
allow_syscall(libc::SYS_gettid),
allow_syscall(libc::SYS_gettimeofday),
allow_syscall(libc::SYS_getuid),
allow_syscall_if(libc::SYS_ioctl, create_vmm_ioctl_seccomp_rule()?),
allow_syscall(SYS_IO_URING_ENTER),
allow_syscall(SYS_IO_URING_SETUP),
allow_syscall(SYS_IO_URING_REGISTER),
allow_syscall(libc::SYS_listen),
allow_syscall(libc::SYS_lseek),
allow_syscall(libc::SYS_madvise),
allow_syscall(libc::SYS_memfd_create),
allow_syscall(libc::SYS_mmap),
allow_syscall(libc::SYS_mprotect),
allow_syscall(libc::SYS_mremap),
allow_syscall(libc::SYS_munmap),
allow_syscall(libc::SYS_nanosleep),
#[cfg(target_arch = "x86_64")]
allow_syscall(libc::SYS_open),
allow_syscall(libc::SYS_openat),
allow_syscall(libc::SYS_pipe2),
allow_syscall(libc::SYS_prctl),
allow_syscall(libc::SYS_pread64),
allow_syscall(libc::SYS_prlimit64),
allow_syscall(libc::SYS_pwrite64),
allow_syscall(libc::SYS_read),
#[cfg(target_arch = "x86_64")]
allow_syscall(libc::SYS_readlink),
allow_syscall(libc::SYS_recvfrom),
allow_syscall(libc::SYS_recvmsg),
allow_syscall(libc::SYS_restart_syscall),
allow_syscall(libc::SYS_rt_sigaction),
allow_syscall(libc::SYS_rt_sigprocmask),
allow_syscall(libc::SYS_rt_sigreturn),
allow_syscall(libc::SYS_sched_getaffinity),
allow_syscall(libc::SYS_sendmsg),
allow_syscall(libc::SYS_sendto),
allow_syscall(libc::SYS_set_robust_list),
allow_syscall(libc::SYS_set_tid_address),
allow_syscall(libc::SYS_sigaltstack),
allow_syscall_if(
libc::SYS_socket,
or![
and![Cond::new(0, ArgLen::DWORD, Eq, libc::AF_UNIX as u64)?],
and![Cond::new(0, ArgLen::DWORD, Eq, libc::AF_INET as u64)?],
],
),
allow_syscall(libc::SYS_socketpair),
#[cfg(target_arch = "x86_64")]
allow_syscall(libc::SYS_stat),
allow_syscall(libc::SYS_statx),
allow_syscall(libc::SYS_tgkill),
allow_syscall(libc::SYS_tkill),
allow_syscall_if(
libc::SYS_umask,
or![and![Cond::new(0, ArgLen::DWORD, Eq, 0o077)?]],
),
#[cfg(target_arch = "x86_64")]
allow_syscall(libc::SYS_unlink),
#[cfg(target_arch = "aarch64")]
allow_syscall(libc::SYS_unlinkat),
allow_syscall(libc::SYS_wait4),
allow_syscall(libc::SYS_write),
])
}
// The filter containing the white listed syscall rules required by the API to
// function.
fn api_thread_rules() -> Result<Vec<SyscallRuleSet>, Error> {
Ok(vec![
allow_syscall(libc::SYS_accept4),
allow_syscall(libc::SYS_bind),
allow_syscall(libc::SYS_brk),
allow_syscall(libc::SYS_close),
allow_syscall(libc::SYS_dup),
allow_syscall(libc::SYS_epoll_create1),
allow_syscall(libc::SYS_epoll_ctl),
allow_syscall(libc::SYS_epoll_pwait),
#[cfg(target_arch = "x86_64")]
allow_syscall(libc::SYS_epoll_wait),
allow_syscall(libc::SYS_exit),
allow_syscall(libc::SYS_futex),
allow_syscall(libc::SYS_getrandom),
allow_syscall_if(libc::SYS_ioctl, create_api_ioctl_seccomp_rule()?),
allow_syscall(libc::SYS_listen),
allow_syscall(libc::SYS_madvise),
allow_syscall(libc::SYS_mprotect),
allow_syscall(libc::SYS_munmap),
allow_syscall(libc::SYS_recvfrom),
allow_syscall(libc::SYS_sigaltstack),
allow_syscall(libc::SYS_socket),
allow_syscall(libc::SYS_write),
])
}
fn get_seccomp_filter_trap(thread_type: Thread) -> Result<SeccompFilter, Error> {
let rules = match thread_type {
Thread::Vmm => vmm_thread_rules()?,
Thread::Api => api_thread_rules()?,
};
Ok(SeccompFilter::new(
rules.into_iter().collect(),
SeccompAction::Trap,
)?)
}
fn get_seccomp_filter_log(thread_type: Thread) -> Result<SeccompFilter, Error> {
let rules = match thread_type {
Thread::Vmm => vmm_thread_rules()?,
Thread::Api => api_thread_rules()?,
};
Ok(SeccompFilter::new(
rules.into_iter().collect(),
SeccompAction::Log,
)?)
}
/// Generate a BPF program based on the seccomp_action value
pub fn get_seccomp_filter(
seccomp_action: &SeccompAction,
thread_type: Thread,
) -> Result<BpfProgram, SeccompError> {
match seccomp_action {
SeccompAction::Allow => Ok(vec![]),
SeccompAction::Log => get_seccomp_filter_log(thread_type)
.and_then(|filter| filter.try_into())
.map_err(SeccompError::SeccompFilter),
_ => get_seccomp_filter_trap(thread_type)
.and_then(|filter| filter.try_into())
.map_err(SeccompError::SeccompFilter),
}
}