| // Copyright (c) 2013 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #ifndef SANDBOX_LINUX_SECCOMP_BPF_HELPERS_SYSCALL_PARAMETERS_RESTRICTIONS_H_ |
| #define SANDBOX_LINUX_SECCOMP_BPF_HELPERS_SYSCALL_PARAMETERS_RESTRICTIONS_H_ |
| |
| #include <unistd.h> |
| |
| #include "build/build_config.h" |
| #include "sandbox/linux/bpf_dsl/bpf_dsl_forward.h" |
| #include "sandbox/sandbox_export.h" |
| |
| // These are helpers to build seccomp-bpf policies, i.e. policies for a |
| // sandbox that reduces the Linux kernel's attack surface. They return a |
| // bpf_dsl::ResultExpr suitable to restrict certain system call parameters. |
| |
| namespace sandbox { |
| |
| // Allow clone(2) for threads. |
| // Reject fork(2) attempts with EPERM. |
| // Don't restrict on ASAN. |
| // Crash if anything else is attempted. |
| SANDBOX_EXPORT bpf_dsl::ResultExpr RestrictCloneToThreadsAndEPERMFork(); |
| |
| // Allow PR_SET_NAME, PR_SET_DUMPABLE, PR_GET_DUMPABLE. |
| // Crash if anything else is attempted. |
| SANDBOX_EXPORT bpf_dsl::ResultExpr RestrictPrctl(); |
| |
| // Allow TCGETS and FIONREAD. |
| // Crash if anything else is attempted. |
| SANDBOX_EXPORT bpf_dsl::ResultExpr RestrictIoctl(); |
| |
| // Restrict the flags argument in mmap(2). |
| // Only allow: MAP_SHARED | MAP_PRIVATE | MAP_ANONYMOUS | |
| // MAP_STACK | MAP_NORESERVE | MAP_FIXED | MAP_DENYWRITE. |
| // Crash if any other flag is used. |
| SANDBOX_EXPORT bpf_dsl::ResultExpr RestrictMmapFlags(); |
| |
| // Restrict the prot argument in mprotect(2). |
| // Only allow: PROT_READ | PROT_WRITE | PROT_EXEC. |
| SANDBOX_EXPORT bpf_dsl::ResultExpr RestrictMprotectFlags(); |
| |
| // Restrict fcntl(2) cmd argument to: |
| // We allow F_GETFL, F_SETFL, F_GETFD, F_SETFD, F_DUPFD, F_DUPFD_CLOEXEC, |
| // F_SETLK, F_SETLKW and F_GETLK. |
| // Also, in F_SETFL, restrict the allowed flags to: O_ACCMODE | O_APPEND | |
| // O_NONBLOCK | O_SYNC | O_LARGEFILE | O_CLOEXEC | O_NOATIME. |
| SANDBOX_EXPORT bpf_dsl::ResultExpr RestrictFcntlCommands(); |
| |
| #if defined(__i386__) || defined(__mips__) |
| // Restrict socketcall(2) to only allow socketpair(2), send(2), recv(2), |
| // sendto(2), recvfrom(2), shutdown(2), sendmsg(2) and recvmsg(2). |
| SANDBOX_EXPORT bpf_dsl::ResultExpr RestrictSocketcallCommand(); |
| #endif |
| |
| // Restrict |sysno| (which must be kill, tkill or tgkill) by allowing tgkill or |
| // kill iff the first parameter is |target_pid|, crashing otherwise or if |
| // |sysno| is tkill. |
| SANDBOX_EXPORT bpf_dsl::ResultExpr RestrictKillTarget(pid_t target_pid, |
| int sysno); |
| |
| // Crash if FUTEX_CMP_REQUEUE_PI is used in the second argument of futex(2). |
| SANDBOX_EXPORT bpf_dsl::ResultExpr RestrictFutex(); |
| |
| // Crash if |which| is not PRIO_PROCESS. EPERM if |who| is not 0, neither |
| // |target_pid| while calling setpriority(2) / getpriority(2). |
| SANDBOX_EXPORT bpf_dsl::ResultExpr RestrictGetSetpriority(pid_t target_pid); |
| |
| // Restricts |pid| for sched_* syscalls which take a pid as the first argument. |
| // We only allow calling these syscalls if the pid argument is equal to the pid |
| // of the sandboxed process or 0 (indicating the current thread). The following |
| // syscalls are supported: |
| // |
| // sched_getaffinity(), sched_getattr(), sched_getparam(), sched_getscheduler(), |
| // sched_rr_get_interval(), sched_setaffinity(), sched_setattr(), |
| // sched_setparam(), sched_setscheduler() |
| SANDBOX_EXPORT bpf_dsl::ResultExpr RestrictSchedTarget(pid_t target_pid, |
| int sysno); |
| |
| // Restricts the |pid| argument of prlimit64 to 0 (meaning the calling process) |
| // or target_pid. |
| SANDBOX_EXPORT bpf_dsl::ResultExpr RestrictPrlimit64(pid_t target_pid); |
| |
| // Restricts the |who| argument of getrusage to RUSAGE_SELF (meaning the calling |
| // process). |
| SANDBOX_EXPORT bpf_dsl::ResultExpr RestrictGetrusage(); |
| |
| // Restrict |clk_id| for clock_getres(), clock_gettime() and clock_settime(). |
| // We allow accessing only CLOCK_MONOTONIC, CLOCK_PROCESS_CPUTIME_ID, |
| // CLOCK_REALTIME, and CLOCK_THREAD_CPUTIME_ID. In particular, this disallows |
| // access to arbitrary per-{process,thread} CPU-time clock IDs (such as those |
| // returned by {clock,pthread}_getcpuclockid), which can leak information |
| // about the state of the host OS. |
| SANDBOX_EXPORT bpf_dsl::ResultExpr RestrictClockID(); |
| |
| } // namespace sandbox. |
| |
| #endif // SANDBOX_LINUX_SECCOMP_BPF_HELPERS_SYSCALL_PARAMETERS_RESTRICTIONS_H_ |