diff options
Diffstat (limited to 'pkg/sentry/syscalls/linux/sys_prctl.go')
| -rw-r--r-- | pkg/sentry/syscalls/linux/sys_prctl.go | 201 |
1 files changed, 201 insertions, 0 deletions
diff --git a/pkg/sentry/syscalls/linux/sys_prctl.go b/pkg/sentry/syscalls/linux/sys_prctl.go new file mode 100644 index 000000000..117ae1a0e --- /dev/null +++ b/pkg/sentry/syscalls/linux/sys_prctl.go @@ -0,0 +1,201 @@ +// Copyright 2018 The gVisor Authors. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +package linux + +import ( + "syscall" + + "gvisor.googlesource.com/gvisor/pkg/abi/linux" + "gvisor.googlesource.com/gvisor/pkg/sentry/arch" + "gvisor.googlesource.com/gvisor/pkg/sentry/fs" + "gvisor.googlesource.com/gvisor/pkg/sentry/kernel" + "gvisor.googlesource.com/gvisor/pkg/sentry/kernel/auth" + "gvisor.googlesource.com/gvisor/pkg/sentry/kernel/kdefs" +) + +// Prctl implements linux syscall prctl(2). +// It has a list of subfunctions which operate on the process. The arguments are +// all based on each subfunction. +func Prctl(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) { + option := args[0].Int() + + switch option { + case linux.PR_SET_PDEATHSIG: + sig := linux.Signal(args[1].Int()) + if sig != 0 && !sig.IsValid() { + return 0, nil, syscall.EINVAL + } + t.SetParentDeathSignal(sig) + return 0, nil, nil + + case linux.PR_GET_PDEATHSIG: + _, err := t.CopyOut(args[1].Pointer(), int32(t.ParentDeathSignal())) + return 0, nil, err + + case linux.PR_GET_KEEPCAPS: + if t.Credentials().KeepCaps { + return 1, nil, nil + } + + return 0, nil, nil + + case linux.PR_SET_KEEPCAPS: + val := args[1].Int() + // prctl(2): arg2 must be either 0 (permitted capabilities are cleared) + // or 1 (permitted capabilities are kept). + if val == 0 { + t.SetKeepCaps(false) + } else if val == 1 { + t.SetKeepCaps(true) + } else { + return 0, nil, syscall.EINVAL + } + + return 0, nil, nil + + case linux.PR_SET_NAME: + addr := args[1].Pointer() + name, err := t.CopyInString(addr, linux.TASK_COMM_LEN-1) + if err != nil && err != syscall.ENAMETOOLONG { + return 0, nil, err + } + t.SetName(name) + + case linux.PR_GET_NAME: + addr := args[1].Pointer() + buf := t.CopyScratchBuffer(linux.TASK_COMM_LEN) + len := copy(buf, t.Name()) + if len < linux.TASK_COMM_LEN { + buf[len] = 0 + len++ + } + _, err := t.CopyOut(addr, buf[:len]) + if err != nil { + return 0, nil, err + } + + case linux.PR_SET_MM: + if !t.HasCapability(linux.CAP_SYS_RESOURCE) { + return 0, nil, syscall.EPERM + } + + switch args[1].Int() { + case linux.PR_SET_MM_EXE_FILE: + fd := kdefs.FD(args[2].Int()) + + file := t.FDMap().GetFile(fd) + if file == nil { + return 0, nil, syscall.EBADF + } + defer file.DecRef() + + // They trying to set exe to a non-file? + if !fs.IsFile(file.Dirent.Inode.StableAttr) { + return 0, nil, syscall.EBADF + } + + // Set the underlying executable. + t.MemoryManager().SetExecutable(file.Dirent) + + case linux.PR_SET_MM_AUXV, + linux.PR_SET_MM_START_CODE, + linux.PR_SET_MM_END_CODE, + linux.PR_SET_MM_START_DATA, + linux.PR_SET_MM_END_DATA, + linux.PR_SET_MM_START_STACK, + linux.PR_SET_MM_START_BRK, + linux.PR_SET_MM_BRK, + linux.PR_SET_MM_ARG_START, + linux.PR_SET_MM_ARG_END, + linux.PR_SET_MM_ENV_START, + linux.PR_SET_MM_ENV_END: + + t.Kernel().EmitUnimplementedEvent(t) + fallthrough + default: + return 0, nil, syscall.EINVAL + } + + case linux.PR_SET_NO_NEW_PRIVS: + if args[1].Int() != 1 || args[2].Int() != 0 || args[3].Int() != 0 || args[4].Int() != 0 { + return 0, nil, syscall.EINVAL + } + // no_new_privs is assumed to always be set. See + // kernel.Task.updateCredsForExec. + return 0, nil, nil + + case linux.PR_GET_NO_NEW_PRIVS: + if args[1].Int() != 0 || args[2].Int() != 0 || args[3].Int() != 0 || args[4].Int() != 0 { + return 0, nil, syscall.EINVAL + } + return 1, nil, nil + + case linux.PR_SET_SECCOMP: + if args[1].Int() != linux.SECCOMP_MODE_FILTER { + // Unsupported mode. + return 0, nil, syscall.EINVAL + } + + return 0, nil, seccomp(t, linux.SECCOMP_SET_MODE_FILTER, 0, args[2].Pointer()) + + case linux.PR_GET_SECCOMP: + return uintptr(t.SeccompMode()), nil, nil + + case linux.PR_CAPBSET_READ: + cp := linux.Capability(args[1].Uint64()) + if !cp.Ok() { + return 0, nil, syscall.EINVAL + } + var rv uintptr + if auth.CapabilitySetOf(cp)&t.Credentials().BoundingCaps != 0 { + rv = 1 + } + return rv, nil, nil + + case linux.PR_CAPBSET_DROP: + cp := linux.Capability(args[1].Uint64()) + if !cp.Ok() { + return 0, nil, syscall.EINVAL + } + return 0, nil, t.DropBoundingCapability(cp) + + case linux.PR_GET_DUMPABLE, + linux.PR_SET_DUMPABLE, + linux.PR_GET_TIMING, + linux.PR_SET_TIMING, + linux.PR_GET_TSC, + linux.PR_SET_TSC, + linux.PR_TASK_PERF_EVENTS_DISABLE, + linux.PR_TASK_PERF_EVENTS_ENABLE, + linux.PR_GET_TIMERSLACK, + linux.PR_SET_TIMERSLACK, + linux.PR_MCE_KILL, + linux.PR_MCE_KILL_GET, + linux.PR_GET_TID_ADDRESS, + linux.PR_SET_CHILD_SUBREAPER, + linux.PR_GET_CHILD_SUBREAPER, + linux.PR_GET_THP_DISABLE, + linux.PR_SET_THP_DISABLE, + linux.PR_MPX_ENABLE_MANAGEMENT, + linux.PR_MPX_DISABLE_MANAGEMENT: + + t.Kernel().EmitUnimplementedEvent(t) + fallthrough + default: + return 0, nil, syscall.EINVAL + } + + return 0, nil, nil +} |