windows/svc: use NtQuerySystemInformation in IsWindowsService

This brings the algorithm more exactly in line with what .NET does for
the identically named function. Specifically, instead of using
OpenProcess, which requires rights that restricted services might not
have, we use NtQuerySystemInformation(SYSTEM_PROCESS_INFORMATION) to
find the parent process image name and session ID.

Fixes golang/go#44921.

Change-Id: Ie2ad7521cf4c530037d086e61dbc2413e4e7777c
Reviewed-on: https://go-review.googlesource.com/c/sys/+/372554
Trust: Jason Donenfeld <Jason@zx2c4.com>
Run-TryBot: Jason Donenfeld <Jason@zx2c4.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Patrik Nyblom <pnyb@google.com>
Trust: Patrik Nyblom <pnyb@google.com>
Run-TryBot: Patrik Nyblom <pnyb@google.com>
This commit is contained in:
Jason A. Donenfeld
2021-12-16 02:10:12 +00:00
committed by Jason Donenfeld
parent 4abf325e02
commit 1d35b9e2eb
2 changed files with 57 additions and 28 deletions
+20 -28
View File
@@ -8,7 +8,6 @@
package svc
import (
"path/filepath"
"strings"
"unsafe"
@@ -74,36 +73,29 @@ func IsWindowsService() (bool, error) {
// Specifically, it looks up whether the parent process has session ID zero
// and is called "services".
var pbi windows.PROCESS_BASIC_INFORMATION
pbiLen := uint32(unsafe.Sizeof(pbi))
err := windows.NtQueryInformationProcess(windows.CurrentProcess(), windows.ProcessBasicInformation, unsafe.Pointer(&pbi), pbiLen, &pbiLen)
var currentProcess windows.PROCESS_BASIC_INFORMATION
infoSize := uint32(unsafe.Sizeof(currentProcess))
err := windows.NtQueryInformationProcess(windows.CurrentProcess(), windows.ProcessBasicInformation, unsafe.Pointer(&currentProcess), infoSize, &infoSize)
if err != nil {
return false, err
}
var psid uint32
err = windows.ProcessIdToSessionId(uint32(pbi.InheritedFromUniqueProcessId), &psid)
if err != nil || psid != 0 {
return false, nil
var parentProcess *windows.SYSTEM_PROCESS_INFORMATION
for infoSize = uint32((unsafe.Sizeof(*parentProcess) + unsafe.Sizeof(uintptr(0))) * 1024); ; {
parentProcess = (*windows.SYSTEM_PROCESS_INFORMATION)(unsafe.Pointer(&make([]byte, infoSize)[0]))
err = windows.NtQuerySystemInformation(windows.SystemProcessInformation, unsafe.Pointer(parentProcess), infoSize, &infoSize)
if err == nil {
break
} else if err != windows.STATUS_INFO_LENGTH_MISMATCH {
return false, err
}
}
pproc, err := windows.OpenProcess(windows.PROCESS_QUERY_LIMITED_INFORMATION, false, uint32(pbi.InheritedFromUniqueProcessId))
if err != nil {
return false, err
for ; ; parentProcess = (*windows.SYSTEM_PROCESS_INFORMATION)(unsafe.Pointer(uintptr(unsafe.Pointer(parentProcess)) + uintptr(parentProcess.NextEntryOffset))) {
if parentProcess.UniqueProcessID == currentProcess.InheritedFromUniqueProcessId {
return parentProcess.SessionID == 0 && strings.EqualFold("services.exe", parentProcess.ImageName.String()), nil
}
if parentProcess.NextEntryOffset == 0 {
break
}
}
defer windows.CloseHandle(pproc)
var exeNameBuf [261]uint16
exeNameLen := uint32(len(exeNameBuf) - 1)
err = windows.QueryFullProcessImageName(pproc, 0, &exeNameBuf[0], &exeNameLen)
if err != nil {
return false, err
}
exeName := windows.UTF16ToString(exeNameBuf[:exeNameLen])
if !strings.EqualFold(filepath.Base(exeName), "services.exe") {
return false, nil
}
system32, err := windows.GetSystemDirectory()
if err != nil {
return false, err
}
targetExeName := filepath.Join(system32, "services.exe")
return strings.EqualFold(exeName, targetExeName), nil
return false, nil
}