[release-branch.go1.17] syscall: do not use handle lists on windows when NoInheritHandles is true

If NoInheritHandles is passed, then we shouldn't attempt to do anything
with handle lists. Otherwise CreateProcess fails with invalid param,
because it's being told both to not inherit handles and to inherit
certain handles.

This commit fixes that by using the same logic for handle lists as it
does for enabling or disabling handle inheritance. It also adds a test
to make sure this doesn't regress again.

Updates #48040
Fixes #48075

Change-Id: I507261baeec263091738ab90157a991d917dc92f
Reviewed-on: https://go-review.googlesource.com/c/go/+/350416
Trust: Jason A. Donenfeld <[email protected]>
Run-TryBot: Jason A. Donenfeld <[email protected]>
TryBot-Result: Go Bot <[email protected]>
Reviewed-by: Patrik Nyblom <[email protected]>

Author: zx2c4

src/os/exec/exec_windows_test.go

@@ -10,6 +10,7 @@ package exec_test
 import (
 	"io"
 	"os"
+	"os/exec"
 	"strconv"
 	"syscall"
 	"testing"
@@ -41,3 +42,16 @@ func TestPipePassing(t *testing.T) {
 		t.Error(err)
 	}
 }
+
+func TestNoInheritHandles(t *testing.T) {
+	cmd := exec.Command("cmd", "/c exit 88")
+	cmd.SysProcAttr = &syscall.SysProcAttr{NoInheritHandles: true}
+	err := cmd.Run()
+	exitError, ok := err.(*exec.ExitError)
+	if !ok {
+		t.Fatalf("got error %v; want ExitError", err)
+	}
+	if exitError.ExitCode() != 88 {
+		t.Fatalf("got exit code %d; want 88", exitError.ExitCode())
+	}
+}

src/syscall/exec_windows.go

@@ -390,8 +390,10 @@ func StartProcess(argv0 string, argv []string, attr *ProcAttr) (pid int, handle
 	}
 	fd = fd[:j]
 
+	willInheritHandles := len(fd) > 0 && !sys.NoInheritHandles
+
 	// Do not accidentally inherit more than these handles.
-	if len(fd) > 0 {
+	if willInheritHandles {
 		err = updateProcThreadAttribute(si.ProcThreadAttributeList, 0, _PROC_THREAD_ATTRIBUTE_HANDLE_LIST, unsafe.Pointer(&fd[0]), uintptr(len(fd))*unsafe.Sizeof(fd[0]), nil, nil)
 		if err != nil {
 			return 0, 0, err
@@ -401,9 +403,9 @@ func StartProcess(argv0 string, argv []string, attr *ProcAttr) (pid int, handle
 	pi := new(ProcessInformation)
 	flags := sys.CreationFlags | CREATE_UNICODE_ENVIRONMENT | _EXTENDED_STARTUPINFO_PRESENT
 	if sys.Token != 0 {
-		err = CreateProcessAsUser(sys.Token, argv0p, argvp, sys.ProcessAttributes, sys.ThreadAttributes, len(fd) > 0 && !sys.NoInheritHandles, flags, createEnvBlock(attr.Env), dirp, &si.StartupInfo, pi)
+		err = CreateProcessAsUser(sys.Token, argv0p, argvp, sys.ProcessAttributes, sys.ThreadAttributes, willInheritHandles, flags, createEnvBlock(attr.Env), dirp, &si.StartupInfo, pi)
 	} else {
-		err = CreateProcess(argv0p, argvp, sys.ProcessAttributes, sys.ThreadAttributes, len(fd) > 0 && !sys.NoInheritHandles, flags, createEnvBlock(attr.Env), dirp, &si.StartupInfo, pi)
+		err = CreateProcess(argv0p, argvp, sys.ProcessAttributes, sys.ThreadAttributes, willInheritHandles, flags, createEnvBlock(attr.Env), dirp, &si.StartupInfo, pi)
 	}
 	if err != nil {
 		return 0, 0, err