Let socket.ControlMessages Release() the underlying transport.ControlMessages.

PiperOrigin-RevId: 284804370

pkg/sentry/socket/socket.go

@@ -43,6 +43,11 @@ type ControlMessages struct {
 	IP   tcpip.ControlMessages
 }
 
+// Release releases Unix domain socket credentials and rights.
+func (c *ControlMessages) Release() {
+	c.Unix.Release()
+}
+
 // Socket is the interface containing socket syscalls used by the syscall layer
 // to redirect them to the appropriate implementation.
 type Socket interface {

pkg/sentry/syscalls/linux/sys_socket.go

@@ -764,7 +764,7 @@ func recvSingleMsg(t *kernel.Task, s socket.Socket, msgPtr usermem.Addr, flags i
 		}
 		if !cms.Unix.Empty() {
 			mflags |= linux.MSG_CTRUNC
-			cms.Unix.Release()
+			cms.Release()
 		}
 
 		if int(msg.Flags) != mflags {
@@ -784,7 +784,7 @@ func recvSingleMsg(t *kernel.Task, s socket.Socket, msgPtr usermem.Addr, flags i
 	if e != nil {
 		return 0, syserror.ConvertIntr(e.ToError(), kernel.ERESTARTSYS)
 	}
-	defer cms.Unix.Release()
+	defer cms.Release()
 
 	controlData := make([]byte, 0, msg.ControlLen)
 
@@ -885,7 +885,7 @@ func recvFrom(t *kernel.Task, fd int32, bufPtr usermem.Addr, bufLen uint64, flag
 	}
 
 	n, _, sender, senderLen, cm, e := s.RecvMsg(t, dst, int(flags), haveDeadline, deadline, nameLenPtr != 0, 0)
-	cm.Unix.Release()
+	cm.Release()
 	if e != nil {
 		return 0, syserror.ConvertIntr(e.ToError(), kernel.ERESTARTSYS)
 	}
@@ -1071,7 +1071,7 @@ func sendSingleMsg(t *kernel.Task, s socket.Socket, file *fs.File, msgPtr userme
 	n, e := s.SendMsg(t, src, to, int(flags), haveDeadline, deadline, controlMessages)
 	err = handleIOError(t, n != 0, e.ToError(), kernel.ERESTARTSYS, "sendmsg", file)
 	if err != nil {
-		controlMessages.Unix.Release()
+		controlMessages.Release()
 	}
 	return uintptr(n), err
 }