--- /dev/null
+diff --color -ur VirtualBox-6.1.18.orig/src/VBox/Runtime/r0drv/linux/memobj-r0drv-linux.c VirtualBox-6.1.18/src/VBox/Runtime/r0drv/linux/memobj-r0drv-linux.c
+--- VirtualBox-6.1.18.orig/src/VBox/Runtime/r0drv/linux/memobj-r0drv-linux.c 2021-01-07 16:42:09.000000000 +0100
++++ VirtualBox-6.1.18/src/VBox/Runtime/r0drv/linux/memobj-r0drv-linux.c 2021-01-21 23:13:58.808360771 +0100
+@@ -536,7 +536,7 @@
+ * @param uAddr The address to apply the new protection to.
+ * @param pvUser The opaque user data.
+ */
+-static DECLCALLBACK(int) rtR0MemObjLinuxApplyPageRange(pte_t *pPte, unsigned long uAddr, void *pvUser)
++static int rtR0MemObjLinuxApplyPageRange(pte_t *pPte, unsigned long uAddr, void *pvUser)
+ {
+ PCLNXAPPLYPGRANGE pArgs = (PCLNXAPPLYPGRANGE)pvUser;
+ PRTR0MEMOBJLNX pMemLnx = pArgs->pMemLnx;