Index: /trunk/src/VBox/Devices/Storage/DevAHCI.cpp
===================================================================
--- /trunk/src/VBox/Devices/Storage/DevAHCI.cpp	(revision 52960)
+++ /trunk/src/VBox/Devices/Storage/DevAHCI.cpp	(revision 52961)
@@ -6743,5 +6743,9 @@
                         rc = ahciIoBufAllocate(pAhciPort, pAhciReq, pAhciReq->cbTransfer);
                         if (RT_FAILURE(rc))
+                        {
+                            /* In case we can't allocate enough memory fail the request with an overflow error. */
                             AssertMsgFailed(("%s: Failed to process command %Rrc\n", __FUNCTION__, rc));
+                            pAhciReq->fFlags |= AHCI_REQ_OVERFLOW;
+                        }
                     }