Changeset 4725 in vbox for trunk/src/VBox/Runtime

Timestamp:

Sep 12, 2007 10:12:31 AM (17 years ago)

Author:

vboxsync

Message:

Use MmSecureVirtualMemory to have some limited protection with usermode allocations

File:

• trunk/src/VBox/Runtime/r0drv/nt/memobj-r0drv-nt.cpp (modified) (7 diffs)

trunk/src/VBox/Runtime/r0drv/nt/memobj-r0drv-nt.cpp

@@ -61 +61 @@
     bool                fAllocatedPagesForMdl;
 #endif
+    /** Pointer returned by MmSecureVirtualMemory */
+    PVOID               pvSecureMem;
     /** The number of PMDLs (memory descriptor lists) in the array. */
     uint32_t            cMdls;
@@ -84 +86 @@
                 MmUnmapLockedPages(pMemNt->Core.pv, pMemNt->apMdls[0]);
                 pMemNt->Core.pv = NULL;
+                if (pMemNt->pvSecureMem)
+                {
+                    MmUnsecureVirtualMemory(pMemNt->pvSecureMem);
+                    pMemNt->pvSecureMem = NULL;
+                }
 
                 MmFreePagesFromMdl(pMemNt->apMdls[0]);
@@ -133 +140 @@
 
         case RTR0MEMOBJTYPE_LOCK:
+            if (pMemNt->pvSecureMem)
+            {
+                MmUnsecureVirtualMemory(pMemNt->pvSecureMem);
+                pMemNt->pvSecureMem = NULL;
+            }
             for (uint32_t i = 0; i < pMemNt->cMdls; i++)
             {
@@ -523 +535 @@
         {
             MmProbeAndLockPages(pMdl, R0Process == NIL_RTR0PROCESS ? KernelMode : UserMode, IoModifyAccess);
+
             pMemNt->apMdls[iMdl] = pMdl;
             pMemNt->cMdls++;
@@ -531 +544 @@
             rc = VERR_LOCK_FAILED;
             break;
+        }
+
+        if (R0Process != NIL_RTR0PROCESS )
+        {
+            /* Make sure the user process can't change the allocation. */
+            pMemNt->pvSecureMem = MmSecureVirtualMemory(pv, cb, PAGE_READWRITE);
+            if (!pMemNt->pvSecureMem)
+            {
+                rc = VERR_NO_MEMORY;
+                break;
+            }
         }
 
@@ -554 +578 @@
         pMemNt->apMdls[iMdl] = NULL;
     }
+    if (pMemNt->pvSecureMem)
+    {
+        MmUnsecureVirtualMemory(pMemNt->pvSecureMem);
+        pMemNt->pvSecureMem = NULL;
+    }
+
     rtR0MemObjDelete(&pMemNt->Core);
-    return VERR_LOCK_FAILED;
+    return rc;
 }
 
@@ -661 +691 @@
             rc = VERR_MAP_FAILED;
         }
+
     }
     else