Index: /trunk/src/VBox/VMM/PGMSharedPage.cpp
===================================================================
--- /trunk/src/VBox/VMM/PGMSharedPage.cpp	(revision 30008)
+++ /trunk/src/VBox/VMM/PGMSharedPage.cpp	(revision 30009)
@@ -140,5 +140,10 @@
     AssertRC(rc);
 
-    return GMMR3CheckSharedModules(pVM);
+    /* Lock it here as we can't deal with busy locks in this ring-0 path. */
+    pgmLock(pVM);
+    rc = GMMR3CheckSharedModules(pVM);
+    pgmUnlock(pVM);
+
+    return rc;
 }