added range check to readBlobHeapUncached

dotnet · Jun 29, 2015 · 0c0c696 · 0c0c696
1 parent 7e2a0db
commit 0c0c696
Showing 1 changed file with 5 additions and 1 deletion.
diff --git a/src/absil/ilread.fs b/src/absil/ilread.fs
@@ -1048,6 +1048,7 @@ type ILReaderContext =
     userStringsStreamPhysicalLoc: int32;
     stringsStreamPhysicalLoc: int32;
     blobsStreamPhysicalLoc: int32;
+    blobsStreamSize: int32;
     readUserStringHeap: (int32 -> string);
     memoizeString: string -> string;
     readStringHeap: (int32 -> string);
@@ -1533,9 +1534,11 @@ let readStringHeapUncached ctxtH idx =
 let readStringHeap          ctxt idx = ctxt.readStringHeap idx 
 let readStringHeapOption   ctxt idx = if idx = 0 then None else Some (readStringHeap ctxt idx) 
 
+let emptyByteArray: byte[] = [||]
 let readBlobHeapUncached ctxtH idx = 
     let ctxt = getHole ctxtH
-    seekReadBlob ctxt.is (ctxt.blobsStreamPhysicalLoc + idx) 
+    if idx < 0 || idx > ctxt.blobsStreamSize then emptyByteArray
+    else seekReadBlob ctxt.is (ctxt.blobsStreamPhysicalLoc + idx) 
 let readBlobHeap        ctxt idx = ctxt.readBlobHeap idx 
 let readBlobHeapOption ctxt idx = if idx = 0 then None else Some (readBlobHeap ctxt idx) 
 
@@ -3971,6 +3974,7 @@ let rec genOpenBinaryReader infile is opts =
                  userStringsStreamPhysicalLoc   = userStringsStreamPhysicalLoc;
                  stringsStreamPhysicalLoc       = stringsStreamPhysicalLoc;
                  blobsStreamPhysicalLoc         = blobsStreamPhysicalLoc;
+                 blobsStreamSize                = blobsStreamSize;
                  memoizeString                  = Tables.memoize id;
                  readUserStringHeap             = cacheUserStringHeap (readUserStringHeapUncached ctxtH);
                  readStringHeap                 = cacheStringHeap (readStringHeapUncached ctxtH);