* More checks for malformed relocation block.

Author: vdisasmdev

PE.Common.pas

@@ -126,6 +126,7 @@ interface
   SCategoryResources    = 'Resources';
   SCategoryImports      = 'Imports';
   SCategoryTLS          = 'TLS';
+  SCategoryRelocs       = 'Relocs';
 
 implementation
 

PE.Parser.Relocs.pas

@@ -46,11 +46,12 @@ function TPERelocParser.Parse: TParserResult;
 
   if not PE.SeekRVA(dir.VirtualAddress) then
   begin
-    PE.Msg.Write('[Reloc Parser] Bad directory RVA (0x%x)', [dir.VirtualAddress]);
+    PE.Msg.Write(SCategoryRelocs, 'Bad directory RVA (0x%x)', [dir.VirtualAddress]);
     exit(PR_ERROR);
   end;
 
   Ofs := 0;
+
   while (Ofs < dir.Size) do
   begin
     tmpRVA := PE.PositionRVA;
@@ -65,18 +66,27 @@ function TPERelocParser.Parse: TParserResult;
       break;
 
     inc(Ofs, SizeOf(block));
+
+    if block.BlockSize < SizeOf(TBaseRelocationBlock) then
+    begin
+      PE.Msg.Write(SCategoryRelocs, 'Bad size of block (%d).', [block.BlockSize]);
+      continue;
+    end;
+
     blCnt := block.Count;
+
     for iBlock := 0 to blCnt - 1 do
     begin
       if (Ofs + SizeOf(entry)) > dir.Size then
       begin
-        PE.Msg.Write('Relocation out of table. PageRVA:0x%x #:%d', [block.PageRVA, iBlock]);
-        PE.Msg.Write('Skipping next relocs.');
+        PE.Msg.Write(SCategoryRelocs, 'Relocation is out of table. PageRVA:0x%x #:%d', [block.PageRVA, iBlock]);
+        PE.Msg.Write(SCategoryRelocs, 'Skipping next relocs.');
         exit(PR_OK);
       end;
 
       if not PE.ReadEx(@entry, SizeOf(entry)) then
         exit(PR_ERROR);
+
       inc(Ofs, SizeOf(entry));
       r_type := entry.GetType;
       r_ofs := entry.GetOffset;
@@ -85,7 +95,6 @@ function TPERelocParser.Parse: TParserResult;
       begin
         reloc.RVA := r_rva;
         reloc.&Type := r_type;
-        // reloc.pos := Ofs;
         PE.Relocs.Put(reloc);
       end;
     end;

PE.Types.Relocations.pas

@@ -3,6 +3,9 @@
 interface
 
 uses
+{$IFDEF DEBUG}
+  System.SysUtils,
+{$ENDIF}
   System.Generics.Collections,
   PE.Common,
   gRBTree;
@@ -23,8 +26,7 @@ interface
     BlockSize: UInt32;
 
     // Get count of relocation elements (entries).
-    function Count: integer; inline;
-
+    function Count: integer; {$IFNDEF DEBUG} inline; {$ENDIF}
     // Check if this block's size:0 or rva:0.
     function IsEmpty: Boolean; inline;
   end;
@@ -84,6 +86,10 @@ implementation
 
 function TBaseRelocationBlock.Count: integer;
 begin
+{$IFDEF DEBUG}
+  if BlockSize < SizeOf(TBaseRelocationBlock) then
+    raise Exception.Create('Relocation block is too small.');
+{$ENDIF}
   result := (BlockSize - SizeOf(TBaseRelocationBlock)) div SizeOf(TBaseRelocationEntry);
 end;