Alexandre Julliard : ntdll: Add some sanity checks for invalid relocation blocks.

[Alexandre Julliard]

Module: wine
Branch: stable
Commit: c1a8456d426673a88cee47b5ac0dbaf25302295c
URL:    http://source.winehq.org/git/wine.git/?a=commit;h=c1a8456d426673a88cee47b5ac...

Author: Alexandre Julliard 
Date:   Mon Jun 30 12:51:35 2008 +0200

ntdll: Add some sanity checks for invalid relocation blocks.
(cherry picked from commit 8e5f28127644344247056337a4eeca71f0e43322)

---

dlls/ntdll/virtual.c |    8 +++++++-
 1 files changed, 7 insertions(+), 1 deletions(-)

diff --git a/dlls/ntdll/virtual.c b/dlls/ntdll/virtual.c
index f14085d..ef97eb2 100644
--- a/dlls/ntdll/virtual.c
+++ b/dlls/ntdll/virtual.c
@@ -1107,8 +1107,14 @@ static NTSTATUS map_image( HANDLE hmapping, int fd, char *base, SIZE_T total_siz
         rel = (IMAGE_BASE_RELOCATION *)(ptr + relocs->VirtualAddress);
         end = (IMAGE_BASE_RELOCATION *)(ptr + relocs->VirtualAddress + relocs->Size);

-        while (rel < end && rel->SizeOfBlock)
+        while (rel <= end - 1 && rel->SizeOfBlock)
         {
+            if (rel->VirtualAddress >= total_size)
+            {
+                WARN_(module)( "invalid address %p in relocation %p\n", ptr + rel->VirtualAddress, rel );
+                status = STATUS_ACCESS_VIOLATION;
+                goto error;
+            }
             rel = LdrProcessRelocationBlock( ptr + rel->VirtualAddress,
                                              (rel->SizeOfBlock - sizeof(*rel)) / sizeof(USHORT),
                                              (USHORT *)(rel + 1), delta );