From b314a253203127a38613d844dc05a82141093cca Mon Sep 17 00:00:00 2001
From: Dmitry Timoshkov <dmitry@baikal.ru>
Date: Fri, 13 Sep 2013 15:45:44 +0900
Subject: [PATCH] ntdll: Make NtWriteFile explicitly check for negative offset
 and fail.

---
 dlls/ntdll/file.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/dlls/ntdll/file.c b/dlls/ntdll/file.c
index dd67b3d09cf..2d0725581f7 100644
--- a/dlls/ntdll/file.c
+++ b/dlls/ntdll/file.c
@@ -982,6 +982,11 @@ NTSTATUS WINAPI NtWriteFile(HANDLE hFile, HANDLE hEvent,
                 }
                 off = st.st_size;
             }
+            else if (offset->QuadPart < 0)
+            {
+                status = STATUS_INVALID_PARAMETER;
+                goto done;
+            }
 
             /* async I/O doesn't make sense on regular files */
             while ((result = pwrite( unix_handle, buffer, length, off )) == -1)