[ros-diffs] [ion] 23302: - Fix multiple bugs in VfatGetNameInformation: * Return the file name length even if the buffer is too small, that's the whole point of the "Query length before comitting a buffer" principle. * FSDs are not supposed to null-terminate the buffer, nor expect the caller to send a buffer large enough for null-termination. * Added a hack in IopQueryFile to handle another VFAT bug which makes it return the total number of bytes written in IoStatus.Information instead of the total number o

Author: ion
Date: Thu Jul 27 04:13:14 2006
New Revision: 23302

URL: http://svn.reactos.org/svn/reactos?rev=23302&view=rev
Log:
- Fix multiple bugs in VfatGetNameInformation:
  * Return the file name length even if the buffer is too small, that's the whole point of the "Query length before comitting a buffer" principle.
  * FSDs are not supposed to null-terminate the buffer, nor expect the caller to send a buffer large enough for null-termination.
  * Added a hack in IopQueryFile to handle another VFAT bug which makes it return the total number of bytes written in IoStatus.Information instead of the total number of bytes *left untouched*.There are probably many other broken things due to this.
- Fix some length calculation bugs in IopQueryFile.

Modified:
    trunk/reactos/drivers/filesystems/vfat/finfo.c
    trunk/reactos/ntoskrnl/io/iomgr/file.c
    trunk/reactos/ntoskrnl/ob/obname.c

Modified: trunk/reactos/drivers/filesystems/vfat/finfo.c
URL: http://svn.reactos.org/svn/reactos/trunk/reactos/drivers/filesystems/vfat/fi...
==============================================================================
--- trunk/reactos/drivers/filesystems/vfat/finfo.c (original)
+++ trunk/reactos/drivers/filesystems/vfat/finfo.c Thu Jul 27 04:13:14 2006
@@ -341,14 +341,13 @@
   ASSERT(NameInfo != NULL);
   ASSERT(FCB != NULL);

-  if (*BufferLength < sizeof(FILE_NAME_INFORMATION) + FCB->PathNameU.Length + sizeof(WCHAR))
+  NameInfo->FileNameLength = FCB->PathNameU.Length;
+  if (*BufferLength < FIELD_OFFSET(FILE_NAME_INFORMATION, FileName[0]) + FCB->PathNameU.Length)
     return STATUS_BUFFER_OVERFLOW;

-  NameInfo->FileNameLength = FCB->PathNameU.Length;
   RtlCopyMemory(NameInfo->FileName, FCB->PathNameU.Buffer, FCB->PathNameU.Length);
-  NameInfo->FileName[FCB->PathNameU.Length / sizeof(WCHAR)] = 0;
-
-  *BufferLength -= (sizeof(FILE_NAME_INFORMATION) + FCB->PathNameU.Length + sizeof(WCHAR));
+
+  *BufferLength -= (FIELD_OFFSET(FILE_NAME_INFORMATION, FileName[0]) + FCB->PathNameU.Length);

return STATUS_SUCCESS;
 }

Modified: trunk/reactos/ntoskrnl/io/iomgr/file.c
URL: http://svn.reactos.org/svn/reactos/trunk/reactos/ntoskrnl/io/iomgr/file.c?re...
==============================================================================
--- trunk/reactos/ntoskrnl/io/iomgr/file.c (original)
+++ trunk/reactos/ntoskrnl/io/iomgr/file.c Thu Jul 27 04:13:14 2006
@@ -915,7 +915,7 @@
                                LocalInfo,
                                Length,
                                &LocalReturnLength);
-    if (!NT_SUCCESS (Status))
+    if (!NT_SUCCESS(Status))
     {
         /* Free the buffer and fail */
         ExFreePool(LocalInfo);
@@ -935,6 +935,14 @@
     /* Advance in buffer */
     p += (LocalInfo->Name.Length / sizeof(WCHAR));

+    /* Check if this already filled our buffer */
+    if (LocalReturnLength > Length)
+    {
+        /* Free the buffer and fail */
+        ExFreePool(LocalInfo);
+        return STATUS_BUFFER_OVERFLOW;
+    }
+
     /* Now get the file name buffer and check the length needed */
     LocalFileInfo = (PFILE_NAME_INFORMATION)LocalInfo;
     FileLength = Length -
@@ -944,7 +952,7 @@
     /* Query the File name */
     Status = IoQueryFileInformation(FileObject,
                                     FileNameInformation,
-                                    Length,
+                                    FileLength,
                                     LocalFileInfo,
                                     &LocalReturnLength);
     if (NT_ERROR(Status))
@@ -953,6 +961,9 @@
         ExFreePool(LocalInfo);
         return Status;
     }
+
+    /* ROS HACK. VFAT SUCKS */
+    if (NT_WARNING(Status)) LocalReturnLength = FileLength;

/* Now calculate the new lenghts left */
     FileLength = LocalReturnLength -
@@ -972,7 +983,7 @@

/* Setup the length and maximum length */
     FileLength = (ULONG_PTR)p - (ULONG_PTR)ObjectNameInfo;
-    ObjectNameInfo->Name.Length = Length - sizeof(OBJECT_NAME_INFORMATION);
+    ObjectNameInfo->Name.Length = FileLength - sizeof(OBJECT_NAME_INFORMATION);
     ObjectNameInfo->Name.MaximumLength = ObjectNameInfo->Name.Length +
                                          sizeof(UNICODE_NULL);

Modified: trunk/reactos/ntoskrnl/ob/obname.c
URL: http://svn.reactos.org/svn/reactos/trunk/reactos/ntoskrnl/ob/obname.c?rev=23...
==============================================================================
--- trunk/reactos/ntoskrnl/ob/obname.c (original)
+++ trunk/reactos/ntoskrnl/ob/obname.c Thu Jul 27 04:13:14 2006
@@ -620,7 +620,7 @@
     }

/* Check if the object doesn't even have a name */
-    if (!LocalInfo || !LocalInfo->Name.Buffer)
+    if (!(LocalInfo) || !(LocalInfo->Name.Buffer))
     {
         /* We're returning the name structure */
         *ReturnLength = sizeof(OBJECT_NAME_INFORMATION);