From a3240c63ec33b704865618aa18eebe64a33a2dba Mon Sep 17 00:00:00 2001
From: Laszlo Ersek <lersek@redhat.com>
Date: Sat, 9 Sep 2017 23:25:33 +0200
Subject: [PATCH] MdeModulePkg/UdfDxe: ASSERT() valid ReadFileInfo Flags for
 INLINE_DATA req

In the ReadFile() function, if "RecordingFlags" is INLINE_DATA, then we
cover the following values of "ReadFileInfo->Flags":

- READ_FILE_GET_FILESIZE
- READ_FILE_ALLOCATE_AND_READ
- READ_FILE_SEEK_AND_READ

We don't do anything (just proceed to the end of the function) if
"ReadFileInfo->Flags" is anything else.

In reality the above three values cover the domain of the
UDF_READ_FILE_FLAGS enum type fully, and "ReadFileInfo->Flags" is only
ever set internally to UdfDxe. Therefore any other flag value would be a
bug in UdfDxe.

ASSERT() specifically that "ReadFileInfo->Flags" has been set correctly,
so that the reader is not left wondering what happens if none of the enum
constants match.

Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Eric Dong <eric.dong@intel.com>
Cc: Paulo Alcantara <pcacjr@zytor.com>
Cc: Ruiyu Ni <ruiyu.ni@intel.com>
Cc: Star Zeng <star.zeng@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Paulo Alcantara <pcacjr@zytor.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
---
 MdeModulePkg/Universal/Disk/UdfDxe/FileSystemOperations.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/MdeModulePkg/Universal/Disk/UdfDxe/FileSystemOperations.c b/MdeModulePkg/Universal/Disk/UdfDxe/FileSystemOperations.c
index 904262a2ba..842c7f8f09 100644
--- a/MdeModulePkg/Universal/Disk/UdfDxe/FileSystemOperations.c
+++ b/MdeModulePkg/Universal/Disk/UdfDxe/FileSystemOperations.c
@@ -962,6 +962,9 @@ ReadFile (
         );
 
       ReadFileInfo->FilePosition += ReadFileInfo->FileDataSize;
+    } else {
+      ASSERT (FALSE);
+      return EFI_INVALID_PARAMETER;
     }
 
     break;