From 9f615301aba1cc54a749950bf9462c5a85217bc4 Mon Sep 17 00:00:00 2001

From: Pierre Ossman <ossman@cendio.se>

Date: Tue, 10 Sep 2019 15:25:30 +0200

Subject: [PATCH] Add write protection to OffsetPixelBuffer

No one should every try to write to this buffer. Enforce that by

throwing an exception if any one tries to get a writeable pointer

to the data.

---

 common/rfb/EncodeManager.cxx | 6 ++++++

 common/rfb/EncodeManager.h   | 3 +++

 2 files changed, 9 insertions(+)

diff --git a/common/rfb/EncodeManager.cxx b/common/rfb/EncodeManager.cxx

index 1653cea..66ba432 100644

--- a/common/rfb/EncodeManager.cxx

+++ b/common/rfb/EncodeManager.cxx

@@ -24,6 +24,7 @@

 #include <rfb/SMsgWriter.h>

 #include <rfb/UpdateTracker.h>

 #include <rfb/LogWriter.h>

+#include <rfb/Exception.h>

 #include <rfb/RawEncoder.h>

 #include <rfb/RREEncoder.h>

@@ -895,6 +896,11 @@ void EncodeManager::OffsetPixelBuffer::update(const PixelFormat& pf,

   setBuffer(width, height, (rdr::U8*)data_, stride_);

 }

+rdr::U8* EncodeManager::OffsetPixelBuffer::getBufferRW(const Rect& r, int* stride)

+{

+  throw rfb::Exception("Invalid write attempt to OffsetPixelBuffer");

+}

+

 // Preprocessor generated, optimised methods

 #define BPP 8

diff --git a/common/rfb/EncodeManager.h b/common/rfb/EncodeManager.h

index 79db950..7d47420 100644

--- a/common/rfb/EncodeManager.h

+++ b/common/rfb/EncodeManager.h

@@ -124,6 +124,9 @@ namespace rfb {

       void update(const PixelFormat& pf, int width, int height,

                   const rdr::U8* data_, int stride);

+

+    private:

+      virtual rdr::U8* getBufferRW(const Rect& r, int* stride);

     };

     OffsetPixelBuffer offsetPixelBuffer;