From 465c2a84ba709d932040c9e80db508e93c138da6 Mon Sep 17 00:00:00 2001 From: Bo Xu Date: Sat, 2 Aug 2014 15:13:46 -0700 Subject: Fix buffer size boundary check offset by 1 When newPos == file size, the current block will not be read or Get. If this block is a crucial part of the document (like m_pTrailer), the program will exit with parse error and the document will not be rendered. BUG=None R=jun_fang@foxitsoftware.com Review URL: https://codereview.chromium.org/440563003 --- fpdfsdk/src/fpdfview.cpp | 46 +++++++++++++++++++++------------------------- 1 file changed, 21 insertions(+), 25 deletions(-) (limited to 'fpdfsdk/src') diff --git a/fpdfsdk/src/fpdfview.cpp b/fpdfsdk/src/fpdfview.cpp index 63d4fbdcde..af24e71b94 100644 --- a/fpdfsdk/src/fpdfview.cpp +++ b/fpdfsdk/src/fpdfview.cpp @@ -35,27 +35,25 @@ FX_BOOL CPDF_CustomAccess::GetByte(FX_DWORD pos, FX_BYTE& ch) FX_BOOL CPDF_CustomAccess::GetBlock(FX_DWORD pos, FX_LPBYTE pBuf, FX_DWORD size) { - FX_SAFE_DWORD newPos = size; - newPos += pos; - if (!newPos.IsValid() || newPos.ValueOrDie() >= m_FileAccess.m_FileLen) { - return FALSE; - } - - return m_FileAccess.m_GetBlock(m_FileAccess.m_Param, pos, pBuf, size); + FX_SAFE_DWORD newPos = size; + newPos += pos; + if (!newPos.IsValid() || newPos.ValueOrDie() > m_FileAccess.m_FileLen) { + return FALSE; + } + return m_FileAccess.m_GetBlock(m_FileAccess.m_Param, pos, pBuf, size); } FX_BOOL CPDF_CustomAccess::ReadBlock(void* buffer, FX_FILESIZE offset, size_t size) { - if (offset < 0) { - return FALSE; - } - FX_SAFE_FILESIZE newPos = base::checked_cast(size); - newPos += offset; - if (!newPos.IsValid() || newPos.ValueOrDie() >= m_FileAccess.m_FileLen) { - return FALSE; - } - - return m_FileAccess.m_GetBlock(m_FileAccess.m_Param, offset,(FX_LPBYTE) buffer, size); + if (offset < 0) { + return FALSE; + } + FX_SAFE_FILESIZE newPos = base::checked_cast(size); + newPos += offset; + if (!newPos.IsValid() || newPos.ValueOrDie() > m_FileAccess.m_FileLen) { + return FALSE; + } + return m_FileAccess.m_GetBlock(m_FileAccess.m_Param, offset,(FX_LPBYTE) buffer, size); } //0 bit: FPDF_POLICY_MACHINETIME_ACCESS @@ -301,15 +299,13 @@ public: virtual FX_FILESIZE GetSize() {return m_size;} virtual FX_BOOL ReadBlock(void* buffer, FX_FILESIZE offset, size_t size) { - if (offset < 0) { - return FALSE; - } - - FX_SAFE_FILESIZE newPos = base::checked_cast(size); - newPos += offset; - if (!newPos.IsValid() || newPos.ValueOrDie() >= (FX_DWORD)m_size) return FALSE; + if (offset < 0) { + return FALSE; + } + FX_SAFE_FILESIZE newPos = base::checked_cast(size); + newPos += offset; + if (!newPos.IsValid() || newPos.ValueOrDie() > (FX_DWORD)m_size) return FALSE; FXSYS_memcpy(buffer, m_pBuf+offset, size); - return TRUE; } private: -- cgit v1.2.3