[PATCH 1/2] gdi32: Check for truncated EMF files.
Vincent Povirk
vincent at codeweavers.com
Tue May 8 12:46:19 CDT 2018
Signed-off-by: Vincent Povirk <vincent at codeweavers.com>
---
There were several bounds-checking bugs filed recently against
EMF code. This doesn't address everything, but it's a start.
dlls/gdi32/enhmetafile.c | 23 ++++++++++++++++++-----
dlls/gdi32/enhmfdrv/init.c | 2 +-
dlls/gdi32/gdi_private.h | 2 +-
3 files changed, 20 insertions(+), 7 deletions(-)
diff --git a/dlls/gdi32/enhmetafile.c b/dlls/gdi32/enhmetafile.c
index 37edc231a37..f2e2930d9ea 100644
--- a/dlls/gdi32/enhmetafile.c
+++ b/dlls/gdi32/enhmetafile.c
@@ -246,11 +246,16 @@ static inline BOOL is_dib_monochrome( const BITMAPINFO* info )
/****************************************************************************
* EMF_Create_HENHMETAFILE
*/
-HENHMETAFILE EMF_Create_HENHMETAFILE(ENHMETAHEADER *emh, BOOL on_disk )
+HENHMETAFILE EMF_Create_HENHMETAFILE(ENHMETAHEADER *emh, DWORD filesize, BOOL on_disk )
{
HENHMETAFILE hmf;
ENHMETAFILEOBJ *metaObj;
+ if (filesize < sizeof(*emh))
+ {
+ WARN("File too small for emf header\n");
+ return 0;
+ }
if (emh->iType != EMR_HEADER)
{
SetLastError(ERROR_INVALID_DATA);
@@ -263,6 +268,11 @@ HENHMETAFILE EMF_Create_HENHMETAFILE(ENHMETAHEADER *emh, BOOL on_disk )
emh->iType, emh->dSignature);
return 0;
}
+ if (filesize < emh->nBytes)
+ {
+ WARN("File truncated (got %u bytes, header says %u)\n", emh->nBytes, filesize);
+ return 0;
+ }
if (!(metaObj = HeapAlloc( GetProcessHeap(), 0, sizeof(*metaObj) ))) return 0;
@@ -318,6 +328,9 @@ static HENHMETAFILE EMF_GetEnhMetaFile( HANDLE hFile )
ENHMETAHEADER *emh;
HANDLE hMapping;
HENHMETAFILE hemf;
+ DWORD filesize;
+
+ filesize = GetFileSize( hFile, NULL );
hMapping = CreateFileMappingA( hFile, NULL, PAGE_READONLY, 0, 0, NULL );
emh = MapViewOfFile( hMapping, FILE_MAP_READ, 0, 0, 0 );
@@ -325,7 +338,7 @@ static HENHMETAFILE EMF_GetEnhMetaFile( HANDLE hFile )
if (!emh) return 0;
- hemf = EMF_Create_HENHMETAFILE( emh, TRUE );
+ hemf = EMF_Create_HENHMETAFILE( emh, filesize, TRUE );
if (!hemf)
UnmapViewOfFile( emh );
return hemf;
@@ -468,7 +481,7 @@ HENHMETAFILE WINAPI SetEnhMetaFileBits(UINT bufsize, const BYTE *buf)
ENHMETAHEADER *emh = HeapAlloc( GetProcessHeap(), 0, bufsize );
HENHMETAFILE hmf;
memmove(emh, buf, bufsize);
- hmf = EMF_Create_HENHMETAFILE( emh, FALSE );
+ hmf = EMF_Create_HENHMETAFILE( emh, bufsize, FALSE );
if (!hmf)
HeapFree( GetProcessHeap(), 0, emh );
return hmf;
@@ -2562,7 +2575,7 @@ HENHMETAFILE WINAPI CopyEnhMetaFileA(
if (!file) {
emrDst = HeapAlloc( GetProcessHeap(), 0, emrSrc->nBytes );
memcpy( emrDst, emrSrc, emrSrc->nBytes );
- hmfDst = EMF_Create_HENHMETAFILE( emrDst, FALSE );
+ hmfDst = EMF_Create_HENHMETAFILE( emrDst, emrSrc->nBytes, FALSE );
if (!hmfDst)
HeapFree( GetProcessHeap(), 0, emrDst );
} else {
@@ -2604,7 +2617,7 @@ HENHMETAFILE WINAPI CopyEnhMetaFileW(
if (!file) {
emrDst = HeapAlloc( GetProcessHeap(), 0, emrSrc->nBytes );
memcpy( emrDst, emrSrc, emrSrc->nBytes );
- hmfDst = EMF_Create_HENHMETAFILE( emrDst, FALSE );
+ hmfDst = EMF_Create_HENHMETAFILE( emrDst, emrSrc->nBytes, FALSE );
if (!hmfDst)
HeapFree( GetProcessHeap(), 0, emrDst );
} else {
diff --git a/dlls/gdi32/enhmfdrv/init.c b/dlls/gdi32/enhmfdrv/init.c
index 35803bcc336..8ff0e6c9f21 100644
--- a/dlls/gdi32/enhmfdrv/init.c
+++ b/dlls/gdi32/enhmfdrv/init.c
@@ -529,7 +529,7 @@ HENHMETAFILE WINAPI CloseEnhMetaFile(HDC hdc) /* [in] metafile DC */
CloseHandle( physDev->hFile );
}
- hmf = EMF_Create_HENHMETAFILE( physDev->emh, (physDev->hFile != 0) );
+ hmf = EMF_Create_HENHMETAFILE( physDev->emh, physDev->emh->nBytes, (physDev->hFile != 0) );
physDev->emh = NULL; /* So it won't be deleted */
free_dc_ptr( dc );
return hmf;
diff --git a/dlls/gdi32/gdi_private.h b/dlls/gdi32/gdi_private.h
index c5e42319b61..5b09b848466 100644
--- a/dlls/gdi32/gdi_private.h
+++ b/dlls/gdi32/gdi_private.h
@@ -268,7 +268,7 @@ extern const struct gdi_dc_funcs *DRIVER_load_driver( LPCWSTR name ) DECLSPEC_HI
extern BOOL DRIVER_GetDriverName( LPCWSTR device, LPWSTR driver, DWORD size ) DECLSPEC_HIDDEN;
/* enhmetafile.c */
-extern HENHMETAFILE EMF_Create_HENHMETAFILE(ENHMETAHEADER *emh, BOOL on_disk ) DECLSPEC_HIDDEN;
+extern HENHMETAFILE EMF_Create_HENHMETAFILE(ENHMETAHEADER *emh, DWORD filesize, BOOL on_disk ) DECLSPEC_HIDDEN;
/* freetype.c */
--
2.14.1
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