Myah Caron : dmband: Avoid cloning stream in parse_bands_list.

[Alexandre Julliard]

Module: wine
Branch: master
Commit: 2cf69bb5a5b43951abb251f415ccb81e809bd32e
URL:    https://source.winehq.org/git/wine.git/?a=commit;h=2cf69bb5a5b43951abb251f41...

Author: Myah Caron <qsniyg(a)protonmail.com>
Date:   Thu Sep 17 05:18:08 2020 -0700

dmband: Avoid cloning stream in parse_bands_list.

A stream that doesn't implement ::Clone can be passed, causing IStream_Seek to crash.

Signed-off-by: Myah Caron <qsniyg(a)protonmail.com>
Signed-off-by: Michael Stefaniuc <mstefani(a)winehq.org>
Signed-off-by: Alexandre Julliard <julliard(a)winehq.org>

---

 dlls/dmband/bandtrack.c | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/dlls/dmband/bandtrack.c b/dlls/dmband/bandtrack.c
index 14d2c7a571..612be063e1 100644
--- a/dlls/dmband/bandtrack.c
+++ b/dlls/dmband/bandtrack.c
@@ -425,21 +425,22 @@ static HRESULT parse_bands_list(IDirectMusicBandTrack *This, DMUS_PRIVATE_CHUNK
 	  StreamSize = Chunk.dwSize - sizeof(FOURCC);
 	  switch (Chunk.fccID) {
 	  case DMUS_FOURCC_BAND_FORM: {
-	    LPSTREAM pClonedStream = NULL;
+	    ULARGE_INTEGER liOrigPos;
 	    TRACE_(dmfile)(": BAND RIFF\n");
-	    
-	    IStream_Clone (pStm, &pClonedStream);
-	    
+
 	    liMove.QuadPart = 0;
+	    IStream_Seek (pStm, liMove, STREAM_SEEK_CUR, &liOrigPos);
+
 	    liMove.QuadPart -= sizeof(FOURCC) + (sizeof(FOURCC)+sizeof(DWORD));
-	    IStream_Seek (pClonedStream, liMove, STREAM_SEEK_CUR, NULL);
+	    IStream_Seek (pStm, liMove, STREAM_SEEK_CUR, NULL);
 
-            hr = load_band(This, pClonedStream, &pBand, &header);
+            hr = load_band(This, pStm, &pBand, &header);
 	    if (FAILED(hr)) {
 	      ERR(": could not load track\n");
 	      return hr;
 	    }
-	    IStream_Release (pClonedStream);
+	    liMove.QuadPart = (LONGLONG)liOrigPos.QuadPart;
+	    IStream_Seek (pStm, liMove, STREAM_SEEK_SET, NULL);
 	    
 	    IDirectMusicTrack_Release(pBand); pBand = NULL; /* now we can release at as it inserted */