Fix crash from reading past end of tr.refdef.drawSurfs

The number of draw surfaces was range checked against number of surfaces for
the current view but needs to check total for the frame otherwise can read
past the end of the tr.refdef.drawSurfs array when there are multiple views.

1 files changed, 10 insertions, 8 deletions

diff --git a/src/renderergl2/tr_main.c b/src/renderergl2/tr_main.c
index 287f95d3..2682d471 100644
--- a/src/renderergl2/tr_main.c
+++ b/src/renderergl2/tr_main.c
@@ -1821,13 +1821,6 @@ void R_SortDrawSurfs( drawSurf_t *drawSurfs, int numDrawSurfs ) {
 		return;
 	}
 
-	// if we overflowed MAX_DRAWSURFS, the drawsurfs
-	// wrapped around in the buffer and we will be missing
-	// the first surfaces, not the last ones
-	if ( numDrawSurfs > MAX_DRAWSURFS ) {
-		numDrawSurfs = MAX_DRAWSURFS;
-	}
-
 	// sort the drawsurfs by sort type, then orientation, then shader
 	R_RadixSort( drawSurfs, numDrawSurfs );
 
@@ -2054,6 +2047,7 @@ or a mirror / remote location
 */
 void R_RenderView (viewParms_t *parms) {
 	int		firstDrawSurf;
+	int		numDrawSurfs;
 
 	if ( parms->viewportWidth <= 0 || parms->viewportHeight <= 0 ) {
 		return;
@@ -2076,7 +2070,15 @@ void R_RenderView (viewParms_t *parms) {
 
 	R_GenerateDrawSurfs();
 
-	R_SortDrawSurfs( tr.refdef.drawSurfs + firstDrawSurf, tr.refdef.numDrawSurfs - firstDrawSurf );
+	// if we overflowed MAX_DRAWSURFS, the drawsurfs
+	// wrapped around in the buffer and we will be missing
+	// the first surfaces, not the last ones
+	numDrawSurfs = tr.refdef.numDrawSurfs;
+	if ( numDrawSurfs > MAX_DRAWSURFS ) {
+		numDrawSurfs = MAX_DRAWSURFS;
+	}
+
+	R_SortDrawSurfs( tr.refdef.drawSurfs + firstDrawSurf, numDrawSurfs - firstDrawSurf );
 
 	// draw main system development information (surface outlines, etc)
 	R_DebugGraphics();