Add a check in R_CheckPlane to prevent stack trashing

Fixes illegal memory writes and freezes that may happen when there's an overrun due to when there's an excessively large number of visplanes added to the visplanes array
AXDOOMER · Nov 20, 2018 · 56ccf3a · 56ccf3a
1 parent 194d0d0
commit 56ccf3a
Showing 1 changed file with 4 additions and 0 deletions.
diff --git a/r_plane.c b/r_plane.c
@@ -306,6 +306,10 @@ R_CheckPlane
     lastvisplane->picnum = pl->picnum;
     lastvisplane->lightlevel = pl->lightlevel;
 
+    // fix: prevent the stack from being trashed
+    if (lastvisplane - visplanes == MAXVISPLANES)
+	I_Error ("R_CheckPlane: no more visplanes");
+
     pl = lastvisplane++;
     pl->minx = start;
     pl->maxx = stop;