Fix T48824: Crash when having too many ray-to-volume intersections

Code might have writing past the array boundaries.

1 files changed, 5 insertions, 4 deletions

diff --git a/intern/cycles/kernel/bvh/qbvh_shadow_all.h b/intern/cycles/kernel/bvh/qbvh_shadow_all.h
index 3a728b388eb..34753ff067d 100644
--- a/intern/cycles/kernel/bvh/qbvh_shadow_all.h
+++ b/intern/cycles/kernel/bvh/qbvh_shadow_all.h
@@ -337,6 +337,9 @@ ccl_device bool BVH_FUNCTION_FULL_NAME(QBVH)(KernelGlobals *kg,
 
 						/* Shadow ray early termination. */
 						if(hit) {
+							/* Update number of hits now, so we do proper check on max bounces. */
+							(*num_hits)++;
+
 							/* detect if this surface has a shader with transparent shadows */
 
 							/* todo: optimize so primitive visibility flag indicates if
@@ -367,13 +370,11 @@ ccl_device bool BVH_FUNCTION_FULL_NAME(QBVH)(KernelGlobals *kg,
 								return true;
 							}
 
-							/* move on to next entry in intersections array */
-							isect_array++;
-							(*num_hits)++;
 #if BVH_FEATURE(BVH_INSTANCING)
 							num_hits_in_instance++;
 #endif
-
+							/* Move on to next entry in intersections array */
+							isect_array++;
 							isect_array->t = isect_t;
 						}