Add test for ctr_drbg_update() input sanitizing
diff --git a/tests/suites/test_suite_ctr_drbg.function b/tests/suites/test_suite_ctr_drbg.function
index fd9f087..a36bab2 100644
--- a/tests/suites/test_suite_ctr_drbg.function
+++ b/tests/suites/test_suite_ctr_drbg.function
@@ -141,6 +141,10 @@
     }
     TEST_ASSERT( last_idx == test_offset_idx );
 
+    /* Call update with too much data (sizeof entropy > MAX(_SEED)_INPUT)
+     * (just make sure it doesn't cause memory corruption) */
+    ctr_drbg_update( &ctx, entropy, sizeof( entropy ) );
+
     /* Now enable PR, so the next few calls should all reseed */
     ctr_drbg_set_prediction_resistance( &ctx, CTR_DRBG_PR_ON );
     TEST_ASSERT( ctr_drbg_random( &ctx, out, sizeof( out ) ) == 0 );