diff --git a/mm/slab.c b/mm/slab.c
index 9a90b00..1a6040d 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -2353,6 +2353,15 @@
 		/* really off slab. No need for manual alignment */
 		slab_size =
 		    cachep->num * sizeof(kmem_bufctl_t) + sizeof(struct slab);
+
+#ifdef CONFIG_PAGE_POISONING
+		/* If we're going to use the generic kernel_map_pages()
+		 * poisoning, then it's going to smash the contents of
+		 * the redzone and userword anyhow, so switch them off.
+		 */
+		if (size % PAGE_SIZE == 0 && flags & SLAB_POISON)
+			flags &= ~(SLAB_RED_ZONE | SLAB_STORE_USER);
+#endif
 	}
 
 	cachep->colour_off = cache_line_size();