diff --git a/mm/slab_common.c b/mm/slab_common.c
index 8f128245b300..c5aacb359de3 100644
--- a/mm/slab_common.c
+++ b/mm/slab_common.c
@@ -1680,6 +1680,13 @@ static __always_inline void *__do_krealloc(const void *p, size_t new_size,
 		ks = ksize(p);
 
 	if (ks >= new_size) {
+		/* Zero out spare memory. */
+		if (want_init_on_alloc(flags)) {
+			kasan_disable_current();
+			memset((void *)p + new_size, 0, ks - new_size);
+			kasan_enable_current();
+		}
+
 		p = kasan_krealloc((void *)p, new_size, flags);
 		return (void *)p;
 	}