diff --git a/ChangeLog b/ChangeLog
index 6e9abacf6..7e0b0af5e 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+2013-10-30  Vladimir Serbinenko  <phcoder@gmail.com>
+
+	* grub-core/kern/mm.c (grub_realloc): Don't copy more data than we have.
+
 2013-10-30  Vladimir Serbinenko  <phcoder@gmail.com>
 
 	* grub-core/io/gzio.c (huft_build): Use zalloc for safety.
diff --git a/grub-core/kern/mm.c b/grub-core/kern/mm.c
index 59e45c7ae..5e53b07f4 100644
--- a/grub-core/kern/mm.c
+++ b/grub-core/kern/mm.c
@@ -483,7 +483,8 @@ grub_realloc (void *ptr, grub_size_t size)
   if (! q)
     return q;
 
-  grub_memcpy (q, ptr, size);
+  /* We've already checked that p->size < n.  */
+  grub_memcpy (q, ptr, p->size << GRUB_MM_ALIGN_LOG2);
   grub_free (ptr);
   return q;
 }