1 files changed, 12 insertions, 4 deletions

diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index e03f4c7307a5..2bb90b1d241c 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -413,11 +413,11 @@ nocache:
                 if (addr + size - 1 < addr)
                         goto overflow;
 
-                n = rb_next(&first->rb_node);
-                if (n)
-                        first = rb_entry(n, struct vmap_area, rb_node);
-                else
+                if (list_is_last(&first->list, &vmap_area_list))
                         goto found;
+
+                first = list_entry(first->list.next,
+                                struct vmap_area, list);
         }
 
 found:
@@ -904,6 +904,14 @@ static void *vb_alloc(unsigned long size, gfp_t gfp_mask)
 
         BUG_ON(size & ~PAGE_MASK);
         BUG_ON(size > PAGE_SIZE*VMAP_MAX_ALLOC);
+        if (WARN_ON(size == 0)) {
+                /*
+                 * Allocating 0 bytes isn't what caller wants since
+                 * get_order(0) returns funny result. Just warn and terminate
+                 * early.
+                 */
+                return NULL;
+        }
         order = get_order(size);
 
 again: