kmemleak: Release the object lock before calling put_object()

The put_object() function may free the object if the use_count
dropped to 0. There shouldn't be further accesses to such object unless
it is known that the use_count is non-zero.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

1 files changed, 6 insertions, 3 deletions

diff --git a/mm/kmemleak.c b/mm/kmemleak.c
index 96106358e042..f06c0921e472 100644
--- a/mm/kmemleak.c
+++ b/mm/kmemleak.c
@@ -1025,11 +1025,14 @@ static void scan_block(void *_start, void *_end,
                  * added to the gray_list.
                  */
                 object->count++;
-                if (color_gray(object))
+                if (color_gray(object)) {
                         list_add_tail(&object->gray_list, &gray_list);
-                else
-                        put_object(object);
+                        spin_unlock_irqrestore(&object->lock, flags);
+                        continue;
+                }
+
                 spin_unlock_irqrestore(&object->lock, flags);
+                put_object(object);
         }
 }