UBI: fix kmem_cache_free on error patch

'kmem_cache_free()' oopeses if NULL is passed, and there is
one error-path place where UBI may call it with NULL object.
This problem was pointed to by Adrian Hunter.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>

1 files changed, 2 insertions, 1 deletions

diff --git a/drivers/mtd/ubi/wl.c b/drivers/mtd/ubi/wl.c
index f25ae2910ad0..acb5520f7f3d 100644
--- a/drivers/mtd/ubi/wl.c
+++ b/drivers/mtd/ubi/wl.c
@@ -826,7 +826,8 @@ static int wear_leveling_worker(struct ubi_device *ubi, struct ubi_work *wrk,
         err = schedule_erase(ubi, e1, 0);
         if (err) {
                 kmem_cache_free(ubi_wl_entry_slab, e1);
-                kmem_cache_free(ubi_wl_entry_slab, e2);
+                if (e2)
+                        kmem_cache_free(ubi_wl_entry_slab, e2);
                 goto out_ro;
         }