ubifs: Fix memory leak on error condition

If the call to ubifs_read_nnode() fails in ubifs_lpt_calc_hash() an
error is returned without freeing the memory allocated to 'buf'.
Read and check the root node before allocating the buffer.

Detected by CoverityScan, CID 1441025 ("Resource leak")

Signed-off-by: Garry McNulty <garrmcnu@gmail.com>
Signed-off-by: Richard Weinberger <richard@nod.at>

1 files changed, 6 insertions, 6 deletions

diff --git a/fs/ubifs/lpt.c b/fs/ubifs/lpt.c
index d1d5e96350dd..b0c5f06128b5 100644
--- a/fs/ubifs/lpt.c
+++ b/fs/ubifs/lpt.c
@@ -1675,6 +1675,12 @@ int ubifs_lpt_calc_hash(struct ubifs_info *c, u8 *hash)
         if (!ubifs_authenticated(c))
                 return 0;
 
+        if (!c->nroot) {
+                err = ubifs_read_nnode(c, NULL, 0);
+                if (err)
+                        return err;
+        }
+
         desc = ubifs_hash_get_desc(c);
         if (IS_ERR(desc))
                 return PTR_ERR(desc);
@@ -1685,12 +1691,6 @@ int ubifs_lpt_calc_hash(struct ubifs_info *c, u8 *hash)
                 goto out;
         }
 
-        if (!c->nroot) {
-                err = ubifs_read_nnode(c, NULL, 0);
-                if (err)
-                        return err;
-        }
-
         cnode = (struct ubifs_cnode *)c->nroot;
 
         while (cnode) {