vfs - fix dentry ref count in do_lookup()

There is a ref count problem in fs/namei.c:do_lookup().

When walking in ref-walk mode, if follow_managed() returns a fail we
need to drop dentry and possibly vfsmount.  Clean up properly,
as we do in the other caller of follow_managed().

Signed-off-by: Ian Kent <raven@themaw.net>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/fs/namei.c b/fs/namei.c
index b753192d8c3f15850abaab3cc36d52ff3cd59460..7d77f24d32a98a115e320605369006eeef30ae0d 100644 (file)
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -1272,8 +1272,10 @@ done:
        path->mnt = mnt;
        path->dentry = dentry;
        err = follow_managed(path, nd->flags);
-       if (unlikely(err < 0))
+       if (unlikely(err < 0)) {
+               path_put_conditional(path, nd);
                return err;
+       }
        *inode = path->dentry->d_inode;
        return 0;