ksmbd: call putname after using the last component

last component point filename struct. Currently putname is called after
vfs_path_parent_lookup(). And then last component is used for
lookup_one_qstr_excl(). name in last component is freed by previous
calling putname(). And It cause file lookup failure when testing
generic/464 test of xfstest.

Fixes: 74d7970febf7 ("ksmbd: fix racy issue from using ->d_parent and ->d_name")
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>

diff --git a/fs/smb/server/vfs.c b/fs/smb/server/vfs.c
index 9bdb01c..6f30291 100644 (file)
--- a/fs/smb/server/vfs.c
+++ b/fs/smb/server/vfs.c
@@ -86,12 +86,14 @@ static int ksmbd_vfs_path_lookup_locked(struct ksmbd_share_config *share_conf,
        err = vfs_path_parent_lookup(filename, flags,
                                     &parent_path, &last, &type,
                                     root_share_path);
-       putname(filename);
-       if (err)
+       if (err) {
+               putname(filename);
                return err;
+       }
 
        if (unlikely(type != LAST_NORM)) {
                path_put(&parent_path);
+               putname(filename);
                return -ENOENT;
        }
 
@@ -108,12 +110,14 @@ static int ksmbd_vfs_path_lookup_locked(struct ksmbd_share_config *share_conf,
        path->dentry = d;
        path->mnt = share_conf->vfs_path.mnt;
        path_put(&parent_path);
+       putname(filename);
 
        return 0;
 
 err_out:
        inode_unlock(parent_path.dentry->d_inode);
        path_put(&parent_path);
+       putname(filename);
        return -ENOENT;
 }