Comment 2 for bug 1704857

Per report, relevant commits:

350be257ea83029daee974c72b1fe2e6f1f8e615 ("CIFS: Fix null pointer deref during read resp processing")
517a6e43c4872c89794af5b377fa085e47345952 ("CIFS: Fix some return values in case of error in 'crypt_message'")