mariadb: improper locking due to unreleased lock in the ds_xbstream.cc

MariaDB Server before 10.7 is vulnerable to Denial of Service. In extra/mariabackup/dsxbstream.cc, when an error occurs streamctxt-destfile == NULL while executing the method xbstreamopen, the held lock is not released correctly, which allows local users to trigger a denial of service due to the...