The Siemens R3964 line discipline driver in drivers/tty/n_r3964.c in the Linux kernel before 5.0.8 has multiple race conditions.
Created kernel tracking bugs for this issue:
Affects: fedora-all [bug 1705499]
This was fixed for Fedora with the 5.0.8 stable kernel updates.
The fix proposed by upstream is not actually fixing the problem, instead they are attempting to mask out the ability to build the code with the buggy implementation. The code with the race condition still exists in the repository, and likely other CVE's may come about if/when this driver gets fixed.
This task is marked as moderate as there is likely a chance for memory corruption, but this hardware is uncommon, it is unlikely that most systems have this hardware.