An issue was discovered in mm/mmap.c in the Linux kernel before 5.7.11. There is a race condition between certain expand functions (expand_downwards and expand_upwards) and page-table free operations from an munmap call, aka CID-246c320a8cfe.
There is no mitigation available at this time. Red Hat is investigating a kpatch as an option to fix this issue on kpatch supported streams.