I recently encountered this bug without using Apache. It is reproducible using Nextcloud PHP on nginx, as explained in this bug report I filed earlier today in the Nextcloud issue queue: https://github.com/nextcloud/server/issues/31361
We saw it on both nginx and Apache, so that rules out Apache as one of the 3 components that are involved in causing the issue. It appears that the issue is related to mmap(), which IMO points to the kernel but I suppose that the Samba/CIFS driver could be handling buffers improperly. We saw this in two different Kubernetes clusters, one running kernel 4.15.0-1113-azure and 5.4.0-1068-azure Guy Elsmore-Paddock | he/him/his Lead Architect/Chief Technology Officer Inveniem [Inveniem Logo]