Security updates for Friday

Security updates have been issued by Debian (lasso), Fedora (mingw-djvulibre, mingw-exiv2, python-lxml, and singularity), openSUSE (ceph, dhcp, inn, nginx, opera, polkit, upx, and xstream), Oracle (firefox, perl, and polkit), Scientific Linux (firefox), SUSE (avahi, csync2, djvulibre, libwebp, polkit, python-py, slurm, slurm_18_08, thunderbird, and umoci), and Ubuntu (linux, linux-aws, linux-aws-5.4, linux-azure, linux-azure-5.4, linux-gcp, linux-gcp-5.4, linux-gke, linux-gke-5.4, linux-gkeop, linux-gkeop-5.4, linux-hwe-5.4, linux-kvm, linux-oracle, linux-oracle-5.4, linux-oem-5.10, and squid, squid3).