Security updates for Thursday

Security updates have been issued by Debian (pillow and redis), Fedora (kernel-headers, kernel-tools, kernelshark, libbpf, libtraceevent, libtracefs, nextcloud, and trace-cmd), Gentoo (chromium and singularity), Mageia (kernel, kernel-linus, and systemd), openSUSE (caribou, chromium, curl, and qemu), Oracle (java-1.8.0-openjdk, java-11-openjdk, kernel, and systemd), Slackware (curl), SUSE (curl, kernel, linuxptp, python-pip, and qemu), and Ubuntu (ruby2.3, ruby2.5, ruby2.7).