Security updates for Friday

Security updates have been issued by Debian (snapd), Fedora (firefox, libetpan, ntfs-3g, samba, thunderbird, and xen), SUSE (busybox, emacs, and virt-v2v), and Ubuntu (linux, linux-aws, linux-aws-5.15, linux-gcp, linux-gkeop, linux-hwe-5.15, linux-ibm, linux-intel-iotg, linux-kvm, linux-lowlatency, linux-lowlatency-hwe-5.15, linux-oracle, linux-oracle-5.15, linux-raspi, linux, linux-aws, linux-aws-5.4, linux-gcp, linux-gcp-5.4, linux-gkeop, linux-hwe-5.4, linux-ibm, linux-ibm-5.4, linux-kvm, linux-oracle, linux-oracle-5.4, linux-raspi, linux-raspi-5.4, linux, linux-aws, linux-dell300x, linux-gcp-4.15, linux-kvm, linux-oracle, linux-raspi2, linux-snapdragon, linux, linux-aws, linux-gcp, linux-ibm, linux-kvm, linux-lowlatency, linux-oracle, linux-raspi, linux, linux-aws, linux-kvm, linux-lts-xenial, linux-aws-hwe, linux-gcp, linux-hwe, linux-oracle, and tiff).