We have experienced a kernel BPF null pointer dereference issue on all our machines since mid of June. It might be related to an upgrade of libvirt/kvm/qemu at that point of time. But we’re not sure. None of the servers can be used with this bug, as they crash latest one hour after reboot. The time period until kernel panic can be easily reduced down to 2 minutes, when starting one or more applications of the following list: - LXD daemon (4.2.1) - libvirtd daemon (6.4.0) with qemu/kvm guests - NFS server 2.5.1 - Mozilla Firefox - Mozilla Thunderbird If none of the applications run, the systems seem to be stable. Intermediate solution: Downgrade Linux kernel to 4.9.226 LTS or 4.4.226 LTS on all the machines Why this solution works is not clear, yet. One of the major differences we saw is, that both kernel packages have been configured with user namespaces disabled. We experienced the kernel freeze on following Arch Linux kernels: - 5.7.0 (5.7.0-3-MANJARO x64) - 5.6.16 (5.6.16-1-MANJARO x64) - 5.4.44 (5.4.44-1-MANJARO x64) - 4.19.126 (4.19.126-1-MANJARO x64) - 4.14.183 (4.14.183-1-MANJARO x64) Kernel configs can be taken from https://gitlab.manjaro.org/packages/core. Subsequent e-mails will contain the relevant extracts from journal or netconsole logs. Help and support on this issue is welcome.
