Ensure unprivileged eBPF is disabled

ÉlevéeNiveau 1Automatiséeazure-container-linux

Description

eBPF (extended Berkeley Packet Filter) allows programs to be loaded and executed within kernel context. Unprivileged users should not be able to load eBPF programs. On Azure Container Linux the kernel parameter kernel.unprivileged_bpf_disabled is set to 1.

Méthode de vérification

Méthode d'audit: Commande shell

shell

chk() { p=$1; allowed=" $2 "; case $p in net.ipv6.*) [ -d /proc/sys/net/ipv6 ] || return 0;; esac; v=$(sysctl -n "$p" 2>/dev/null) || { echo "$p: not available"; return 1; }; case "$allowed" in *" $v "*) ;; *) echo "$p is $v (running)"; return 1;; esac; sd=$(readlink -e /lib/systemd/systemd-sysctl || readlink -e /usr/lib/systemd/systemd-sysctl); f=$("$sd" --cat-config 2>/dev/null | grep -Po "^\h*${p//./\.}\h*=\h*\K\H+" | tail -n1); [ -n "$f" ] || { echo "$p is not set in any sysctl configuration file"; return 1; }; case "$allowed" in *" $f "*) ;; *) echo "$p is $f in configuration"; return 1;; esac; }; if chk kernel.unprivileged_bpf_disabled 1; then echo compliant; fi

Sortie attendue: compliant

Méthode de correction

Méthode de correction: Recommandation ou correctif d'infrastructure

Set the following parameter in /etc/sysctl.conf or a file in /etc/sysctl.d/ ending in .conf: kernel.unprivileged_bpf_disabled = 1 Example: # printf '%s\n' "kernel.unprivileged_bpf_disabled = 1" >> /etc/sysctl.d/60- kernel_sysctl.conf Run the following command to set the active kernel parameter: # sysctl -w kernel.unprivileged_bpf_disabled=1

Propriétés

Systèmes d'exploitation: Tous
Étiquettes: azure-container-linuxcis-convertedkernelsysctl
Référence: CIS Azure Container Linux Benchmark v1.0.0 - 1.4.8 Ensure unprivileged eBPF is disabled

Vérifier cet hôte

Exécutez cette commande sur une machine que vous êtes autorisé à auditer. L'analyse est en lecture seule.

shell

tmaegis scan --target azure-container-linux