TMA-COS-1.2.1

Ensure dm-verity is enabled

MoyenneNiveau 1Automatiséecos

Description

device-mapper-verity (dm-verity) kernel feature feature provides transparent integrity checking of block devices using a cryptographic digest provided by the kernel crypto API. When a dm-verity device is configured, it is expected that the caller has been authenticated in some way (cryptographic signatures, etc). After instantiation, all hashes will be verified on-demand during disk access. If they cannot be verified up to the root node of the tree, the root hash, then the I/O will fail. This should detect tampering with any data on the device and the hash data. The Container-Optimized OS root filesystem is always mounted as read-only. Additionally, its checksum is computed at build time and verified by the kernel on each boot. This mechanism prevents against attackers from "owning" the machine through permanent local changes.

Méthode de vérification

Méthode d'audit: Commande shell

shell

alt0() { command -v grep >/dev/null 2>&1 || { echo "step1: grep not installed"; return 1; }; command -v zcat >/dev/null 2>&1 || { echo "step1: zcat not installed"; return 1; }; o=$(bash -c 'zcat /proc/config.gz | grep CONFIG_DM_VERITY' 2>&1); printf '%s\n' "$o" | tr -s ' \t' '  ' | sed 's/^ //;s/ $//' | grep -Fxq -- CONFIG_DM_VERITY=y || { echo step1: missing CONFIG_DM_VERITY=y; return 1; }; }; if alt0; then echo compliant; fi

Sortie attendue: compliant

Méthode de correction

Méthode de correction: Recommandation ou correctif d'infrastructure

An OS image update that has the dm-verity enabled kernel is required.

Propriétés

Systèmes d'exploitation: Tous
Étiquettes: container-optimized-oscos
Référence: CIS Google Container-Optimized OS Benchmark v1.2.0 - 1.2.1 Ensure dm-verity is enabled

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 cos