SELinux System Administration - Second Edition

Information flow analysis

Another analytical investigation of SELinux policy is information flow analysis. Unlike domain transitions, which look at how one domain can gain a certain set of permissions through transitions toward other domains, information flow analysis looks at how a domain could leak (purposefully or not) information toward another domain.

Information flow analysis is performed by looking at all operations that occur between two types. A source type can be read by a domain, which subsequently can write information to another type. This simple approach is a two-step flow analysis.

However, it is not as simple as just checking read and write operations (although that is of course perfectly possible). Information can be leaked through ...