  In this paper we investigate the feasibility of denial-of-service (DoS)
attacks on shared caches in multicore platforms. With carefully engineered
attacker tasks, we are able to cause more than 300X execution time increases on
a victim task running on a dedicated core on a popular embedded multicore
platform, regardless of whether we partition its shared cache or not. Based on
careful experimentation on real and simulated multicore platforms, we identify
an internal hardware structure of a non-blocking cache, namely the cache
writeback buffer, as a potential target of shared cache DoS attacks. We propose
an OS-level solution to prevent such DoS attacks by extending a
state-of-the-art memory bandwidth regulation mechanism. We implement the
proposed mechanism in Linux on a real multicore platform and show its
effectiveness in protecting against cache DoS attacks.
