Memory deduplication as a threat to the guest OS
Proceedings of the Fourth European Workshop on System Security, 2011•dl.acm.org
Memory deduplication shares same-content memory pages and reduces the consumption of
physical memory. It is effective on environments that run many virtual machines with the
same operating system. Memory deduplication, however, is vulnerable to memory
disclosure attacks, which reveal the existence of an application or file on another virtual
machine. Such an attack takes advantage of a difference in write access times on
deduplicated memory pages that are re-created by Copy-On-Write. In our experience on …
physical memory. It is effective on environments that run many virtual machines with the
same operating system. Memory deduplication, however, is vulnerable to memory
disclosure attacks, which reveal the existence of an application or file on another virtual
machine. Such an attack takes advantage of a difference in write access times on
deduplicated memory pages that are re-created by Copy-On-Write. In our experience on …
Memory deduplication shares same-content memory pages and reduces the consumption of physical memory. It is effective on environments that run many virtual machines with the same operating system. Memory deduplication, however, is vulnerable to memory disclosure attacks, which reveal the existence of an application or file on another virtual machine. Such an attack takes advantage of a difference in write access times on deduplicated memory pages that are re-created by Copy-On-Write. In our experience on KSM (kernel samepage merging) with the KVM virtual machine, the attack could detect the existence of sshd and apache2 on Linux, and IE6 and Firefox on WindowsXP. It also could detect a downloaded file on the Firefox browser. We describe the attack mechanism in this paper, and also mention countermeasures against this attack.