A heap allocator in the Linux kernel is, as he describes it, beautifully exploitable . Meet SLOB. There are three main allocators: SLUB, SLAB and SLOB. The allocator is mainly used in embedded systems, favored there because of its small footprint. The lack of exploit mitigations could be due to just a lack of someone stepping up to take charge of the effort, the researcher said. SLOB is used in Linux systems on many routers and switches and some firmware systems.
Source: https://threatpost.com/smashing-linux-heap-011312/76097/