It was found that the net_dma code in tcp_recvmsg() in the 2.6.32 kernel as shipped in RHEL6 is thread-unsafe. So an unprivileged multi-threaded userspace application calling recvmsg() for the same network socket in parallel executed on ioatdma-enabled hardware with net_dma enabled can leak the memory, crash the host leading to a denial-of-service or cause a random memory corruption.