fs/proc/root.c in the procfs implementation in the Linux kernel before 3.2 does not properly interact with CLONE_NEWPID clone system calls, which allows remote…

fs/proc/root.c in the procfs implementation in the Linux kernel before 3.2 does not properly interact with CLONE_NEWPID clone system calls, which allows remote attackers to cause a denial of service (reference leak and memory consumption) by making many connections to a daemon that uses PID namespaces to isolate clients, as demonstrated by vsftpd.