Describe CVE-2015-8709.
What is CVE-2015-8709?
kernel/ptrace.c in the Linux kernel through 4.4.1 mishandles uid and gid mappings, which allows local users to gain privileges by establishing a user namespace, waiting for a root process to enter that namespace with an unsafe uid or gid, and then using the ptrace system call.  NOTE: the vendor states "there is no kernel bug here..