The mpi_powm function in lib/mpi/mpi-pow.c in the Linux kernel through 4.8.11 does not ensure that memory is allocated for limb data, which allows local users to cause a denial of service (stack memory corruption and panic) via an add_key system call for an RSA key with a zero exponent. http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2016-8650
