The blk_rq_map_user_iov function in block/blk-map.c in the Linux kernel before 4.8.14 does not properly restrict the type of iterator, which allows local users to read or write to arbitrary kernel memory locations or cause a denial of service (use-after-free) by leveraging access to a /dev/sg device. http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2016-9576
