The key_reject_and_link function in security/keys/key.c in the Linux kernel through 4.6.3 does not ensure that a certain data structure is initialized, which allows local users to cause a denial of service (system crash) via vectors involving a crafted keyctl request2 command.<a href=http://cwe.mitre.org/data/definitions/416.html>CWE-416: Use After Free</a> http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2016-4470
