The do_double_fault function in arch/x86/kernel/traps.c in the Linux kernel through 3.17.4 does not properly handle faults associated with the Stack Segment (SS) segment register, which allows local users to cause a denial of service (panic) via a modify_ldt system call, as demonstrated by sigreturn_32 in the linux-clock-tests test suite. http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2014-9090
