The __get_user_asm_ex macro in arch/x86/include/asm/uaccess.h in the Linux kernel before 4.7.5 does not initialize a certain integer variable, which allows local users to obtain sensitive information from kernel stack memory by triggering failure of a get_user_ex call.
git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=1c109fabbd51863475cd12ac206bdd249aee35af
www.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.7.5
www.openwall.com/lists/oss-security/2016/11/04/4
www.securityfocus.com/bid/94144
bugzilla.redhat.com/show_bug.cgi?id=1391908
github.com/torvalds/linux/commit/1c109fabbd51863475cd12ac206bdd249aee35af