The amd64_set_ldt() function in sys/amd64/amd64/sys_machdep.c in the FreeBSD kernel code is prone to an integer signedness error when processing a system call with specially crafted parameters originated from user space. This issue ultimately leads to a kernel heap overflow, which can be used by unprivileged local attackers to cause a kernel panic and crash the machine.
This module exploits a vulnerability in Linux. The ovl_setattr function in fs/overlayfs/inode.c in the Linux kernel through 4.3.3 attempts to merge distinct setattr operations, which allows local users to bypass intended access restrictions and modify the attributes of arbitrary overlay files via a crafted application.