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.

Affected: Ubuntu:14.04:LTS: linux-lts-vivid

Nathan Williams discovered that overlayfs in the Linux kernel incorrectly handled setattr operations. A local unprivileged attacker could use this to create files with administrative permission attributes and execute arbitrary code with elevated privileges.