CVE-2015-8839 on Ubuntu 12.04 LTS (precise) - medium.
Description:
Multiple race conditions in the ext4 filesystem implementation in the Linux kernel before 4.5 allow local users to cause a denial of service (disk corruption) by writing to a page that is associated with a different user's file after unsynchronized hole punching and page-fault handling. Multiple race conditions where discovered in the Linux kernel's ext4 file system. A local user could exploit this flaw to cause a denial of service (disk corruption) by writing to a page that is associated with a different users file after unsynchronized hole punching and page-fault handling.