Canonical has recently announced that they have patched the Kernels of Ubuntu 15.04 Vivid Vervet, Ubuntu 14.10 Utopic Unicorn, Ubuntu 14.04 Trusty Tahr and Ubuntu 12.04 Precise Pangolin, so all the users are advised to upgrade:
$ sudo apt-get update
$ sudo apt-get dist-upgrade
After you have triggered the update and upgrade commands, you will most likely get Kernel 3.19.0-21.21 on Ubuntu 15.04, Kernel 3.16.0-41.55 on Ubuntu 14.10, Kernel 3.13.0-55.92 on Ubuntu 14.04 and Kernel 3.2.0-86.123 on Ubuntu 12.04.
Also, since the Ubuntu derivative systems use the official Ubuntu repositories, you will get the updates on Ubuntu derivatives like Linux Mint 17.2 Rafaela, Linux Mint 17.1 Rebecca, Linux Mint 17 Qiana, Linux Mint 13 Maya, Pinguy OS 14.04, Elementary OS 0.3 Freya, Elementary OS 0.2 Luna, Deepin 2014, Peppermint 6, Peppermint 5, LXLE 14.04 and Linux Lite 2.