Several security issues were fixed in the Linux kernel.
It was discovered that the f2fs filesystem implementation in the Linux kernel did not handle the noflush_merge mount option correctly. An attacker could use this to cause a denial of service (system crash). (CVE-2017-18241)
15 March 2019
A security issue affects these releases of Ubuntu and its derivatives:
Several security issues were fixed in the Linux kernel.
It was discovered that the f2fs filesystem implementation in the Linux kernel did not handle the noflush_merge mount option correctly. An attacker could use this to cause a denial of service (system crash). (CVE-2017-18241)
It was discovered that the procfs filesystem did not properly handle processes mapping some memory elements onto files. A local attacker could use this to block utilities that examine the procfs filesystem to report operating system state, such as ps(1). (CVE-2018-1120)
Hui Peng and Mathias Payer discovered that the Option USB High Speed driver in the Linux kernel did not properly validate metadata received from the device. A physically proximate attacker could use this to cause a denial of service (system crash). (CVE-2018-19985)
It was discovered that multiple integer overflows existed in the hugetlbfs implementation in the Linux kernel. A local attacker could use this to cause a denial of service (system crash). (CVE-2018-7740)
Jann Horn discovered a race condition in the fork() system call in the Linux kernel. A local attacker could use this to gain access to services that cache authorizations. (CVE-2019-6133)
The problem can be corrected by updating your system to the following package versions:
To update your system, please follow these instructions: https://wiki.ubuntu.com/Security/Upgrades.
After a standard system update you need to reboot your computer to make all the necessary changes.
ATTENTION: Due to an unavoidable ABI change the kernel updates have been given a new version number, which requires you to recompile and reinstall all third party kernel modules you might have installed. Unless you manually uninstalled the standard kernel metapackages (e.g. linux-generic, linux-generic-lts-RELEASE, linux-virtual, linux-powerpc), a standard system upgrade will automatically perform this as well.