2016-11-15 (last updated at July 2nd, 2018) Michael BoelenSoftware 10 comments

Understand and configure core dumps on Linux

Every system needs running processes to fulfill its primary goal. But sometimes things go wrong and a process may crash. Depending on the configuration of the system a core dump is created. In other words, a memory snapshot of the crashed process is stored. The term core actually refers to the old magnetic core memory from older systems. Although this type of memory is no longer being used, we still use this term on Linux systems. Enough for history, let’s […]

2016-10-24 (last updated at June 25th, 2018) Michael BoelenKernel 2 comments

Linux and ASLR: kernel/randomize_va_space

Configuring ASLR with randomize_va_space The Linux kernel has a defense mechanism named address space layout randomization (ASLR). This setting is tunable with the randomize_va_space setting. Before making changes to this setting, it is good to understand what this Linux security measure actually does and how it works. Understanding ASLR In 2001 the term ASLR was first introduced as a patch to the Linux kernel. Its main goal was to randomize memory segments to make abuse by malicious programs harder. A […]

2016-07-07 (last updated at July 6th, 2018) Michael BoelenKernel Leave a comment

Linux hardening with sysctl settings

The GNU/Linux kernel powers a lot of systems, from big mainframes to the Android device in your pocket. If you want to achieve more security on your Linux systems, it would make sense to start hardening there, right? While securing the kernel looks easy at first sight, there is more to it than initially meets the eye. We will have a look at some kernel options and how to select the best sysctl values for Linux systems. After reading this article […]

2014-04-27 (last updated at June 26th, 2018) Michael BoelenHardening, Kernel, Linux

Linux kernel security and how to improve it

Every system is as strong as its weakest link. In the case of an operating system like Linux, one weakness in the kernel could result in a security breach. This article covers the Linux kernel features and how they work. Kernel features Live kernel patching As the kernel is similar to other software, it receives updates to improve it. Now and then a security weakness is discovered in one of the subsystems of the Linux kernel. This means that Linux […]