CVE-2016-5195: Linux kernel local privilege escalation vulnerability Dirty COW

dirty-cowA very serious security problem has been found in the Linux kernel, it’s a 0-day local privilege escalation vulnerability, which has existed for eleven years since 2005 ( since Linux kernel version 2.6.22+ ). This bug affects all sort of of Android or Linux kernel to escalate privileges. Any users can become root in seconds. Continue reading…


How To Install and Configure Rocket.Chat on CentOS

Rocket.Chat logo 300x300Rocket.Chat is one of the most feature-rich open-source Slack alternatives, featuring group chat, direct messaging, private rooms, desktop notifications, media embedding, link previews, file uploading, voice/video chat, screensharing, and more. There are native applications for Windows, Mac, and Linux, as well as mobile applications for iOS and Android. Developers can also use hubot to integrate with popular services like GitHub, Gitlab, Confluence, JIRA, and more.

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Whois: command line query for spam-infected domains

WhoisWhen run whois in command line, we sometimes cannot get the expected whois information, but something like below,

$ whois

Whois Server Version 2.0

Domain names in the .com and .net domains can now be registered
with many different competing registrars. Go to
for detailed information.


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The CGroup Subsystems in Red Hat Linux

Control groups (a.k.a. cgroups) allow you to allocate resources — such as CPU time, system memory, network bandwidth, or combinations of these resources — among user-defined groups of tasks (processes) running on a system.

You can monitor the cgroups you configure, deny cgroups access to certain resources, and even reconfigure your cgroups dynamically on a running system.
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How to change the Grub2 boot order?

How can I change the boot order in grub2? Here is a step by step guide,

In a terminal type,

# grep menuentry /boot/grub2/grub.cfg
menuentry 'CentOS Linux (4.6.4-1.el7.elrepo.x86_64) 7 (Core) with debugging' --class rhel fedora --class gnu-linux --class gnu --class os --unrestricted $menuentry_id_option 'gnulinux-3.10.0-229.el7.x86_64-advanced-169f51f6-092c-43b8-bea9-bdc484dc66c6' { Continue reading...