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Tecmint

Syndicate content Tecmint: Linux Howtos, Tutorials & Guides
Tecmint - Linux Howtos, Tutorials, Guides, News, Tips and Tricks.
Updated: 1 hour 51 min ago

Webinoly – Install Optimized WordPress Website with Free SSL

Thursday 21st of February 2019 05:56:32 AM
If you are looking to self host your own WordPress website, there are numerous ways to do that. You have probably heard about LAMP and LEMP stacks. In this article, we are going to...

How to Install ImageMagick 7 on Debian and Ubuntu

Wednesday 20th of February 2019 06:12:06 AM
ImageMagick is a free and open source, feature-rich, text-based and cross-platform image manipulation tool used to create, edit, compose, or convert bitmap images. It runs on Linux, Windows, Mac Os X, iOS, Android OS,...

Install ImageMagick (Image Manipulation) Tool on RHEL/CentOS and Fedora

Tuesday 19th of February 2019 09:17:27 AM
ImageMagick is a free open source simple software suite for any kind of image manipulation that is used for creating, editing, converting, displaying image files. It can able to read and write over 200...

fd – A Simple and Fast Alternative to Find Command

Monday 18th of February 2019 06:49:05 AM
Most of the Linux users are well familiar with the find command and the many cases it can be used. Today we are going to review an alternative to find command, called fd. fd,...

10 Cool Software to Try from COPR Repo in Fedora

Saturday 16th of February 2019 07:22:02 AM
In this article, we will share 10 cool software projects to try in Fedora distribution. All the apps or tools covered here can be found in COPR repository. However, before we move any further,...

How to Install and Setup Zsh (Z Shell) in Fedora

Thursday 14th of February 2019 07:02:38 AM
Zsh (short for Z Shell) is a feature-rich and powerful shell program for Unix-like operating systems with lots of interactive features. It is an extended version of the Bourne Shell (sh), with a large...

Load Testing Web Servers with Siege Benchmarking Tool

Thursday 14th of February 2019 05:42:49 AM
Knowing how much traffic your web server can handle when under stress is essential for planning future grow of your website or application. By using tool called siege, you can run a load test...

Streama – Create Your Own Personal “Netflix” in Linux

Wednesday 13th of February 2019 07:51:48 AM
Streama is a free self hosted media streaming server running on Java, that you can install on your Linux distribution. Its features are similar to those of Kodi and Plex and it is simply...

8 Best Linux Console File Managers

Tuesday 12th of February 2019 06:09:49 AM
Linux console file managers can be very helpful in a day to day tasks, when managing files on a local machine or when connected to a remote one. The visual console representation of the...

MultiCD – Create a MultiBoot Linux Live USB

Monday 11th of February 2019 06:25:52 AM
Having a single CD or USB drive with multiple available operating systems, for install, can be extremely useful in all kind of scenarios. Either for quickly testing or debugging something or simply reinstalling the...

How to Configure Software Repositories in Fedora

Saturday 9th of February 2019 05:41:25 AM
Your Fedora distribution obtains its software from repositories and each of these repositories comes with number of free and proprietary software applications available for you to install. The official Fedora repositories have thousands of...

Top Hex Editors for Linux

Friday 8th of February 2019 07:09:01 AM
In this article, we are going to review some of the best hex editors for Linux. But before we start, let’s look at what a hex editor really is. What is Hex editor In...

Bash-it – Bash Framework to Control Your Scripts and Aliases

Thursday 7th of February 2019 06:48:03 AM
Bash-it is a bundle of community Bash commands and scripts for Bash 3.2+, which comes with autocompletion, themes, aliases, custom functions, and more. It offers a useful framework for developing, maintaining and using shell...

How to Install Java in Fedora

Wednesday 6th of February 2019 06:23:44 AM
Java is a general-purpose programming language that is fast, reliable, secure, popular and widely used. It is an environment to develop and run a wide range of applications, from mobile applications to desktop and...

Ranger – A Nice Console File Manager with VI Key Bindings

Tuesday 5th of February 2019 06:02:50 AM
Ranger is a simple, efficient text-based file manager with smooth integration into the Unix/Linux shell with VI key bindings. It comes with a minimalistic and nice curses interface that displays the directory hierarchy allowing...

How to File a Software Bug to Fedora

Monday 4th of February 2019 07:13:00 AM
A bug or software bug is an error, mistake, failure or fault, in a program that causes it to produce undesired or incorrect results. A bug prevents a program/application/software from functioning as intended. Like...

10 Cool Command Line Tools For Your Linux Terminal

Saturday 2nd of February 2019 05:39:38 AM
In this article, we will share a number of cool command-line programs that you can use in a Linux terminal. By the end of this article, you will learn about some free, open source,...

Terminalizer – Record Your Linux Terminal and Generate Animated GIF

Friday 1st of February 2019 06:49:19 AM
Terminalizer is a free, open source, simple, highly customizable and cross-platform program to record your Linux terminal session and generate animated gif images or share a web player. It comes with custom: window frames,...

How to Install MariaDB 10 on RHEL 8

Wednesday 30th of January 2019 07:55:16 AM
MariaDB is a popular alternative to the MySQL database management system. It is developed by the original MySQL developers and is meant to remain open source. MariaDB is fast and reliable, supports different storage...

How to Check Integrity With AIDE in Fedora

Tuesday 29th of January 2019 07:35:49 AM
AIDE (Advanced Intrusion Detection Environment) is a program for checking the integrity of a file and directory on any modern Unix-like system. It creates a database of files on the system, and then uses...

More in Tux Machines

Games: Surviving Mars and OpenMW

Kernel and Security: BPF, Mesa, Embedded World, Kernel Address Sanitizer and More

  • Concurrency management in BPF
    In the beginning, programs run on the in-kernel BPF virtual machine had no persistent internal state and no data that was shared with any other part of the system. The arrival of eBPF and, in particular, its maps functionality, has changed that situation, though, since a map can be shared between two or more BPF programs as well as with processes running in user space. That sharing naturally leads to concurrency problems, so the BPF developers have found themselves needing to add primitives to manage concurrency (the "exchange and add" or XADD instruction, for example). The next step is the addition of a spinlock mechanism to protect data structures, which has also led to some wider discussions on what the BPF memory model should look like. A BPF map can be thought of as a sort of array or hash-table data structure. The actual data stored in a map can be of an arbitrary type, including structures. If a complex structure is read from a map while it is being modified, the result may be internally inconsistent, with surprising (and probably unwelcome) results. In an attempt to prevent such problems, Alexei Starovoitov introduced BPF spinlocks in mid-January; after a number of quick review cycles, version 7 of the patch set was applied on February 1. If all goes well, this feature will be included in the 5.1 kernel.
  • Intel Ready To Add Their Experimental "Iris" Gallium3D Driver To Mesa
    For just over the past year Intel open-source driver developers have been developing a new Gallium3D-based OpenGL driver for Linux systems as the eventual replacement to their long-standing "i965 classic" Mesa driver. The Intel developers are now confident enough in the state of this new driver dubbed Iris that they are looking to merge the driver into mainline Mesa proper.  The Iris Gallium3D driver has now matured enough that Kenneth Graunke, the Intel OTC developer who originally started Iris in late 2017, is looking to merge the driver into the mainline code-base of Mesa. The driver isn't yet complete but it's already in good enough shape that he's looking for it to be merged albeit marked experimental.
  • Hallo Nürnberg!
    Collabora is headed to Nuremberg, Germany next week to take part in the 2019 edition of Embedded World, "the leading international fair for embedded systems". Following a successful first attendance in 2018, we are very much looking forward to our second visit! If you are planning on attending, please come say hello in Hall 4, booth 4-280! This year, we will be showcasing a state-of-the-art infrastructure for end-to-end, embedded software production. From the birth of a software platform, to reproducible continuous builds, to automated testing on hardware, get a firsthand look at our platform building expertise and see how we use continuous integration to increase productivity and quality control in embedded Linux.
  • KASAN Spots Another Kernel Vulnerability From Early Linux 2.6 Through 4.20
    The Kernel Address Sanitizer (KASAN) that detects dynamic memory errors within the Linux kernel code has just picked up another win with uncovering a use-after-free vulnerability that's been around since the early Linux 2.6 kernels. KASAN (along with the other sanitizers) have already proven quite valuable in spotting various coding mistakes hopefully before they are exploited in the real-world. The Kernel Address Sanitizer picked up another feather in its hat with being responsible for the CVE-2019-8912 discovery.
  • io_uring, SCM_RIGHTS, and reference-count cycles
    The io_uring mechanism that was described here in January has been through a number of revisions since then; those changes have generally been fixing implementation issues rather than changing the user-space API. In particular, this patch set seems to have received more than the usual amount of security-related review, which can only be a good thing. Security concerns became a bit of an obstacle for io_uring, though, when virtual filesystem (VFS) maintainer Al Viro threatened to veto the merging of the whole thing. It turns out that there were some reference-counting issues that required his unique experience to straighten out. The VFS layer is a complicated beast; it must manage the complexities of the filesystem namespace in a way that provides the highest possible performance while maintaining security and correctness. Achieving that requires making use of almost all of the locking and concurrency-management mechanisms that the kernel offers, plus a couple more implemented internally. It is fair to say that the number of kernel developers who thoroughly understand how it works is extremely small; indeed, sometimes it seems like Viro is the only one with the full picture. In keeping with time-honored kernel tradition, little of this complexity is documented, so when Viro gets a moment to write down how some of it works, it's worth paying attention. In a long "brain dump", Viro described how file reference counts are managed, how reference-count cycles can come about, and what the kernel does to break them. For those with the time to beat their brains against it for a while, Viro's explanation (along with a few corrections) is well worth reading. For the rest of us, a lighter version follows.

Blacklisting insecure filesystems in openSUSE

The Linux kernel supports a wide variety of filesystem types, many of which have not seen significant use — or maintenance — in many years. Developers in the openSUSE project have concluded that many of these filesystem types are, at this point, more useful to attackers than to openSUSE users and are proposing to blacklist many of them by default. Such changes can be controversial, but it's probably still fair to say that few people expected the massive discussion that resulted, covering everything from the number of OS/2 users to how openSUSE fits into the distribution marketplace. On January 30, Martin Wilck started the discussion with a proposal to add a blacklist preventing the automatic loading of a set of kernel modules implementing (mostly) old filesystems. These include filesystems like JFS, Minix, cramfs, AFFS, and F2FS. For most of these, the logic is that the filesystems are essentially unused and the modules implementing them have seen little maintenance in recent decades. But those modules can still be automatically loaded if a user inserts a removable drive containing one of those filesystem types. There are a number of fuzz-testing efforts underway in the kernel community, but it seems relatively unlikely that any of them are targeting, say, FreeVxFS filesystem images. So it is not unreasonable to suspect that there just might be exploitable bugs in those modules. Preventing modules for ancient, unmaintained filesystems from automatically loading may thus protect some users against flash-drive attacks. If there were to be a fight over a proposal like this, one would ordinarily expect it to be concerned with the specific list of unwelcome modules. But there was relatively little of that. One possible exception is F2FS, the presence of which raised some eyebrows since it is under active development, having received 44 changes in the 5.0 development cycle, for example. Interestingly, it turns out that openSUSE stopped shipping F2FS in September. While the filesystem is being actively developed, it seems that, with rare exceptions, nobody is actively backporting fixes, and the filesystem also lacks a mechanism to prevent an old F2FS implementation from being confused by a filesystem created by a newer version. Rather than deal with these issues, openSUSE decided to just drop the filesystem altogether. As it happens, the blacklist proposal looks likely to allow F2FS to return to the distribution since it can be blacklisted by default. Read more

gitgeist: a git-based social network proof of concept

Are you tired of not owning the data or the platform you use for social postings? I know I am. It's hard to say when I "first" used a social network. I've been on email for about 30 years and one of the early ad-hoc forms of social networks were chain emails. Over the years I was asked to join all sorts of "social" things such as IRC, ICQ, Skype, MSN Messenger, etc. and eventually things like Orkut, MySpace, Facebook, etc. I'll readily admit that I'm not the type of person that happily jumps onto every new social bandwagon that appears on the Internet. I often prefer preserving the quietness of my own thoughts. That, though, hasn't stopped me from finding some meaningfulness participating in Twitter, Facebook, LinkedIn and more recently Google+. Twitter was in fact the first social network that I truly embraced. And it would've remained my primary social network had they not killed their own community by culling the swell of independently-developed Twitter clients that existed. That and their increased control of their API effectively made me look for something else. Right around that time Google+ was being introduced and many in the open source community started participating in that, in some ways to find a fresh place where techies can aggregate away from the noise and sometimes over-the-top nature of Facebook. Eventually I took to that too and started using G+ as my primary social network. That is, until Google recently decided to pull the plug on G+. While Google+ might not have represented a success for Google, it had become a good place for sharing information among the technically-inclined. As such, I found it quite useful for learning and hearing about new things in my field. Soon-to-be-former users of G+ have gone in all sorts of directions. Some have adopted a "c'mon guys, get over it, Facebook is the spot" attitude, others have adopted things like Mastodon, others have fallen back to their existing IDs on Twitter, and yet others, like me, are still looking. Read more