Asahi Linux Brings Better Gaming To Apple Silicon

October 29, 2024 by Navarre Bartz 8 Comments

For those of you longing for better gaming on an Apple Silicon device, Asahi Linux is here to help.

While Apple’s own line of CPUs are relatively new kids on the block, they’ve still been around for four years now, giving hackers ample time to dissect their innards. The team behind Asahi Linux has now brought us “the only conformant OpenGL®, OpenCL™, and Vulkan® drivers” for Apple’s M1 and M2.

The emulation overhead of the system means that most games will need at least 16 GB of RAM to run. Many games are playable, but newer titles can’t yet hit 60 frames per second. The developers are currently focused on “correctness” and hope to improve performance in future updates. Many indie titles are reported to already be working at full speed though.

You can hear more about some of the fiddly bits of how to “tessellate with arcane compute shaders” in the video below. Don’t worry, it’s only 40 minutes of the nine hour video and it should start right at the presentation by GPU dev [Alyssa Rosenzweig].

If you want to see some of how Linux on Apple Silicon started or some of the previous work on hacking the M1 GPU, we have you covered.

Continue reading “Asahi Linux Brings Better Gaming To Apple Silicon” →

This Week In Security: Zimbra, DNS Poisoning, And Perfctl

October 4, 2024 by Jonathan Bennett 6 Comments

Up first this week is a warning for the few of us still brave enough to host our own email servers. If you’re running Zimbra, it’s time to update, because CVE-2024-45519 is now being exploited in the wild.

That vulnerability is a pretty nasty one, though thankfully requires a specific change from default settings to be exposed. The problem is in postjournal. This logging option is off by default, but when it’s turned on, it logs incoming emails. One of the fields on an incoming SMTP mail object is the RCPT TO: field, with the recipients made of the to, cc, and bcc fields. When postjournal logs this field, it does so by passing it as a bash argument. That execution wasn’t properly sanitized, and wasn’t using a safe call like execvp(). So, it was possible to inject commands using the $() construction.

The details of the attack are known, and researchers are seeing early exploratory attempts to exploit this vulnerability. At least one of these campaigns is attempting to install webshells, so at least some of those attempts have teeth. The attack seems to be less reliable when coming from outside of the trusted network, which is nice, but not something to rely on.

New Tool Corner

What is that binary doing on your system? Even if you don’t do any security research, that’s a question you may ask yourself from time to time. A potential answer is WhoYouCalling. The wrinkle here is that WYC uses the Windows Event Tracing mechanism to collect the network traffic strictly from the application in question. So it’s a Windows only application for now. What you get is a packet capture from a specific executable and all of its children processes, with automated DNS capture to go along. Continue reading “This Week In Security: Zimbra, DNS Poisoning, And Perfctl” →

This Week In Security: Password Sanity, Tank Hacking, And The Mystery 9.9

September 27, 2024 by Jonathan Bennett 15 Comments

It looks like there’s finally hope for sane password policies. The US National Institue of Standards and Technology, NIST, has released a draft of SP 800-63-4, the Digital Identity Guideline.

There’s password guidance in there, like “SHALL NOT impose other composition rules (e.g., requiring mixtures of different character types) for passwords” and “SHALL NOT require users to change passwords periodically.” NIST approved passwords must be at least 8 characters long, with a weaker recommendation of at least 15 characters. Security questions like name of first pet get the axe. And it’s strongly recommended that all ASCII and Unicode characters should be acceptable for passwords.

This is definitely moving in the right direction. NIST guidelines are only binding for government services and contractors, though they do eventually get picked up by banks and other industries. So there’s hope for sane password policies eventually.

Tank Hacking

Researchers at Bitsight are interested in infrastructure security, and they opted to take a closer look at Automatic Tank Gauging (ATG) systems. Those are found at gas stations, as well as any other facility that needs automated monitoring of liquids or gasses in a tank. There is an actual ATG message format, originally designed for RS-232 serial, and woefully unprepared for the interconnected present. The protocol allows for an optional security code, but it maxes out at only six alpha-numeric characters.

Among the vulnerabilities getting announced today, we have a pair of CVSS 10 command injection flaws, a quartet of 9.8 authentication bypass flaws, with one of those being a hardcoded credential — AKA a backdoor. The other CVSS9+ flaw is a SQL injection, with a trio of slightly less serious flaws. Continue reading “This Week In Security: Password Sanity, Tank Hacking, And The Mystery 9.9” →

Reviving A 15-Year Old Asus EeePC With Modern MX Linux

September 25, 2024 by Maya Posch 67 Comments

It’s often said these days that computers don’t become outdated nearly as quickly as they did in the past, with even a decade-old computer still more than capable of handling daily tasks for the average person. Testing that theory, [Igor Ljubuncic] revisited the Asus eeePC which he purchased back in 2010. Although it’s not specified exactly which model it is, it features an Intel Atom N450 (1 core, 2 threads) running at 1.67 GHz, 1 GB of 667 MHz DDR2 and a 250 GB HDD, all falling into that ultra-portable, 10.1″ Netbook category.

When new, the netbook came with Windows 7 Starter Edition, which [Igor] replaced with Ubuntu Netbook Remix 10.04, which was its own adventure, but the netbook worked well and got dragged around the world on work and leisure assignments. With increasingly bloated updates, Ubuntu got replaced by MX Linux 18, which improved matters, but with the little CPU struggling more and more, [Igor] retired the netbook in 2019. That is, until reviving it recently.

Upon booting, the CMOS battery was of course empty, but the system happily continued booting into MX Linux. The Debian update repositories were of course gone, but changing these to the archive version allowed for some (very old) updates. This raised the question of whether modern Linux would even run on this ancient Atom CPU, the answer of which turned out to be a resounding ‘yes’, as MX Linux still offers 32-bit builds of its most recent releases. A 15 minute upgrade process later, and a 2 minute boot later, the system was running a Linux 6.1 kernel with Xfce desktop.

As for the performance, it’s rather what you expect, with video playback topping out at 480p (on the 1024×600 display) and applications like Firefox lacking the compact density mode, wasting a lot of screen space. Amazingly the original battery seems to still deliver about half the runtime it did when new. All of which is to say that yes, even a ‘low-end’ 2010-era netbook can still be a very usable system in 2024, with a modern OS.

Linux, Now In Real Time

September 21, 2024 by Bryan Cockfield 27 Comments

Although Linux runs almost every supercomputer, most of the web, the majority of smart phones, and a few writers’ ancient Macbooks, there’s one major weak point in the Linux world that will almost always have developers reaching for a different operating system. Linux is not a real-time operating system (RTOS), meaning that it can’t respond to requests in the real world within a set timeframe. This means that applications needing computer control in industry, medicine, robotics, and other real-world situations generally need a purpose-built RTOS. At least, that was true until recently when an update to the Linux kernel added real-time capabilities.

The feature, called PREEMPT_RT, forces the Linux kernel to respond to certain request within a set limit of time. This means that a system with this support built into the kernel can “preempt” any current task, stopping everything else a computer is doing in order to execute that task right away. There are some existing solutions to getting a functional equivalent system working with Linux now, but they can be clunky or inelegant, requiring the user to install patches or other software to get it to work. With the support built directly into the kernel this will become much less of a pain point for anyone who needs this functionality going forward.

This feature has been in the works for around two decades now, so with this entering general use now we would expect to start seeing it show up in various projects as well as in commercial offerings soon, especially since other RTOS solutions can be pricey. Don’t recompile the kernel in your desktop for this feature just yet, though; real-time function can cause some unintended consequences with normal use you’ll need to account for. There’s some more discussion on this in the /r/Linux subreddit and there are some other real-time operating systems available for computers not typically capable of running Linux to take a look at as well.

There’s No Lower Spec Linux Machine Than This One

September 21, 2024 by Jenny List 47 Comments

It’s not uncommon for a new distro version to come out, and a grudging admission that maybe a faster laptop is on the cards. Perhaps after seeing this project though, you’ll never again complain about that two-generations-ago 64-bit multi-core behemoth, because [Dimitri Grinberg] — who else! — has succeeded in booting an up-to-date Linux on the real most basic of processors. We’re not talking about 386s, ATmegas, or 6502s, instead he’s gone right back to the beginning. The Intel 4004 was the first commercially available microprocessor back in 1971, and now it can run Linux.

So, given the 4004’s very limited architecture and 4-bit bus, how can it perform this impossible feat? As you might expect, the kernel isn’t being compiled to run natively on such ancient hardware. Instead he’s achieved the equally impossible-sounding task of writing a MIPS emulator for the venerable silicon, and paring back the emulated hardware to the extent that it remains capable given the limitations of the 1970s support chips in interfacing to the more recent parts such as RAM for the MIPS, an SD card, and a VFD display. The result is shown in the video below the break, and even though it’s sped up it’s clear that this is not a quick machine by any means.

We’d recommend the article as a good read even if you’ll never put Linux on a 4004, because of its detailed description of the architecture. Meanwhile we’ve had a few 4004 stories over the years, and this one’s not even the first time we’ve seen it emulate something else.

Continue reading “There’s No Lower Spec Linux Machine Than This One” →

From High Level Language To Assembly

September 18, 2024 by Al Williams 24 Comments

If you cut your teeth on Z-80 assembly and have dabbled in other assembly languages, you might not find much mystery in creating programs using the next best thing to machine code. However, if you have only used high level languages, assembly can be somewhat daunting. [Shikaan] has an introductory article aimed to get you started at the “hello world” level of x86-64 assembly language. The second part is already up, too, and covers control structures.

You can argue that you may not need to know assembly language these days, and we’ll admit it’s certainly not as important as it used to be. However, there are unusual cases where you really need either the performance or the small footprint, which is only possible in assembly language. What’s more, it is super useful to be able to read assembly from your high-level tools when something goes wrong.

Of course, one of the problems is that each assembly language is different. For example, knowing that the x86 assembly doesn’t completely transfer to ARM instructions. However, in most cases, the general concepts apply, and it is usually fairly easy to learn your second, third, or fourth instruction set.

We’ve had our own tutorials on this topic. You can also debate if you should learn assembly first or wait, although in this case, the audience is people who waited.