InfoSec Person | Alt-Account#2

  • 5 Posts
  • 22 Comments
Joined 1 year ago
Cake day: September 28th, 2023
  • A Basil Plant@lemmy.worldtoFediverse@lemmy.world•Instance Admins: Check Your Instance for Vote Manipulation Accounts [PSA]English
    51·
    2 months ago

    My bachelor’s thesis was about comment amplifying/deamplifying on reddit using Graph Neural Networks (PyTorch-Geometric).

    Essentially: there used to be commenters who would constantly agree / disagree with a particular sentiment, and these would be used to amplify / deamplify opinions, respectively. Using a set of metrics [1], I fed it into a Graph Neural Network (GNN) and it produced reasonably well results back in the day. Since Pytorch-Geomteric has been out, there’s been numerous advancements to GNN research as a whole, and I suspect it would be significantly more developed now.

    Since upvotes are known to the instance administrator (for brevity, not getting into the fediverse aspect of this), and since their email addresses are known too, I believe that these two pieces of information can be accounted for in order to detect patterns. This would lead to much better results.

    In the beginning, such a solution needs to look for patterns first and these patterns need to be flagged as true (bots) or false (users) by the instance administrator - maybe 200 manual flaggings. Afterwards, the GNN could possibly decide to act based on confidence of previous pattern matching.

    This may be an interesting bachelor’s / master’s thesis (or a side project in general) for anyone looking for one. Of course, there’s a lot of nuances I’ve missed. Plus, I haven’t kept up with GNNs in a very long time, so that should be accounted for too.

    Edit: perhaps IP addresses could be used too? That’s one way reddit would detect vote manipulation.

    [1] account age, comment time, comment time difference with parent comment, sentiment agreement/disgareement with parent commenters, number of child comments after an hour, post karma, comment karma, number of comments, number of subreddits participated in, number of posts, and more I can’t remember.

  • A Basil Plant@lemmy.worldtoLinux@lemmy.ml•33 years ago...
    25·
    3 months ago

    https://www.linuxjournal.com/article/10754

    MINIX originally was developed in 1987 by Andrew S. Tanenbaum as a teaching tool for his textbook Operating Systems Design and Implementation. Today, it is a text-oriented operating system with a kernel of less than 6,000 lines of code. MINIX’s largest claim to fame is as an example of a microkernel, in which each device driver runs as an isolated user-mode process—a structure that not only increases security but also reliability, because it means a bug in a driver cannot bring down the entire system.

    In its heyday during the early 1990s, MINIX was popular among hobbyists and developers because of its inexpensive proprietary license. However, by the time it was licensed under a BSD-style license in 2000, MINIX had been overshadowed by other free-licensed operating systems.

    Today, MINIX is best known as a footnote in GNU/Linux history. It inspired Linus Torvalds to develop Linux, and some of his early work was written on MINIX. Probably too, Torvalds’ early decision to support the MINIX filesystem is responsible for the Linux kernel’s support of almost every filesystem imaginable.

    Later, Torvalds and Tanenbaum had a frank e-mail debate about the relative merits of macrokernels (sic) and microkernels. This early history resurfaced in 2004 when Kenneth Brown of the Alexis de Tocqueville Institution prepared a book alleging that Torvalds borrowed code from MINIX—a charge that Tanenbaum, among others, so comprehensively debunked, and the book was never actually published (see Resources).

    See also: https://en.wikipedia.org/wiki/Tanenbaum–Torvalds_debate

  • A Basil Plant@lemmy.worldtoFediverse@lemmy.ml•Mastodon rolls out built-in bylines for journalists in the fediverse
    1·
    4 months ago

    I think the difference lies in two things:

    • You can share an article from a user of a different instance. In this case, your instance will have to look up the rel=“author” tag and check whether the URL is a fediverse instance. I’m not sure whether this is scalable as compared to a tag that directly indicates that the author is on the fediverse. Imagining a scenario where there are 100, 1000, 10,000, or 100,000 instances on different versions.

    • The tag is to promote that the author is on the fediverse. If the rel=“author” tag points to twitter for example, maybe Eugen Rochko + team didn’t want a post on the fediverse to link to twitter.

    These are my thoughts and idk if they’re valid. But I think just reusing the rel=“author” isn’t the most elegant solution.

    I know that mastodon already uses rel=“me” for link verification (I use it on mu website + my mastodon account), but that’s a different purpose - that’s more for verification. There’s still no way of guaranteeing that the rel=“author” tag points to a fediverse account. You’re putting the onus on the mastodon instance.

  • A Basil Plant@lemmy.worldtoLinux@lemmy.ml•Arch Linux, made immutable, declarative and atomic: blendOS v4 released
    471·
    5 months ago

    No. Fuck this shit. Don’t do this.

    It’s already bad when everyone in this community shoves their distro down potential linux-converts’ throats, thereby confusing them even more. Don’t tell (or imply to) freshly converted users that they potentially made a wrong choice.

    TF do you think they’re going to do now? Move to fedora? The commenter above already stated that it was a hassle to install Ubuntu and now you’re telling them to change distros already???

    Ubuntu is still great… compared to Windows. Sure. It may not hold to your ideals. Compared to other distros, canonical may make some questionable choices. BUT THEY DON’T IMPLEMENT A FUCKING RECALL. So it’s fine (for now).

    Ubuntu is fine for newcomers. It has a shit ton of support online and you can easily search questions whose answers are likely to be found within the first few results.

    So stop shoving distros down people’s throats, especially fresh users.

    I know you said:

    Sorry if I sound too hard… take it with a laugh 😁

    It doesn’t come across that way. You come off as a gatekeeper.

  • A Basil Plant@lemmy.worldtoLinux@lemmy.ml•"Hardware Error" after power failure
    82·
    6 months ago

    You haven’t given us much information about the CPU. That is very important when dealing with Machine Check Errors (MCEs).

    I’ve done a bit of work with MCEs and AMD CPUs, so I’ll help with understanding what may be going wrong and what you probably can do.

    I’ve done a bit of searching from the microcode & the Dell Wyse thin client that you mentioned. From what I can garner, are you using a Dell Wyse 5060 Thin Client with an AMD steppe Eagle GX-424 [1]? This is my assumption for the rest of this comment.

    Machine Check Errors (MCEs) are hard to decipher find out without the right documentation. As far as I can tell from AMD’s Data Sheet for the G-Series [2], this CPU belongs to family 16H.

    You have two MCEs in your image:

    • CPU Core 0, Bank 4: f600000000070f0f
    • CPU Core 1, Bank 1: b400000001020103

    Now, you can attempt to decipher these with a tool I used some time ago, MCE-Ryzen-Decoder [4]; you may note that the name says Ryzen - this tool only decodes MCEs of Ryzen architectures. However, MCE designs may not change much between families, but I wouldn’t bank (pun not intended) on it because it seems that the G-Series are an embedded SOC compared to the Ryzen CPUs which are not. I gave it a shot and the tool spit out that you may have an issue in:

    $ python3 run.py 04 f600000000070f0f
Bank: Read-As-Zero (RAZ)
Error:  ( 0x7)

$ python3 run.py 01 b400000001020103
Bank: Instruction Fetch Unit (IF)
Error: IC Full Tag Parity Error (TagParity 0x2)

    Wouldn’t bank (pun intended this time) on it though.

    What you can do is to go through the AMD Family 16H’s BIOS and Kernel Developer Guide [3] (Section 2.16.1.5 Error Code). From Section 2.16.1.1 Machine Check Registers, it looks like Bank 01 corresponds to the IC (Instruction Cache) and Bank 04 corresponds to the NB (Northbridge). This means that the CPU found issues in the NB in core 0 and the IC in core 1. You can go even further and check what those exact codes decipher to, but I wouldn’t put in that much effort - there’s not much you can do with that info (maybe the NB, but… too much effort). There are some MSRs that you can read out that correspond to errors of these banks (from Table 86: Registers Commonly Used for Diagnosis), but like I said, there’s not much you can do with this info anyway.

    Okay, now that the boring part is over (it was fun for me), what can you do? It looks like the CPU is a quad core CPU. I take it to mean that it’s 4 cores * 2 SMT threads. If you have access to the linux command line parameters [5], say via GRUB for example, I would try to isolate the two faulty cores we see here: core 0 and core 1. Add isolcpus=0,1 to see the kernel boots. There’s a good chance that we see only two CPU cores failing, but others may also be faulty but the errors weren’t spit out. It’s worth a shot, but it may not work.

    Alternatively, you can tell the kernel to disable MCE checks entirely and continue executing; this can be done with the mce=off command line parameter [6] . Beware that this means that you’re now willingly running code on a CPU with two cores that have been shown to be faulty (so far). isolcpus will make sure that the kernel doesn’t execute any “user” code on those cores unless asked to (via taskset for example)

    Apart from this, like others have pointed out, the red dots on the screen aren’t a great sign. Maybe you can individually replace defective parts, or maybe you have to buy a new machine entirely. What I told you with this comment is to check whether your CPU still works with 2 SMT threads faulty.

    Good luck and I hope you fix your server 🤞.

    Edited to add: I have seen MCEs appear due to extremely low/high/fluctuating voltages. As others pointed out, your PSU or other components related to power could be busted.

    [1] https://www.dell.com/support/manuals/en-us/wyse-5060-thin-client/5060_wie10_ug/system-specifications?guid=guid-cbeecec5-25ac-4103-8b4b-7d3a975e91f0&lang=en-us

    [2] https://www.amd.com/content/dam/amd/en/documents/archived-tech-docs/datasheets/52259_KB_G-Series_Product_Data_Sheet.pdf

    [3] https://www.amd.com/content/dam/amd/en/documents/archived-tech-docs/programmer-references/52740_16h_Models_30h-3Fh_BKDG.pdf

    [4] https://github.com/DimitriFourny/MCE-Ryzen-Decoder

    [5] https://www.kernel.org/doc/html/latest/admin-guide/kernel-parameters.html

    [6] https://elixir.bootlin.com/linux/v6.9.2/source/Documentation/arch/x86/x86_64/boot-options.rst