Untitled Linux Show 232: "Mobius Strip" (December 7, 2025)

Episode Overview

This episode of the Untitled Linux Show, hosted by Bryan and Jeff Massey, dives deep into the latest Linux kernel developments (including the 6.19 merge window and the new 6.18 LTS release), graphics hardware driver changes (with a focus on Nvidia and AMD developments), intriguing updates for Fedora and KDE, the continuing Steam Linux survey progress, npm security woes, and fascinating technical and command-line tips. The duo's tone is lively, geeky, and occasionally self-deprecating, with technical digressions, banter, and even a dash of poetry at the close.

Hosts

• Bryan – Main host, facilitating discussions and covering kernel/Linux news.
• Jeff Massey – Co-host, technical insights, and hardware library connoisseur.

Main Discussion Segments

1. Kernel 6.19: Merge Window Highlights and Graphics Improvements

[08:45]

• DRM Color Pipeline API: Standardizes color/HDR/high-gamut display support across drivers. Now merged, supporting AMD GPU and VMKS drivers.
  • "HDR is more than just turning on more color bits. There's a lot of different ways HDR can be interpreted—color palettes, different color gamuts, brightness—just to name a few." – Jeff Massey [08:55]
• Intel's Nova Lake Integrated Graphics & Crescent Island AI Accel.: Early support with XE3P code being merged, more patches to come.
• AMD GPU Driver Updates: First-generation GCN 1.0/1.1 cards now default to the AMDGPU driver, rather than the old Radeon DRM driver.
• Nvidia 'Nova' Driver Updates:
  • Support for larger pages, compression, and clearer error codes.
  • "6.19 isn't going to make Nova ready for the average user yet... They're still adding features and working on the code. It's not as feature rich as Nouveau, but it's getting there." – Jeff Massey [11:20]
• Other Kernel Developments: More Rust language support, blue-screen-style panic screens for Intel DRM, SR-IOV (virtualizing one GPU as several for VMs), and much more in the graphics stack.

2. KDE/Plasma & Color Management Advancements

[14:15]

• Plasma 6.6 will support the new DRM color pipeline for improved efficiency and fidelity, thanks to new kernel APIs.
• Better color matching, printing improvements, tablet input features, and low-ink alerts are incoming.
• Performance Upshot: "In terms of user visible impact, this means videos play more efficiently and games run a bit faster, especially when HDR, Night Light, and color profiles are involved." – Xavier Huggle via Bryan [15:35]
• KDE Fundraiser: The campaign quickly raised over €100,000 in five days via an unobtrusive annual pop-up to users.
  • "That's one of the best things KDE's ever done... once a year, but it is so effective for them." – Bryan [18:00]

3. LTS Kernel Policies: 6.18 In, 5.4 Out

[24:19]

• 6.18 Released as 2025's LTS Kernel: From now, LTS kernels receive only two years’ support. Distributions mostly manage their own patches.
• 5.4 Reaches End of Life: After six years and over 300 releases, it's out of support with 1,539 known unfixed CVEs.
  • "If you're still using 5.4 then you should upgrade... The latest is always best if you want the most support." – Jeff Massey [26:54]
• CVEs Context: Not all are critical, as any bug in the kernel can get a CVE, even those not security-relevant.
  • "In the kernel context, any bug is a CVE—that's the line Torvalds and the rest of the kernel maintainers have drawn." – Bryan [28:34]
  • "There’s gotta be at least a handful, say five, that are, oh, this is bad." – Jeff Massey [30:30]

4. Fedora 44: KMSCon Replacing FBCON for Console Graphics

[31:12]

• Proposal Passed: Fedora 44 will move the text console from kernel-space (fbcon) to user-space with KMSCon.
• This means switching terminals (Ctrl-Alt-F1, etc.) will access a userland, more flexible console, paving the way for better font support and other features.
• Discussed bugs and workarounds for monitor wakes, as this change impacts those behaviors.
• Nostalgia for running simultaneous X sessions with CTRL-ALT-Fm keys.

5. Nvidia 590 Driver Series: End of the Line for Older GPUs

[39:59]

• Nvidia 590.x Beta Released:
  • Ups the minimums: Wayland >=1.20, glibc >=2.27, Xorg >=1.17.
  • Fixes bugs (Wayland settings persistence, Vulkan swapchain stutter, Samsung Odyssey Neo G9 DPI issues, Venus virtual GPUs).
  • Crucially: Drops support for Maxwell (900 series) & Pascal (1000 series) cards; these remain on the 580 series driver.
    • "What you have now is what you're going to have unless Nova or Nouveau catch up." – Jeff Massey [41:40]
    • "That's impressive—it was supported for a decade, from 2014 to now." – Bryan [44:21]
  • Preempt-RT kernel support improved.
  • Discussion: Nova (Nvidia's open driver) is coming fast (maybe 2026).

6. npm Security Catastrophe: The "Shai Hulud" Worm

[54:46]

• NPM Worm Recap: "Shai Hulud" self-replicates by compromising packages, extracting credentials, and infecting new ones—754 packages were affected in the most recent wave.
• At least 33,000 credentials captured; 10% still valid after days had passed.
• The risk of automatic/instant repository installation was highlighted: "It seems to me this is an inherent danger... It's less likely to pwn your machine if you have manual package approval." – Bryan [57:15]
• Comparison to broader Microsoft security issues.

7. Kernel 6.19: Direct Memory Access, iouring, and DMA Improvements

[64:10]

• Block Layer & Peer-to-Peer DMA: Major improvements in how memory regions transfer directly between devices like NVMe drives and GPUs, bypassing the CPU for better performance and less memory copying.
  • "Peer to peer direct memory transfer means that two devices on a PCIe bus can transfer data to each other directly rather than having to go through the cpu, which would slow down the process." – Jeff Massey [65:15]
• iouring backgrounder: efficient, circular memory buffers—avoid copying, faster I/O.
• Tangent: Jeff and Bryan riff on the concept of a Mobius strip, referencing the episode title.

8. Quick Hits

• Flowblade Video Editor is migrating to GTK4 and will be Wayland-only soon.
• Steam Survey: Linux hits 3.2% of users (November 2025), up 0.15% in a month.
  • "Was 2025 the year of the Linux desktop? We’ll only know in retrospect." – Bryan [72:54]
• Estimating Linux Desktop Market Share: Various methodologies make precise measurement impossible, but It’s almost certainly higher than “unknown” metrics often suggest.

Notable Quotes & Memorable Moments

• On the challenges of color management:

  • "Blue looks the same to me as it does to everybody else in the audience... It knows gamuts and shifts and brightness levels and they can do all sorts of work to make, make colors more accurate." – Jeff Massey [13:03]

• On KDE's fundraiser:

  • "It's not obtrusive, it's not constantly begging for money. It's once a year. But it is so effective for them." – Bryan [18:00]

• On LTS kernel CVEs:

  • “In the kernel context, any bug is a CVE” – Bryan [28:34]
  • “There's gotta be a handful, say five, that are, oh, this is bad.” – Jeff Massey [30:30]

• On Nvidia legacy hardware support:

  • "I don't want people with the older hardware to feel totally dejected... it's gonna run at its current performance level for years longer." – Jeff Massey [44:00]

• Mobius strip joke (after a tangent about IOU ring):

  • “If you twist it in the middle, do you get a Mobius strip?” – Bryan [69:52]
  • “Mobius strip! Thank you.” – Bryan acknowledges a listener [69:55]

• Linux adoption and nostalgia:

  • “For me, the year of the Linux desktop was like back in 2006 or 2007. That happened a long time ago in my life.” – Bryan [75:50]
  • “Half the fun was just installing and debugging... I remember compiling KDE 2.0 and installing it.” – Jeff Massey [79:17]

Command Line & Tech Tips

Extensible Kernel Scheduling with scx

[86:19]

• scx (Scheduler extensible via eBPF): Lets you experiment with, implement, and swap out custom CPU scheduler policies at runtime using BPF, without rebooting or recompiling. Rich documentation linked in show notes.
  • “SCX is the easy way to get those operations going on the fly of schedule changes.” – Jeff Massey [88:23]

KDE/Fedora YaQuake — Fixing Quake Dropdown Terminal

[89:48]

• If YaQuake (KDE's Quake-style drop-down terminal) stops working, set Focus Stealing Prevention (Windows Behavior > Focus in KDE settings) to "Low."
  • “If you are on KDE and you too use YaQuake and it's not working—that’s the fix!” – Bryan [91:01]

Hardware & Geekery Tangents

• Northbridge/Southbridge Modernization [48:22]: Explains how modern CPUs integrate what used to be Northbridge functions, minimizing latency and complexity.
• Speed of light in chip design: Side conversation about picoseconds, inches, and signal propagation inside computer hardware. “In one picosecond, light moves about 10-thou – that's about the smallest gap you can see with a micrometer.” – Jeff Massey [58:26]

"Poetry Corner" & Listener Stories

[93:09] – Jeff closes with a custom tech poem:

"The user didn't like how his office was set
He felt rearrangement would be best
Upon completion, to his dismay
The computer would not respond in any way
Frantically he called the help desk
Submitted an emergency request
The deployed tech knew just what to expect
Into the receptacle the power cable was set
Have a great week everybody."

• Bonus: Jeff confesses to having plugged his optical DisplayPort cable backwards after rearranging his office, echoing the poem’s moral!

Closing Notes

• Bryan plugs Hackaday’s FLOSS Weekly for deeper Linux geekery.
• Thanks to live and download listeners—see you next week!

Useful Timestamps

• [08:45] Kernel 6.19 Merge Window & Graphics News
• [14:53] KDE/Plasma 6.6 Color Pipeline Progress
• [24:19] 6.18 LTS Kernel Released; 5.4 EOL Details
• [31:12] Fedora 44 KMSCon User-space Console Changes
• [39:59] Nvidia 590 Driver, Legacy support ends
• [54:46] npm "Shai Hulud" Security Incident
• [64:10] DMA, iouring, and Peer-to-Peer Kernel Improvements
• [86:19] Command Line Tips (scx)
• [89:48] KDE/YaQuake Focus Stealing Workaround
• [93:09] Poetry Corner: Tech Troubleshooting

Overall: A packed, lively episode for Linux, open-source, and hardware fans, with depth, details, and plenty of personality.