dru

beep boop in cloud & backend

[International Cyber Digest @IntCyberDigest]

‼️🚨 BREAKING: An AI found a Linux kernel zero-day that roots every distribution since 2017. The exploit fits in 732 bytes of Python. Patch your kernel ASAP.

The vulnerability is CVE-2026-31431, nicknamed "Copy Fail," disclosed today by Theori. It has been sitting quietly in the Linux kernel for nine years.

Most Linux privilege-escalation bugs are picky. They need a precise timing window (a "race"), or specific kernel addresses leaked from somewhere, or careful tuning per distribution. Copy Fail needs none of that. It is a straight-line logic mistake that works on the first try, every time, on every mainstream Linux box.

The attacker just needs a normal user account on the machine. From there, the script asks the kernel to do some encryption work, abuses how that work is wired up, and ends up writing 4 bytes into a memory area called the "page cache" (Linux's high-speed copy of files in RAM). Those 4 bytes can be aimed at any program the system trusts, like /usr/bin/su, the shortcut to becoming root.

Result: the next time anyone runs that program, it lets the attacker in as root.

What should worry most: the corruption never touches the file on disk. It only exists in Linux's in-memory copy of that file. If you imaged the hard drive afterwards, the on-disk file would match the official package hash exactly. Reboot the machine, or just put it under memory pressure (any normal system load that needs the RAM), and the cached copy reloads fresh from disk.

Containers do not help either. The page cache is shared across the whole host, so a process inside a container can use this bug to compromise the underlying server and reach into other tenants.

The original sin was a 2017 "in-place optimization" in a kernel crypto module called algif_aead. It was meant to make encryption slightly faster. The change broke a critical safety assumption, and nobody noticed for nine years. That bug then rode every kernel update from 2017 to today.

This vulnerability affects the following:
🔴 Shared servers (dev boxes, jump hosts, build servers): any user becomes root
🔴 Kubernetes and container clusters: one compromised pod escapes to the host
🔴 CI runners (GitHub Actions, GitLab, Jenkins): a malicious pull request becomes root on the runner
🔴 Cloud platforms running user code (notebooks, agent sandboxes, serverless functions): a tenant becomes host root

Timeline:
🔴 March 23, 2026: reported to the Linux kernel security team
🔴 April 1: patch committed to mainline (commit a664bf3d603d)
🔴 April 22: CVE assigned
🔴 April 29: public disclosure

Mitigation: update your kernel to a build that includes mainline commit a664bf3d603d. If you cannot patch immediately, turn off the vulnerable module:

echo "install algif_aead /bin/false" > /etc/modprobe.d/disable-algif.conf
rmmod algif_aead 2>/dev/null || true

For environments that run untrusted code (containers, sandboxes, CI runners), block access to the kernel's AF_ALG crypto interface entirely, even after patching. Almost nothing legitimate needs it, and blocking it shuts the door on this whole class of bug...

[Aakash Gupta @aakashgupta]

There's a physicist at Stanford named Safi Bahcall who modeled this exact principle and the math is wild.

He calls it "phase transitions in human networks." When you're stationary, your probability of a lucky event is limited to your existing surface area: the people you already know, the places you already go, the ideas you've already been exposed to. Your opportunity window is fixed.

When you move, your collision rate with new nodes in a network increases nonlinearly. Double your movement (new conversations, new cities, new projects) and your probability of a serendipitous encounter doesn't double. It roughly quadruples. Because each new node connects you to their entire network, not just to them.

Richard Wiseman ran a 10-year study at the University of Hertfordshire tracking self-described "lucky" and "unlucky" people. The single biggest differentiator wasn't IQ, education, or family money. Lucky people scored significantly higher on one trait: openness to experience. They talked to strangers more, varied their routines more, and said yes to invitations at nearly twice the rate.

The "unlucky" group followed the same routes, ate at the same restaurants, and talked to the same 5 people. Their networks were closed loops. No new inputs, no new collisions.

Luck isn't random. Luck is surface area. And surface area is a function of movement.

The lobster emoji is doing more work than most people realize. Lobsters grow by shedding their shell when it gets too tight. The growth requires a period of total vulnerability. No protection, no armor, soft body exposed to the ocean.

That's the cost of movement nobody posts about. You have to be uncomfortable first. The new shell only hardens after you've already moved.

[OpenAI @OpenAI]

We’re live streaming the OpenAI DevDay keynote on Monday at 10AM PST.

Tune in! https://t.co/5ZQ1slMhwJ

[anson ⁂ @ansonyuu]

i think a noble reason to learn things is to have more surface area to make jokes about

[dru @l0calhost]

how quickly you'd be able to find friends who are also interested in that niche thing you are reading an article about

[Gaby Goldberg @gaby_goldberg]

You should generally have the ability to chat with anyone on the same website as you at a given time

[dru @l0calhost]

To be an EM or not to be.

That is the question.

[dru @l0calhost]

Company awards are just psychological manipulation tools

[dru @l0calhost]

@natotodoroki Sometimes I think universities in the developed nations are just infinite export for the developing nations at this point

[dru @l0calhost]

The amount of stuff I read on my phone just out of laziness and without a care for my eyes astonishes me:

• Code
• Webpages in desktop mode
• Books ffs

[dru @l0calhost]

@robconery This is such an amazing idea, thank you!

[dru @l0calhost]

Not to mention the unique characters you have to escape now

[dru @l0calhost]

The awesome feeling when your long ass regex finally works on https://t.co/eFWUI27MXd

... and then you copy it into your code and the engine is completely different

[dru @l0calhost]

Cloud Plumber is such a cool title

[Matt Moore ⛓🚀 @mattomata]

You don't learn in your comfort zone and leaving your comfort zone is always scary.

[dru @l0calhost]

what are the odds omg screw this guy, first GME and now the constitution

[tina 🍄 @patagucci_girl]

So we were bidding against a certified villain the whole time 😂https://t.co/CSS7XsgcCv

[geoff @GeoffreyHuntley]

💀OMG WHO RIGHT CLICKED ALL OF THE #NFTs?☠️
🛳🏴‍☠️ https://t.co/o0YRK78AkL 🏴‍☠️🛳
👀

[dru @l0calhost]

Catch me constantly finding excuses to upgrade my homelab so that I can run a cluster to orchestrate a single container that prints hello world

[dru @l0calhost]

DevOps Engineer title exists because YAML engineer doesn't sound that prestigious

[dru @l0calhost]

@inika__ when you request a custom item because you can't find it in the app and they actually find that item

[dru @l0calhost]

@cindohahahaha I'd also like to know the science behind this phenomenon