Significant research starts with a humble beginning.
As we graduate from the Agentic AI 1.0 era, we probably should have learned some lessons: Vibe coding service Replit deleted user’s production database, faked data, told fibs galore (July 21, 2025) Cursor AI YOLO mode lets coding assistant run wild, security firm warns (July 21, 2025) Google’s Antigravity AI deleted a developer’s drive and then apologized (December 3, 2025) Meta Security…
copy.fail ( CVE-2026-31431 ) is a Linux kernel bug where an in-place modification of a pipe scatter list by the algif_aead module (crypto module's AEAD algorithm) can be used to modify the disk cache of any file, potentially a setuid binary, by an unprivileged user. It allows local privilege escalation from an unprivileged user to root. This vulnerability was a performance optimization presumably…
Yesterday, I gave a talk about my earlier post Economies of AI with supplemental material to illustrate the point ( slides in Chinese ). One addendum in my talk is that I referenced a book by George Polya, How to Solve It (1945), to illustrate the comparative strengths of AI and humans when it comes to problem solving. Polya broke down problem solving in four phases: Definition: what are the…
This is a cost-benefit analysis on using AI to solve problems and comparing how it fares with classical methods, e.g. deterministic algorithms or manual labor, and the cost of the creation of automation. A fair warning: currently, LLM is not able to summarize this article correctly because of my unique perspective ( example ), as this article is not about the H-word at all. You should try to read…
Fiber optics are becoming cheaper and more affordable for homes nowadays, and they could be a fantastic alternative for RJ-45 10GBase-T Ethernet. Fiber transceivers at the same speed use less power and run cooler. They also don't need to be upgraded like you would need to upgrade an Ethernet cable from Cat5e to Cat6a to now Cat8. I have worked with fiber network designs at work, at least in…
Yesterday, I was looking for whether OpenBSD supports ZFS (it may have been briefly, but the code is no longer there). As I peruse Ted Unangst's blog, I found a benchmark showing that creating a socket is 10x slower on Linux than OpenBSD, referencing a post by Jann Horn . People quickly put the culprit on RCU, in particular rcu_synchronize(). Read-Copy Update (see also What is RCU, Fundamentally?…
(Insert obligatory AI generated Ghibli styled graphics here.) If you are a 13 year old vibe coding to become the next Bill Gates, here are the computer science concepts you will need to know to successfully direct AI to do the right things. I assume you want to build the next big thing and not just fixated about the 70's BASIC interpreter that Bill Gates wrote when he was 20 without AI. Also, if…
On an old MacBook Pro 2019, I've been trying out Secretive ( secretive.dev ) to let me use the Touch ID (aka SecureEnclave) as a hardware SSH key, like how I would use Yubikey on other computers. One of the things I would like to do is to create a certificate authority for key signing, to avoid having to manually add new keys to each host I have to SSH into. The certificate authority needs to tell…
PKCS #10 ( RFC 2986 ) certificate signing request (X509_REQ) typically contains at minimum the subject and the public key to be signed into a X.509 certificate issued by a certificate authority (CA). Here is an example of what I send to Let's Encrypt: $ openssl asn1parse -item X509_REQ -in worship.likai.org.csr X509_REQ: req_info: version: 0 subject: CN=worship.likai.org pubkey: X509_PUBKEY:…
For long-running microservices that can act as both client and server, it is possible the lifetime of the microservice might outlive its TLS certificate validity, especially if an organization opts for a security policy to rotate TLS certificates quickly (e.g. every day). We need to be able to reload both the client and server certificates without exiting the service. OpenSSL provides the…
s3backer allows you mount a single large file split into smaller chunks on S3 as a local file, via FUSE. In contrast, s3fs-fuse mounts S3 objects as individual files. s3backer is useful for hosting disk images formatted with a native filesystem. Although Apple subsequently introduced the Sparse Bundle image format, which also internally splits the image into multiple files, some reported that…
Breaking news! Vibe coding achieved the utterly impressive feat! Macintosh System 7 Ported To X86 With LLM Help . The original System7 ran on Motorola 68K. The author claimed that they ported the OS to x86 in 3 days, with a fully functional Finder and GUI, and no access to the original source code. The project files can be found on GitHub . It is understood that the port ran under QEMU to simplify…
In C++ creator calls for help to defend programming language from 'serious attacks' , the article mentioned a few proposals: Profiles (C++) by Bjarne Stroustrup, work in progress on GitHub. TrapC by Robin Rowe, news report also has example code. Fil-C by Filip Pizlo. Mini-C by Aymeric Fromherz (Inria) and Jonathan Protzenko (Microsoft). Safe C++ (also known as Circle C++ ) by Sean Baxter. Assuming…
Recently there is news reverberating across the interwebs that Tiny Linux kernel tweak could cut datacenter power use by 30% . The claim is based on this code commit detailed by the paper Kernel vs. User-Level Networking: Don't Throw Out the Stack with the Interrupts . The main idea is to mix the use of polling and interrupt driven I/O to get the best of both worlds. Polling is just busy looping…
In this article, we discuss why RAID 1+0 (stripes of mirrors) is better than RAID 0+1 (mirror of stripes) for those who are building a storage array. Image credit: Network Storage Server (angle view with case open) from Wikimedia Commons What is RAID, and why? RAID (redundant array of independent disks) describes a system of arrangements to combine a bunch of disks into a single storage volume.…
Update: I was only able to get irony to work up to the 2019 version, but irony has been unmaintained since 2023 and has now since suffered significant bit-rot, and I could not get the 2023 version to work. There seems to be other alternatives (e.g. lsp-mode ). However, I'm keeping this page for the record. The irony server provides symbol completion for irony-mode on Emacs. Under the hood, it uses…
A backdoor compromising SSH server introduced in xz/liblzma 5.6.0 and 5.6.1 was reported today to oss-security by Andres Freund . According to the analysis, when the sshd binary is initialized by the dynamic linker at startup, the initialization code in liblzma installs a hook to the dynamic linker that modifies subsequent dynamic library symbol tables (before they are made read-only) that…
A few weeks ago, I saw this video by Techmoan introducing the MQA-CD. MQA-CD is an audio CD that can be played back in a regular CD player, which is limited to 16-bit samples at 44.1 kHz. However, when played back through an MQA decoder, it promises better sound quality at 24-bit at 192 kHz. Before we dig into the MQA marketing material, we need to understand that MQA is an encoding scheme that…
Carrot and stick security design is the idea to have frontend and backend work together to enforce security policies in software. The frontend interacts with the user and steers them towards compliance, while the backend enforces the security rules. Although we don’t necessarily use carrot and stick to mean reward and punishment, the carrot is a “soft nudge” and the stick is a “hard boundary.” If…
There has been renewed interest in programming languages after The White House recently published a recommendation suggesting the transition to a memory safe language as a national security objective. Although I am not an author of the report, I want to explain the rationale that someone might use to consider whether their infrastructure meets the memory safety recommendations. This is more of an…
If you let a monkey hit random keys on a typewriter for an infinite amount of time, will it happen to write the complete works of Shakespeare? Common wisdom says that not only will it write Shakespeare, but it will “almost surely” type every possible text an infinite number of times. The proof idea goes like this: the probability to produce a permutation matching the complete works of Shakespeare…
This recent article about AlphaGeometry being able to solve Olympiad geometry proof problems brings to my attention that there have been active research in recent years to combine deep learning with theorem proving. The novelty of AlphaGeometry is that it specializes in constructing geometry proofs, using synthetic training data guided by the theorem prover, which previous approaches have had…
My camera journey is a little meandering, but it can roughly be roughly summarized as " all I want is the perfect camera ." My first camera is a Canon PowerShot A50 , bought in 1999, which is a compact CCD camera. It can do 10-bit RAW, which I later discovered allowed me to correct underexposed photos more easily, and the colors actually looked decent! The camera writes to an original…
I saw a post like this fly by on my Facebook feed today. I lost it when I closed the window, but the question lingered. Why is a Transformer rated in kVA, not in kW? I did not know the answer, but I should know because I have also seen kVA rating used in datacenter contract rather than kW. Many electricians point out that kVA represents apparent power, and kW is the available amount of work under…
Since the last time I built my ZFS pool in 2016 with 4x 1TB SSDs in a thunderbolt 2 enclosure, I ran out of space in 2019 and upgraded the SSDs to 4x 2TB. I didn't have an extra enclosure, so I took a fairly risky approach to yank each SSD out, put in a new SSD, and let ZFS resilver. It only worked because my pool is a raidz1. During resilvering, the pool was in a degraded state due to the lack of…