Bismuth: Building a Cloud
This year, a good friend and I have been working on a new startup: Bismuth.
Nick Gregory
Latest posts
Warpspeed: Building a Record/Replay Debugger for macOS
This is a (long) overdue post to accompany the REcon 2023 talk Pete Markowsky and I gave talking about our work on Warpspeed: a time travel debugger for macOS.
Improving Fuzzing Speed with userfaultfd
About the same time I wrote up my previous post about snapshot fuzzing, I was thinking about other ways to restore program state for fuzzing, ideally in userland for ease of use.
diffusion.gallery - A Constantly Changing Machine Generated Art Gallery
tl;dr: diffusion.gallery is a website I put together which feeds random prompts from OpenAI into Stable Diffusion. It’s pretty neat.
Using Graphs to Search for Code
Some time ago, I was working on a server to generate images from weather RADAR data (a separate post on this will come at some point). As part of this, I spent a few hours profiling my code and found a tiny “bug” in the open source library I was using to parse one type of RADAR data.
Seeing the Clouds with the Cloud
If you follow AWS closely, you may have heard about a niche product launch a few years back called Ground Station which lets you rent, well, a ground station (basically a big antenna plus supporting equipment to communicate with satellites). A friend recently linked me an AWS blog post with a sample use case which described using it as a way of receiving real time imagery from orbiting weather…
The Discovery and Exploitation of CVE-2022-25636
A few weeks ago, I found and reported CVE-2022-25636 - a heap out of bounds write in the Linux kernel. The bug is exploitable to achieve kernel code execution (via ROP), giving full local privilege escalation, container escape, whatever you want.
A snapshotting kernel module for fuzzing
Right as the pandemic was starting in March/April 2020, I spent a couple of weekends writing a Loadable Kernel Module (LKM) for Linux, designed to add a syscall which could be used by a fuzzer to quickly restore program state instead of using a conventional fork/exec loop. This was originally suggested on the AFL++ Ideas page, and it nicely intersected a bunch of stuff I’m familiar with so I…
DIY Environmental Monitor
Early on in the pandemic, there was a good amount of discussion on Twitter about indoor CO2 levels as more people were spending time exclusively at home, often in a single, small room for hours on end. Since I was one of those people spending nearly the entire day in a single room, I decided to look around for a CO2 monitoring system. While a simple “alert after levels rise above x ppm” is…
Overkilling Website Performance
Given the recent series of issues with Google Cloud, I decided it was time to jump ship and look at other providers for this blog (and eventually the rest of my sites most likely).