> So I set off on a journey that would lower my GPA and occasionally leave me questioning my sanity
Amazing! Sacrificing GPA for projects is always a good time
anyfoo · 9h ago
I really liked the old German university concept, the one before we just took over Bachelor/Master.
Throughout my CS studies, I was just collecting "tickets" (very hard to translate the actual word, "Schein"), which basically just attested that you have passed a course. They (often) had a grade on it, but it did not matter. Instead, once in the middle ("pre-diploma") and once at the very end of your time at university, you'd have oral exams. And those determined your grade. To attend them, you needed the right combination of "tickets".
The glaring downside of this system is that if you had a bad time in those few months of your very final exams, you could screw up your entire grade.
The upside of it, is that I was free (and encouraged) to pursue whatever I wanted, without each course risking to have an effect on my "GPA". I had way more tickets than I needed in the end, and still time and energy to pursue whatever else I wanted (playing with microcontrollers etc.).
klysm · 9h ago
I had a couple of classes in USA uni that worked quite similarly. The professor said we can take the quizzes if we want, and if we didn't then the later quizzes would constitute more of your grade. The ultimate play was to only take the final quiz.
cherryteastain · 8h ago
> The ultimate play was to only take the final quiz.
This is how a lot of British undergrad courses ('modules') work. One giant exam at the very end determining everything; no quizzes, no problem sheets, no midterms.
twic · 7h ago
Modules? We just had six massive exams at the end of three years!
wbl · 7h ago
Chicago used to be that way in the long ago times.
xen2xen1 · 9h ago
Would not be a surprise if AI brought this back.
dudus · 9h ago
As a teacher once told me.
"Never let school limit your education"
nzeid · 9h ago
For those wondering this is a common paraphrase of Grant Allen and Mark Twain. Here we say "Never let school get in the way of a good education."
technothrasher · 9h ago
I learned a ton while at my university. Much of it was outside of my classwork.
cperciva · 3h ago
Agreed. My GPA suffered significantly in 1999 when I was writing a web service to help me calculate Pi, but it was absolutely worth it.
chc4 · 9h ago
Going for the pipe spray is a kinda weird technique, and I'm honestly surprised that it worked. Usually just the fact that you are able to spray over the allocation at all isn't enough, and you also have to worry about your sprayed data containing additional pointers or things that also have to be valid.
I probably would have gone for turning the UaF into an type confusion style attack: if you spray more sockets you'll end up with two files, the original and the new one, that have aliased sk members, but the vsock code will incorrectly cast the new one to a `vsock_sock`. From there you can probably find some other socket type that puts controllable data over some field that vsock treats as a pointer or vice versa, and use it as both a kaslr leak and data-only r/w primitive.
benwilber0 · 9h ago
> I probably would have gone for turning the UaF into an type confusion style attack
I'm aware that Linux is nearly 40 years old at this point, and C is even decades older. But it is mind-boggling to me that we're still talking about UAFs and jumping from dangling pointers to get privileged executions in the 21st century.
(rewrite it in Rust)
Ygg2 · 24m ago
Nonsense, the C guy told me those happen to people that make mistakes, and that he, being the offspring of the Elemental of Logic, and "Hyperspace cybernetic intelligence and juvenile delinquent John Carmack" is completely immune to such pathetic issues. He works at Linux. Yes, all of Linux.
This is an apples-oranges comparison, unless things have changed drastically since the last time I worked on L4 (about 10 years ago). L4 is very secure and easy to reason about. But that's because it doesn't really do anything. It makes a lot of sense as a platform to build a general purpose OS on, and as a bottom layer for what would otherwise be a unikernel. But you'd run a browser on top of something that itself runs on seL4, not on seL4 itself.
surajrmal · 4h ago
It's becoming more and more common to use non Linux based hypervisors to isolate workloads where security matters. Isolating applications within a given VM is not seen as important and therefore ditching Linux isn't really necessary. Applications can continue to be written against Linux APIs and we can create isolation domains separately. This is no longer just a server concept as even phones and cars are starting to employ this technique. It has high cost to RAM, but as RAM gets cheaper it's not as big of a deal.
fc417fc802 · 4h ago
The obvious question is why Linux is so widely used in the first place. I don't think "APIs" is enough to explain it. One obvious answer is the incredibly broad hardware support. Any alternative selected for use as the hypervisor is going to be at a serious disadvantage in that regard.
surajrmal · 2h ago
Not necessarily. You can forward a lot of hardware as is to a Linux VM if you have an iommu. It comes down to whether you need multiple VMs to share access to some hardware or not, which is not all that common based on the way the isolation domains work out. This can start to become more challenging when that hardware has shared resources such as clocks, buses, or power rails to manage, but soc makers are likely going to make hardware increasingly easier to work in this modality as customers require it.
signa11 · 5h ago
don’t mind if you do guv.
Dwedit · 10h ago
Yay Rop Chains!
dang · 9h ago
[stub for offtopicness]
cyberpunk · 10h ago
Cool writeup, and you have exceptional taste in fonts.
ohc · 10h ago
I can't read the dark blue links on the black background
gerdesj · 10h ago
Engage reading mode and relax.
Ylpertnodi · 7h ago
Victim blaming.
las_balas_tres · 9h ago
For the love of god please change the blue on black text to something more readable
yapyap · 9h ago
The dark blue on black reads absolutely terribly
neuronflux · 9h ago
Try the Reader View feature of Firefox.
xyst · 9h ago
yet another "use-after-free" sploit
Rust for Linux, wen?
It's a damn shame the current maintainers are so hostile to its adoption that many of the original rust 4 linux folks have left the project.
poincaredisk · 5h ago
Counterargument: Linux is almost 35 years old (wow, time flies). Rust for Linux is a project started at the moment of biggest rust hype. It's understandable that the Linux maintainers are wary of introducing too much rust dependence, in case, for example, all the rust people leave in 5 years and current/old maintainers are stuck with it forever
Ygg2 · 16m ago
Counterargument Counterargument: one would think 35 years is enough to work out the memory safety kinks. If C people can't sort it, a new solution needs to be used.
Not necessarily Rust, but something memory safe. Perhaps Java (if maintenance is that important) :P
doug713705 · 9h ago
Did they start their own project ? Linux is free, just fork it.
surajrmal · 4h ago
There are a lot of entities involved that need to be able to work together. Creating a form fractures things and requires all partners to move to said fork. It's far easier to work upstream even with resistance. Anyone who has maintained a long standing Linux fork understands the costs of trying to rebase thousands of patches. There will never be enough of a migration to make it unnecessary to need to rebase.
riehwvfbk · 17m ago
"Hey upstream maintainer, let me commit a bunch of code in a language you can't even read. You get to maintain it forever while I get to move on to bigger and better things. I am better that you after all: I know this cool new language and you don't."
Amazing! Sacrificing GPA for projects is always a good time
Throughout my CS studies, I was just collecting "tickets" (very hard to translate the actual word, "Schein"), which basically just attested that you have passed a course. They (often) had a grade on it, but it did not matter. Instead, once in the middle ("pre-diploma") and once at the very end of your time at university, you'd have oral exams. And those determined your grade. To attend them, you needed the right combination of "tickets".
The glaring downside of this system is that if you had a bad time in those few months of your very final exams, you could screw up your entire grade.
The upside of it, is that I was free (and encouraged) to pursue whatever I wanted, without each course risking to have an effect on my "GPA". I had way more tickets than I needed in the end, and still time and energy to pursue whatever else I wanted (playing with microcontrollers etc.).
This is how a lot of British undergrad courses ('modules') work. One giant exam at the very end determining everything; no quizzes, no problem sheets, no midterms.
"Never let school limit your education"
I probably would have gone for turning the UaF into an type confusion style attack: if you spray more sockets you'll end up with two files, the original and the new one, that have aliased sk members, but the vsock code will incorrectly cast the new one to a `vsock_sock`. From there you can probably find some other socket type that puts controllable data over some field that vsock treats as a pointer or vice versa, and use it as both a kaslr leak and data-only r/w primitive.
I'm aware that Linux is nearly 40 years old at this point, and C is even decades older. But it is mind-boggling to me that we're still talking about UAFs and jumping from dangling pointers to get privileged executions in the 21st century.
(rewrite it in Rust)
Looks like we've got an encoding issue too.
You should pretty much always use one.
The document itself also lacks a declared character set.
It's about time to look at a sane design, such as seL4[0].
https://sel4.systems/About/seL4-whitepaper.pdf
Rust for Linux, wen?
It's a damn shame the current maintainers are so hostile to its adoption that many of the original rust 4 linux folks have left the project.
Not necessarily Rust, but something memory safe. Perhaps Java (if maintenance is that important) :P
And this didn't go over well. Shocking.