A thousand fewer paths to root
116 points by dangelosaurus 3 hours ago | 74 comments

Plasmoid 3 hours ago
How did we get to the point where there are a thousand privilege escalation exploits in the kernel?

Is the kernel simply too complex to reason about? Is it an underlying flaw in the security model or language implementation?

Should we assume that all software is more compromised than the kernel?

reply
pianopatrick 47 minutes ago
Because the large corporations that fund Linux development and use Linux value speed over security.

Speed requires a lot of code in the kernel, where that code can run fast.

There are kernels that do not have a thousand privilege escalation exploits. These kernels are smaller and much easier to check for bugs. But those kernels are significantly slower.

For many use cases, slower is not a problem. But for the large corporations who fund a lot of Linux development and use Linux in large data centers, every 1% slower can literally be millions of dollars worth of additional servers that are required.

OpenBSD shows that you can have a Unix security model without a thousand privilege escalation exploits. But OpenBSD is like 10% slower. So corporations won't use it because it would cost millions of dollars more per year and some of their software requires access that OpenBSD does not grant precisely because that access leads to security exploits (i.e. io_uring, eBPF etc. etc.)

You could also use like seL4, but that's slow too

So that's why. It's a business tradeoff between cost of servers vs cost of getting hacked, and cost of servers wins.

reply
Gigachad 30 minutes ago
It also used to just be fine patching the bugs as they were found. Its only recently where that model has fallen apart and we now need to prevent the bugs from existing in the first place.
reply
mikestylz 2 hours ago
> Should we assume that all software is more compromised than the kernel?

Absolutely, the front door has always been unlocked. We were previously protected by the economics of exploit detection favoring the developers, but now we have entered a new world.

The issues arise almost everywhere we look. It's frustrating because the user experience in edge systems has barely changed in the last fifteen years. We could have rode the advances in semiconductor manufacturing to embed more layers of protection such as CHERI while slightly slowing down the rate of performance improvements. Instead we have only marginally upgraded security and largely added features which the users scarcely notice.

I am hopeful about the long term prospects of formal verification, but having humans reviewing the proof statements and confirming they match our desired properties will take many years. Meanwhile, AI assisted hacking is an urgent issue. So we will have to delegate implementation, proof specification, and proof development to the AIs in the short term. Maybe that goes well, but who knows. Interesting times.

reply
asveikau 2 hours ago
For all of my time being aware of this industry, it has generally been understood that privilege escalation bugs are common. This has always been a thing. A lot of people say, commonly and for many years, that if your security depends on there not being privilege escalation bugs, you don't have security.
reply
chrismarlow9 2 hours ago
This. Privilege escalation locally is almost a given in most cases.
reply
bombcar 2 hours ago
The dirty secret is multi-user died in the 90s and privilege escalation has basically been considered table-stakes since then.
reply
tptacek 2 hours ago
I think this is basically true, but it didn't "die" in the sense that we gave up on it; it just never worked. Systems software was much worse in the 1990s than it today; you could breathe on something with a string of AAAA's and get a 0x41414141 register core dump.
reply
blooalien 30 minutes ago
> ... it didn't "die" in the sense that we gave up on it ...

It died in the sense that the "people in charge" hired us for our expertise and then ignored our every suggestion and fought us tooth and nail every inch of the way when we suggested that security or reliability ever mattered in the slightest until after the disaster happened, and then straight-up scapegoated us for "not pushing back harder" against the threats of "go work somewhere else then, code-monkey!" until we gave up and did the "code-monkey" thing for our paycheck and no longer cared about quality or "a job well done".

reply
hibikir 42 minutes ago
Back in the 90s, it's not as if any semi competent cs student couldn't slice your typical college server like swiss cheese. People thought null terminated strings were fine back then, and patching everything immediately was rare. So multi user was already dubious.
reply
Muromec 2 hours ago
>Is the kernel simply too complex to reason about? Is it an underlying flaw in the security model or language implementation?

There is nothing magical about kernel. Look at the code anywhere and it has bugs, lots of them.

Security bugs are just bugs. More often than not they are silently there and don't prevent you from using the software and you can't react and fix them because of that.

Give it time and they accumulate

reply
NooneAtAll5 2 hours ago
> How did we get to the point where there are a thousand privilege escalation exploits in the kernel?

it's been rule of thumb basically forever that there is 1 bug per ~10KLOC for any project

linux kernel is millions of lines, so thousands of bugs being hidden there is about on point

(tho obviously far smaller serious escalation ones, obviously, but you're exaggerating as well)

reply
jiggawatts 17 minutes ago
> 1 bug per ~10KLOC for any project

1 bug per 10 lines -- not kilolines -- is much closer to the actual "bug rate".

You may be thinking "1 serious security vulnerability bug", but in my experience that too is much closer to 1 per 100 lines to 1 per 1,000 lines, depending on the type of application.

reply
p-e-w 2 hours ago
How can it be surprising that a software made from 40+ million lines of memory-unsafe code has hundreds of critical bugs?
reply
wahern 2 hours ago
More than half of those lines are from drivers, drivers which wouldn't be relevant to a VM environment. Core kernel code for any particular architecture is less than 10 million, but some of that is filesystems or subsystems not in use or available to an unprivileged user on a typical server, so possibly maybe 5 million or less. And the article says they only targeted 2.8 million SLoC.
reply
hoppp 2 hours ago
There are always more left.
reply
ChickeNES 2 hours ago
And memory safety doesn't prevent logic errors (or using 4 as a private key for that matter)
reply
0xbadcafebee 2 hours ago
Funny how OpenBSD is "memory-unsafe" yet doesn't have these issues. Could it be that the programmer might have something to do with it?
reply
icepush 2 hours ago
As an OpenBSD lover and frequent user I will tell you it does not support but a significant fraction of the hardware Linux does, and has many features that are reduced in functionality or just gone compared to Linux.

Is it bulletproof? Definitely! But you need the genius of Albert Einstein as well as the patience of Mother Theresa to actually use it in production.

reply
Muromec 59 minutes ago
Can't have a bug in a feature you never implemented and can't have another arising from unexpected interaction of two features you didn't implement.

It's the one security practice that actuuuualy works

reply
wahern 2 hours ago
For most server setups OpenBSD's hardware support is adequate, and this is especially true for VMs. It's laptops, peripherals, and bleeding edge, high-performance or specialized devices where driver support is a PITA. But that's not something I've encountered running my own private servers. It would be nice to have something like ZFS, but mostly that's a peace and convenience thing--would be nice to be able to stream backups somewhere rather than push around dumps and tarballs, though I have a script for that.
reply
cyberax 2 hours ago
Is anyone spending millions of dollars on checking OpenBSD?

But it also got its share of use-after-free and OOB access vulnerabilities this year: https://feedly.com/cve/vendors/openbsd

reply
esseph 2 hours ago
> Funny how OpenBSD is "memory-unsafe" yet doesn't have these issues.

First of all... Do you really believe that to be true?

reply
est31 2 hours ago
The kernel has the problem that basically every bug in it is also a security vulnerability. All software has bugs. Had Linux been written in Rust, and I strongly recommend a rewrite, it would still have bugs, and thus would still have vulnerabilities. But they'd be way less.
reply
anonymous908213 2 hours ago
> and I strongly recommend a rewrite,

Oh, you strongly recommend rewriting tens of millions of lines of code? Why don't you do it yourself? Just a prompt away, right?

reply
est31 31 minutes ago
> Just a prompt away, right?

Humans manually typing out the bytes of source code has been an outdated method, since around a year. It simply doesn't scale as much as those same humans directing agentic teams. So yes, it would be about prompts.

The hard part isn't the technology for the language transition, that one is present today. pgrust shows the way. It's ensuring maintainers are cooperative, i.e. a social problem. Eventually you diverge too much if you do a fork, so it's better done in cooperation with upstream.

Just check how long it took LLVM or GCC to switch off svn for example, and a language switch is much more involved than a VCS switch.

reply
anonymous908213 29 minutes ago
> pgrust shows the way.

You mean the pgrust which was recently caught for cheating benchmarks and incapable of even performing basic queries outside the benchmark set? Would love to see pgrust debunked by Jepsen like this other AI-generated, written in Rust, "formally verified" scam.

https://jepsen.io/analyses/particledb-1.1.4

reply
est31 14 minutes ago
I think the pgrust controversy should be resolved now?

https://news.ycombinator.com/item?id=50209450

reply
anonymous908213 6 minutes ago
I don't consider a cheater downplaying their cheating to resolve the fact that they cheated, no. Every cheater has a defense when caught, and theirs was not convincing. At this point I think the only thing that could redeem their brand would be paying for a Jepsen analysis to verify pgrust is as good as they claim it is; I have zero reason to trust the words from the horse's mouth.
reply
Muromec 2 hours ago
Kernel will eventually move to rust, but not the dramatic and fast way
reply
shoobiedoo 46 minutes ago
Won't AI's ability to discover these bugs reduce the need to rewrite things in rust? If the major benefit to rewriting them is memory safety, I mean...
reply
Gigachad 24 minutes ago
That's assuming the current models are able to find all the bugs, and that we won't have a better model out every few months that will be able to find even more obscure bugs.

We would also have to burn a trillion tokens a day verifying all the C code the hard way forever going forward. It would be cheaper to rewrite the kernel in Rust, subsystem and driver by driver at a time.

reply
shoobiedoo 2 minutes ago
I see. Fair enough
reply
jkelleyrtp 2 hours ago
fwiw at work we've been looking at what the options are more memory-safe kernels out there. Not many options. If there were a "safe linux" maintained by like canonical or redhat or whatever we'd use it. For datacenter workloads like sandboxes and virtualization I think it'd do well.
reply
ventedmouse 60 minutes ago
“Claude rewrite this project, its 40 million LOC, make no mistake”
reply
AnimalMuppet 2 hours ago
I recall reading that every IBM mainframe OS release had 1000 bugs in it. (This was in the 1970s/80s.) Sorry I can't supply a source, after 4-5 decades. It was probably an article in Datamation magazine.

Now, I don't know how many of those bugs were privilege escalations, or could be leveraged to be. I'm not sure that people tried to exploit in the same way back then (or, if they did, if they said anything publicly about the results). Still, even if the majority of those bugs were not exploitable, OSes were much smaller then.

So that's my conclusion of how we got here: We've always been here.

reply
esseph 2 hours ago
The surrounding systems that connect to mainframe also expect and support those bugs. For 40+ yr now :)
reply
perching_aix 17 minutes ago
amazing things happen when you decide that device drivers should be a part of your kernel codebase
reply
antonvs 3 hours ago
> How did we get to the point where there are a thousand privilege escalation exploits in the kernel?

We developed AIs that can find them.

reply
spartanatreyu 2 hours ago
> How did we get to the point where there are a thousand privilege escalation exploits in the kernel?

> > We developed AIs that can find them.

We could already find them before AI.

We already knew they were there, and we already knew how to prevent them in the first place.

See previous discussion: https://news.ycombinator.com/item?id=49705794

reply
antonvs 9 minutes ago
Why do you think we didn’t find these 948 vulnerabilities before now?
reply
esseph 2 hours ago
> We could already find them before AI.

Not at this speed and cost.

reply
spartanatreyu 42 minutes ago
> Not at this speed and cost.

I'd argue that the resources (i.e. time, money and effort) needed to create the tooling that would have prevented all of these issues would have been orders of magnitude less than the resources that have gone into "AI".

reply
dangelosaurus 3 hours ago
This is my team’s work. I’m happy to try to answer questions or take questions back to the team.

And we're hiring! https://openai.com/careers/search/?q=cyber

reply
0x00cl 18 minutes ago
I'm going to assume that there was "old" code that caused LPE vulnerabilities, but, The Linux Foundation have their own project Sashiko (https://sashiko.dev/), which analyzes each commit to the Linux Kernel for bugs and vulnerabilities using Googles models, my question is then, how many of the vulnerabilities you found were also caught by Sashiko?
reply
BoppreH 3 hours ago
It's a bittersweet result, like finding asbestos in your house. I'd rather know than not, but I would much prefer not having it in the first place.

I understand this work was based on a dated snapshot. Will there be any continuous effort, scanning new PRs as they land, to prevent new weaknesses from being added?

reply
ky1ebot1337 2 hours ago
(I am the author the pipeline, just created an account to answer some questions :D) My goal is to work towards a vuln-free Internet. What I observed is that stronger models can find many more vulnerabilities that weaker models cannot. If compute permits (there are other projects to secure besides Linux), I plan to scan Linux again with every newer generation of cyber models.
reply
konaraddi 3 hours ago
As models get more advanced and generate an increasing throughput of increasingly higher quality results, how are you determining when to trust its results and when human review is needed on what?

E.g., 948 results is a high number to review in a timely manner unless your team is very large or spending several months combing through the results

EDIT: nvm i shouldve kept reading, answered

> At this scale, manually investigating every report is impractical for our research team. We therefore focused on validating findings that a) were reachable by a low-privileged user, b) required no special capabilities, and c) produced measurable evidence of memory corruption.

reply
ahsillyme 2 hours ago
Thanks. I'm not a programmer so I can't understand what is happening in the kernel by looking at the changelog, so I'll ask: Are the problems remediated structurally so that nothing like it can occur in the future, rather than just patching it up? Are there "lessons learned" that are being applied and documented here (like, "this problem looks like it's shape transports to other subsystems as well, let's fix them all in a disciplined way")?
reply
esseph 2 hours ago
I can't comment specifically on the Linux kernel piece, but I want to point out, broadly, that security has generally been an afterthought, and very little gets invested into it in terms of time and money - as a general rule.

Multiply that behavior times the number of commercial and mobile and b2b apps over 50+ years, and that's where we are.

There will likely be many more leaks, and hacks, and outages. And then in trying to be proactive to fix old systems, that will cause new proactive outages, and then eventually many things will be better.

But, it's going to take a lot of time and investment, and a lot of (majority) of currently unsupported devices will have to be complete replaced / scrapped / ewaste. On the scale of Nation-State initiatives.

This is across all operating systems, firmware, software and devices of all kinds, etc.

LLMs to security are like a bomb went off. We still have to wait for things to fall over before the dust will even clear enough to see what we have to work with.

reply
basilikum 2 hours ago
The high number is really impression to the point of making me skeptic. Are these distinct vulnerabilities or are a lot of the related in the way vulns often are?

The article says "The target virtual machines ran a stock desktop operating system". Are the vulns in the kernel specifically or does this include software running as root?

reply
ky1ebot1337 2 hours ago
These are distinct vulnerabilities counted by the number of patches. The patch generation system performs variant analysis. So, each patch can potentially stop multiple exploits. The raw exploits number is higher than what we reported in the post. We don't want to cause the confusion why #patch != #exploit, so we used the smaller number there. These vulns are all kernel specific. Userspace software running as root was not in scope of the analysis.
reply
emmelaich 2 hours ago
I'd like to see a break down by age of code and part of kernel (drivers, networking, core ,etc ..)
reply
farisght 3 hours ago
I wish these blog posts included statistics on the categories of deficiencies that cause these vulnerabilities, and proposed measures to avoid them

A system that admits THOUSANDS of such vulnerabilities is certainly flawed in several fundamental aspects

reply
jethro_tell 2 hours ago
It sounds like they can’t go through them all enough to have that data yet.
reply
esseph 47 minutes ago
Kernel is far too big to throw at a single LLM, just like a human. It is.. I think somebody said 40mil lines of code.

So you have to chunk it down to workable pieces over time, and then if you collect enough data of that process you can look at higher level stats.

You're also talking about hundreds of thousands (millions?) of individual contributors to the Linux kernel over 30+ yr. That process is likely to take years.

Same for every other existing piece of software, btw.

reply
shalom1112 38 minutes ago
[dead]
reply
rmbryan 16 minutes ago
With these vulnerabilities and the ones not listed that are sure to exist, how is the internet still up? How are my lights on? Why aren't power plants exploding by the dozens?

What are the mitigating factors that prevent this level of vulnerability from being an existential threat to humanity?

reply
tantalor 10 minutes ago
In general computer systems have been known unreliable since the 1980s, especially when networked. The entire cyber security industry operates not by preventing intrusions in the first place, but by rapidly mitigating them when they inevitably happen.

Hopefully this type of work to automatically discover & patch vulnerability leads to much more reliable software, and the remove the need for cyber security.

reply
rmbryan 8 minutes ago
Okay, thank you. That's a helpful reframing.
reply
nomel 13 minutes ago
The governments buy them up [1]. Nukes wouldn't be required for WW3.

[1] https://www.cyberdefensemagazine.com/zero-day-market-the-gov...

reply
rmbryan 9 minutes ago
article from 2013
reply
bzmrgonz 29 minutes ago
I wonder what Sidero Labs has to say about this article. My hopes are pegged on their efforts. I have my wagon ready to hitch on their horses. They are not a one pony show anymore guys, Talos OS can be standalone server OS, a hypervisor server or cluster, and their flagship of k8s node or cluster. We get all that in an immutable gitops ready OS. I'm practically sold on their offering.
reply
IcyWindows 55 minutes ago
I think this is one area where Windows has an advantage.

ACLs, Appcontainers with capabilities, etc have been something in the OS for more than a decade.

reply
jasonjayr 53 minutes ago
There are a lot of LPE's in Windows too. Remember that it started out as a single user operating system, it took a long time to get software on board to not always running as admin.
reply
perching_aix 18 minutes ago
Considering the amount of crazy shit even just user access allows you to do, by design, an LPE is not even really necessary.
reply
nas 2 hours ago
I've always considered local escalations to be possible in Linux (i.e. having user access almost certainly means you can get root). However, 948 vulnerabilities is kind of shocking. Hopefully we are getting to the end of the part where it "gets worse before it gets better".
reply
ksec 25 minutes ago
I wonder if they could run it on OpenBSD and FreeBSD as well.
reply
getcrunk 3 hours ago
> For the near and medium term, having access to a low-privileged account on an operating system, that isn’t up-to-date on its latest available patches should be considered functionally equivalent to root access for a well-resourced threat actor.

*buries head in sand*

*cries*

reply
kccqzy 2 hours ago
LPEs are frequent enough that people no longer use them to sandbox potentially malicious software. They are only used to control access for well-behaving human users without any intent to subvert the system, not attackers.
reply
rubinlinux 2 hours ago
This has been true for DECADES.
reply
basilikum 2 hours ago
Regular LPEs are not novel. The frequency has just increased a lot.
reply
zahlman 3 hours ago
> We've developed an autonomous vulnerability discovery, exploitation, and patching pipeline. In one run with our cyber model, it validated and generated patches for 948 local privilege escalation vulnerabilities in Linux at an API cost of $1.2 million.

Imagine if open-source organizations other than the Linux Foundation (and Mozilla I guess) could throw $1.2M of API-rate LLM usage at security.

reply
tamimio 2 hours ago
These are becoming more and more marketing materials than actual findings, because OAI probably hit the wall in making their models smarter (just like how google try to specialize their models in legal or whatever), but they need to remain relevant in the news. Sol 6.1 sucked so bad in reasoning that either it’s actually a bad model or users behind the scenes get degraded outcome while using all the resources for these marketing stunts. Stop, it’s embarrassing, make better models or be gone, at least we will get cheaper RAM to advance the development of open weights models.
reply
hoppp 2 hours ago
Well at least they are doing public service while hacking the planet.
reply