CrowdStrike's Falcon Sensor also linked to Linux kernel panics and crashes

Btw - The article mentions Dave Plummer's analysis of the issue which might be easier for people to understand and worth a watch. - https://www.youtube.com/watch?v=wAzEJxOo1ts

After all, who exactly would benefit from such a nefarious scheme to crash windows computers? Certainly not Crowdstrike.

Also, for Linux and especially BSD admins: has this incident affected your perspective on EDR/XDR systems in the kernel? What would you suggest as an alternative to ensure regulatory compliance?

But indeed, this really sounds like it was an internal error.

What am I missing?

Edit: I know it is supposed to implement "EDR", but it's always explained in the vaguest of terms.

EDR solutions hook into the kernel to log, and block system calls. They use this information to try and generically identify malware. For example you could detect ransomware by identifying a process that is enumerating a large number of files, reading from those files, and then saving those files.

For a SOC, you can also use an EDR to identify files, hashes, connections to given IPs across your fleet of servers. This can allow you to see what devices have been compromised. The EDR can then isolate them, by blocking network syscalls and allow only the SOC to access to investigate and remediate.

This is the value they provide (or at least claim to) to a cyber team

But they could be right, they may have an issue in their engineering department recently.

---

Speaking of,I wanted to mention a slightly related observation I've had recently scrolling through twitter (unfortunately) looking for information on this crisis. There are a lot of people who at least know enough technical jargon to probably work in IT or technology but they're using arguments like "it must be because of a DEI hire", for those who are unaware they're using "DEI" as a replacement for a hard-r N-word. In other words, I just learned that blatant racists are not a rarity in our corner of the world. If you're not one of them, I wanted to inform you of what they really mean. Fortunately I haven't seen this on HN so far :)

For example, patching nginx is not going to help if your user gets phished of an suth token that was explicitly supposed to let them run code on the server - bit catching that the code started browsing files elsewhere and sending data out will help you notice the breach.

Russia or China would certainly benefit from the ability to do this at a time of their choosing, and it's possible they could have an agent inside Crowdstrike, especially given China's history of industrial espionage.

This is actually the most important thing happening with EDR as a concept, it handles novel cases that have never been seen before, with a human review very quickly. Our csirt has an SLA of 3 minutes.

It's right there in the name acronym. Detection and Response.

Of course, white people making mistakes is unheard of.

Yeah it's quite frustrating how easily people latch on to the daily meme if it reinforces their preexisting prejudices.

Republicans calling Kamala Harris the DEI candidate in 3, 2, 1...

State Actors, given the current Geo-Political tensions.

You have to take a all-in-all broader view. I remember a while ago Kaspersky was accused of data-siphoning/spying from computers it was installed on and other nefarious activities. See New Government Ban on Kaspersky Would Prevent Company from Updating Malware Signatures in U.S. - https://www.zetter-zeroday.com/new-government-ban-on-kaspers...

As for your opening statement "Some part of a company already aware of an issue but different part still ships is a pretty common tale" is not applicable here since this code runs in kernel mode (in both OSes) and thus would be subject to far far greater scrutiny and testing than an ordinary app. As Dave Plummer points out in his analysis Microsoft Kernel Drivers are signed and certified after an exhaustive testing process. Even if Crowdstrike wrote their drivers as an interpreter and the data update files were actually programs in some p-code, Microsoft would have definitely known of it and its inherent vulnerabilities. I would bet money that Microsoft knows all about preventing threats/vulnerabilities than any other company simply because of their long experience and large userbase and thus would not have allowed Crowdstrike such a free hand.

That's what you get if you browse Twitter. Stay off mainstream Twitter for your own sanity.

> Fortunately I haven't seen this on HN so far :)

Here people just blame offshore workers for this bug or other such critical bugs, as if US workers don't make mistakes. Peoples' egos are just unbelievable. If it's not DEI developers, then it must be those filthy foreign programmers from developing nations responsible for poor quality software and I've even seen here mentioned that Windows worldwide dominance also be blamed on SW devs from developing nations for being too poor to own Macs. I despise this "holier than thou" mentality of some privileged tech workers.

I'm curious about what you mean though, if you have any sample threads.

There is a certain type of tech person (well, they probably exist elsewhere, but the tech variety is particularly noisy) who seems absolutely determined to use this one every time a company does something stupid; there seems to be an odd unwillingness to blame _process_, rather than some sort of imagined individual saboteur (who would, preferably, in the minds of these people, be someone other than a straight white man).

A particularly extreme example, to the point that it almost read as parody; when the door plug blew out of that 737, there was a certain amount of fixation by the weirdos on Twitter on how the pilot was a woman. Quite how this was supposed to have anything to do with it was unclear.

The whole thing is pretty weird, and feels quite new. Sometimes, a poorly-run company is just a poorly-run company.

Like, this is not new. They, as an industry, have been a byword for shoddy nonsense for literally decades.

Imagine actually being a minority, woman or any group like that and making a mistake. sucks.

The redhat kernel panics were caused by a bug in the kernel ebpf implementation, likely a regression introduced by a rhel-specific patch. Blaming crowdstrike for this is stupid (just like blaming microsoft for the crowdstrike bsod is stupid).

For background, I also work on a product using eBPFs, and had kernel updates cause kernel panics in my eBPF probes.

In my case, the panic happened because the kernel decided to change an LSM hook interface, adding a new argument in front of the others. When the probe gets loaded, the kernel doesn’t typecheck the arguments, and so doesn’t realise the probe isn’t compatible with the new kernel. When the probe runs, shit happens and you end up with a kernel panic.

eBPF probes causing kernel panics are almost always indication of a kernel bug, not a bug in the ebpf vendor. There are exceptions of course (such as an ebpf denying access to a resource causing pid1 to crash). But they’re very few.

Yeah, it isn't as if crowdstrike was specifically advertising certified support for RedHat Linux and related products.

https://www.crowdstrike.com/partners/falcon-for-red-hat/

In that case are you telling me their pitch is that they detect this behavior, dispatch some human agent from their CSIRT within 3 minutes to remotely but manually come check the binary, dump some strings, do some reverse engineering and track the CC server etc?

I love a good conspiracy just like anyone. And i certainly hope the relevant authorities will take a good, deep look at what knocked over the dominoes CrowdStrike set up in a line. But i just don’t see how those state actors would benefit from this. There is damage, both financial and humans harmed, but is that the best a state actor could do? I would have thought they would sync such an action with other measures for maximum impact.

> You have to take a all-in-all broader view.

That is always wise. Can you tell us more? In particular could you spell out how the Kaspersky ban factors in here in your opinion?

> As for your opening statement "Some part of a company already aware of an issue but different part still ships is a pretty common tale" is not applicable here since this code runs in kernel mode (in both OSes) and thus would be subject to far far greater scrutiny and testing than an ordinary app.

Are you saying that this scrutiny is somehow enough to overcome companies natural tendency to be disparate and unorganised?

But that doesn't seem to be what happened here.

Random idea that I haven't fully thought through: continue to run the kernel at Ring 0 and userland at Ring 3, but move "tools" like this to Ring 1.

My perspective is that it is a very very poor idea to have an anti-malware solution running on a Linux system. CrowdStrike is very persistent in their sales pitches and do FUD campaigns better than the competition to convinse people with decision making authority that Linux and Containers and what needs an antivirus.

It's new because, 10-20 years ago in America at least, it finally became extremely unfashionable to utter blatantly racist stuff in public, to the point where it cost you your friends and maybe your job, depending on who heard it. But then Trump happened, and casual racism became OK again among half the population, like the 50s have returned.

Linux has been a viable alternative for decades now for many tasks. This problem wasn't caused by a lack of money. If you want to blame someone for the dominance of Windows, blame corporations and managers, because they're the ones that have chosen it. SW devs from developing nations have only been doing what they perceived to be in their best economic interest.

And even if it has ring 0 access it can’t really verify anything without secureboot or something like it verifying that nothing else started before it. This is also why Riots anti cheat runs as ring 0 as it has to protect the game against the owner/admin of the machine.

(And after that there is still bios or firmware level exploits)

Wait, how is this stupid? Unless I'm missing something, wasn't the patch part of a Microsoft payload that included an update to Crowdstrike? Surely Crowdstrike is culpable, but that doesn't completely absolve Microsoft of any responsibility, as its their payload.

Obviously OS updates come out a lot more often these days than they used to - but we're also better at test automation than ever before, and beta software is easier to get than ever.

It sure would be nice if companies that decide to produce kernel modules and to support certain OSes could test those kernel modules against those OSes at the beta stage.

But how are they supposed to prevent a bug in a newly released kernel update? You can't test your software on future updates that aren't out yet.

If RHEL breaks some core functionality you depend on, in a newly released update, you can't really do much to prevent breakage, even with the best QA in the world. At best, they could have caught it as soon as RHEL published the new kernel... but by then it's already too late, all your currently-deployed probes now have a ticking time bomb, and need to be updated before the RHEL kernel update is applied, lest you kernel panic.

2. RHEL didn't provide beta kernels before very recently, as far as I can tell.

3. Even if you caught an error then, you're still at the mercy of RHEL to fix it. If RHEL breaks a feature, you report it to them, and they decide to ship anyways... well, your product will still kpanic. I'm not talking hypotheticals: I haven't seen RHEL do that, but I've seen other distros do it.

Crowdstrike is not in the business of selling to people who know WTF any of that means.

Crowdstrike is in the business of selling to people like the CEO of Southwest Airlines. Their pitch is "The definitive AI-native SOC platform; Forrester named CrowdStrike a Leader in The Forrester Wave for Managed Detection and Response (MDR) in Europe; IDC MarketScape name CrowdStrike Named a Leader in Worldwide Risk-Based Vulnerability Management Platforms 2023 Vendor Assessment"

If the CEO consults people lower in the hierarchy, the pitch is "Some asshole has decided you need to be SOC2 compliant, that means you need to run antivirus, our product will check that checkbox and though our product is not good, it is at least better than mcafee or symantec"

this comment right here sums it up:

> Sure, but Windows shares some portion of the blame for allowing third-party security vendors to “shit in the kernel”.

https://news.ycombinator.com/item?id=41006176

If say you support a distro, you can’t turn around and complain that supporting the newest version is hard, no matter who caused the problem. Plenty of products say ‘this works on $x but it’s not officially supported’.

nowadays i work at a place that uses a different solution and guess what: it's also a f-ing cpu (and i/o) hog -- it makes my m1 pro macbook slow to a crawl and there's no way to disable it.

For decades?! Maybe on the servers, but on PCs, hardly. Also, even if that may be the case now, it doesn't change the fact that at your job they'll most likely use Windows not Linux on the workstations. Linux is king on the servers, but PCs everywhere will mostly still be Windows, especially in corporate environments.

How many Linux machines did crash a few days ago? How many Windows machines did crash a few days ago? Case closed.

Where Microsoft is to blame however is the unrelated Azure outage in the Central US region that happened (and was fixed) just before the CrowdStrike faulty update.

What is the point of driver signing if a vendor can basically build in a back door and Microsoft doesn't validate that this back door is at least somewhat reasonable

While it wasn't as easy as it is today, I've been running Linux on my home desktop since around 1999. It's never been that hard, and it did require more careful hardware selection (no, you can't just grab some random dirt-cheap piece-of-shit "winprinter" and expect it to work with Linux), but it's always been quite doable for anyone who claims to be skilled with computers. We're talking about IT workers here, not grandma.

>at your job they'll most likely use Windows not Linux on the workstations

This is exactly my point in my prior post.

> always indication of a kernel bug and before

but:

> blaming microsoft for the crowdstrike bsod is stupid

and who owns the kernel in windows land? Microsoft. how is it stupid to blame Microsoft for not making kernel safe?

Maybe most of these "drivers" shouldn't be in Ring0 to begin with? This is a general problem and the norm, Windows is just another OS that allows this this way.

And as security tools break a lot of security norms - like sandboxing, least privilege, and running in userspace - you might think such enthusiasts would make sure they were coded with the utmost care. That this team of secure coding all-stars would be code reviewing, managing scope, fuzz testing, static analysing, formally validating and suchlike, as befits code running with the highest privilege levels.

Surely huge multinational corporations wouldn't grant unlimited privileges to kernel modules written by clowns.... would they?

If you believe the crowdstrike marketing, I can see how you might think shadowy saboteurs are the only plausible explanation.

This update was buggy and it caused the host machine to go into a BSOD boot loop.

The fact that the host machine happened to be running Windows has very little to nothing to do with it.

It's like blaming a pothole for your car going exploding. Yes there was a pothole, yes it shouldn't have been there, yes it could have been avoided, but the fact that your car self immolated because of mere pothole points to possibly other underlying issues with your car.

You should never stop at obvious/superficial explanations but look at all scenarios (i.e. Game Theory probabilities) including "false flag" operations. Eg. a) What might have happened elsewhere when the world's attention was focused on this one incident? Did we miss something of greater importance? b) Was this a dry run/false flag to get businesses to tighten their cyber defences because somebody knows something about what might be forthcoming? c) The Russia/Ukraine war seems to be entering a critical phase with increasing incidents across NATO countries; see https://edition.cnn.com/2024/07/10/europe/russia-shadow-war-... etc. etc. At the minimum there has already been billions in damage and counting; one Australian report - https://www.youtube.com/watch?v=YedowOtznNo

> how the Kaspersky ban factors in here in your opinion?

Because this is very recent news; see https://www.zetter-zeroday.com/kaspersky-lab-closing-u-s-div... Is somebody flexing their attack capabilities just to demonstrate they can do it without Kaspersky? Also the US govt. has specifically banned "updating of malware signatures" in Kaspersky software which was exactly the vector used with Crowdstrike.

> Are you saying that this scrutiny is somehow enough to overcome companies natural tendency to be disparate and unorganised?

Yes. Companies do not treat kernel mode code with the same laissez-faire attitude that they might take with user mode apps. In particular, Microsoft has the most experience with this given their long history/evolution/problems and sheer number of installations. That they would allow some third-party software to bypass their testing/certifications is unbelievable to me. I am sure they would have also done some formal verifications on this as well. Remember Crowdstrike was meant to help prevent zero-day vulnerabilities and hence they would have looked at it closely.

When certain things happen at a global scale, you have to take a global view, factor in parameters like Geopolitical tensions, Economic advantages/disadvantages, Propaganda, etc. and simulate all possible scenarios one by one w.r.t. all parameters.

Remember Clausewitz, “War is not merely a political act but a real political instrument, a continuation of political intercourse, a carrying out of the same by other means”.

Also Sun Tzu, “All warfare is based on deception. Hence, when we are able to attack, we must seem unable; when using our forces, we must appear inactive; when we are near, we must make the enemy believe we are far away; when far away, we must make him believe we are near.”

Finally, you might find the classic Deception - The Invisible War Between the KGB and the CIA by Edward Jay Epstein very relevant here - https://archive.org/details/Deception-TheInvisibleWarBetween... "Deception" is the foundation for everything and "Asymmetric Warfare (Cyber and others)" is the name of the game today.

Was it though? Your second paragraph is written in a way that it can easily be interpreted as "all critics of DEI hiring are racists". Is that a more sophisticated statement than "all minorities are incompetent"? Is being a racist the only reason someone might be opposed to quota-based hiring?

Eh, I mean, you might think that, absent any other information about the industry, but they're largely not.

AIUI, Microsoft actually has good tooling for validating drivers before they are deployed, but it requires that you actually run the validation...

For the kernel mode, their software will flag an unknown kernel as unsupported and go into a reduced functionality mode (rfm).

The idiots didn’t know that RH E4S was a thing for like 3+ years.. I’m still baffled by how clueless most of the security people and vendors are when it comes to backporting and different streams / channels that are offered by multiple Linux OS vendors.

https://access.redhat.com/solutions/7001909

Wherever I've seen diversity initiatives, the point is to expand the hiring pool, not shrink it. In other words this is people who, for whatever reason, want to portray the situation as precisely the opposite of what it is.

> Missing a check (or precondition, or validation) is squarely on Microsoft.

Missing a check for presence of dynamite before allowing me to start the car is squarely on Volvo!

You see how silly that sounds?

Now, back to being serious: MS cannot possibly control and validate everything you decide to install and run on your system, specially if the things you install are kernel drivers. It is simply impossible. If you install a kernel driver developed by a 3rd party company, and that driver crashes your system because the devs at that company forgot to perform proper validation of data, well... that's on them. Even if MS wanted, they wouldn't be able to verify the soundness of any piece of code that is installed as a driver and runs with kernel level privileges. That'd require solving the halting problem.

Very easily could be one highly technical or just highly resourced individual with a bot farm..

Isn't that exactly the problem though: hiring is currently based on race/gender in favor of white/male hard enough that you get interior people from that hiring pool?

Backdoors of all kinds can be installed to most any operating system without vendor co-operation. That is the nature of general-purpose operating systems.

But then you are in position to share your customers that this will happen before it actually does and they can choose their way of proceeding.

One such way would be being careful with the update and then exercising their own support contracts with RH.

Personal anecdotes are not statistics or cases representative for the average user or business. What others do with their systems and their requirements and apps could be very different than yours. You think if Linux was that usable at everything in 1999 companies and individuals wouldn't have loves to use that instead of paying thousand of dollars to Microsoft?

Just because you could set it up and use it in 1999 doesn't mean it was the norm. Some people know how to change their own oil while most don't and don't care to since they prefer to pay someone else to do it as they have other hobbies than learning to tinker with their car. Similarly some people like you like to thinker and find out how to get Linux to work in 1999 while most prefer to just pay to use Windows NT/MacOS and get to work.

my zsh config spawns in ~90ms on my macbook air m2 while it takes 600ms in the m1 pro.

Probably because they had already looked at the modification which was benign so slower escalation path in absence of other indicators.

eBPF is a bytecode that is interpreted in the kernel, with the explicit goal to allow writing code that executes at the kernel-level in a safe way. Any kernel panic (again, short of pid1 kills) is considered a bug, and could even potentially be exploited to gain capabilities in some cases. Here, the kernel explicitly says "this is safe", so any problem within is a bug in the kernel.

In contrast, a kernel module/driver is just some third-party code that is loaded in the kernel. Here, all bets are off: it is up to the third-party to do their job properly and make sure their code is correct.

In this case, CrowdStrike explicitly opted into writing a kernel module, and then failed to, as you say, "handle their null check". The segfault wasn't in Windows code, it was in CrowdStrike code that lives in the kernel. Crowdstrike should have handled their nullcheck, failed, and that will lead to a BSOD.

To be clear: the only way microsoft could make the kernel safer here is by disallowing kernel modules entirely. While there is an argument to be made that this could be a good idea, it is a bit beside the point.

On the other hand, Linux is similarly crippled: eBPF LSM are fairly recent and don't work everywhere (I'm looking at you Ubuntu[0]), and the only real alternative if you want to be able to block processes is a kernel module. Which comes with the same dangers as Windows.

[0]: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2054810

If you expect software to be future-bug-proof, well, I guess you live in a far better world than I do.

If you advertise your software to be compatible with RHEL, but a glibc bug gets in and causes your sw to crash for a couple of days, before RHEL realises the problem and fixes it, does that mean your software should instantly no longer be advertised as RHEL compatible? That'd make things a lot more confusing, if you ask me.

From my understanding the CS driver lives in the kernel space and parses configs/applications downloaded in the user space. Hence the system even does a BSOD.

"CrowdStrike doesn't have kernel-level ACE" please provide your source.

oh the jargon

> We're making progress by the minute

I better hope you do.

To clarify, I'm not to keen on DEI either, but we're not really talking about DEI here are we now?

Except where Apple does not allow vendors loose in key places like the kernel. One of the interesting questions here is whether Microsoft could possibly do that: Windows users would be better if the kernel was restricted to first-party code, things like AV used the same kind of interface which macOS has, and third-party code was forced into more moderated channels (malware uses many of the same techniques) – but there’s a security industry with revenue measured in tens of billions of dollars annually who would be running to the regulators if there was anything which could remotely be seen as favoring Defender over their products. I still think it’d be possible but hard enough that I’m not surprised they’ve slowly been letting awareness of the downsides build, especially on the enterprise IT side.

I was wondering whether this debacle might push them to have a roadmap for restricting kernel drivers in favor of the Windows eBPF implementation which has been approaching production grade. Sometimes you need a huge blowup to remove support for the status quo.

That would be grounds for blacklisting indeed (out of experience). However, that's not the case here, no matter how you put it.

I hate all the EDR nonsense on laptops. I wonder if the added cost for lost workhours and electricity wouldn't be more than the tiny chance of catching a malware.

I have my doubts, but that's at least what they give as the reason for the kernel-level access of EDR tools.

Once I got new laptop due to some internal migration, it was blazingly fast. Well, not so much anymore. I literally don't install anything on it since receiving it, I simply can't (unless its just about copying to c: and it runs). Some colleagues have stuff like windows firewall running constantly on 50% cpu, nothing admins can fix apart from replacing ntb.

I would really hate to be anyone on the team responsible for the Falcon Sensor, right now. I suspect that their printer is churning out CVs, like nobody's business.

> and will update this story if we receive substantial information.

I'll lay odds that there's folks at Crowdstrike that are thinking of just responding with poop emojis.

Inertia is a strong force in corporations. I wouldn't count on reason there, inertia triumphs it.

Personal anecdotes is something that shows it can be done. In few corps I worked since 2004 I was also able to switch windows to linux (as many other developers there) and we didn't loose functionality. But I get it that for people that work mostly in excel it would be a blocker, as it doesn't have Linux version - so not all work could be done on Linux. But having options is good.

My current corp decided to give people a choice (after a decade of asking for it) and since 2 years we can choose between Windows, macOS and Linux.

(I'm still amazed that most developers chose macOS, as it is less power user friendly than Windows). Before I was the only one with Linux, now there are > 20% of us. And possibly more in the future when hardware will be upgaded.

RHEL 'updates' can mean different things. A patch release won't change kernel ABI. A minor release will. Writing a non-CORE eBPF program for, say RHEL 8.6, might break on RHEL 8.7. It's not advisable to update across minor releases without lots of testing. Most of the time, things 'just work' but RHEL is a very complex product with a specific support cycle, and laziness of users and 3rd party vendors is not their fault.

Before you downvote that comment, I'd like to remind everyone that this was already happening. Realtek's driver cert was leaked, and a lot of malware used this cert to sign their drivers for _a decade_ until anything happened about it.

Microsoft's driver signing workflow is utterly pointless and it doesn't mean anything. Any vendor that takes their security serious should never trust those driver signatures.

but AFIK no sources I trust have yet claimed it

but it's probably where the idea comes from

How would you stop, detect and/or remove this threat from this machine on a linux server without antivirus / EDR?

It would be one thing Microsoft could do to focus 100% of the attention/blame away from Windows and onto CloudStrike. And customers will want their pound of flesh from somewhere.

Really, this should serve as a wake up call w/in Microsoft to start to harden the kernel against such vulnerabilities.

Was the crash the fault of Windows? No. But did a Windows design decision make this possible? yes.

I’m sure the design decision made sense at the time (at least business sense). Keeping the kernel more open for others to add drivers to makes it easier to write/add drivers, but makes the system more vulnerable. This a good opportunity within Microsoft to get support for changing that.

Perhaps you should push this change up in the food chain, then, and if the company is good the request will be taken seriously. As I understand it, while CrowdStrike is the biggest name in EDR, it's far from the only one, if that's what your company requires to pass some checkboxes in certifications.

user-land drivers are a thing, heck they are the standard for modern micro kernel architectures

and even with hybrid kernels pushing part of the code out of the kernel into something like "user land co-processes" is more then doable, now it's now trivial to retrofit in a performant way and flexible way but possible

Mac has somewhat done that (but I don't know the details).

On Linux it's also possible, through with BPF a bit of a in-between hybrid (leaving some parts of the drivers in kernel, but as BPF programs which are much less likely to cause such issues compared to "normal" drivers).

A good example for that is how graphic drivers have developed on Linux, with most code now being in a) the user-land part of the driver and b) on the GPU itself leaving the in kernel part to be mostly just memory management.

And the thing is Windows has not enforced such direction, or even pushed hard for it AFIK, and that is something you can very well blame then for. You in general should not have a complicated config file parser in a kernel driver, that's just a terrible idea, some would say negligent and Windows shouldn't have certified drivers like that. (But then given that CrowdStrike insists that it _must_ be loaded on start (outside of recovery mode) I guess it would still have hung all systems even if the parsing would have been outsourced because it can't start if it can't parse it's config).

CrowdStrike doesn't remove threats. It would stop the process and quarantine the file. It requires knowledge on how to actually remove the threat beyond the quarantined file.

If by changing the system you mean adding some kind of in-kernel isolation to it, then I don't think it would be worth the effort to make that kind of major change to the way operating systems work just to give arguably a minor risk reduction to systems—in particular if CrowdStrike and other vendors take some learnings from this event.

Microsoft might improve their system rollback mechanism to also include files that are not strictly integrated to the system, merely used by the parts that are (the channel files loaded by the driver).

Actually I think we can just be happy that the incident was a mistake, not an attack. Had this kind of "first ever" situation been an attack, it could be extremely difficult to recover from it. I wonder how well EDRs deal with "attacks from within"..

CrowdStrike pulled off the update within 1.5 hours. I wonder if they actually use Falcon themselves? But then somehow missed the problem? Doesn't seem like they eat their own dog food :). (Or at least their own channel files.)

- apache2 crashed on VM (had not happened in 8 months--our entire tenure at Hetzner

- another VM become entirely unresponsive--would only respond to ping. could not even access via control panel provided console. had to do a reboot. after that, the box seems to be ok.

- we are still waiting on a response to our ticket from Hetzner.

In reality, that's way too much data for anyone to make sense of, but giant companies spend tens of millions of dollars per year to deploy all the things so they can say they're doing it.

On the other hand, funny things can happen. I got called out by the security team at one job because the EDR agent on my workstation registered that I had put a file on disk that had a malware signature. Well, it turns out that I had checked out the security team's git repo containing malware signatures...

But I did get called out in about 20 minutes by a random security engineer I'd never met who told me the exact path on my PC where the file was. Is that a good thing? I'm not sure.

Not on Kernel level. Not without active support by the vendor.

Some people have built their own car from scratch in their garage that they use to drive to work, but it's unrealistic most people do that at scale, even though someone proved it's possible. The same way, why aren't you building your own car to daily drive and instead paying Ford/Toyota? Someone proved it's possible.

> In few corps I worked since 2004 I was also able to switch windows to linux

The vast majority of Windows/MacOS users are not SW-developers, nor to they have any deeper interest in tinkering with computers and learn Linux. They're content with what they're already familiar with.

You keep taking highly niche technical cases from your SW dev bubble and trying to extrapolate that experience as being mainstream when you're far from it. The photo studio or flower shop down the road in 2004 was no way gonna switch to Linux even if it was technically possible.

Actually I could easily see a buggy remote system management update could just decide to uninstall everything and nuke the system, because it thinks it's stolen. And it would be designed functionality for it.

> An eBPF probe should never cause kernel panics.

Should, but did. This is the point at which to learn and adapt.

Also, kernels are software just like nearly everything else, and software is buggy. It's a balance obviously, but some basic defensive development can be a real savior for your users.

I don't know the details about this CrowdStrike incident, but I would also be surprised if you couldn't write an automated test (even a "smoke test") to quickly test out these new kernels before they hit your customers. Given what happened, it seems like negligence not to do that.

Then you better tell your customers not to `dnf update` until you've had a chance to whitelist the new kernel and ship it in your own stream. Otherwise everyone who updates before you do ends up broken. If a vendor told me that, I would laugh, realize they were serious, thank them for their time but let them know that we will be going a different direction.

To me this feels like a complicated question - both Linux and Windows organisations are quite good at kernel reliability engineering even though quite different organisational structures and engineering approaches are involved.

Yes "the wrong people were trusted" but I don't see how we can completely solve this with engineering.

I talked to my dad (retired enterprise operations/IT) this weekend and he was telling me that the next computer he buys will probably be a Mac, largely because he doesn’t want to deal with the possibility of a crash like this. Does he run CloudStrike? Not at all. Does he know who they are? Nope. (He’s been retired for a while) What he does know (well, thinks) is that Windows now has an unstable kernel.

And Microsoft has no control over distribution policies for other vendors. How those vendors distribute updates is up to them. Even if a sane deployment strategy could have avoided the larger global problems, Microsoft can’t control that.

So, if you have Microsoft dealing with negative publicity and public sentiment, with no way to control errors like this in the future, what can you do? To me, the best they can do is kneecap CloudStrike, put the full blame on them, and use this as an excuse to change the kernel/driver model to one where they can have more control over the stability of the OS.

Even here it's pretty hard to blame them due to antitrust concerns. Just google the word Patchguard.

If we were _really_ serious about endpoint security we'd be pushing business users towards operating systems with more modern security architectures, like Android, iOS or Chrome OS. That would be a lot of work though due to the fact that most legacy software is not compatible with those systems.

Though as this article and its Red Hat respondents admit eBPF isn't a perfect solution either because it is still a somewhat Turing Complete scripting language and bad vendors will find ways to get kernel panics out of eBPF scripts no matter how hardened the eBPF driver gets.

Microsoft is probably in a good position to use this debacle to push more vendors to Windows' implementation of eBPF. It doesn't solve the crisis that a vendor like CrowdStrike exists that is "beloved" by Enterprise Solution Architects for all the compliance boxes it checks, but is run as a terrible software company with bad standards and has multiple "accidents" in recent weeks.

That's my understanding as well, but not quite the same as

> execute arbitrary code on the kernel level without any checks

At least for me, when we talk about kernel-level ACE, it's something like libcapcom[0], which allowed executing arbitrary unsigned code in the kernel.

Here, the driver can only execute the code present within itself, which was signed by Microsoft. The configuration itself isn't signed by microsoft, but the config isn't code (at least, as far as I can tell - I see some people claiming the CS-0000.sys files are essentially bytecode, but have yet to see conclusive proof of this).

Now, we could argue that it's weird that Microsoft signed a buggy driver, and MS should do better qualification of third-party drivers. But in practice, MS doesn't really vet driver quality. From what I can tell, the driver signing is mostly there so they can easily attribute provenance of drivers, and revoke the certs if it ends up in the hands of malicious actors.

[0]: https://github.com/notscimmy/libcapcom

Maybe I'm wrong and Microsoft does some QA on drivers before they are signed?

"We have magic code that watches everyone's computer and sends it all back to our system, where we apply magic to detect malware and then send the code back to all of your systems and until we can say we have AI, we're going to lie that a human will be able to review this information in 3 minutes.

I've worked for a company that installs Falcon on all its fleet and I never run into issues like yours.

Bullshit about "they had already looked at the modification which was benign".

So your "security" is to totally expose every operation of your software to an external party with absolutely no auditing of what data they are exfiltrating from your system?

CIO/CISO don't select vendors lightly.

There seems to be a typical/classical Engineer's mindset of "make a claim first, ask later" around the subject lately.

"My boss plays golf with Sales Rep" might need more proof because if they selected the lesser capable vendors and they got hit with ransomware, bet my ass your boss will no longer play Golf with any Sales Rep ever.

macOS has a userland API for this, called EndpointSecurity, which allows doing all the things an EDR needs, without ever touching kernelland. Microsoft could introduce a similar API, and EDRs would no longer need a driver.

It would certainly help solving this particular problem, even if not the kernel-integration in general.

Microsoft could even reinstate CloudStrike at some point, but only after an extensive review process. And then probably require similar process reviews/checks for any other vendor that requires the same kernel access.

Or just remove the need for kernel access at all and migrate to a better driver architecture at the sacrifice of backwards compatibility. Security software doesn’t need to run in kernel space… there are other ways.

Also, tripwire was limited to periodically scanning files, couldn't scan for example syscalls and trace relationships between them.

But yes, tripwire is a very early EDR/XDR.

I’m sure the reason why Apple migrated was because of all of the bugs/crashes security companies kept introducing into the kernel with kexts. Apple had the ability to change their architecture on a whim because of they aren’t quite a beholden to backwards compatibility as Windows.

Microsoft could take this as an opportunity to make some major changes that would be more readily accepted by the market.

Imagine if any minority or woman was involved in any crowdstrike team that had anything to do with this outage and consider how the DEI debate is being raised in that context. If those people are hired, does it make them a DEI hire by default? of course not! that is silly, that's not even what DEI is. It is a slur in this context, nothing short of it.

I wouldn't be saying this if DEI was in any way relevant to the topic at hand, then we can discuss how DEI was to blame. Honestly, I don't even agree with the corporate approach of DEI, but bringing it up in this context would indeed be racism. Imagine making a mistake and someone say "this is what you get for allowing white privilege" is that fair? is that not racism? that's what's happening here. Everyone deserves fair treatment.

No we don't we just have compliance checklists to get through.

I think russia or china are probably the least likely purpotrators possible. Their incentives strongly disalign with this.

I disagree. If state actors had this type of capability they would use it to spy on big companies. The espionage potential is huge. They wouldn't waste it on causing a minor inconvinence.

> is not applicable here since this code runs in kernel mode (in both OSes) and thus would be subject to far far greater scrutiny and testing than an ordinary app

Lol. What next? Politicians always tell the truth? Everyone gets a free unicorn? This is just obviously not how the world works. There is a long history of anti-virus software being kind of crap.

I bet you a lot of people think DEI is companies go "you're black, you're hired". Instead you're absolutely right, it's manipulating the pipeline so that 50% are the overall best and 50% are diverse. The "diverse" ones also have to do great in their interviews, no one is automatically hired.

Who says that is not ongoing? You just don't hear about it that much because the companies downplay/hide it for obvious reasons.

> They wouldn't waste it on causing a minor inconvinence.

This is not a "minor" inconvenience. The losses to the Economy are already running into billions and counting. See for example https://www.youtube.com/watch?v=YedowOtznNo

> Lol. What next? Politicians always tell the truth? Everyone gets a free unicorn? This is just obviously not how the world works. There is a long history of anti-virus software being kind of crap.

Snark/Glibness is not an argument. I have worked in Network Security and know for a fact that Kernel mode code is treated differently than User mode code in terms of scrutiny/testing/staging/release. Second, Crowdstrike is not just another anti-virus software; they are far more broader in scope/complex and hence their wide user base. Microsoft with their wide experience would have definitely processes in place to validate them comprehensively. Hence one should be cautious in taking this incident at face value and investigate everything thoroughly. I am almost sure multiple lawsuits are in the offing but am not so sure whether the full story will come out.

They're different because linux promises "eBPF are safe and cannot crash the kernel", and failed to deliver on that, while Microsoft says "drivers are all-powerful and as such must be written with care", and CrowdStrike did not heed this warning.

> Yes "the wrong people were trusted" but I don't see how we can completely solve this with engineering.

I mean, we could solve the "third party software fucks the kernel up" problem easily with engineering: providing userspace APIs to do stuff that currently need kernelspace access. There's no inherent reason security products (or, really, any products) needs to live in the kernel, it's just that there are no APIs to do this job, so security products have to go there. If Microsoft provided a good API doing what the custom drivers currently do, most security products would drop their driver in a heartbeat.

For instance, macOS fixed this exact issue a couple years ago by introducing Endpoint Security Framework, a userspace API that allows watching a bunch of events, and authorizing whether they should be allowed or blocked. It's a well-designed API that should obsolete the need for kernelspace access in security products.

We're not talking about regular people here. Try reading the prior messages for context before commenting. We're talking about people who claim to be IT professionals. If they were really as smart as they claimed, they could have done the same thing I did easily. They didn't, not because they loved Windows that much (maybe they did, maybe they didn't, it's irrelevant), but because it was seen as essential for their career.

Why is it so hard for you to understand that we're not talking about average users here?

we have crowdstrike in our usual production environment and i was always against it because i was always afraid of something like what happened. but security department pushed it through because this is something that they understand and can control. "security architecture of product" it's not concept that they understand.

but answering your question, fedramp does requires EDR to be present. according to our fedramp advisors clamav is sufficient for passing audit.

Not even that; it’s changing the pipeline so that it has a lower weighting on upper-middle-class white men who went to one of about four universities (which does not actually equate with ‘overall best’). One surprisingly simple thing that companies can do is be realistic about their requirements in the job spec. There’s a fair bit of evidence that if you have an aspirational job spec, then some candidates will go “well, I meet some of that” and apply, and others will go “well, I only have five years of experience in [whatever], not six like it says in the job spec” and won’t apply. And group 2 tends to be less male, less white, and more working-class.

They did not choose Windows because a bunch of devs from India were too poor to buy Macs, which was the original assertion.

But if it runs on the same privilege level as the rest of the kernel, then isn't it, for the purposes of this discussion, in effect "a kernel module"?

Sure, in a well-functioning market economy without any distortions. But there are lots of those at play, so competition is severely hampered (by network effects, regulatory capture, and on and on... Up to and including, I suspect, mere ephemeral fashion). What we actually have in many areas of the "tech market" are oligopolies and near-monopolies, not perfect competition.

> CIO/CISO don't select vendors lightly.

Muahaha. Seems rather more like they're at least as naïve as any Web-surfing consumer on their sofa, easily bamboozled by trendy buzzwords and slick marketing campaigns.

Falcon uses apis like eBPF when available/usable , they are not stupid if they can use something which is more secure and reliable why should they not use it.

E.g. they use it on Linux, even through they could have created a custom kernel module (idk. if they maybe also have a custom kernel module tbh.).

And pushing for something doesn't mean banning other things. E.g. they could certify "following best security practices" and not give it to vendors not using the more modern APIs, while they can't block drivers based on it with the right marketing customers of CrowdStrike wouldn't want to buy it without such cert.

I.e. while MS doesn't provide viable ways to get the functionality Falcon and similar need without kernel modules it indeed would be a bit ridiculous for them to ban such software, and as of yet the do not.

According to the comments on https://access.redhat.com/solutions/7068083, RHEL became aware of the issue on May 3, 2024.

A workaround was identified (configuring CS to use the kernel module backend instead of the ebpf backend) on May 9, 2024.

RHEL then fixed it in kernel-5.14.0-427.18.1.el9_4, in May 23, 2024.

So the bug was fixed in ~20 days from the moment it was reported.

It's unclear whether this issue was caused by a RHEL-specific backport/patch or was also present in mainline kernels.

1) Those Crowdstrike unit files aren't ebpf probes, so the whole subject of ebpf probes is irrelevant here; or

2) They're obviously able to stop the rest of the kernel from even booting up (as Crowdstrike so convincingly demonstrated millions of times over[1]), so yes, they do indeed have at least as much power as any other bit of the kernel.

Either way, hunting around for nits to pick is a bit pathetic.

[1]: In July 0000002024...

i wasn't hunting around for nits to pick; i was hunting around to see if you'd ever contributed any useful comments to the site. instead i found you making authoritative pronouncements about ebpf that were so wrong that you had evidently never read so much as a one-line summary of what ebpf was for. do you have a more promising historical comment to offer? perhaps something where people complimented your contribution as being informative?

have you ever made a worthwhile comment on hn?

on thursday, wahern posted this comment https://news.ycombinator.com/item?id=41061179 where they traced through the illumos/opensolaris source code to track down how a peculiar solaris interprocess communication mechanism worked, an investigation i had started but gotten stuck on. why can't you make comments like that instead of harassing me about how i format my comments?

the reason i'm asking is because i'd like to be able to talk to more people like wahern, but most of them avoid this site. a major reason why is that comments here frequently receive vacuous, aggressive responses like the comment you made the day before in https://news.ycombinator.com/item?id=41056718, where you launched a personal attack on me because you didn't like how i was formatting my comments

i'd like you to ⓐ apologize for doing that (this is not the first time you've done that to me personally; so far i haven't looked through your comment history far enough to find out how many other people you have a history of repeatedly harassing) and ⓑ commit to not doing it again

because i'm sure you're capable of making comments that make the site better instead of worse

> have you ever made a worthwhile comment on hn?

I might answer that. If I thought you were owed any justifications from me. Which I don't.

And no, I'm neither “harassing” you nor being “vacuous, aggressive”. This isn't ad hominem, it's ad habitem. You write here for other people to read, and I'd even appreciate many of your comments -- if they weren't so infuriatingly idiosyncratically formatted as to disrupt fluent reading. Have the fucking courtesy to write like a normal person, and you'll be treated like a normal person. To begin with, get the shift key on your keyboard unstuck so you can start your sentences with capitals. And in case your dot / period / full-stop key is totally gone, copy-paste some of these: ........... So you can end them properly too.

Because I'm sure you're capable of making comments without coming off like an illiterate buffoon.

And yes, BTW, you totally were. Careful now, you don't want to end up like chockablock again, do you?