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Critical Security Hole in Linux Wi-Fi
Posted by
CmdrTaco
on Sun Apr 15, 2007 10:34 AM
from the nobody's-perfect dept.
from the nobody's-perfect dept.
thisispurefud writes "A flaw has been found in a major Linux Wi-Fi driver that can allow an attacker to run malicious code and take control of a laptop, even when it is not on a Wi-Fi network."
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patched already (Score:4, Insightful)
So here is a Linux driver problem, a patch is available, though not widely dispersed. The news here is that even in a largely neglected (though it shouldn't be) slice of the Open Source technology, specifically the deadly difficult wi-fi landscape, bugs are found and fixed right away (at least that's the gist of part of the article).
I'm more afraid of the neglected patches MSFT deems behind closed doors as not important enough to reveal to the public. How many zero-day exploits is MSFT discussing behind those closed doors right now, and what are they deciding about the fate of security to my machines?
I know I'm spinning here, but I don't find it much of a stretch to interpret this as good PR for the Linux world -- they find problems, they fix them.
(It doesn't seem to fix the other problem... I'm so sad and tired of trying to get laptops running linux reliably with wi-fi, I barely even bother messing with it anymore... If I want wireless linux on a laptop, I'm doing via Vmware's bridge. It shouldn't be like this.)
Re: (Score:3, Informative)
Re:patched already (Score:5, Insightful)
Parent
Re: (Score:2, Informative)
Re:patched already (Score:4, Informative)
The module in question is found here [madwifi.org]. (slow to load)
Parent
Re:patched already (Score:5, Informative)
Or rather, a small open-source Linux compatibility shim around the actual, binary only driver.
Look further into that link you pasted:
http://madwifi.org/browser/trunk/hal/public [madwifi.org]
Those
> The module in question is found here. (slow to load)
Ah, so the flaw is in the open source shim part. Fooey. =/
As an aside, and as I suspect you might already know, there is an effort to replace the binary-only part of that driver with Free software, and the Madwifi people have cooperated as much as they're able. They even host the development in their own repository:
http://madwifi.org/browser/branches/madwifi-old-o
Cheers!
Parent
Re: (Score:3, Informative)
Re: (Score:3, Interesting)
So the binary HAL layer is less than half of my driver and doesn't include frame parsing and generation or rate control, yet you'd like to call it a small compatibility shim? I'd say the driver is mostly open source.
As for the effort to reverse engineer the HAL, I think the chip versions are revised too quickly for that to be widely successful. Seems like a lot of work for little return.
Re: (Score:3, Interesting)
root@Callooh ~ =) # lsmod | grep ^ath
ath_rate_sample 11776 1
ath_pci 87456 0
ath_hal 189584 3 ath_rate_sample,ath_pci
root@Callooh ~ =) #
-shrug- No disrespect. I like, use and recommend to others your driver. It's by far the most complete of the many wireless ethernet drivers I've used with Linux.
Granted, when there's a fully free-software driver that will run my card, even if it isn't as complete, I'll be swit
Re:Freedom matters. (Score:4, Funny)
What part of "the flaw was in the open portion of the driver" did you manage to miss?
Parent
There's more to the world than Microsoft. (Score:5, Insightful)
What I see is more the horrible state of software security. A security model that relies on all the writers of driver code in your computer to do their job right is a poor security model.
I know I'm spinning here, but I don't find it much of a stretch to interpret this as good PR for the Linux world -- they find problems, they fix them.
Great.. I guess I'd rather have the Linux World where there aren't any serious problems to begin with. The larger picture here is that computer security kinda sucks, not that Microsoft is better/worse at it than Linux is.
I'm so sad and tired of trying to get laptops running linux reliably with wi-fi, I barely even bother messing with it anymore
Huh. I've had very good luck recently with Ubuntu. The built in wifi in my laptop worked out of the box with Ubuntu, and two other cards I own worked as well.
It hasn't always been like this of course. A couple years ago WiFi support was extremely lacking.
Parent
Re:There's more to the world than Microsoft. (Score:5, Insightful)
1. It just isn't possible to make software ultra-secure and free of vulnerabilities. I.e. you cannot expect *any* piece to be 100% secure, ever.
2. It is possible, but the costs of making software ultra-secure is so high that it's not worth it. Customers would rather pay a lower price for a slightly less secure system than a much larger price for a 100% secure system.
Parent
Re: (Score:3, Insightful)
In the real world, there are just too many variables, both in software and hardware - OSs and hardware are much more complicated than they were 20 years ago - for that to be practical unless you're prepared to sacrifice a lot of functionality (ie. use a platform tha
Re:There's more to the world than Microsoft. (Score:5, Insightful)
3. C/C++ make it really easy to screw up.
Parent
Re:There's more to the world than Microsoft. (Score:5, Interesting)
The good news is that the rise of virtualisation means that IOMMUs are going to become a lot more common in the next few years.
Parent
Re:There's more to the world than Microsoft. (Score:4, Informative)
What I see is more the horrible state of software security. A security model that relies on all the writers of driver code in your computer to do their job right is a poor security model.
You're right. Unfortunately with the current design of PC hardware it's difficult to provide protection from poorly written drivers. For example, it's very common for drivers to be able to (a) initiate DMA transfers to/from any part of physical memory, and (b) lock the PCI bus by messing with the bus arbitration. You can do things like having an exokernel [wikipedia.org] -- small trusted multiplexers go in the kernel and the larger parts of your drivers sit (untrusted) in userspace, but performance generally sucks. Some hardware (eg. graphics cards) makes it hard even to do this.
Luckily virtualisation is driving better solutions, and they're coming to a PC near you soon (in fact, they've already come to the PCs I'm using daily, but those are test articles). Primarily with virtualisation we want to be able to hand off devices to untrusted guest operating systems. For example give each guest its own physical network card. That won't work too well if guests can stomp on each others memory using DMA transfers. The new hardware actually has hardware support to stop the guests doing bad things.
Look at Intel's VT-d [intel.com] for example.
Rich.
Parent
Re:patched already (Score:4, Insightful)
Wireless works out-of-the-box (or soon after) - with a recent distribution of Linux - on most laptops these days.
Parent
Re:Mod parent down (Score:4, Insightful)
In this case, the vulnerability is in a 3rd party driver and not in the kernel itself. Nevertheless the not-so-techie reader just reads "Linux vulnerability".
Btw. Dont forget that the public is used to hear about Windows vulnerabilities, they dont notice them anymore.
Parent
Re: (Score:3, Insightful)
People who are secure in the choices they've made don't need to trumpet them all over the place. In particular, they don't segue any possible (tenuous) link into a rant about the superiority of their choice.
Patched! (Score:2)
Fixed! (Score:5, Insightful)
You are overlooking the way that most Joe Linux users get their updates - automatically. When security flaws are found and patches are delivered, you can guarantee that the people who package that software at Redhat, Ubuntu, Debian and other major distributions are aware of the update. Those security patches will be tested and rolled out into the main update repositories, probably within 24 hours to all the mirrors worldwide. The automatic update daemon on Joe User's modern Linux distro will be downloading the update within the next 24 hours or sooner. From security patch being announced to patched home computer in 48 hours in the worst-case scenario.
One of the nicest things about the distro's automatic updates is that this applies to ALL packages in the distro. I don't need to worry about Apache needing it's own updater. So no - the average Joe running Linux does not suffer - he gets informed about the update or even has it applied without manual intervention depending on the settings. Joe benefits and so does the community who recognise that fixing security flaws promptly is key.
Cheers,
Toby Haynes
Parent
Re:Fixed! -not! (Score:5, Interesting)
It gets worse. I don't even know if I'm running a madwifi driver or not. I looked at the running processes, but there's nothing obvious there. I don't know if madwifi is called something else in the process list. I do know I have a Atheros chip.
The point I'm trying to make is more than just displaying ignorance. The point is that it may be hard for those of you who are close to the subject to realize just how opaque it is to those of us who aren't. If you're in the know, share their knowledge. It's kind of frustrating, from my perspective, to hear, "It's all automatic, and if it's not, you're just too hopeless to deal with."
(All that said, you're quite right that when updates are applied automatically and effectively, both the clueless and the clued benefit. That's why I'm getting my next system with Ubuntu on it!)
Parent
Re:Fixed! -not! (Score:5, Informative)
You won't be getting any updates for FC3 since the Fedora Project has dropped support for that. If you like the Fedora distribution you can go with FC6 or wait for May 24 when FC7 is due to be released. Otherwise, Ubuntu is a fine distribution.
Try this:
Parent
Any clue on the extent? (Score:2)
I'm lucky my laptop has a switch on the side, when switched OFF wireless networking seems to be disabled. It seems to be a hardware disconnect for the antenna.
PC World Article?! (Score:2, Troll)
madwifi links. (Score:5, Informative)
The madwifi howto is here [madwifi.org]. It seems that you can type, "lsmod | grep ath_pci" to find out if you are running the supposedly exploited module. My simple Etch system does not have this or wlanconfig tools by default, though those tools look very nice and I'm sure this little problem will be fixed quickly.
I have to agree with you about the uselessness of the PC World article. Besides not having any useful information, it's filled with FUD about free software wifi and confused "popularity argument" babble. In short it's more of a, "everyone else has these problems too, so Windoze away," pacifier than it is a news article.
Parent
Re: (Score:3, Interesting)
You can also type "modinfo ath_pci | grep version" to find which version you have.
The patched driver is 0.9.2.1 [madwifi.org] or newer.
Complex Hack (Score:5, Funny)
Once again, Linux is safe from such a common attack because only seven people have successfully set up WPA. If this had been a Windows flaw, where every machine natively understands WPA and no work at the command prompt is needed, this would be disastrous.
This shows that Linux has been taking the right stand. By making the machine difficult to get running, it's unlikely that the machine will be able to connect to anything and become infected. Windows made the mistake of making the machine easy to use, allowing for simply network connection and ease of ownership (OWN3D).
Not Overly Complex Hack (Score:4, Interesting)
Parent
Tag.. (Score:5, Funny)
First reported December 2006 (Score:5, Informative)
I am a bit confused... (Score:5, Informative)
http://madwifi.org/changeset/1842 [madwifi.org]
Fixed Dec 15th on my box (Score:5, Informative)
It looks that way to me.
Unless this is a different vulnerability, Debian applied the fix [debian.org] over four months ago, two days after the patch was available, and eight days after the vulnerability was first reported [grok.org.uk]
I saw the article and immediately started aptitude to get the fix, only to discover that I already got it, two weeks before Christmas. Nice.
Parent
Re:Fixed Dec 15th on my box (Score:5, Funny)
Parent
Re: (Score:3, Informative)
Article Tagging: "haha"???? (Score:3, Interesting)
Here's an idea: (Score:3, Interesting)
Then, you dont need specific 'drivers' for wifi hardware (you just need to support ethernet)
Apply the same consideration (Score:3, Interesting)
Vulnerabilities, particularly serious ones, are never good news. At the very least it would cost businesses who have deployed Linux engineer time in fixing (applying patch(es)) the problem, it generates uncertainty in the market - it creates the potential for business managers who just scan the IT news pages to say "didn't Linux have that serious problem not long ago?". This much is true of any OS, particularly one that businesses need to rely on.
I'm a firm believer in open-source, and I use both Windows and Linux in equal measure both at work and at home. I don't however believe fundamentally that the fact Windows and IE are closed-source automatically make them "poorly written". As has already been remarked a lot of this comes down to usage statistics... with a 90%+ market share you can guarantee that every hacker out there is trying to find fault in every single DLL that Windows ships with. As Linux gains more traction in the desktop & server markets as time goes on you can be sure that there will be most vulnerabilities like this being found. Programmers make mistakes, and there is no such thing as bug-free software.
I really wish Slashdot could dispense with the hidden agendas, partisan attitudes and blatent fanboyism and not sweep serious vulnerabilities like this under the carpet as if they aren't a big deal. Dimissing them as trivial is - if anything - more damaging than giving them the proper attention.
What!? (Score:5, Funny)
Okay, easy...just saying this is one area that's always been behind in Linux.
Re:What!? (Score:4, Insightful)
Parent
Re: (Score:2)
Re:Oh, madwifi. Surprise! Closed source still suck (Score:4, Informative)
Parent
Re: (Score:3, Informative)
Re:In other news.. (Score:5, Informative)
Actually, this kind of crap goes away when you stop using NULL terminated strings and put in size checks.
Parent
Re:In other news.. (Score:4, Insightful)
It's a much more complex problem than simply using 'safe' functions. People don't always put the correct size into the size field, and there are entire classes of exploits, e.g. format string vulnerabilities [wikipedia.org], that don't use the traditional buffer overflow mechanism at all.
I've heard that the BSD folks have a saying that a bug is just an attack nobody has the intelligence to turn into an exploit yet. I take it you've never written code that crashes?
Parent
Re:In other news.. (Score:4, Insightful)
Or perhaps you prefer Java, and think that running your code in a VM is a silver bullet. Think again. If you want that code to actually do anything, you're going to have to give it access to the outside world. Your web app can still let people do things they shouldn't. Security is not just about buffer overflows and SQL injection; it's about anything that could let someone get access they shouldn't have. Which can happen from plain old bad logic.
Admittedly, it is easy to make mistakes with C. But C is pretty much the only thing to write a kernel in. In a device driver, you have to mess around with real memory, and real IO, and that sort of thing. More importantly, C is old enough so that its common security mistakes are already known. You'd have a much harder time with some random language.
Basically, a "secure" language is not one that prevents you from doing things you shouldn't. What you want is a language that makes it easier to write secure code than to write insecure code.
Parent
Re: (Score:3, Informative)
Re: (Score:3, Informative)
Of course, I did have the foresight to ask my friends about what works on Linux, which I'm sure helped tremendously. However the laptop I bought didn't really let me choose a wifi card, and it still works w
Ummmm, no. (Score:3, Informative)
Okay, what is it about the "average user" that makes Linux not ready for prime time?
Okay, now you're talking about Windows. And I'll disagree about 90% of Microsoft's security problems being the fault of the users. The default install of a system should be secure enough W
Re: (Score:3, Informative)
An issue with madwifi is an issue which can affect linux, but is not a bug in linux per se (since its not in the default kernel).
It may be a bug with a particular distribution of linux, if that distribution were to include these drivers.
Similarly, a bug in firefox or apache could also affect windows users if they chose to install it, but it won't be flagged as a windows bug because it's not present by default. Conversely, it will be fla