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Copy Fail, Dirty Frag, and Fragnesia kernel vulnerabilities

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Re: Copy Fail, Dirty Frag, and Fragnesia kernel vulnerabilities

#11

Post by bombcar »

TacticalCoder wrote: post #8
himata4113 wrote: post #4

Expanding on gentoo's recommendations: I wonder if we should just universally accept that live patching should become part of the linux kernel? An automatic job that updates (much like some system packages in some distros) that installs (signed) live patches from upstream? Of course we would run into a problem where a malicious patch can now be distributed reliably to hundreds of thousands of machines, but we already…

> I wonder if we should just universally accept that live patching should become part of the linux kernel? I think we can learn many lessons from the recent SNAFUs before going all wild on auto-patching. One lesson for example is that you shouldn't compile into the kernel modules that only about 0.00001% of all Linux installations out there are ever going to use. Another lesson is that even if the modules are compile…

It used to be relatively standard even on the "big" distros to compile your own kernel if you needed something outside of the bog-standard. Modularization and all the related auto-detect auto-mod tools have resulted in most distros shipping a "works for almost everyone" kernel that has everything available as a module.

Perhaps we should tend toward the first.

Re: Copy Fail, Dirty Frag, and Fragnesia kernel vulnerabilities

#12

Post by yjftsjthsd-h »

bombcar wrote: post #11
TacticalCoder wrote: post #8

Earlier quoted context omitted.

> I wonder if we should just universally accept that live patching should become part of the linux kernel? I think we can learn many lessons from the recent SNAFUs before going all wild on auto-patching. One lesson for example is that you shouldn't compile into the kernel modules that only about 0.00001% of all Linux installations out there are ever going to use. Another lesson is that even if the modules are compile…

It used to be relatively standard even on the "big" distros to compile your own kernel if you needed something outside of the bog-standard. Modularization and all the related auto-detect auto-mod tools have resulted in most distros shipping a "works for almost everyone" kernel that has everything available as a module. Perhaps we should tend toward the first.

It seems like a reasonable middle ground for most distros is to put things in kernel modules, but then package those modules into separate packages. If you don't need somedriver.ko, then you don't `apt install linux-driver-somedriver`; if you do need it, just install the package and it just works without needing to compile anything and you get automatic updates and everything.

For Gentoo, of course, "just recompile the kernel as desired" is more reasonable, though they have binary packages including for the kernel and I don't see why the same idea shouldn't work there.

Re: Copy Fail, Dirty Frag, and Fragnesia kernel vulnerabilities

#13

Post by ordu »

c7b wrote: post #7
himata4113 wrote: post #4

Expanding on gentoo's recommendations: I wonder if we should just universally accept that live patching should become part of the linux kernel? An automatic job that updates (much like some system packages in some distros) that installs (signed) live patches from upstream? Of course we would run into a problem where a malicious patch can now be distributed reliably to hundreds of thousands of machines, but we already…

After the npm supply chain attacks people suggested automating delays before installing updates, now we're talking about automating update delivery... I'm afraid there won't be any easy or quick fix after decades of treating security as an afterthought.

Linux distros are not npm. It doesn't mean they are infallible to malicious actors, but I believe it is possible to make them infallible for some small set of packages at least.

Attacks are still possible, but if we look at xz backdoor attack[1] it was insanely complicated attack and it still failed. Its fail doesn't look promising, attack could succeed just the attacker was unlucky. Still it shows that the success is not guaranteed.

Theoretically npm can be improved in this way, if there were a separate "distro" for packaged, with dedicated maintainers for packages, who don't write code, just pull it from a mainstream and review it. It is not being done because of tragedy of commons, not because it is impossible.

[1] https://en.wikipedia.org/wiki/XZ_Utils_backdoor

Re: Copy Fail, Dirty Frag, and Fragnesia kernel vulnerabilities

#14

Post by ordu »

yjftsjthsd-h wrote: post #9

> We recommend exploring ways to automate upgrading your kernel Like, running emerge -u @world on a regular basis, or ... /me searches Okay, so https://wiki.gentoo.org/wiki/Live_patching exists but says, > A note of caution: Kernel live patching is risky. Count on hard freezing or panics to become normal... That's not encouraging. --- Another approach: Can we make the kernel vulns less important? Has anyone had luck…

> Like, running emerge -u @world on a regular basis

You can run emerge -u sys-kernel/whatever-kernel-u-use, maybe followed by `cd /usr/src/linux; make bzImage modules install modules_install...` well, probably you'd use genkernel or something like that, instead of hand-crafted scripts.

The point is: `emerge -u @world` can run into issues esp. if you customized a lot, it can't be automated fully, but I've never run into any issues with updating the kernel, and it can be automated.

It is not so hard to upgrade kernel, the issue is with the reboot you need do automate. Or with live patching, which doesn't seem encouraging, as you say.

Re: Copy Fail, Dirty Frag, and Fragnesia kernel vulnerabilities

#15

Post by ordu »

clircle wrote: post #2

Is Gentoo an outlier or do all Linux distributions deal with this problem?

All of them need to do it. There maybe differences, like different number of versions of kernel supported, so less of backporting, but still distros have to provide fixed kernels.

With Gentoo I believe it is more fun, because of all the options gentoo provides out of a box. More kernels, more work to do.

    ls /var/db/repos/gentoo/sys-kernel/
    asahi-sources/       git-sources/         linux-next/          scx-loader/
    bliss-initramfs/     gnumach/             metadata.xml         udev-hid-bpf/
    cryptodev/           hurd/                mips-sources/        ugrd/
    dkms/                installkernel/       modprobed-db/        vanilla-kernel/
    dracut/              kci-dev/             pf-sources/          vanilla-sources/
    dracut-crypt-ssh/    kergen/              raspberrypi-image/   virtme-ng/
    genkernel/           kpatch/              raspberrypi-sources/ zen-sources/
    gentoo-kernel/       linux-docs/          rt-sources/
    gentoo-kernel-bin/   linux-firmware/      rumpkernel/
    gentoo-sources/      linux-headers/       scx/
Not all these directories are different kernel packages, but anything with -kernel or -sources at the end is.

Re: Copy Fail, Dirty Frag, and Fragnesia kernel vulnerabilities

#16

Post by romaniv »

Clearly, the future is LLM-generated patches that get instantly vibecoded and installed on all machines without any human review. In fact, this is such a good idea that it should be illegal and impossible to run your computer without being connected to such a system. There are no other alternatives. /sarcasm

Re: Copy Fail, Dirty Frag, and Fragnesia kernel vulnerabilities

#17

Post by ahartmetz »

ordu wrote: post #13
c7b wrote: post #7

Earlier quoted context omitted.

After the npm supply chain attacks people suggested automating delays before installing updates, now we're talking about automating update delivery... I'm afraid there won't be any easy or quick fix after decades of treating security as an afterthought.

Linux distros are not npm. It doesn't mean they are infallible to malicious actors, but I believe it is possible to make them infallible for some small set of packages at least. Attacks are still possible, but if we look at xz backdoor attack[1] it was insanely complicated attack and it still failed. Its fail doesn't look promising, attack could succeed just the attacker was unlucky. Still it shows that the success i…

Whenever you read about an incredibly unlucky criminal, there's a chance that the unlucky event is a parallel construction to the classified real reason why they were caught. Not sure how exactly that would have worked in this case.

Re: Copy Fail, Dirty Frag, and Fragnesia kernel vulnerabilities

#18

Post by throwa356262 »

himata4113 wrote: post #4

Expanding on gentoo's recommendations: I wonder if we should just universally accept that live patching should become part of the linux kernel? An automatic job that updates (much like some system packages in some distros) that installs (signed) live patches from upstream? Of course we would run into a problem where a malicious patch can now be distributed reliably to hundreds of thousands of machines, but we already…

I dont belive in live patching unless you are AWS.

But I absolutely belive we should have a method for changing kernel configuration (e.g. kernel module blacklists) and syscall firewalls and alike.

Re: Copy Fail, Dirty Frag, and Fragnesia kernel vulnerabilities

#19

Post by Muromec »

yjftsjthsd-h wrote: post #12
bombcar wrote: post #11

Earlier quoted context omitted.

It used to be relatively standard even on the "big" distros to compile your own kernel if you needed something outside of the bog-standard. Modularization and all the related auto-detect auto-mod tools have resulted in most distros shipping a "works for almost everyone" kernel that has everything available as a module. Perhaps we should tend toward the first.

It seems like a reasonable middle ground for most distros is to put things in kernel modules, but then package those modules into separate packages. If you don't need somedriver.ko, then you don't `apt install linux-driver-somedriver`; if you do need it, just install the package and it just works without needing to compile anything and you get automatic updates and everything. For Gentoo , of course, "just recompile…

>but then package those modules into separate packages. If you don't need somedriver.ko, then you don't `apt install linux-driver-somedriver

But I don't want to know what drivers I need and will need next. Tomorrow I could buy a different wifi module and then what? Spend 3 hours googling which rtl378326973268632aahaxhabt.ko to install? Thanks but no thanks.

Re: Copy Fail, Dirty Frag, and Fragnesia kernel vulnerabilities

#20

Post by patmorgan23 »

Muromec wrote: post #19
yjftsjthsd-h wrote: post #12

Earlier quoted context omitted.

It seems like a reasonable middle ground for most distros is to put things in kernel modules, but then package those modules into separate packages. If you don't need somedriver.ko, then you don't `apt install linux-driver-somedriver`; if you do need it, just install the package and it just works without needing to compile anything and you get automatic updates and everything. For Gentoo , of course, "just recompile…

>but then package those modules into separate packages. If you don't need somedriver.ko, then you don't `apt install linux-driver-somedriver But I don't want to know what drivers I need and will need next. Tomorrow I could buy a different wifi module and then what? Spend 3 hours googling which rtl378326973268632aahaxhabt.ko to install? Thanks but no thanks.

So why can't someone (probably the distro) build a utility that detects the hardware and installs the required kernal module?

We can have security and convenience.

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