Greg K-H
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@alwayscurious @sima @sourcejedi That's one reason, the other one was "power just glitched, my printer better be on the same device node it was before it was turned off". Same for keyboards, mice, disks, etc.
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@alwayscurious @sima "Normal" PCI hotplug systems should export this information, as the BIOS expects a user to add/remove PCI devices on a slot basis. Otherwise why would a BIOS care about exporting the slot number at all. So it's not required, and you are lucky if it shows up. good luck!
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Greg K-H
gregkh
@joshbressers Linux is only #6? We better get on that to reclaim our 2nd ranked spot of last year despite only participating for 10 1/2 months, not the full 12 everyone else was able to have! :)
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Greg K-H
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daniel:// stenberg://
bagder@mastodon.socialThe short summary of if it has been worth the hassle: yeah I think so. It is now easy and fast to get new CVE IDs. We have a seat at a table where I can complain loudly on the system and what I say actually might have a (small) impact.
We have yet to deny someone else's crazy CVE attempts against curl.
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Greg K-H
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daniel:// stenberg://
bagder@mastodon.social#curl has been a CNA for a year now https://daniel.haxx.se/blog/2024/01/16/curl-is-a-cna/
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Greg K-H
gregkh
@monsieuricon I wish someone would tell me the steps for CVE repair for the kernel so we don't have to keep making them up as we go along :)
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@alwayscurious @sima @sourcejedi Again, reuse of major/minor numbers was a design requirement at the time. And, you know the path / label / metadata / whatever for the block device before you mount it, so go off of that information if you don't trust the device major/minor number information.
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@alwayscurious @sima PCI devices, at the bus/slot/function level do not have device nodes, so I don't understand the issue here.
They might have a specific PCI driver bound to them, at the function level, and if so, the parent of the device node for that class device (i.e. input, tty, drm, etc.) will then point to that PCI function. But PCI slots don't always match up to PCI bus and device numbers either, as that's a physical thing and many PCI systems don't expose or even know that information (i.e. the BIOS doesn't know.)
Also, PCI bus numbers can change at boot, so you can't know what is happening.
Driver probing can be deferred at any time by userspace for USB devices, and I think that was recently added for PCI devices too, look for the "trusted" device information in the documentation somewhere.
Good luck!
They might have a specific PCI driver bound to them, at the function level, and if so, the parent of the device node for that class device (i.e. input, tty, drm, etc.) will then point to that PCI function. But PCI slots don't always match up to PCI bus and device numbers either, as that's a physical thing and many PCI systems don't expose or even know that information (i.e. the BIOS doesn't know.)
Also, PCI bus numbers can change at boot, so you can't know what is happening.
Driver probing can be deferred at any time by userspace for USB devices, and I think that was recently added for PCI devices too, look for the "trusted" device information in the documentation somewhere.
Good luck!
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@alwayscurious @sima @sourcejedi That ship sailed decades ago as we had to support device node reuse a long time ago, it was a requirement! But obviously not your requirement :)
You have full control over device node creation in userspace, that's what udev gives you if you want (or any udev-like program). set up a whole different /dev/ with just your naming/numbering scheme. The kernel gives you the interface and the information to do this, why not take advantage of it if you need it?
You have full control over device node creation in userspace, that's what udev gives you if you want (or any udev-like program). set up a whole different /dev/ with just your naming/numbering scheme. The kernel gives you the interface and the information to do this, why not take advantage of it if you need it?
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@alwayscurious @sima Then do that,the kernel provides you this information through sysfs, that is what it was explicitly designed for.
But yes, the race condition of "parse the topology, determine the device node, and go to open it" when the device is removed and a different one added right between those last two steps is real. Luckily in real-hardware situations, almost extremely rare if not physically impossible due to hardware debounce times, and one that we explicitly did not care about when we created sysfs and udev (i.e. physical access trumps anything).
But yes, the race condition of "parse the topology, determine the device node, and go to open it" when the device is removed and a different one added right between those last two steps is real. Luckily in real-hardware situations, almost extremely rare if not physically impossible due to hardware debounce times, and one that we explicitly did not care about when we created sysfs and udev (i.e. physical access trumps anything).
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Greg K-H
gregkh
New year, new hardware failure, must be time for a new motherboard, any recommendations of what the "best" AMD workstation motherboard is these days?
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Greg K-H
gregkh
@sourcejedi @sima Yeah, no blog posts, just loads of lkml emails over the years, sorry.
That machine that randomly reassigned PCI ids at boot time is no longer with me, but it was great for testing. I'm sure you can do the same with virtual machines these days, passing in different virtual pci devices to them.
Persistent naming is for userspace to handle, the kernel just uses "grab the next free number" as it's naming "policy" as that's all it can really do.
That machine that randomly reassigned PCI ids at boot time is no longer with me, but it was great for testing. I'm sure you can do the same with virtual machines these days, passing in different virtual pci devices to them.
Persistent naming is for userspace to handle, the kernel just uses "grab the next free number" as it's naming "policy" as that's all it can really do.
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Greg K-H
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Greg K-H
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Mike [SEC=OFFICIAL]
mike@chinwag.org"Free Copilot in your GitHub account" is the 2020s version of "Free U2 album on your iPod".
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Greg K-H
gregkh
@vegard Yes, that would miss the normal "review all the stable commits" process. If you think there is a mainline-only commit that needs to have a CVE, please let us know at the cve@k.o address and we can assign it then.
But better yet, backport the fix to stable and it all happens automatically for you :)
But better yet, backport the fix to stable and it all happens automatically for you :)
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Greg K-H
gregkh
@matttbe @kernellogger Maybe, maybe not. Please see my old post here: http://www.kroah.com/log/blog/2021/02/03/helping-out-with-lts-kernel-releases/ for what drives all of this (hint, people actually asking that they need it AND providing the help to make it possible.)
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Greg K-H
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Natalie Silvanovich
natashenka@infosec.exchangeCan you find an ITW 0-day from crash logs? Project Zero finds out
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