Decode kernel panic from QR Code photo

 (gist.github.com)

40 points | by modinfo 2 days ago

3 comments

  • jolmg 1 day ago
    For context, kernel panics seem to sometimes be encoded as a URL in the QR code by distros. The panic text is encoded as a numeric parameter. For example:

      https://jexposit.fedorapeople.org/drm-panic/#?a=x86_64&v=6.17.0-rc2+&z=64016708045408584681305161836175901065787789727173061004041671633088591186286363786562987653814347942450168430510852681524688435157911241621365859153819732690406649525043247774110913752991389170560320455163781439079986337356710273501164645667555084821480237326301207073831710176482850121513079951455217310046422632328303510474264780788030301611164774573122018172510304672562667379831349924441560360997679573341401750485619388375493[... many more digits]
    That's from the QR code image at:

    https://discussion.fedoraproject.org/t/f45-change-proposal-d...

    This script is to decode such kernel panics without needing to provide it to an external service.

    In the particular URL example, the panic is not necessarily sent to a server, because it's in a URL fragment (`#`), but still.

    [-]
    • userbinator 22 hours ago
      The panic text is encoded as a numeric parameter.

      This script is to decode such kernel panics without needing to provide it to an external service.

      WTF. A solution for an entirely self-inflicted problem.

      [-]
      • jolmg 22 hours ago
        > self-inflicted

        Distro developers and user are separate people. Also, a person viewing the QR code is not necessarily the owner of the panicked system.

        [-]
        • userbinator 11 hours ago
          Distro developers and user are separate people.

          No, they don't have to be. How did this user-hostile attitude infect Linux too?

          Also, a person viewing the QR code is not necessarily the owner of the panicked system.

          So what? Stop hiding things from users. If they don't care they don't have to read. If they do, don't make them jump through additional hoops.

          [-]
          • jolmg 7 hours ago
            It being user-hostile is debatable. It's meant to be friendlier, as described in the Fedora link I shared. Coincidentally though, I got a panic yesterday and my phone wasn't able to scan the QR code, lol, so who knows what the panic was.

            The non-QR/textual panics can be restored with a kernel/module parameter as described here:

            https://wiki.archlinux.org/title/Kernel#QR_code_on_a_blue_sc...

            The QR code can be made to provide the text itself (non-URL-encoded) by rebuilding the kernel with CONFIG_DRM_PANIC_SCREEN_QR_CODE_URL unset.

  • userbinator 22 hours ago
    I hope this is Windows-inspired satire. If I get a kernel panic I want something I can actually read.
    [-]
    • kouosi 22 hours ago
      It's been there for like 2 years (6.12 iirc) so it is not satire it is real.
  • natas 1 day ago
    I think that's a really good idea! Would love to see this upstream
    [-]
    • bri3d 1 day ago
      It is? This is drm-panic qr codes from Linux 6.12. It’s a neat feature but I’m not sure why this random implementation is particularly interesting.
      [-]
      • theowaway213456 1 day ago
        Can't a phone decode a QR code natively? I don't even get what it does
        [-]
        • hamandcheese 1 day ago
          If you decode it and open the link, you are potentially leaking data to whoever controls the domain of the URL.
          [-]
          • creatonez 21 hours ago
            It's a possibility, but it's not how these kernel panic viewer websites are currently implemented. They do the decoding on the clientside, with the data stored in the URL fragment, which is not sent to the server by default.

            Still good to have alternative implementations, though. The Javascript could be silently stealing the URL fragment on only specific requests, so there's no real way to audit it to be sure.

          • ranger_danger 1 hour ago
            This is why I like to use Binary Eye, it never acts on anything automatically when scanning a code, you have to tell it to.
          • catlifeonmars 1 day ago
            Link previews even! Just paste it into a group chat and everyone’s message clients will happily issue a GET request.
            [-]
            • charcircuit 1 day ago
              That's not how it works. The chat app requests the link preview and caches it.
              [-]
              • catlifeonmars 7 hours ago
                That’s how link previews work on iOS (it was the cause of the zero click RCE a few years ago by executing row hammer through WebView), so I guess it depends on your software.
          • ErroneousBosh 23 hours ago
            This sounds like the panicky adverts from 20-odd years ago "YOUR COMPUTER IS LEAKING YOUR IP ADDRESS!!11!!""2!!2!!"
            [-]
        • catlifeonmars 1 day ago
          You can decode a QR code by hand. It’s usually not worth your while but it’s understandable.
        • kzrdude 1 day ago
          This is about a second step of decoding.

          Qr -> URL -> Panic Log