back to article Linux kernel 5.19.12 'may harm' Intel laptop screens

A bug in version 5.19.12 of the Linux kernel "may harm" screens on laptops powered by Intel's 12th-generation Core processors. The Alder Lake family of chips are significantly different from earlier Intel generations, and this has caused previous problems in the open source kernel, though those were relatively modest …

  1. BOFH in Training Silver badge

    Wow, thats going to bring back flashbacks

    I was hoping that as time passes it will be harder and harder for hardware to be forced to fail via software.

    Looks like destructive malware just got another tool in it's toolkit.

    1. Michael Wojcik Silver badge

      Re: Wow, thats going to bring back flashbacks

      Looks like destructive malware just got another tool in it's [sic] toolkit.

      How so? Is the malware going to install kernel 5.19.12 (after detecting you have a vulnerable system)?

      If malware already has kernel-level access, it's game over. Messing with the cooling system, for example; there are already third-party fan-control utilities for laptops which come with stern warnings about incorrect settings. Attacks against firmware which can brick devices (Viasat terminals, say) are well known. Around five years ago, Brickerbot made the news by bricking IoT devices it encountered; a couple of years ago, Trickbot was doing the same to general-purpose PCs by trashing UEFI firmware.

      1. BOFH in Training Silver badge

        Re: Wow, thats going to bring back flashbacks

        The code which creates the issue is in the 5.19.2 kernel.

        Malware authors can look at that code and embed it into other stuff.

        You don't need the whole kernel to do this, just presumably few lines of code. And if you are not sure which of the code that creates this issue, it should be relatively easy to look at 5.19.3 changes and figure out what code is probably involved.

        No doubt it will not be a simple cut and paste job, but malware authors have proven to be inventive in all the bad ways. May need a chain of exploits to get there, but if they want to, they will get there.

        Hopefully they don't think it is worth working on.

  2. Snowy Silver badge


    Did that make it into the kernel, some more of Intel's great driver code?

    1. Ace2 Silver badge

      Re: How

      From the report on lore - sounds like a patch was auto-selected for backport. It applied and built cleanly, but misbehaved due to the lack of other patches.

  3. Martin Gregorie

    May depend on your hardware

    I was running 5.19.12 all last week with no flashing on either my Lenovo T440 laptop or my ancient dual Athlon desktop house server.

    This afternoon I'd updated both systems to 5.19.13 as part of my weekly 'first backup and then update' session before this story had appeared on either Ars Technica or El Reg. Ars was first to describe the problem.

    1. MatthewSt

      Re: May depend on your hardware

      Does depend on your hardware indeed. Says so right in the first paragraph...

  4. Updraft102 Silver badge

    My 11th gen i5 XPS is fine with 5.19.12 (OpenSUSE TW). JFYI, YMMV, wrc.

  5. Anonymous Coward
    Anonymous Coward


    I thought Linux was meant to be 100% foolproof and unbuggy?

    1. Updraft102 Silver badge

      Re: How?

      Nope... no one ever said that. It's just worlds better than anything Microsoft put out, which is a rather low bar.

      1. ecofeco Silver badge

        Re: How?


        1. John Brown (no body) Silver badge

          Re: How?

          Well, for a start, printing doesn't get borked as often by monthly patches.

          1. VoiceOfTruth Silver badge

            Re: How?

            I have seen Linux people struggling for hours to print a document. Printing from Linux is not always easy or straightforward. And don't blame the lack of drivers. That is just part of the problem.

            1. John Brown (no body) Silver badge

              Re: How?

              "I have seen Linux people struggling for hours to print a document. Printing from Linux is not always easy or straightforward. And don't blame the lack of drivers. That is just part of the problem."

              And your point is?

              I have seen Windows people struggling for hours to print a document. Printing from Windows is not always easy or straightforward. And don't blame the lack of drivers. That is just part of the problem.

        2. ecofeco Silver badge

          Re: How?

          Why the downvotes?

          Linux does indeed work far better than Windows.

    2. Sandtitz Silver badge

      Re: How?

      It's called double standards.

      Bug appears in Microsoft code - "Micros~1 doesn't do QA"

      Bug in Linux (or other FOSS) - "nothing to see here"

      It's not like Intel 12th gen mobile is a rare beast - apparently no-one tested the kernel changes.

      1. Anonymous Coward

        Re: How?

        C'mon, all those eyeballs vetting every and each line of the Linux kernel were blinded by the LCD flashes and couldn't spot the bug...

  6. tgpips

    Boy did I find this one out the hard way. Updated the Arch install on my Framework laptop not long after the release of 5.19.12 by chance, a bit of a fright, followed by wondering if I had done something wrong!

  7. abetancort


    How come hardware interfaces directly with the OS without the intervention of any firmware?

    I bet this snafu is the fault of intel. The firmware in their GPU doesn’t protect some LCD screens connected to them from what ever the OS commands. Blaming a bug in Linux is just pathetic.

    1. Justthefacts Silver badge

      Re: Why?

      And this additional firmware, which you reckon is Intel’s problem….

      Now obviously we don’t want to allow evil Intel to snoop on what we’re writing to the screen, without knowing what’s running on our silicon. So….we’ll want an open-source firmware, right? Which will run on what OS….well, Linux is the best for embedded, right.

      And which CPU should it run on? Clearly not the x86 that the user space is running on, because that’s running Linux and it needs to be partitioned. But on the same die to minimise I/O. I guess would be there to manage the device, so let’s call it a Management Engine. Intel Management Engine. Great!

    2. ChrisC Silver badge

      Re: Why?

      As an embedded systems engineer, I read the opening paragraphs of this article and thought WTaF?!? Exactly as you've done, I couldn't believe the OS is expected to be responsible for something as fundamental as power supply sequencing, so a) I'm rather bemused by why you've received so many downvotes vs so few upvotes, and b) I'm rather irritated by the number of said downvoters who haven't then bothered to take the time to explain why they think you (and thus also me) are so wrong about this that it deserved a downvote. I honestly don't mind being wrong about stuff, I'd just like to be given the chance to understand WHY I'm wrong as part of being told I'm wrong...

      1. Mike 137 Silver badge

        Re: Why?

        As another embedded guy I'm wondering about the description of the problem's cause. None of the linked sources give any explicit information, but I can see two obvious possibilities, both of which result in confusing the display's onboard processor. The first and most obvious is sending a command to the display before it has finished initialising on power up, and the second (and less likely) is sending an invalid command. Either case suggests that the display processor is fragile. This has happened before - I remember the Intel 8271 floppy disk controller, which was an excellent device but could be irrevocably burnt out by sending a specific illicit byte to a specific register.

        1. Anonymous Coward
          Anonymous Coward

          Re: Why?

          remember the Intel 8271 floppy disk controller - yes I do - and what a pig it was to get the servo interface working properly.

          But it did do 8" floppies - oodles of space - them was the days.

          Nowadays you might just be able to store your phone number on such huge devices

      2. tekHedd

        Failure Modes

        I agree. I've done my share of OS and driver level software, and this sounds like a hardware design fail. Granted, it's almost certainly done for cost reduction, which is not a bad thing, but the failure mode is unacceptable and IMO good engineering would design it to fail in a safe way.

        The downvotes are because we've normalized cost reduction as the greatest good above all other goals, and also normalized "shipping broken hardware that depends on OS level workarounds to even function because that's cheaper than spinning another rev of the chip".

      3. Anonymous Coward
        Anonymous Coward

        Re: Why?

        It's probably the Microsoft shills giving downvotes because the OP didn't trash-talk Linux. It does happen, you know. I guess El Reg isn't just read by nerds avoiding work anymore, it's grown up and professional now. The corporate butt-hurt brigades like to come in and beat down on the opposition. Sometimes it's Googlers, sometimes it's Microsofties, sometimes it's Amazonians.

  8. Steve Graham

    Funny, I compiled and booted that version on an Intel-based laptop just the other day. But since it's a 2007 Thinkpad with the LCD unused, I think I'm OK.

  9. disgruntled yank Silver badge

    The old days

    I remember the days when installing Open X could lead to the monitor shaking and emitting a "chuff" sound. I found it amusing, probably because the monitors weren't my property.

    1. captain veg Silver badge

      Re: The old days

      I remember my late '90s supermarket special beige PC had a generic 14" CRT that just wouldn't play with X.

      I emailed the "manufacturer" (i.e. the importer) to ask if they could give me a set of X parameters that would, you know, actually put an image on the screen.

      To their credit, they promptly replied, stating that they had attached a device driver file for it.

      Sadly it was a Windows (95/98) .INF file. Chocolate spanner territory.

      I never did get it to work. In the end I bought an LCD panel. Cost a fair amount and could only display 4096 colours, at 1024x768, but it worked straight out of the box. Never had a CRT since.


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