Can you blow a PC speaker with a Linux kernel module?
Sometimes you come across a story that’s equally weird and delightful, and this is definitely one of them. Oleksandr Natalenko posted a link on Mastodon to a curious email sent to the Linux Kernel Mailing List, which apparently gets sent to the LKML every single year. The message is very straightforward. Is it possible to write a kernel module which, when loaded, will blow the PC speaker? ↫ R.F. Burns on the LKML Since this gets sent every year, it’s most likely some automated thing that’s more of a joke than a real request at this point. However, originally, there was a real historical reason behind the inquiry, as Schlemihl Schalmeier on Mastodon points out. They link to the original rationale behind the request, posted to the LKML after the request was first made, all the way back in 2007. At the time, the author was helping a small school system manage a number of Linux workstations, and the students there were abusing the sound cards on those workstations for shenanigans. They addressed this by only allowing users with root privileges access to the sound devices. However, kids are smart, and they started abusing the PC speaker instead, and even unloading the PC speaker kernel module didn’t help because the kids found ways to abuse the PC speaker outside of the operating system (the BIOS maybe? I have no idea). And so, the author notes, the school system wanted them to remove the PC speakers entirely, but this would be a very fiddly and time-consuming effort, since there were a lot of PCs, and of course, this would all have to be done on-site – unlike the earlier solutions which could all be done remotely. So, the idea was raised about seeing if there was a way to blow the PC speaker by loading a kernel module. If so, a mass-deployment of a kernel module overnight would take care of the PC speaker problem once and for all. ↫ R.F. Burns on the LKML So, that’s the original story behind the request. It’s honestly kind of ingenious, and it made me wonder if the author got a useful reply on the LKML, and if such a kernel module was ever created. The original thread didn’t seem particularly conclusive to me, and the later yearly instances of the request don’t seem to yield much either. It seems unlikely to me this is possible at all. Regardless, this is a very weird bit of Linux kernel lore, and I’d love to know if there’s more going on. Various parts of the original rationale seem dubious to me, such as the handwavy thing about abusing the PC speaker outside of the operating system, and what does “abusing” the PC speaker even mean in the first place? As Natalenko notes, it seems there’s more to this story, and I’d love to find out what it is.
