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Comment by nikbackm | Hacker News Reader

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nikbackm

Well, you could at one time brick your computer by by executing an ill-advised "rm -rf" from Linux.

Made the news some years back I think.

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You're referring to this?

https://www.phoronix.com/scan.php?page=news_item&px=UEFI-rm-...

I guess this explains why I was not able to boot by USB the other day. I tried out Ubuntu 17.10 on my Y50-70 recently. :(

You can do a similar thing in any OS - delete the vast majority of your file system by running a command as root/administrator and ignoring warnings. FYI rm -rf no longer recurses upwards (. and ..) and hasn't done so for a very, very long time.

This problem is about breaking the BIOS in some way, something that you should not be able to do.

You used to be able (maybe still are?) to "rm" the files on a mounted efivarfs. See the relevant systemd issue ([1]).

[1] https://github.com/systemd/systemd/issues/2402

well windows can get write access to these aswell. (just not by using rm or any other tool to remove files by default). I think this is a big difference and should probably be addressed. make /sys read-only and allow to write them differently with a interface where I need to call THIS_METHOD_CAN_BREAK_A_SYSTEM_IF_USED_INCORRECT_WRITE_SYS() command. but well, systemd guys will/won't do that.

It wasn't a systemd thing. The people who relate the tale as if it were a systemd thing or something that the systemd people did are ill-informed. Much as in the case of the headlined bug at hand, it was entirely a kernel thing. This was even stated outright at the time by the creator of that particular kernel mechanism.

To learn the real story, go and read https://news.ycombinator.com/item?id=11152880 where you will find Matthew Garrett xyrself participating in the discussion.

Not any more. Non-spec variables are initially immutable, so can't be removed until you toggle that.

This is in reference to the issue a few years ago where it was easy to wipe EFI vars via /sys, which would happen if you rm -rf / .[1] Wiping the EFI vars would brick your system.

[1]: https://www.phoronix.com/scan.php?page=news_item&px=UEFI-rm-...

And which you could do a few years back by rm-ing files from a virtual device that mapped to BIOS configuration.

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