5 ms·

That's true only of distributions that alias rm with rm -i. Now, almost 20 years ago only RedHat did it. And it felt wrong to me :-/

jeroenhd 7y ago
Modern versions of rm require you to pass --no-preserve-root. According to Wikipedia [1] this has been the default (in upstream) since 2006. Of course it took distros some time to actually update to the GNU utils 6.4 (especially long-term support systems like CentOS) but it's been a decade since the change should've been implemented everywhere. [1]: https://en.wikipedia.org/wiki/Rm_%28Unix%29#Protection_of_the_filesystem_root https://en.wikipedia.org/wiki/Rm_%28Unix%29#Protection_of_th...
- AdmiralGinge 7y ago
  Isn't that only a GNU and FreeBSD thing? I think other Unixes will still let you rm -rf /. On FreeBSD you can do sudo dd if=/dev/random of=/dev/mem and it will do exactly that, write random crap into your memory without any sort of safeguard, causing a spectacular crash and a console that looks like it's having a seizure. Linux won't let you do that unless it's been compiled with a flag to enable full access to /dev/mem and /dev/kmem.
  - 0xdeadb00f 7y ago
    I want to try that dd command. For fun. Just to see what happens on OpenBSD. No lasting effects are there? Besides a crash, afterwards I shouldn't have any memory issues, right?
    - AdmiralGinge 7y ago
      I tried this in a FreeBSD VM and it booted fine afterwards. OpenBSD wouldn't let me do it at all for some reason. Obviously no warranty on bare metal/systems that are actually used for anything.
- Lex-2008 7y ago
  worth noting that it can be trivially workarounded by adding an asterisk at the end: `rm -rf /*` still works.
  - tomjakubowski 7y ago
    That version will helpfully leave behind any .files lingering in /
  - jeroenhd 7y ago
    Fair enough, but on the other hand there's nothing preventing you from just putting --no-preserve-root in the command either. I see the feature as something to prevent accidents, not as a way to secure the rm command.
- deleted 7y ago
  [deleted]

jeroenhd 7y ago

Modern versions of rm require you to pass --no-preserve-root. According to Wikipedia [1] this has been the default (in upstream) since 2006. Of course it took distros some time to actually update to the GNU utils 6.4 (especially long-term support systems like CentOS) but it's been a decade since the change should've been implemented everywhere. [1]: https://en.wikipedia.org/wiki/Rm_%28Unix%29#Protection_of_the_filesystem_root https://en.wikipedia.org/wiki/Rm_%28Unix%29#Protection_of_th...

AdmiralGinge 7y ago
Isn't that only a GNU and FreeBSD thing? I think other Unixes will still let you rm -rf /. On FreeBSD you can do sudo dd if=/dev/random of=/dev/mem and it will do exactly that, write random crap into your memory without any sort of safeguard, causing a spectacular crash and a console that looks like it's having a seizure. Linux won't let you do that unless it's been compiled with a flag to enable full access to /dev/mem and /dev/kmem.
- 0xdeadb00f 7y ago
  I want to try that dd command. For fun. Just to see what happens on OpenBSD. No lasting effects are there? Besides a crash, afterwards I shouldn't have any memory issues, right?
  - AdmiralGinge 7y ago
    I tried this in a FreeBSD VM and it booted fine afterwards. OpenBSD wouldn't let me do it at all for some reason. Obviously no warranty on bare metal/systems that are actually used for anything.
Lex-2008 7y ago
worth noting that it can be trivially workarounded by adding an asterisk at the end: `rm -rf /*` still works.
- tomjakubowski 7y ago
  That version will helpfully leave behind any .files lingering in /
- jeroenhd 7y ago
  Fair enough, but on the other hand there's nothing preventing you from just putting --no-preserve-root in the command either. I see the feature as something to prevent accidents, not as a way to secure the rm command.
deleted 7y ago
[deleted]