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Edit: The link.
There were lots of good titles for this submission, as in "Breaking news: Poettering clueless?" to finally disprove Betteridge's law, or "systemd surprisingly not as good as advertised" or "Breaking new: systemd broken" or "Poettering censors critics after epic fail".
Systemd implementation of "rm -rf .*" will follow ".." to upper directory and erase /
How to reproduce:
# mkdir -p /foo/dir{1,2}
# touch /foo/.bar{1,2}
# cat /etc/tmpfiles.d/test.conf
R! /foo/.* - - - - -
Reboot.
After the issue was fixed, finally Poettering added this gem of wisdom:
I am not sure I'd consider this much of a problem. Yeah, it's a UNIX pitfall, but "rm -rf /foo/.*" will work the exact same way, no?
The answer to this question, as many clarified for him, obviously is a loud "NO!". After being told a couple of times in no uncertain terms, the thread was closed for non-developers
poettering locked and limited conversation to collaborators 4 hours ago
for which I proposed the "freedom-of-speech" department (although I admit it is a weak proposal).
(Score: 2, Troll) by Ken_g6 on Monday April 17 2017, @09:28PM (10 children)
(Karma to burn)
I heard `rm -rf .*` would erase things up the .. chain years ago. I didn't know it was a bug.
Then again, I'm not a developer of any Linux system utilities. I also don't disagree with changing the behavior.
(Score: 2) by wonkey_monkey on Monday April 17 2017, @09:49PM (4 children)
I'm not sure I'd call it a bug either. It should be fairly clear that it's a stupid thing to do without checking, but also yes, it's probably best all round that the OS stops you, but a bug?
systemd is Roko's Basilisk
(Score: 4, Informative) by rleigh on Monday April 17 2017, @11:26PM
The OS doesn't stop you, only the standard behaviour of rm(3) which they weren't using. If you implement a recursive delete, you need to unlink(2) and rmdir(2) every file and directory in a recursive fashion. Checking that you never follow '..' is the programmer's responsibility. One of the first things you learn when systems programming and walking directories is that '..' needs special handling. Truly amazing these "skilled experts" did this; it really is amateur hour in the systemd world.
(Score: 5, Insightful) by sjames on Tuesday April 18 2017, @03:38AM (2 children)
Definitely a bug. Utilities are supposed to descend only when given the recursive (-r) flag. Ascending is incorrect. Beyond being wrong based on the definition of the flag, ascending reduces the semantic expressiveness of the -r flag. If I actually WANT to recurse over the entire file system when it descends only, I can specify "-r /", but if it also ascends I have no way to specify here and below.
I'm not surprised that he would screw semantics up that way, the unit files implement COMEFROM logic.
(Score: 0) by Anonymous Coward on Tuesday April 18 2017, @10:36PM (1 child)
> the unit files implement COMEFROM logic.
...wut...
(Score: 3, Interesting) by sjames on Wednesday April 19 2017, @12:40AM
That's what I thought when I saw it. COMEFROM [wikipedia.org] is a humorous suggestion as a counterpart to GOTO. It's frequently considered a GREAT way to encourage impossible to debug obfuscated code.
By allowing a unit file to declare that another unit depends on it, systemd effectively implements COMEFROM with all of the pitfalls that entails.
(Score: 0) by Anonymous Coward on Tuesday April 18 2017, @01:50AM (1 child)
DOS used to do that. If you deleted the . file the system would crash and you'd get no useful data off the disk. FreeBSD hasn't done that in the decades I've been using it. Same goes for Linux, I've never typed that into Linux and had anything other than all the files and directories starting with a . deleted.
The bug here is that the . isn't supposed to be treated like a regular file or directory. It's something that's used to represent the current directory in the same way that the .. is there to represent the directory that the current directory is in. They require special treatment or weird things happen.
(Score: 0) by Anonymous Coward on Tuesday April 18 2017, @02:45AM
I think possibly before glibc 2 though, so maybe libc4 libc5 era. And I am not sure which rm implementation it was (maybe one used on an early version of Slackware?
(Score: 1) by DeVilla on Tuesday April 18 2017, @03:16AM
I've heard stories of Admins from the DOS/Win32 world who would be forced into the UNIX world and as root, on a system with root access over NFS would run:
cd /tmp
rm -rf *.*
Actually it would be 'del -rf' because people would actually alias up del, dir, etc. And yes, once this would delete everything until the system hung or crashed.
(Score: 2) by FatPhil on Tuesday April 18 2017, @07:52AM
Great minds discuss ideas; average minds discuss events; small minds discuss people; the smallest discuss themselves
(Score: 0) by Anonymous Coward on Tuesday April 18 2017, @02:30PM
Yes and no. Rm implementations on most _nix these days have code that checks if you are trying to delete he root directory.
https://linux.die.net/man/1/rm [die.net]
--preserve-root
do not remove '/' (default)
(Score: 5, Insightful) by maxwell demon on Monday April 17 2017, @09:29PM (17 children)
My first thought when reading the title was: Why on earth does an init system need its own implementation of rm?
But then, this is systemd, the Borg init system. Probably I should be astonished if something has not yet been affected by it.
The Tao of math: The numbers you can count are not the real numbers.
(Score: 3, Interesting) by Azuma Hazuki on Monday April 17 2017, @09:34PM (5 children)
> My first thought when reading the title was: Why on earth does an init system need its own implementation of rm?
Mine too. This went from "WTF?" to feeling deeply, deeply unclean and doomed, something like I imagine you'd feel if someone told you that 5 years ago you'd had a blood transplant that turned out to have syphilis in it...
I am "that girl" your mother warned you about...
(Score: 2) by FatPhil on Tuesday April 18 2017, @07:55AM (4 children)
(Just for reference, it's "blood transfusion" not transplant, transplants are for solid bits.)
Great minds discuss ideas; average minds discuss events; small minds discuss people; the smallest discuss themselves
(Score: 0) by Anonymous Coward on Tuesday April 18 2017, @11:54AM
Maybe it was clotted.
(Score: 2) by Azuma Hazuki on Tuesday April 18 2017, @01:53PM (2 children)
Good point...I meant to type transfusion, but haven't been sleeping properly for months so...yeah. And I would be a little wary of Devuan; at this point you may as well go full-on FreeBSD or Gentoo if you have the hardware for it. I am beginning to wonder if at some point around 2019 or 2020 Gentoo, Slackware, etc will fork off and call themselves something different, maybe even maintaining their own Linux kernel without the creeping systemd hooks...
I am "that girl" your mother warned you about...
(Score: 2) by FatPhil on Tuesday April 18 2017, @02:14PM (1 child)
Great minds discuss ideas; average minds discuss events; small minds discuss people; the smallest discuss themselves
(Score: 2) by tibman on Tuesday April 18 2017, @05:04PM
I've had good success with melatonin as well. Using some random gummi brand from amazon.
SN won't survive on lurkers alone. Write comments.
(Score: 2, Informative) by Anonymous Coward on Monday April 17 2017, @10:05PM (4 children)
My first thought when reading the title was: Why on earth does an init system need its own implementation of rm?
It does not have its own rm. It has an internal command called R! that calls a function called rm_rf().
It is right there in the summary.
This whole story is a big bag of nothing hyped by people who don't know what they are talking about.
The fact that there was no link to the github issue in the submission should have been a clue to the editors that it was low-grade crap.
(Score: 3, Touché) by cubancigar11 on Tuesday April 18 2017, @05:45AM (2 children)
And does rm_rf() call rm -rf or does it try to implement it internally?
(Score: 0) by Anonymous Coward on Tuesday April 18 2017, @03:14PM (1 child)
What do you think? If it called the system rm would this bug report ever have been opened?
I don't get it, why are you hung up on the name of the function call?
Its like people are so amped up to bag on poettering that you all are willing to lose your shit over tiniiest thing.
Ermagad somebody on the internet made a dumb comment!
Should you be judged by every dumbass comment you've made?
(Score: 2) by cubancigar11 on Wednesday April 19 2017, @03:17AM
I have no interest in the name I am talking about duplicating functionality and breaking it - which is basically the biggest problem everyone has with systemd and poettring.
Seriously, systemd is GPLv2 and there are enough version of coreutils in GPLv2 to not implement it again.
(Score: 2, Touché) by Anonymous Coward on Tuesday April 18 2017, @06:35AM
Thank you, Lennart, for joining our discussion and setting us straight. You're right- "rm -rf /" is a great way to clean up tons of crap on a Linux filesystem. Way better than bleachbit.
(Score: 2) by NotSanguine on Tuesday April 18 2017, @02:32AM (2 children)
My first thought when reading the title was: Why on earth does an init system need its own implementation of rm?
But then, this is systemd, the Borg init system. Probably I should be astonished if something has not yet been affected by it.
The "functionality" in question is part of systemd-tmpfiles(8) [fordham.edu]:
No, no, you're not thinking; you're just being logical. --Niels Bohr
(Score: 0) by Anonymous Coward on Tuesday April 18 2017, @02:33PM (1 child)
Given that it is meant to handle files and directories inside one or two special directories, it is really surprising that the commands are not only run as root, but allowed to exit those directories.
One would think that making use of a special config file format rather than shell scripts and core utils for this was to avoid just such events happening...
(Score: 2) by NotSanguine on Tuesday April 18 2017, @05:04PM
IIUC, there is functionality which allows the use of functions from systemd-tmpfiles in a systemd pseudo-shell. a command within that pseudo-shell (R!) purported to mimic 'rm -rf' but the function didn't treat '.' and '..' (as /bin/rm does) as special cases, making sure that deletions only occurred downwards in the directory tree.
I suppose one could make the argument that only careless users would go with 'R! .*'. However, given that /bin/rm had mitigated that issue for a number of years, (not sure when, but as a novice user back in the late 80s/early 90s I made that mistake with rm and it happily deleted half my root filesystem before I realized what was happening) by refusing to delete up the directory tree.
As such, refusing to delete up the tree is (and has been for some time) the expected behavior, so that argument is pretty weak.
Poettering, et al showed a glaring lack of common sense in their implementation and didn't consider edge cases.
No, no, you're not thinking; you're just being logical. --Niels Bohr
(Score: 2) by Alphatool on Tuesday April 18 2017, @11:16AM (1 child)
Well, from a systemd point of view you've got this backwards! Why should the operating system have a duplicated implementation of rm when there can be a perfectly good one built into the init system?? It's even better at deleting things than the legacy implementation was!! Next up, twitter integration!!!
(Score: 3, Funny) by maxwell demon on Tuesday April 18 2017, @06:38PM
I'm looking forward to the binary twitter messages. ;-)
The Tao of math: The numbers you can count are not the real numbers.
(Score: 2) by digitalaudiorock on Tuesday April 18 2017, @08:11PM
Nothing surprises me (or anyone with two brain cells to rub together) at all about any of this, nor do the requisite troll apologists putting their $.02 in the comments here. Anyone defending what we're seeing here is being paid by someone or is simply a fucking idiot.
It's been clear since day one the the intentional approach of the systemd devs, unlike the entire history of unix and Linux is basically is to NOT reuse anything prior, and to re-invent every possible wheel...because you know..."how difficult could it be?" and "what do a bunch of fucking old grey-beards know?". I guess they're starting to find out right? Arrogant know-it-all jackasses at work. Thank God for my systemd-less Gentoo systems.
(Score: 1, Insightful) by Anonymous Coward on Monday April 17 2017, @09:49PM (1 child)
Don't pick on one little bug - it doesn't really matter. The larger problem is that systemd takes away choice. I don't understand why we can't have a choice in init systems. More and more higher level SW seems to have unnecessary deps on init system. Isn't Linux all about choice?
(Score: 0) by Anonymous Coward on Monday April 17 2017, @10:01PM
The Aryan choice, brother!
Or so I heard from Lennart at the last meeting.
(Score: 2, Informative) by Anonymous Coward on Monday April 17 2017, @09:57PM (3 children)
poettering locked and limited conversation to collaborators 4 hours ago
Guys, this is a non-story.
He didn't stop all conversation. He stopped drive-bys who were throwing shade nearly two weeks after it had been asked an answered.
Like thelounge-zz [github.com] who's made two contributions in 3 years and neither were systemd related, but felt it necessary to write two posts suggesting poettering is an idiot but otherwise adding no new information to the discussion.
Project collaborators weren't locked out.
This submission should never have made it past the editors.
(Score: 0) by Anonymous Coward on Monday April 17 2017, @11:20PM (1 child)
Ive made thousands of commits to private repos and maybe 2 to github. Does that mean I too am unqualified to state he is a NIH narcissistic idiot?
(Score: 0) by Anonymous Coward on Tuesday April 18 2017, @01:17AM
Yes, actually it does mean you are unqualified because posting an irrelevant comment like that to a bug report would be a far greater narccisism.
(Score: 0) by Anonymous Coward on Tuesday April 18 2017, @02:40PM
Well Poettering presented himself as an idiot by making the comment. Because it shows that the creator and maintainer of systemd do not know how a present day rm behaves. And if he is that disconnected from daily operations of _nix, why is he developing a project that is re-implementing large swaths of _nix core code?!
(Score: 4, Funny) by Anonymous Coward on Monday April 17 2017, @10:01PM (25 children)
Well, I'm done with SN permanently. I am disgusted that SN posted this gleeful, cackling attack piece and didn't even have the integrity to provide a single link. Goodbye, SN.
(Score: 4, Touché) by Bot on Monday April 17 2017, @10:09PM (7 children)
See you soon AC
Account abandoned.
(Score: 0) by Anonymous Coward on Monday April 17 2017, @10:20PM (6 children)
I'm Back!!!!!
(Score: 0) by Anonymous Coward on Monday April 17 2017, @11:09PM (3 children)
Oh good, I was beginning to miss myself.
(Score: 0) by Anonymous Coward on Monday April 17 2017, @11:24PM (2 children)
Stop replying to yourself!
(Score: 0) by Anonymous Coward on Tuesday April 18 2017, @12:15AM (1 child)
Why?
(Score: 2) by hemocyanin on Tuesday April 18 2017, @02:23AM
Because you look like a psycho. Put the BT earpiece in as cover.
(Score: 0) by Anonymous Coward on Tuesday April 18 2017, @08:42AM (1 child)
I'm the original AC. Just letting you know I'm really quitting this site for good.
(Score: 0) by Anonymous Coward on Tuesday April 18 2017, @09:12AM
I'm the original AC.
No, you're not, and so's my wife! How many ACs does it take to change a lightbulb?
(Score: 4, Funny) by bob_super on Monday April 17 2017, @10:22PM (1 child)
Goodbye, AC.
Your insights will be sorely missed, your jokes repeated with a tear of sadness, and no-one will ever word an informative post into a slam-dunk touche mod quite the way you did...
May your travels, away from this imperfect experiment, be as safe and rewarding as we should all aspire our lives to be.
Go in peace, AC. Your name will not be usurped and your memory tarnished. You have served proudly and valiantly, and your legend will be forever honored with a two pronged-approach of recurrent plugs.
You have always been the most prolific and best of us.
(Score: 3, Funny) by aristarchus on Tuesday April 18 2017, @09:23AM
"'E's not quite dead, yet!"
"I know, but he will be soon. Can you take 'im on the cart?"
"No, I cannot. It' against regulations! I could loose my license!"
"I feel happy, so happy! I think I'll take a walk!"
"Shut up! You're not fooling anyone, you know!"
"Isn't there any thing you could do?"
Thunk.
"Bring out your dead ACs! Bring out your dead ACs!"
"Who's that, then?"
"Must be Lennart Poettering."
"How can you tell?"
"'E's got shit all over him!"
[Apologies to Monty Python's Flying Circus. Or Fliegender Zirkus [youtube.com] ]
(Score: 2) by VanessaE on Monday April 17 2017, @10:40PM
Yeah, AC. Goodbye, and good riddance.. to you.
(Score: 3, Funny) by zafiro17 on Monday April 17 2017, @10:57PM (13 children)
rm -rf AnonymousCoward/
Dad always thought laughter was the best medicine, which I guess is why several of us died of tuberculosis - Jack Handey
(Score: 0) by Anonymous Coward on Monday April 17 2017, @11:25PM (12 children)
Wow, all you guys getting tribal and 'defending' SN, none of you holding the editors to account for this piss-poor story.
I see now why some people think trump can do no wrong.
(Score: 3, Insightful) by takyon on Monday April 17 2017, @11:37PM (8 children)
A couple people make a minor mistake which is quickly fixed in the comments. Then a non-user decides to quit the site. I'm sure no mockery is justified.
[SIG] 10/28/2017: Soylent Upgrade v14 [soylentnews.org]
(Score: 0) by Anonymous Coward on Tuesday April 18 2017, @01:20AM (3 children)
A couple people make a minor mistake which is quickly fixed in the comments.
You and I have different definitions of "quickly" and "fixed."
That is seeing as how no correction is scored above +2 and yet there are scores of comments about how poettering is the idiot, many of them posted after the correction, modded higher than the correction.
Meanwhile lots of people virtue signaling because an AC triggered them.
(Score: 0) by Anonymous Coward on Tuesday April 18 2017, @03:32AM
Well I, for one, am shocked that OP is throwing a tantrum like a little bitch instead of following through its loudly proclaimed threats to leave.
I would say to not let the door hit you on the way out (not out of any concern for your well being, mind you, but more of an "avoid spreading AIDs in the common area" courtesy to the other visitors), but we both know that you never had any intention of actually leaving.
(Score: 0) by Anonymous Coward on Tuesday April 18 2017, @09:39AM
Here, look at my virtue! It's this big! Really! And now that it has been "triggered" by some AC, who keeps saying he is leaving, my virtue is getting even bigger. In fact, stand back! I don't know how big this virtue is going to get! Perhaps if I signaled for some "virtue reduction", if you know what I mean! Heh, heh, heh.
Meanwhile lots of people virtue signaling because an AC triggered them.
(Score: 0) by Anonymous Coward on Tuesday April 18 2017, @10:05AM
Fellow AC, the question is simple: is the story made up or the link genuine? in the latter case the argument raised by the migrant AC is inconsistent.
(Score: 0) by Anonymous Coward on Tuesday April 18 2017, @02:46AM (3 children)
A "non-user", someone hiding behind a pseudonym as an Anonymous Coward, unlike our brave "tachyon" !
(Score: 2) by takyon on Tuesday April 18 2017, @03:30AM (2 children)
Be brave like me and sign up for an account.
[SIG] 10/28/2017: Soylent Upgrade v14 [soylentnews.org]
(Score: 0) by Anonymous Coward on Tuesday April 18 2017, @03:33PM (1 child)
Be brave and sign up under your real name, takyon.
Anything else is (shudder!) anonymity. Not that there's anything wrong with that.
(Score: 2) by takyon on Wednesday April 19 2017, @12:29AM
If an account is anonymous, you should sign up for one.
[SIG] 10/28/2017: Soylent Upgrade v14 [soylentnews.org]
(Score: 2) by tangomargarine on Tuesday April 18 2017, @05:38AM (2 children)
Literally the first three top-level comments were about the lack of a link. WTF are you talking about
"Is that really true?" "I just spent the last hour telling you to think for yourself! Didn't you hear anything I said?"
(Score: 2) by PiMuNu on Tuesday April 18 2017, @12:11PM
> WTF are you talking about
Its like watching drunk people in a bar. Once they are done fighting about nothing, they will be onto philosophy in no time.
(Score: 0) by Anonymous Coward on Tuesday April 18 2017, @02:14PM
The lack of a link is just a sign this is a shit story.
The actual content of the story is the real problem.
Its an exaggeration nearly to the point of being a conspiracy theory.
To recap:
(1) Not an rm unix command, its a systemd internal function call
(2) Not censored, comments limited to collaborators
(3) Limit only made after 3 drive-by flame posts that literally added no new technical information, 10 days after last informative post
It's also interesting to note that the story was submitted here just 4 hours after the discussion was limited to collaborators.
Makes me suspicious that the submitter was one of the flamers and is butthurt that his anti-social behavior was rejected.
What are the chances that some random person 'discovers' this horrible case of censorship so quickly?
(Score: 0) by Anonymous Coward on Tuesday April 18 2017, @12:19AM (7 children)
Okay, I'm really confused now. I once ran a "chmod -r +777 .*" in a silly attempt to change the property files of all the ".whatever" folders, and realized to my chagrin that it propagated up to "/". This was years ago, way before systemd was a thing.
Am I to understand now that ".*" is not supposed to affect ".."? I quite dislike systemd, but is this behavior really a bug?
Can somebody explain what is going on?
(Score: 2, Insightful) by Anonymous Coward on Tuesday April 18 2017, @01:23AM (4 children)
Modern implementations of rm have fail-safe in them that prevents recursing up the directory tree rather than down it.
They special-case looking for the user to do something stupid like that and abort out. AFAICT there is no way to over-ride it in case you really meant to do it.
But this isn't actually about rm, its about a command in systemd's own command-language that deletes files.
(Score: 2) by sjames on Tuesday April 18 2017, @03:42AM
If you really want it to ascend to / and then delete everything, just specify "-r /".
(Score: 2) by cubancigar11 on Tuesday April 18 2017, @05:48AM (2 children)
I would also add that the special handling of '..' is a very recent development, relatively speaking.
(Score: 3, Insightful) by rleigh on Tuesday April 18 2017, @07:07AM (1 child)
I'm not so sure about that. Any implementation which doesn't handle '..' will recurse through every directory in the filesystem, and will likely never terminate because it has an infinite recursion between each parent and child. You *have* to handle '..' and '.' specially, and this isn't a recent development--it's been necessary since their invention. You'd notice this on the first invocation of your tool.
(Score: 2) by cubancigar11 on Tuesday April 18 2017, @10:38AM
You may be right. I might be confusing rm with other utilities. But I distinctively remembering waiting a long time for tar to finish when I realized it is compressing the whole system.
(Score: 1, Insightful) by Anonymous Coward on Tuesday April 18 2017, @07:40AM
Yep, I did a "chown -R [owner:group] .*" and learned the hard way it also ascends. I usually assume I'm the idiot but I think ascending is IDIOTIC behavior.
Also did "rm -rf .*" once trying to get rid of .mozilla and other dot-prefixed files and directories. Did a very fast crtl-C when it didn't finish as fast as I expected.
(Score: 0) by Anonymous Coward on Tuesday April 18 2017, @02:37PM
https://linux.die.net/man/1/rm [die.net]
--preserve-root
do not remove '/' (default)
(Score: 2) by OrugTor on Tuesday April 18 2017, @03:59PM (2 children)
and counting. Fuck me sideways.
(Score: 0) by Anonymous Coward on Tuesday April 18 2017, @10:28PM (1 child)
This story is the systemd equivalent of Benghazi:
Poettering said something dumb when he didn't have all the information. People who are desperate to bash him for their own reasons decided to blow it way out of proportion and then a bunch of low-information suckers took those people at their word and ran with it. Demonstrating that fact-checking and critical thinking are in short supply wherever amateurs gather.
(Score: 0) by Anonymous Coward on Tuesday April 18 2017, @10:40PM
> Demonstrating that fact-checking and critical thinking are in short supply wherever amateurs gather.
Perhaps parent is an exemplar?
Came here to say - this "1 (2)" business at the bottom, whaaat up? really? aren't we grownups who can manage a page or two of text? Many lols for multipages!