25 Apr
2017
25 Apr
'17
3:42 a.m.
Hello all.
It's off-topic for this list, but there is turmoil in Linux-land. A bug
was discovered in systemd, whereby systemd re-implemented "rm"
functionality without following POSIX "rm" behaviour. This could kill a
system, as explained here: https://github.com/systemd/systemd/issues/5644
The reference POSIX "rm" behaviour is that "rm -rf .*" should NOT
delete
the current and parent directories, as stated here:
http://pubs.opengroup.org/onlinepubs/9699919799/utilities/rm.html#tag_20_11…
So, to get on-topic, I have a question for UNIX historians: when was it
first defined in the UNIX realm that "rm -r .*" should NOT delete the
current and parent directories? Would the command "cd /tmp ; rm -rf .*"
be able to kill a V6 or V7 UNIX system?
Regards,
--
Josh Good
25 Apr
25 Apr
3:48 a.m.
New subject: There is turmoil in Linux-land - When did rm first avoid going upwards?
Off-topic but funny: I have personally witnessed a 4.1BSD Vax where someone
accidentally did "mv . .." (or possibly "mv .. .") and it worked,
with
resulting horrible mess.
-a
3:59 a.m.
New subject: There is turmoil in Linux-land - When did rm first avoid going upwards?
Having done exactly this with one of my own systems back in the early
90's, I decided to test this out - I have some Solaris 8 VM's that I was
able to clone easily and rip off the networking.
kilowatt# mkdir a
kilowatt# cd a
kilowatt# touch .a .b .c
kilowatt# rm -rf .*
kilowatt# ls -a
. ..
kilowatt# rm -rf .*
rm of . is not allowed
rm of .. is not allowed
Now I need to go check some of the other VM's I have of early SVR4... I
think it was either SunOS or an early SVR4 where this had catastrophic
results :)
On 4/24/2017 5:48 PM, Alec Muffett wrote:
Off-topic but funny: I have personally witnessed a
4.1BSD Vax where
someone accidentally did "mv . .." (or possibly "mv .. .") and it
worked, with resulting horrible mess.
-a
4:10 a.m.
New subject: There is turmoil in Linux-land - When did rm first avoid going upwards?
On Mon, Apr 24, 2017 at 11:42:14PM +0200, Josh Good wrote:
So, to get on-topic, I have a question for UNIX historians: when was it
first defined in the UNIX realm that "rm -r .*" should NOT delete the
current and parent directories? Would the command "cd /tmp ; rm -rf .*"
be able to kill a V6 or V7 UNIX system?
V7 has a dotname function it uses to protect against this.
khm
2799
days inactive
2799
days old
3 comments
4 participants
participants (4)
-
Alec Muffett -
Arthur Krewat -
Josh Good -
Kurt H Maier