Mdthbs

I was trying to chown within /opt and for some reason chown jumped up to the parent and chowned everything.

Can anyone suggest why/how this might happened, and how to avoid doing it in future? It's a bit concerning that running a command in a given dir can effectively jump up and run it in root dir.

ubuntu: /opt > sudo chown -R root:www-data .*

chown: changing ownership of '../var/lib/lxcfs/proc/cpuinfo': Operation not permitted

chown: changing ownership of '../var/lib/lxcfs/proc/meminfo': Operation not permitted

chown: changing ownership of '../var/lib/lxcfs/proc/stat': Operation not permitted

chown: changing ownership of '../var/lib/lxcfs/proc/uptime': Operation not permitted

chown: changing ownership of '../var/lib/lxcfs/proc/diskstats': Operation not permitted

chown: changing ownership of '../var/lib/lxcfs/proc/swaps': Operation not permitted

chown: changing ownership of '../var/lib/lxcfs/proc': Operation not permitted

chown: changing ownership of '../var/lib/lxcfs/cgroup/devices': Operation not permitted

chown: changing ownership of '../var/lib/lxcfs/cgroup/blkio': Operation not permitted

chown: changing ownership of '../var/lib/lxcfs/cgroup/hugetlb': Operation not permitted

chown: changing ownership of '../var/lib/lxcfs/cgroup/rdma': Operation not permitted

chown: changing ownership of '../var/lib/lxcfs/cgroup/pids': Operation not permitted

chown: changing ownership of '../var/lib/lxcfs/cgroup/freezer': Operation not permitted

chown: changing ownership of '../var/lib/lxcfs/cgroup/cpuset': Operation not permitted

chown: changing ownership of '../var/lib/lxcfs/cgroup/memory': Operation not permitted

chown: changing ownership of '../var/lib/lxcfs/cgroup/perf_event': Operation not permitted

chown: changing ownership of '../var/lib/lxcfs/cgroup/cpu,cpuacct': Operation not permitted

chown: changing ownership of '../var/lib/lxcfs/cgroup/net_cls,net_prio': Operation not permitted

chown: changing ownership of '../var/lib/lxcfs/cgroup/name=systemd': Operation not permitted

chown: changing ownership of '../var/lib/lxcfs/cgroup/unified': Operation not permitted

chown: changing ownership of '../var/lib/lxcfs/cgroup': Operation not permitted

chown: changing ownership of '../var/lib/lxcfs': No such file or directory

^C

:ubuntu: /opt >

This happened because you used:

sudo chown -R root:www-data .*

when you should have used this instead:

sudo chown -R root:www-data ./*

First, ./* is recursive for all directories under the current directory.

Additionally, * is also recursive for all directories under the current directory.

Next, .* is recursive for all directories, one directory above the current directory.

Finally ../* is also recursive for all directories one directory above the current directory.

To avoid this in the future, you can use the ls command to verify the path before you execute the chown command like in these examples:

ls -a ./*

ls -a *

ls -a .*

ls -a ../*

Another way to avoid this is to always use the full path to the directory you wish to run a command to.

Here is an example:

sudo chown -R root:www-data /opt/*

Edit:

You can use the following command to chmod all hidden files directly under /opt This will not apply to directories.

for i in $(ls -a /opt | grep -P "^.[A-Z,a-z]"); do sudo chmod root:www-data $i; done

You can verify what files this will chmod by running the following command:

ls -a /opt | grep -P "^.[A-Z,a-z]"

The first part of the command: for i in $(ls -a /opt | grep -P "^.[A-Z,a-z]") says that, for all the results of the command ls -a /opt | grep -P "^.[A-Z,a-z]" assign each result to the variable "i".

Also, grep -P "^.[A-Z,a-z]" uses the -P option which I think stands for perl and this allows us to use regex to match the result.

The regex here says that the first matching character ^. must be . and that the next character [A-Z,a-z] must be any character that is A-Z or a-z.

This will exclude the results . and .. which represent the current directory and the directory above the current directory and will only include hidden.

The second part of the command: do sudo chmod root:www-data $i says to run the command for all variables that match "i".

The third part of the command: done says that I am finished.

Additionally, you used the -R option with chmod and the -R option is recursive and will apply to all directories.

Because chmod is such a dangerous command sometimes, the -R option is added to apply to directories and files.

When you only only use the chmod command with no options, the command will only apply to files and will not apply recursively to directories.

The shell glob .* matches .. (the parent directory) in this case unfortunately that's /:

steeldriver@t400s:/opt$ ls .*

.:



..:

bin  boot  cdrom  dev  etc  home  initrd.img  initrd.img.old  lib  lib32  lib64

libx32  lost+found  media  mnt  opt  proc  root  run  sbin  snap  srv  swapfile  sys

tmp  usr  var  vmlinuz  vmlinuz.old

For additional discussion see:

• Does “chmod 777 .* -R” chmod parent directories (..)?


• how to glob every hidden file except current and parent directory