We have complaints "from the field" (i.e. from sysadmins installing software) that cygwin "messes up" windows permissions on NTFS (Windows 7/10/2008/2012, etc).
Problem Usecase
The general usecase is this:
Sysadmin launches some 'software installer' from the cygwin bash cmd line
Installer runs fine
Sysadmin tries to start windows services
Result:
Service fails to start
Workaround Steps
These steps seem to get past the problem:
Sysadmin resets ntfs permissions with windows ICACLS command : (in this example "acme" is the newly created directory. This command sets acme and its children to re-inherit permissions from folder "d:\instances"
d:\instances> icacls acme /RESET /T /C /Q
Sysadmin starts service
Result:
Windows service starts
Question
What makes cygwin handle permissions for newly-written files differently than powershell? Is it a matter of a wrong version of umask?
Can the sysadmin take steps in advance to ensure cygwin sets up permissions properly?
thanks in advance
I found the answer here; it refers to this mailing-list letter.
You need to edit Cygwin's /etc/fstab and add "noacl" to the list of mount-options.
To add to the answer of ulathek here is the copy-paste of the two URLs:
First:
How to fix incorrect Cygwin permission in Windows 7
Cygwin started to behave quite strangely after recent updates. I was not able to edit files in vim, because it was complaining that files are read only. Even cp -r didn’t work correctly. Permission of new directory was broken and I was not able to remove it. Pretty weird behavior.
E.g. ls -l
total 2
----------+ 1 georgik None 34 Jul 14 18:09 index.jade
----------+ 1 georgik None 109 Jul 14 17:40 layout.jade
Hm. It is clear that something is wrong with permission. Even owner has no permission on those files.
Output of mount command:
C: on /cygdrive/c type ntfs (binary,posix=0,user,noumount,auto)
I found a solution at cygwin forum. It’s quite easy to fix it.
Open /etc/fstab and enter following line:
none /cygdrive cygdrive binary,noacl,posix=0,user 0 0
Save it. Close all cygwin terminals and start new terminal.
Output of mount:
C: on /cygdrive/c type ntfs (binary,noacl,posix=0,user,noumount,auto)
Output of ls -l
total 2
-rw-r--r-- 1 georgik None 34 Jul 14 18:09 index.jade
-rw-r--r-- 1 georgik None 109 Jul 14 17:40 layout.jade
Second:
7/14/2010 10:57 AM
> Drive Y is a mapping to a network location. Interestingly, ls -l
>> /cygdrive returns:
>> d---------+ 1 ???????? ???????? 24576 2010-07-09 11:18 c
>> drwx------+ 1 Administrators Domain Users 0 2010-07-14 06:58 y
>>
>> The c folder looks weird, the y folder looks correct.
>>
> Try ls -ln /cygdrive. The user and group ownerships on the root of the
> C: drive are most likely not found in your passwd and group files. The
> -n option for ls will print the user and group IDs rather than try to
> look up their names. Unfortunately, I can't think of any way offhand to
> generate the passwd and group entries given only user and group IDs.
> Maybe someone else can comment on that.
>
I think your answer is correct:
$ ls -ln /cygdrive
total 24
d---------+ 1 4294967295 4294967295 24576 2010-07-09 11:18 c
drwx------+ 1 544 10513 0 2010-07-14 11:45 y
I edited my /etc/fstab file (it contained only commented lines) and
added this line at the end of the file:
none /cygdrive cygdrive binary,noacl,posix=0,user 0 0
I closed all my Cygwin processes, opened a new terminal and did an ls-l
on visitor.cpp again:
-rw-r--r-- 1 cory Domain Users 3236 2010-07-11 22:37 visitor.cpp
Success!!! The permissions are now reported as 644 rather than 000 and I
can edit the file with Cygwin vim and not have bogus read-only issues.
Thank you Jeremy.
cory
Related
We are getting the error "permission denied" when trying to write to a file that is owned by a service user and a shared group. In particular that is www-data:www-data and the user trying to write to it is in the group www-data.
There is no acl on none of the parent folders and the permissions to the file and folders are correct.
Here some details:
$ sudo -u deploy id -Gn
www-data
$ ls -lah /tmp
drwxrwxrwt 17 root root 4.0K Jul 11 11:22 .
drwxr-xr-x 23 root root 4.0K Jul 8 10:08 ..
...
-rw-rw-r-- 1 www-data www-data 0 Jul 11 10:50 test
...
$ echo 'hello world' | sudo -u deploy tee -a /tmp/test
tee: /tmp/test: Permission denied
hello world
we tried that on different folders and made sure there is no acl on any of the folders or parents or files...
Unfortunately that is not described in the link stark posted in the comment. And also not in any other page I found until I found an answer here on stackoverflow that clarified it.
2018 two new filesystem configurations got added to sysctl that should prevent regular files and fifos from beeing opened with the O_CREAT flag (as append mode is doing) in directories with the sticky bit set unless the user is the owner of the file. This commit added the settings: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=30aba6656f61ed44cba445a3c0d38b296fa9e8f5
To change that behaviour you have to set fs.protected_regular to 0:
sudo sysctl fs.protected_regular=0
Or to persist the change add fs.protected_regular=0 to your sysctl.conf.
side node: since O_CREAT is not deleting or renaming the file I'm wondered why it is connected to the sticky bit. It really is possible to create a file in directories with the stick bit set.
I am trying to use rsync to backup some data from one computer (PopOS! 21.04) to another (Rocky 8.4). But no matter which flags I use with rsync, file permissions and ownership never seem to be saved.
What I do, is run this command locally on PopOS:
sudo rsync -avz /home/user1/test/ root#192.168.10.11:/root/ttt/
And the result I get something link this:
[root#rocky_clone0 ~]# ls -ld ttt/
drwxrwxr-x. 2 user23 user23 32 Dec 17 2021 ttt/
[root#rocky_clone0 ~]# ls -l ttt/
total 8
-rw-rw-r--. 1 user23 user23 57 Dec 17 2021 test1
-rw-rw-r--. 1 user23 user23 29 Dec 17 2021 test2
So all the file ownership change to user23, which is the only regular user on Rocky. I don't understand how this happens, with rsync I am connecting to root on the remote host, but as the result files are copied as user23. Why isn't -a flag work properly in this case?
I have also tried these flags:
sudo rsync -avz --rsync-path="sudo -u user23 rsync -a" /home/user1/test root#192.168.10.11:/home/user23/rrr
This command couldn't copy to the root directory, so I had to change the remote destination to user23's home folder. But the result is the same.
If someone could explain to me what am I doing wrong, and how to backup files with rsync so that permissions and ownership stay the same as on the local computer I would very much appreciate it.
Have a look at how the (target)filesystem is mounted on the Rocky(target) system.
Some mounted filesystems (such as many FUSE mounts) do not support the classical unix permissions, and simply use the name of the user who mounted the filesystem as owner/group.
Any attempt to chown/chmod/etc (either by you or by rsync) will just silently be ignored, but appear to "succeed" (no errors reported).
My linux umask is 002.
$ umask
0002
Therefore new files have 664 permissions.
$ touch new-file
$ ls -l
-rw-rw-r-- 1 david www-data 0 feb 11 11:37 new-file
However if I create a new file from netbeans (right click / New / Empty file) it have 644 permissions.
$ ls -l
-rw-r--r-- 1 david www-data 0 feb 11 11:40 netbeans-file
Can I configure which permissions have new files created from netbeans?
As #tripleee says Netbeans was not a child of the shell where umask were set.
umask command were at .bashrc which is executed only when a shell window is opened but not on session login.
After moving the umask command to .profile all GUI programs including netbeans take the umask properly.
umask is a mask with it the intended permissions, when creating a file, are mixed. That means that if Netbeans wanted a file with rw-r--r-- and the mask is 002 (means that you want to remove writing for others), real protections will be rw-r--r--. The operation behind this is:
real_rights = wanted_rights & ~umask
An application have preferences about protection over a file it creates, and user have preferences on what he do not want on permissions.
The commands
cd c:/p4
ls -ld . c:/p4 /cygdrive/c/p4
shows
d---------+ 1 jgunter Domain Users 0 Apr 27 18:41 .
d---------+ 1 jgunter Domain Users ? 0 Apr 27 18:41 /cygdrive/c/p4
drwxr-xr-x 1 jgunter Domain Users ? 0 Apr 27 18:41 c:/p4
ls shows the perms I want to see only for files specified with a C:/ path.
I know about getfacl, but I'm hoping there's some ls option that will show me what I want without requiring I spell out absolute paths.
I can do something like:
ls -ld `cygpath -da $#`
but when I'm in a deeply nested folder, the output is cluttered by full pathnames.
DOS path makes cygwin treat the file system as not having ACLs. It means that ls shows the correct ACLs, but the same directory is mounted with different options. Therefore ls doesn't have such an option, you need a workaround.
https://cygwin.com/cygwin-ug-net/ov-new1.7.html states at 1.7.2:
Handle native DOS paths always as if mounted with "posix=0,noacl"
Beside this, I think, that d---------+ is strange. I've tried it on my PC, with 1.7.31 cygwin version, and it shows drwx------+, which is a bit better. I had experienced other bugs and strange behaviour in cygwin ACL handling. I guess there is confusion and some hacks about this. chmod 777 was a good workaround in my case.
I have a script in /etc/cron.daily/backup.sh file is allowed to execute and run but do not start happening, I read the manual and used the search but not mastered decision.
ls -l /etc/cron.daily/
total 52
-rwxr-xr-x 1 root root 8686 2009-04-17 10:27 apt
-rwxr-xr-x 1 root root 314 2009-02-10 19:45 aptitude
-rwxr-xr-x 1 root root 103 2011-05-22 19:08 backup.sh
-rwxr-xr-x 1 root root 502 2008-11-05 03:43 bsdmainutils
-rwxr-xr-x 1 root root 89 2009-01-27 00:55 logrotate
-rwxr-xr-x 1 root root 954 2009-03-19 16:17 man-db
-rwxr-xr-x 1 root root 646 2008-11-05 03:37 mlocate
The cron job filename can't have a period in it on certain ubuntus. See this. Particularly, this quote within:
Although the directories contain periods in their names, run-parts
will not accept a file name containing a period and will fail silently
when encountering them
Properly, this is a problem with run-parts, which the ubuntu cron runs, and not with cron itself. Still, it's what bit me.
pls check:
1a) is the script executable and has correct owner/group settings?
1b) does it start with the correct #! line? and do you specify the full path to the shell you're using,
e.g. #!/bin/bash ?
2) does the script generate an error while being executed?
e.g. can you write to a log file from it, and do you see the log messages?
also: check in the email inbox of the user who owns the crontab -- errors are emailed to the user / e.g. root
what does the output of ls -l /etc/cron.daily/ look like? can you post that?
NOTE:
you can always create a crontab entry for this yourself, outside of those cron.xxx directory structure ;-)
See: man 5 crontab
10 1 * * * /somewhere/backup.sh >> /somewhere/backup.log 2>&1
this has the advantage that you get to pick the exact time when it runs (e.g. 1:10am here), and you can redirect STRERR and STDOUT to append to a log file for that particular script
For testing purposes you could run it ever 10 minutes, like this:
0,10,20,30,40,50 * * * * /somewhere/backup.sh >> /somewhere/backup.log 2>&1
do touch /somewhere/backup.log to make sure it exists