Bug 89604 - Cannot delete file with correct group permissions
Summary: Cannot delete file with correct group permissions
Alias: None
Product: Red Hat Linux
Classification: Retired
Component: kernel
Version: 9
Hardware: i386
OS: Linux
Target Milestone: ---
Assignee: Stephen Tweedie
QA Contact: Brian Brock
Depends On:
TreeView+ depends on / blocked
Reported: 2003-04-24 21:49 UTC by Dan Forsyth (Dataforge Canada)
Modified: 2007-04-18 16:53 UTC (History)
0 users

Clone Of:
Last Closed: 2003-04-30 13:48:57 UTC

Attachments (Terms of Use)

Description Dan Forsyth (Dataforge Canada) 2003-04-24 21:49:16 UTC
From Bugzilla Helper:
User-Agent: Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0)

Description of problem:
There seems to be a problem with group permissions under redhat 9.0.  If a file 
is created and proper group write permissions are applied, users can only 
modify the file, and not delete it.

*** The above has been confirmed by RH Support as of 04/24/2003

I have also found that using the SUID as root on programs does not work, ie; 
make a batch script and suid as root when run, it will not run as root?

Version-Release number of selected component (if applicable):
default redhat 9.0 kernel

How reproducible:

Steps to Reproduce:
- Make a user name 'test' in the 'test' group.

(as root)
echo hello > hi
chgrp test hi
chmod a+rwx hi

(as test)
rm hi = permission denied
echo bye > hi = <--- THIS WORKS!

Actual Results:  The file was not deleted.

Expected Results:  The file should be deleted.

Additional info:

This is set HIGH due to the fact that this is a core system function, and could 
corrupt flat file databases using temp files with group permissions.

Comment 1 Arjan van de Ven 2003-04-25 08:37:01 UTC
deleting a file is a directory operation, so the user needs permission on the

setuid shellscripts don't work in linux for security reasons

Comment 2 Dan Forsyth (Dataforge Canada) 2003-04-25 12:54:23 UTC
I did some more testing, I have found the problem.  It seems to happen only when
the sticky bit is on the directory that the file is in?

drwxrwx--T    2 reedsjewelers bscbrar      4096 Apr 25 08:49 test

cd test

-rw-rwx---    1 root     bscbrar         3 Apr 25 08:49 hi

rm: cannot remove `hi': Operation not permitted

rm hi = permission denied.  When user is IN the bscbrar group

Comment 3 Stephen Tweedie 2003-04-30 13:48:57 UTC
This is expected behaviour --- the whole point of sticky directories is to
restrict deletes and renames to the owner of the file (or root).

"man chmod" for the full definition of the behaviour of sticky directories.

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