Hi, I think there is a permissions bug with cgroups. In the example below, I am able to create a cgroup directory under /cgroups/jobs as a non-root user (starting out as root and then calling setgid and setuid, both of which are effective) without sufficient permissions. Then, if I change the group write permission to off, I am denied. Note: when I try mkdir in a regular login shell as myself, the permissions seem to work correctly as I am denied, whether on not to group write bit is set. This happens on 2.6.32 (ubuntu 10.04) and 3.2.0 (ubuntu 12.04). Thanks, John root@mel-fe01:/cgroups# ls -ld /cgroups/jobs drwxrwxr-x 2 root root 0 Jul 27 15:20 /cgroups/jobs root@mel-fe01:/cgroups# python Python 2.6.5 (r265:79063, Apr 16 2010, 13:57:41) [GCC 4.4.3] on linux2 Type "help", "copyright", "credits" or "license" for more information.
import os os.setgid(108) os.setuid(859) os.mkdir("/cgroups/jobs/1") os.rmdir("/cgroups/jobs/1")
[1]+ Stopped python root@mel-fe01:/cgroups# chmod g-w /cgroups/jobs root@mel-fe01:/cgroups# fg python
os.mkdir("/cgroups/jobs/1")
Traceback (most recent call last): File "<stdin>", line 1, in <module> OSError: [Errno 13] Permission denied: '/cgroups/jobs/1'
root@mel-fe01:/cgroups# uname -a Linux mel-fe01 2.6.32-38-server #83-Ubuntu SMP Wed Jan 4 11:26:59 UTC 2012 x86_64 GNU/Linux -- To unsubscribe from this list: send the line "unsubscribe cgroups" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
