[Chilli] ioctl Permission Errors in net.c

[David Bird]

The risks are the same as with any network service running as root,
which is that a possible buffer overflow exploit capable of rendering a
shell becomes a root-shell...

Btw, in subversion (1.2.7-svn), I made a change that will prevent the
"re-opening" (when using uid/gid option) of the dhcpif when a write
causes EWOULDBLOCK (this is responsible for the permissions error). 

On Mon, 2011-03-28 at 20:43 +1000, Timothy White wrote:
> Having run a few days as root now and having no problems at ether
> site. The question is, what are the security risks of running as root?
> Do most people run coova chilli as root, or as it's own user?
> 
> Thanks
> 
> Tim
> 
> On Fri, Mar 25, 2011 at 4:21 PM, David Bird <david at coova.com> wrote:
> > It is a runtime option to switch users after start.. See uid and gid options
> >
> > http://dev.coova.org/svn/coova-chilli/src/cmdline.ggo
> >
> > --
> >   David
> > On Mar 25, 2011, at 4:45 AM, Timothy White <timwhite88 at gmail.com> wrote:
> >
> > I have an issue that I thought was isolated to a single server with
> > coova chilli randomly crashing with error messages. I've since upgrade
> > them from 1.2.5 to 1.2.6 and the issues continued. Thinking it might
> > be hardware related I just added a cronjob at 5 minute intervals to
> > check if chilli is running and restart if not.
> > Since then I have another freshly installed server also having the
> > same issue. I've checked for IRQ interrupt conflicts and found none
> > that I can see.
> >
> > The errors are as below, and sometimes just happen a few times. Other
> > times they repeat a good number of times before chilli shutsdown
> >
> > Mar 25 11:32:16 HotSpot coova-chilli[3279]: net.c: 114: 13 (Permission
> > denied) ioctl(SIOCSIFFLAGS) failed
> > Mar 25 11:32:18 HotSpot coova-chilli[3280]: net.c: 114: 13 (Permission
> > denied) ioctl(SIOCSIFFLAGS) failed
> > Mar 25 11:32:43 HotSpot coova-chilli[3281]: net.c: 114: 13 (Permission
> > denied) ioctl(SIOCSIFFLAGS) failed
> > Mar 25 11:32:50 HotSpot coova-chilli[3282]: net.c: 114: 13 (Permission
> > denied) ioctl(SIOCSIFFLAGS) failed
> > Mar 25 11:32:51 HotSpot coova-chilli[3283]: net.c: 114: 13 (Permission
> > denied) ioctl(SIOCSIFFLAGS) failed
> > Mar 25 11:33:42 HotSpot coova-chilli[3233]: chilli.c: 5801:
> > CoovaChilli shutting down
> > Mar 25 11:33:42 HotSpot coova-chilli[3325]: main-script.c: 93: Running
> > /etc/chilli/down.sh (105/0)
> > Mar 25 11:33:42 HotSpot coova-chilli[3233]: net.c: 114: 13 (Permission
> > denied) ioctl(SIOCSIFFLAGS) failed
> >
> > When it shutsdown it that's the last messages in the syslog until the
> > cronjob starts it back up again.
> >
> > Any ideas? The things that comes to my mind first of all is that the
> > thread trying to work on the device (not sure if it's tun0 or eth1) is
> > running as chilli and not as root. I believe most of chilli drops root
> > privs early on, but a thread/fork/process holds onto root for iptables
> > and other things like that?
> >
> > Is there a compile time option to prevent it dropping privs so I can
> > test that theory?
> >
> > Thanks
> >
> > Tim
> > _______________________________________________
> > Chilli mailing list
> > Chilli at coova.org
> > http://lists.coova.org/cgi-bin/mailman/listinfo/chilli
> >
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