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Re: Things changing overnight



On Sat, Aug 09, 2003 at 10:47:27PM -0700, Ken Bloom wrote:
> Sometime in the past few days, my modem /dev/ttyS4 changed its 
> permissions from 660 to 640 without my intervention. My first question: 
> is there any kind of security package on debian that might have done 
> this as a cronjob? I don't use devfs.

I had this happen a while back.  Not sure about the exact permissions,
but my permissions for my serial port were reduced and I couldn't access
it due to this.

On investigation, I found that when pppd (I think it was) starts up,
the permissions for the port are reduced, and are _supposed_ to be
restored.. I decided that for some reason, pppd didn't restore the
permissions after shutdown..

One possibility for this.. I cannot recall the exact procedure, but I
believe that pppd stores the original setting for the permissions..
perhaps I tried to start pppd while I had a pppd session open.. the
second pppd may have overwritten the saved permission with the current,
which would have been the "reduced" permission and this would have been
what the original pppd would have "restored" to..  My modem is ttyS1, so
I just set the permissions to that of the other ttyS's and the problem
hasn't happened again.



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