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Re: Sudden “operation not permitted”




David Christensen <dpchrist@xxxxxxxxxxxxxxxx> writes:

>On 4/16/19 11:25 PM, Mark Fletcher wrote:
>> (Apologies if this mail comes through poorly formatted for the list; my
>> main machine is unavailable due to this problem and I’m writing on an
>> iPad...)
>>
>> Running Stretch on a circa-2009 self-built machine which has run happily
>> without serious issues since it was built, apart from the odd annoyance
>> with Bluetooth audio which the list has already had the pleasure of hearing
>> about.
>>
>> This morning I unlocked it before leaving home, and noticed that load was
>> fairly constant at about 1.0 when it should have been at 0 as the machine
>> should have been idle. I listed processes with top and noticed that upowerd
>> was taking up a whole CPU to itself. Normally I wouldn’t notice this daemon
>> doing its thing.
>>
>> Google turned up nothing relevant.
>>
>> I decided to try a reboot, which cleared the upowerd problem and returned
>> load to 0 or close to it. But now, network activity is not working. Any
>> attempt to ping an IP address (eg my router) results in “Operation not
>> permitted” even when run as root. Attempt to access any web page results in
>> failing to find the site. Attempting to ping a text domain (eg
>> www.google.com) results in an error message (instantly) saying could not
>> resolve...
>>
>> It seems like networking is bejiggered suddenly on this machine. I did not
>> install updates before rebooting, last time updates were installed was
>> Sunday, and all has been well since then until this morning, although I did
>> not reboot during that period until this morning. The machine is attached
>> to my network via an Ethernet cable running to a WiFi+wired router. That is
>> obviously working as the machine was able to get an IP address by DHCP
>> after the reboot (ip route after reboot showed IP address correctly
>> assigned) but unable to resolve any address and unable to ping an IP
>> address of the form 192.168.xx.yy with the “Operation not permitted” error.
>>
>> All the pinging I’ve been trying worked without issues before this problem
>> occurred, both as root and as an unprivileged user.
>>
>> Looking through the journalctl since my reboot, I do not see anything that
>> obviously points to the problem. Network Manager seems to start OK, as far
>> as I can tell. I don’t see any significant errors except postgreSQL failing
>> to start, which is normal and I don’t use it. The first sign of trouble (to
>> my eye, anyway) in the boot log is when services that want the network eg
>> ntp start trying to interact with it, and failing.
>>
>> A second reboot produced exactly the same result. Other devices on my
>> network are working fine.
>>
>> Putting the upowerd behavior together with the suddenness of this problem,
>> I’m very afraid that this isn’t really permissions and is in fact some sort
>> of hardware issue — the machine is 10 years old, was built by me, and has
>> been in continuous use since it was built... Any suggestions for what I can
>> do to diagnose?
>>
>> Thanks in advance
>>
>> Mark
>
>If you updated/ upgraded but did not reboot, then there could be a
>problem with one or more upgrades.  (I try to reboot immediately after
>upgrading to avoid delayed surprises.)
>
>
>I would pull the system drive, put it into a second machine, boot it,
>and see if the problems persist.  I would also run the system drive
>manufacturer's diagnostic tool and test the system drive.
>
>
>While testing the system drive in another machine, I would test the
>first machine -- e.g. verify all cables fully seated, test the power
>supply with a hardware tester, run any motherboard firmware
>diagnostics, run software memory diagnostics, etc..
>
>
>David

Wouldn't it make more sense to boot a rescue CD and see if the hardware
works - specifically the networking?