[tor-bugs] #6572 [Tor]: “Bug: Circuit somehow completed a hop while the network was not live.”

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#6572: “Bug: Circuit somehow completed a hop while the network was not live.”
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 Reporter:  bpmcontrol                 |          Owner:  mikeperry         
     Type:  defect                     |         Status:  needs_information 
 Priority:  normal                     |      Milestone:  Tor: 0.2.4.x-final
Component:  Tor                        |        Version:                    
 Keywords:  tor-client 024-deferrable  |         Parent:                    
   Points:                             |   Actualpoints:                    
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Comment(by mikeperry):

 There are only 4 places where timestamp_began gets updated in the source:

 1. circuit_deliver_create_cell() - When we first decide to send the
 initial CREATE cell
 2. pathbias_send_usable_probe() - At circuit close when we decide to probe
 it
 3. circuit_extend_to_new_exit() - Some cannibalization cases
 4. circuit_launch_by_extend_info() - Other cannibalization cases

 1 should not cause this issue, because in this case the circuit still has
 not completed any hops.

 2 should not cause this issue, because the circuit is already opened, and
 this log message is in a code block that checks has_opened.

 3 and 4 should not cause this issue, again because they should only be
 caused for has_opened circuits. Additionally, they also increment the
 desired_path_len, which this code block also checks is exactly 3...

 I suppose we could beef up this log line to make extra sure none of the
 above have happened somehow, but otherwise I am at a loss...

-- 
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/6572#comment:13>
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