[tor-bugs] #16585 [Core Tor/Tor]: Long-running activity in scheduler_run() blocks network, creating information leaks (was: Network activity from scheduler_run() creates multiple side channel information leaks)

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#16585: Long-running activity in scheduler_run() blocks network, creating
information leaks
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 Reporter:  starlight                      |          Owner:  (none)
     Type:  defect                         |         Status:  new
 Priority:  Medium                         |      Milestone:  Tor:
                                           |  unspecified
Component:  Core Tor/Tor                   |        Version:  Tor: 0.2.6.10
 Severity:  Normal                         |     Resolution:
 Keywords:  tor-client guard side-channel  |  Actual Points:
Parent ID:                                 |         Points:
 Reviewer:                                 |        Sponsor:
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Comment (by mikeperry):

 Actually in this case it is not network activity that is the cause. CPU
 activity in scheduler_run() is blocking the network from sending anything.

 If we focus on just making sure the network can always read and send, that
 might be an easier thing to do in another thread. Of course, the send side
 depends on there being sufficiently encrypted traffic ready to be sent,
 and then the crypto parallelism problem shows up
 (https://trac.torproject.org/projects/tor/wiki/org/projects/Tor/MultithreadedCrypto)

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Ticket URL: <https://trac.torproject.org/projects/tor/ticket/16585#comment:31>
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