[tor-bugs] #24903 [Core Tor/Tor]: Bug: Line unexpectedly reached at pathbias_should_count at src/or/circpathbias.c:372

[Tor Bug Tracker & Wiki]

#24903: Bug: Line unexpectedly reached at pathbias_should_count at
src/or/circpathbias.c:372
-------------------------------------------------+-------------------------
 Reporter:  starlight                            |          Owner:  (none)
     Type:  defect                               |         Status:
                                                 |  reopened
 Priority:  High                                 |      Milestone:  Tor:
                                                 |  0.3.3.x-final
Component:  Core Tor/Tor                         |        Version:  Tor:
                                                 |  0.3.2.9
 Severity:  Normal                               |     Resolution:
 Keywords:  tor-assert-nonfatal, regression?,    |  Actual Points:
  033-must, 033-triage-20180320,                 |
  033-included-20180320                          |
Parent ID:  #24907                               |         Points:  1
 Reviewer:                                       |        Sponsor:
-------------------------------------------------+-------------------------
Changes (by nickm):

 * cc: mikeperry (added)


Comment:

 Hm.  So, the issue here has nothing to do with AllowOneHopExits -- it
 happens when the 'onehop_tunnel' and 'desired_path_len' fields don't match
 each other any more.  Ordinarily, this is always true, UNLESS the
 controller has been messing with things.

 One fix here would be to set a flag on a circuit when the controller has
 extended it, and ignore all circuits with this flag in
 pathbias_should_count().

 Another fix here would be to clear onehop_tunnel when a controller has
 extended a circuit that previously had it.  I don't know the implication
 there.

--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/24903#comment:7>
Tor Bug Tracker & Wiki <https://trac.torproject.org/>
The Tor Project: anonymity online