[tor-bugs] #21415 [Core Tor/Tor]: tor_bug_occurred_: Bug: src/or/entrynodes.c:1845: select_entry_guard_for_circuit: Non-fatal assertion !(!guard_has_descriptor(guard)) failed.

[Tor Bug Tracker & Wiki]

#21415: tor_bug_occurred_: Bug: src/or/entrynodes.c:1845:
select_entry_guard_for_circuit: Non-fatal assertion
!(!guard_has_descriptor(guard)) failed.
--------------------------+------------------------------------
 Reporter:  cypherpunks   |          Owner:  nickm
     Type:  defect        |         Status:  assigned
 Priority:  Medium        |      Milestone:  Tor: 0.3.0.x-final
Component:  Core Tor/Tor  |        Version:  Tor: 0.3.0.3-alpha
 Severity:  Normal        |     Resolution:
 Keywords:                |  Actual Points:
Parent ID:                |         Points:
 Reviewer:                |        Sponsor:
--------------------------+------------------------------------

Comment (by nickm):

 The warning here seems to be here, in select_entry_guard_for_circuit()...
 {{{
   SMARTLIST_FOREACH_BEGIN(gs->primary_entry_guards, entry_guard_t *,
 guard) {
     entry_guard_consider_retry(guard);
     if (! entry_guard_obeys_restriction(guard, rst))
       continue;
     if (guard->is_reachable != GUARD_REACHABLE_NO) {
       if (need_descriptor && BUG(!guard_has_descriptor(guard))) {
         continue;
       }
 }}}

 And this, in turn, looks like a problem with our 21242 code. We're not
 supposed to be calling select_entry_guard_for_circuit() with
 need_descriptor set while
 guard_selection_have_enough_dir_info_to_build_circuits() is false, right?

 Though hm, that function only checks to make sure that the first
 num_primary possibly reachable guards all have descriptors.  If enough of
 them seem down, there's a decent chance that we'll turn to a position
 where we might have to update our 'can build circuits' flag.

 If that's so, then the right fix here is probably either to remove the BUG
 guard on the check.

--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/21415#comment:4>
Tor Bug Tracker & Wiki <https://trac.torproject.org/>
The Tor Project: anonymity online