[tor-bugs] #27841 [Core Tor/Tor]: Surprise race: Intro point closes circuit after NACK, at the same time as client tries to extend circuit to new intro point (was: Close intro circuit after introduction has been completed)

[Tor Bug Tracker & Wiki]

#27841: Surprise race: Intro point closes circuit after NACK, at the same time as
client tries to extend circuit to new intro point
--------------------------+------------------------------------
 Reporter:  asn           |          Owner:  neel
     Type:  defect        |         Status:  merge_ready
 Priority:  Medium        |      Milestone:  Tor: 0.3.5.x-final
Component:  Core Tor/Tor  |        Version:
 Severity:  Normal        |     Resolution:
 Keywords:  tor-hs dos    |  Actual Points:
Parent ID:                |         Points:
 Reviewer:  dgoulet       |        Sponsor:
--------------------------+------------------------------------
Changes (by arma):

 * keywords:  tor-hs dos 033-backport, 034-backport => tor-hs dos
 * milestone:  Tor: 0.3.4.x-final => Tor: 0.3.5.x-final


Comment:

 Also agreed, no need to backport before 0.3.5.

 This is a pretty important fix for v3 onion services, because in 0.3.4.x,
 if you try an intro point and it has rotated away, then simultaneously (a)
 you will try to extend that intro circuit to the next intro point, and (b)
 the first one will start tearing down the circuit. I could easily believe
 that the client doesn't handle it well and waits for something to time out
 before launching a new one.

 I'm going to retitle the ticket to be what we actually did. And I'm going
 to go back in time and change this entry in the ChangeLog to be a major
 bugfix, so it will be noted that way in the 0.3.5 ReleaseNotes.

--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/27841#comment:23>
Tor Bug Tracker & Wiki <https://trac.torproject.org/>
The Tor Project: anonymity online