[tor-bugs] #25733 [Core Tor/Tor]: Bug: Assertion bin_counts > 0 failed in circuit_build_times_get_xm at ../src/or/circuitstats.c:772.

[Tor Bug Tracker & Wiki]

#25733: Bug: Assertion bin_counts > 0 failed in circuit_build_times_get_xm at
../src/or/circuitstats.c:772.
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 Reporter:  cstest        |          Owner:  (none)
     Type:  defect        |         Status:  new
 Priority:  Medium        |      Milestone:  Tor: unspecified
Component:  Core Tor/Tor  |        Version:  Tor: 0.3.2.10
 Severity:  Normal        |     Resolution:
 Keywords:  034-proposed  |  Actual Points:
Parent ID:                |         Points:
 Reviewer:                |        Sponsor:
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Comment (by mikeperry):

 Quick thought: This crash might be avoided by the fix for #23100. If a
 client is learning its circuit build timeout from only a few non-hidden
 service circuits, and the rest are hidden service circuits that are being
 ignored by the 0.3.2 CBT, then it is possible that it picked a timeout
 that is too low for the hidden service circuits to ever complete, and thus
 all are timing out without being counted properly. I could see this
 happening under DDoS. #23100 changes the CBT code to count HS circs in
 build times.

 If this is a critical problem, it is worth trying the latest Tor
 0.3.3.4-alpha or above, which has this fix. 0.3.3 should be released as
 either rc or stable next week, so it should be in good shape for
 production. If you try this, please report if it continues to happen or
 not.

 Regardless, we should try to fix the underlying assert, of course. I
 suppose we could make it a tor_fragile_assert or similar for now, also.

--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/25733#comment:3>
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