[tor-bugs] #7212 [Tor]: circuitmux assertion failure in 0.2.4.4-alpha

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#7212: circuitmux assertion failure in 0.2.4.4-alpha
-----------------------+----------------------------------------------------
 Reporter:  nickm      |          Owner:                    
     Type:  defect     |         Status:  needs_review      
 Priority:  major      |      Milestone:  Tor: 0.2.4.x-final
Component:  Tor        |        Version:  Tor: 0.2.4.4-alpha
 Keywords:  tor-relay  |         Parent:                    
   Points:             |   Actualpoints:                    
-----------------------+----------------------------------------------------
Changes (by nickm):

  * status:  new => needs_review


Comment:

 Aha, Maybe.

 Both of the failures had this pair of stack frames in common:

 {{{
 #4  0x00007ffff7eee224 in circuit_mark_for_close_ (circ=0x7ffff99f4eb0,
     reason=8, line=1461, file=0x7ffff7fb3a0f "src/or/circuitlist.c")
     at src/or/circuitlist.c:1441
         conn = <optimized out>
         __PRETTY_FUNCTION__ = "circuit_mark_for_close_"
         __func__ = "circuit_mark_for_close_"
 #5  0x00007ffff7eee513 in circuit_mark_for_close_ (circ=0x7ffff8decff0,
     reason=8, line=1047, file=0x7ffff7fb3a0f "src/or/circuitlist.c")
     at src/or/circuitlist.c:1461
         __PRETTY_FUNCTION__ = "circuit_mark_for_close_"
         __func__ = "circuit_mark_for_close_"
 }}}

 That's a circuit_mark_for_close_() calling a circuit_mark_for_close_() on
 its spliced rendezvous circuit at what is now line 1471 of circuitlist.c.
 That's a clue, perhaps.

 Also, circuit_mark_for_close_() doesn't call update_circuit_on_cmux()
 directly; it only calls circuit_cell_queue_clear().  That could be another
 clue.

 I've taken a wild stab at a workaround in branch "bug7212_wild_stab" in my
 public repository.  Andrea, what do you think of this one? Do you think
 it's safe to merge?

-- 
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/7212#comment:17>
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