[tor-bugs] #29607 [Core Tor/Tor]: Denial of service on v2 and v3 onion service

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#29607: Denial of service on v2 and v3 onion service
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 Reporter:  pidgin        |          Owner:  pidgin
     Type:  defect        |         Status:  accepted
 Priority:  Immediate     |      Milestone:
Component:  Core Tor/Tor  |        Version:
 Severity:  Normal        |     Resolution:
 Keywords:                |  Actual Points:
Parent ID:                |         Points:
 Reviewer:                |        Sponsor:
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Comment (by asn):

 Hey Pidgin,

 I looked at the logs but nothing jumped out at me as super weird. There is
 obviously lots of activity on the HS, but doesn't seem like something that
 would 100% CPU your Tor (you are receiving a rendezvous request every two
 seconds). There is probably something else going on that I couldn't see
 from that first look.

 Another approach would be to try to profile Tor to see which functions are
 causing the CPU increase:
 https://gitweb.torproject.org/tor.git/tree/doc/HACKING/HelpfulTools.md#n183
 It's likely that this might also not bear any fruit, but it might be worth
 trying...

 Also, take extra care in sanitizing guard nicknames when sending logs
 (grep "for guard").

 Finally, I'm pretty overwhelmed with stuff for March, so I will probably
 not have much time to look at this until April.

--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/29607#comment:29>
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