[tor-bugs] #21129 [Core Tor/Tor]: Bug: src/or/entrynodes.c:1204: remove_guard_from_confirmed_and_primary_lists: Non-fatal assertion !(guard != found_guard) failed.

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#21129: Bug: src/or/entrynodes.c:1204:
remove_guard_from_confirmed_and_primary_lists: Non-fatal assertion !(guard
!= found_guard) failed.
------------------------------+--------------------------------
     Reporter:  asn           |      Owner:
         Type:  defect        |     Status:  new
     Priority:  Medium        |  Milestone:  Tor: 0.3.0.x-final
    Component:  Core Tor/Tor  |    Version:  Tor: 0.3.0.1-alpha
     Severity:  Normal        |   Keywords:  tor-guard
Actual Points:                |  Parent ID:
       Points:                |   Reviewer:
      Sponsor:                |
------------------------------+--------------------------------
 Similar to #21128, I was messing around with my state file to simulate
 various guard scenarios, and I ended up getting the following non-fatal
 assert. This happened when I replaced `confirmed_on=2016` with
 `confirmed_on=2014` and `sampled_on=2016` with `sampled_on=2014` in my
 state file, so that I test guard expiry:

 {{{
 Jan 03 14:20:52.000 [warn] Removing sampled guard quadhead
 ($BF0FB582E37F738CD33C3651125F2772705BB8E8): it was sampled over 120 days
 ago, and confirmed over 60 days ago.
 Jan 03 14:20:52.000 [warn] tor_bug_occurred_(): Bug:
 src/or/entrynodes.c:1204: remove_guard_from_confirmed_and_primary_lists:
 Non-fatal assertion !(guard != found_guard) failed. (on Tor 0.3.0.0-alpha-
 dev 5a97a46e60c95b6f)
 Jan 03 14:20:52.000 [warn] Bug: Non-fatal assertion !(guard !=
 found_guard) failed in remove_guard_from_confirmed_and_primary_lists at
 src/or/entrynodes.c:1204. Stack trace: (on Tor 0.3.0.0-alpha-dev
 5a97a46e60c95b6f)
 Jan 03 14:20:52.000 [warn] Bug:     /usr/lib/x86_64-linux-
 gnu/libasan.so.1(backtrace+0x3a) [0x7fb92745b48a] (on Tor 0.3.0.0-alpha-
 dev 5a97a46e60c95b6f)
 Jan 03 14:20:52.000 [warn] Bug:     /home/user/tor-browser_en-
 US/Browser/TorBrowser/Tor/tor(log_backtrace+0x46) [0x7fb928e1b806] (on Tor
 0.3.0.0-alpha-dev 5a97a46e60c95b6f)
 Jan 03 14:20:52.000 [warn] Bug:     /home/user/tor-browser_en-
 US/Browser/TorBrowser/Tor/tor(tor_bug_occurred_+0x12f) [0x7fb928e6b6df]
 (on Tor 0.3.0.0-alpha-dev 5a97a46e60c95b6f)
 Jan 03 14:20:52.000 [warn] Bug:     /home/user/tor-browser_en-
 US/Browser/TorBrowser/Tor/tor(entry_guards_update_all+0x12f2)
 [0x7fb928de5b82] (on Tor 0.3.0.0-alpha-dev 5a97a46e60c95b6f)
 Jan 03 14:20:52.000 [warn] Bug:     /home/user/tor-browser_en-
 US/Browser/TorBrowser/Tor/tor(guards_update_all+0x83) [0x7fb928dea8e3] (on
 Tor 0.3.0.0-alpha-dev 5a97a46e60c95b6f)
 Jan 03 14:20:52.000 [warn] Bug:     /home/user/tor-browser_en-
 US/Browser/TorBrowser/Tor/tor(directory_info_has_arrived+0xa5)
 [0x7fb928aa8fe5] (on Tor 0.3.0.0-alpha-dev 5a97a46e60c95b6f)
 Jan 03 14:20:52.000 [warn] Bug:     /home/user/tor-browser_en-
 US/Browser/TorBrowser/Tor/tor(do_main_loop+0x17b) [0x7fb928aa9b6b] (on Tor
 0.3.0.0-alpha-dev 5a97a46e60c95b6f)
 Jan 03 14:20:52.000 [warn] Bug:     /home/user/tor-browser_en-
 US/Browser/TorBrowser/Tor/tor(tor_main+0x1385) [0x7fb928aaebc5] (on Tor
 0.3.0.0-alpha-dev 5a97a46e60c95b6f)
 Jan 03 14:20:52.000 [warn] Bug:     /home/user/tor-browser_en-
 US/Browser/TorBrowser/Tor/tor(main+0x1c) [0x7fb928a9cddc] (on Tor 0.3.0.0
 -alpha-dev 5a97a46e60c95b6f)
 Jan 03 14:20:52.000 [warn] Bug:     /lib/x86_64-linux-
 gnu/libc.so.6(__libc_start_main+0xf5) [0x7fb924f35b45] (on Tor 0.3.0.0
 -alpha-dev 5a97a46e60c95b6f)
 Jan 03 14:20:52.000 [warn] Bug:     /home/user/tor-browser_en-
 US/Browser/TorBrowser/Tor/tor(+0x574e9b) [0x7fb928a9ee9b] (on Tor 0.3.0.0
 -alpha-dev 5a97a46e60c95b6f)
 }}}

 Seems like some assumption is not true during guard removal. Please let me
 know if you think my manual state string replacements might have put Tor
 into some unrealistic state and hence this bug is bogus.

--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/21129>
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