[tor-bugs] #32048 [- Select a component]: Loading a high number of Onion V3 Descriptors trough Tor Control Port lead to sustained 100% CPU

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#32048: Loading a high number of Onion V3 Descriptors trough Tor Control Port lead
to sustained 100% CPU
--------------------+--------------------------------------
 Reporter:  naif    |          Owner:  (none)
     Type:  defect  |         Status:  new
 Priority:  Medium  |      Component:  - Select a component
  Version:          |       Severity:  Normal
 Keywords:          |  Actual Points:
Parent ID:          |         Points:
 Reviewer:          |        Sponsor:
--------------------+--------------------------------------
 Loading a high number of Onion V3 Descriptors trough Tor Control Port lead
 to sustained 100% CPU.

   PID USER      PR  NI    VIRT    RES    SHR S  %CPU  %MEM     TIME+
 COMMAND
  1516 debian-+  20   0  136604 122136   8880 R 100.0   6.0  95:16.49 tor

 This is a GlobaLeaks system, try.globaleaks.org that have more than 1200
 evaluation whistleblowing sites.

 Trying profiling with strace and ltrace gives those data, if could be
 interesting to diagnose what's the issue:

 root at scw-nostalgic-stonebraker:/var/log# strace -f -c -p 1516
 strace: Process 1516 attached
 strace: [ Process PID=1516 runs in x32 mode. ]
 strace: [ Process PID=1516 runs in 64 bit mode. ]
 ^Cstrace: Process 1516 detached
 % time     seconds  usecs/call     calls    errors syscall
 ------ ----------- ----------- --------- --------- ----------------
 100.00    0.008475          15       560           getpid
   0.00    0.000000           0        36           read
   0.00    0.000000           0        22           write
   0.00    0.000000           0         1           close
   0.00    0.000000           0         6           ioctl
   0.00    0.000000           0         7           sendto
   0.00    0.000000           0         6           getsockopt
   0.00    0.000000           0         1           rename
   0.00    0.000000           0         2           epoll_wait
   0.00    0.000000           0        14           epoll_ctl
   0.00    0.000000           0         1           openat
   0.00    0.000000           0        64           getrandom
 ------ ----------- ----------- --------- --------- ----------------
 100.00    0.008475                   720           total

 root at scw-nostalgic-stonebraker:/var/log# ltrace -c -f -p 1516
 ^C% time     seconds  usecs/call     calls      function
 ------ ----------- ----------- --------- --------------------
  25.29    2.614242         127     20496 strlen
  24.99    2.583754         126     20489 free
  24.93    2.577376         125     20496 memset
  24.70    2.553016         124     20485 strchr
   0.02    0.002249         173        13 gettimeofday
   0.02    0.001980          94        21 time
   0.01    0.001290          86        15 __vsnprintf_chk
   0.01    0.000653         130         5 pthread_mutex_lock
   0.01    0.000642         128         5 pthread_mutex_unlock
   0.00    0.000494          82         6 strcasecmp
   0.00    0.000494          98         5 __vasprintf_chk
   0.00    0.000439          87         5 pthread_getspecific
   0.00    0.000423          84         5 event_active
   0.00    0.000420          84         5 malloc
 ------ ----------- ----------- --------- --------------------
 100.00   10.337472                 82051 total

 Tor version 0.3.5.8-1 is stock on Ubuntu Bionic .

--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/32048>
Tor Bug Tracker & Wiki <https://trac.torproject.org/>
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