[Bug 1836329] Re: Regression running ssllabs.com/ssltest causes 2 apache process to eat up 100% cpu, easy DoS

[Andreas Hasenack]

Cosmic verification


First, reproducing the bug with:
 *** 2.4.34-1ubuntu2.2 500
        500 http://us.archive.ubuntu.com/ubuntu cosmic-updates/main amd64 Packages


Then I enabled the required modules, restarted apache, kept monitoring cpu usage per process using top, and asked ssllabs for the test run

After the test finished, I still had apache processes using as much cpu as they could:
  PID USER      PR  NI    VIRT    RES    SHR S  %CPU  %MEM     TIME+ COMMAND                                                                                                                                       
 4709 www-data  20   0  759644   7616   5292 S  48.5   0.8   1:46.23 apache2                                                                                                                                       
 4710 www-data  20   0  759448   5068   2988 S  48.5   0.5   1:55.00 apache2                               

Installing the packages from proposed now:
 *** 2.4.34-1ubuntu2.3 500
        500 http://us.archive.ubuntu.com/ubuntu cosmic-proposed/main amd64 Packages
        100 /var/lib/dpkg/status
     2.4.34-1ubuntu2.2 500
        500 http://us.archive.ubuntu.com/ubuntu cosmic-updates/main amd64 Packages

Hitting "clear cache" in the ssl labs report page triggers a re-run.

Test finished, and no sign of apache processes near the top:
  PID USER      PR  NI    VIRT    RES    SHR S  %CPU  %MEM     TIME+ COMMAND                                                                                                                                       
 4818 root      20   0   13808   4016   2848 S   1.0   0.4   0:05.14 tmux -u -2 -f /usr/share/byobu/profiles/tmuxrc new-session -n - /usr/bin/byobu-shell                                                          
    1 root      20   0  123356   9388   6752 S   0.0   0.9   0:06.27 /sbin/init                                    

Cosmic verification succeeded.

** Tags removed: verification-needed-cosmic
** Tags added: verification-done-cosmic

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Title:
  Regression running ssllabs.com/ssltest causes 2 apache process to eat
  up 100% cpu, easy DoS

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