<html> <head> <base href="https://bugs.freedesktop.org/" /> </head> <body> <div> <a class="bz_bug_link bz_status_NEW " title="NEW - PulseAudio gets reliably killed upon a big number of client connections" href="https://bugs.freedesktop.org/show_bug.cgi?id=94629#c2">Comment # 2</a> on <a class="bz_bug_link bz_status_NEW " title="NEW - PulseAudio gets reliably killed upon a big number of client connections" href="https://bugs.freedesktop.org/show_bug.cgi?id=94629">bug 94629</a> from <a class="email" href="mailto:darwish.07@gmail.com" title="Ahmed S. Darwish <darwish.07@gmail.com>"> Ahmed S. Darwish</a> <pre>Hi Alex, On Sun, Mar 20, 2016 at 05:48:28AM +0000, <a href="mailto:bugzilla-daemon@freedesktop.org">bugzilla-daemon@freedesktop.org</a> wrote: > > <a class="bz_bug_link bz_status_NEW " title="NEW - PulseAudio gets reliably killed upon a big number of client connections" href="show_bug.cgi?id=94629">https://bugs.freedesktop.org/show_bug.cgi?id=94629</a> > > --- <a href="show_bug.cgi?id=94629#c1">Comment #1</a> from Alexander E. Patrakov <<a href="mailto:patrakov@gmail.com">patrakov@gmail.com</a>> --- > Thanks for the report. The kills may happen because of exceeding the allowed > real-time budget. To verify this, please modify /etc/pulse/daemon.conf: > > realtime-scheduling=no > Thanks! This indeed confirms that PA reliably exceeds its RT budget. Adding `realtime-scheduling=no' makes the bug completely vanish. Reset the option back to yes, and PA gets reliably killed again. After applying Arun's kernel rlimits verbosity patch, here is what I see in dmesg when PA gets unsolicitedly killed: [23891.784010] CPU Watchdog Timeout (hard): alsa-sink-VT170[7131] So this also adds another confirmation and shows why the bug does not appear by using NULL sinks.. [ Hmm, .. thinking about solutions ] Unfortunately lowering the maximum amount of clients is not a solution: on Tanu's machine, sometimes even just 18 clients did the trick :-( One of the reasons of the memfd + making pools per-client patches is to make PA a little bit safer as a system daemon (a fuzzer may also be built down the road). If clients can trigger a reliable PulseAudio kill, we have a reliable DoS attack on our hands.. So now the question is, how to modify PA to make sure it does not exceed its RT budget? Regards, Darwish</pre> </div> <hr> You are receiving this mail because: <ul> <li>You are the assignee for the bug.</li> <li>You are the QA Contact for the bug.</li> </ul> </body> </html>