[saucy] unity-panel-service crashes every login session

[B Bobo]

After upgrading a netbook to Ubuntu 13.04 Saucy, unity-panel-service crashes, together with compiz, at every login session:

44.343220 unity-panel-service: segfault at 393a7b0 ip 4f1bb2c6 sp 4f8ce220 error 4 in libgobject-2.0.so.0.3701.0[4f16a2c6+51000]
44.865704 compiz: segfault at 3665356c ip 47841eb6 sp 4f21a6b2 error 6 in libSM.so.6.0.1[47840000+7000]
44.883478 mtrr: no MTRR for 70000000,7b0000 found

The GUI will not start. There is a furious load average persistently around 3 due to dbus-daemon, NetworkManager, and rsyslog. The following errors in syslog are repeated 1000s of times:

Jun 19 18:28:30 ubuntu dbus[1220]: [system] Activating service name='fi.w1.wpa_supplicant1' (using servicehelper)
Jun 19 18:28:30 ubuntu dbus[1220]: [system] Activated service 'fi.w1.wpa_supplicant1' failed: The permission of the setuid helper is not correct
Jun 19 18:28:30 ubuntu rsyslogd-128: imuxsock begins to drop messages from pid 1220 due to rate-limiting

This all started after applying saucy updates dated 2013-06-14

[B Bobo (yout-bobo123)]

The above errors are followed by these errors repeated 1000s of times:

Jun 19 18:28:31 ubuntu NetworkManager[1203]: <error> [12376533434.343433] [nm-supplicant-interface.c:997] interface_add_cb(): (wlan0): error adding interface: The permission of the setuid helper is not correct
Jun 19 18:28:31 ubuntu NetworkManager[1203]: dbus_g_proxy_cancel_call: assertion 'pending != NULL' failed
Jun 19 18:28:31 ubuntu NetworkManager[1203]: <info> (wlan0): supplicant interface state: starting -> down
Jun 19 18:28:31 ubuntu NetworkManager[1203]: <warn> Trying to remove a non-existant call id.

[B Bobo (yout-bobo123)]

regression-update seems an appropriate tag because the problem started with a set of updates in saucy. If you remove the regression-update tag, please explain why!

[Andrea Azzarone (azzar1)]

I'm going to close it because no stacktrace has been provided and because of the long inactivity. Please open a new one if you can still reproduce this bug.