[Bug 74682] Mysterious segfault of many GNOME programs makes gnome-session unresponsive

[Matt Zimmerman]

Public bug reported:

We have observed a situation where several GNOME programs appear to
segfault in quick succession, causing several instances of gnome_segv
and bug-buddy to be launched.  One of these is directed back at gnome-
session itself.

When this happens, gnome-session stops responding to new client
connections, so applications fail to start.  strace shows gnome-session
blocked in waitpid(2) waiting for the gnome_segv process for itself.

1000      4386  0.0  1.1  20980 10684 ?        Ss   11:26   0:00 x-session-manager
1000      4421  0.0  0.0   4488   732 ?        Ss   11:26   0:00  \_ /usr/bin/ssh-agent /usr/bin/dbus-launch --exit-with-session x-session-manager
1000     15113  0.0  0.6  17944  6144 ?        S    17:29   0:00  \_ /usr/lib/libgnomeui-0/gnome_segv gnome-session 11 2.16.1
1000     15116  0.0  0.0   1660   472 ?        S    17:29   0:00      \_ sh -c /usr/bin/bug-buddy --appname="gnome-session" --pid=4386 --package-ver="(null)" 
1000     15117  0.0  0.6  22028  6312 ?        S    17:29   0:00          \_ /usr/bin/bug-buddy --appname=gnome-session --pid=4386 --package-ver=(null)
[...]
1000      4487  0.0  0.8  50452  7412 ?        Ss   11:26   0:00 gnome-power-manager
1000     15110  0.0  0.6  17944  6152 ?        S    17:29   0:00  \_ /usr/lib/libgnomeui-0/gnome_segv gnome-power-manager 11 2.16.1
1000     15120  0.0  0.0   1660   476 ?        S    17:29   0:00      \_ sh -c /usr/bin/bug-buddy --appname="gnome-power-manager" --pid=4487 --package-ver="(null)" 
1000     15121  0.0  0.6  22024  6312 ?        S    17:29   0:00          \_ /usr/bin/bug-buddy --appname=gnome-power-manager --pid=4487 --package-ver=(null)
[...]
1000      4478  0.0  1.0  59008  9932 ?        Ssl  11:26   0:00 /usr/lib/evolution/2.8/evolution-alarm-notify
1000     15109  0.0  0.6  17948  6148 ?        S    17:29   0:00  \_ /usr/lib/libgnomeui-0/gnome_segv evolution-alarm-notify 11 2.8.1
1000     15122  0.0  0.0   1664   468 ?        S    17:29   0:00      \_ sh -c /usr/bin/bug-buddy --appname="evolution-alarm-notify" --pid=4478 --package-ver="(null)" 
1000     15123  0.0  0.6  22028  6308 ?        S    17:29   0:00          \_ /usr/bin/bug-buddy --appname=evolution-alarm-notify --pid=4478 --package-ver=(null)
[...]
1000      4472  0.0  1.2  52428 11732 ?        Ss   11:26   0:00 update-notifier
1000     15111  0.0  0.6  17948  6156 ?        S    17:29   0:00  \_ /usr/lib/libgnomeui-0/gnome_segv update-notifier 11 
1000     15114  0.0  0.0   1664   472 ?        S    17:29   0:00      \_ sh -c /usr/bin/bug-buddy --appname="update-notifier" --pid=4472 --package-ver="(null)" 
1000     15115  0.0  0.6  22028  6308 ?        S    17:29   0:00          \_ /usr/bin/bug-buddy --appname=update-notifier --pid=4472 --package-ver=(null)
[...]
1000      4463  0.0  0.6  18256  5432 ?        Ss   11:26   0:00 gnome-volume-manager --sm-client-id default4
1000     15112  0.0  0.6  17948  6156 ?        S    17:29   0:00  \_ /usr/lib/libgnomeui-0/gnome_segv gnome-volume-manager 11 2.15.0
1000     15118  0.0  0.0   1660   476 ?        S    17:29   0:00      \_ sh -c /usr/bin/bug-buddy --appname="gnome-volume-manager" --pid=4463 --package-ver="(null)" 
1000     15119  0.0  0.6  22028  6308 ?        S    17:29   0:00          \_ /usr/bin/bug-buddy --appname=gnome-volume-manager --pid=4463 --package-ver=(null)

$ strace -p 4386 # x-session-manager (gnome-session)
Process 4386 attached - interrupt to quit
waitpid(15113,  <unfinished ...>

$ strace <anything which attempts to connect to the session manager>
[...]
socket(PF_FILE, SOCK_STREAM, 0)         = 10
uname({sys="Linux", node="christina-laptop", ...}) = 0
connect(10, {sa_family=AF_FILE, path="/tmp/.ICE-unix/4386"}, 21) = 0
fcntl64(10, F_SETFD, FD_CLOEXEC)        = 0
write(10, "\0\1\0\0\0\0\0\0", 8)        = 8
read(10,  <unfinished ...> # hangs here indefinitely

No bug-buddy window is visible on the desktop.

No stack traces can be obtained from the processes which apparently
segfaulted ("Failed to read a valid object file image from memory."),
though this may be specific to one system and has not been confirmed.

** Affects: Ubuntu
     Importance: Undecided
         Status: Unconfirmed

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Mysterious segfault of many GNOME programs makes gnome-session unresponsive
https://launchpad.net/bugs/74682