Crash in return from function avahi_client_is_connected

[reinouts]

Forwarded from GNOME bug 348977. Most relevant comments are #33 and #35:

Debug backtrace on Ubuntu feisty:

Core was generated by `epiphany'.
Program terminated with signal 11, Segmentation fault.
#0  0xffffe410 in __kernel_vsyscall ()
(gdb) bt
#0  0xffffe410 in __kernel_vsyscall ()
#1  0xb7e33df0 in raise () from /lib/tls/i686/cmov/libc.so.6
#2  0xb7f9b2b6 in nsProfileLock::FatalSignalHandler (signo=11) at
nsProfileLock.cpp:206
#3  <signal handler called>
#4  avahi_client_is_connected (client=0x636f6c29) at client.c:884
#5  0xb73576f6 in avahi_service_browser_free (b=0x81af148) at browser.c:700
#6  0xb75e9805 in gnome_vfs_dns_sd_stop_browse (handle=0x81a8060) at
gnome-vfs-dns-sd.c:1189
#7  0x080aaaf5 in ephy_bookmarks_new ()
#8  0xb6fc79fc in IA__g_object_unref (_object=0x81a7410) at gobject.c:1788
#9  0x0807ccc0 in ephy_shell_get_session ()
#10 0xb6fc795b in IA__g_object_unref (_object=0x8166b20) at gobject.c:1760
#11 0x080bf011 in mozilla_embed_get_type ()
#12 0xb6fc79fc in IA__g_object_unref (_object=0x81845c0) at gobject.c:1788
#13 0xb6fc7d48 in IA__g_object_run_dispose (object=0x81845c0) at gobject.c:574
#14 0xb7a21dfe in IA__gtk_object_destroy (object=0x81845c0) at gtkobject.c:403
#15 0xb7b1cf25 in IA__gtk_widget_destroy (widget=0x81845c0) at gtkwidget.c:2168
#16 0xb792d49f in gtk_bin_forall (container=0x86288b8, include_internals=0,
callback=0x51286669, callback_data=0x0)
    at gtkbin.c:133
#17 0xb796c41b in IA__gtk_container_foreach (container=0x86288b8,
callback=0xb7b1cee0 <IA__gtk_widget_destroy>, 
    callback_data=0x0) at gtkcontainer.c:1288
...



 Comment #35 from Sebastien Bacher    (developer, points: 26)
2006-12-03 17:54 UTC [reply]

from gdb:

avahi version is 0.6.15, it crashes on the return from that function:

"int avahi_client_is_connected(AvahiClient *client) {
    assert(client);

    return
        client->bus &&
        dbus_connection_get_is_connected(client->bus) &&
        (client->state == AVAHI_CLIENT_S_RUNNING || client->state ==
AVAHI_CLIENT_S_REGISTERING || client->state == AVAHI_CLIENT_S_COLLISION);
}"

(gdb) p client->bus
Cannot access memory at address 0x636f6c2d

[lathiat]

Thanks for your report, I suspect this may be related to what epiphany specifically is doing but requires further investigation.

[lennart]

i am quite sure that this is a bug in epiphany and not in avahi.

it seems to free the AvahiClient? object before it frees an attached AvahiServiceBrowser? object. That's nothing you should do unless you want to shoot yourself in the foot.

[lennart]

I am very sure that this is a bug in gnome-vfs. I am also very sure that is has recently been fixed there: http://svn.gnome.org/viewcvs/gnome-vfs/trunk/libgnomevfs/gnome-vfs-dns-sd.c?r1=4873&r2=5313

Because I am as sure as I am I am closing this bug now as "invalid".

Should I, on the other hand, not be right as much as I thought, feel free to reopen this bug.

[reinouts]

We have just received another duplicate (#432740), which happened with gnome-vfs 2.18.0 and avahi 0.6.17. Reopening.

[lennart]

Renouts: How did you come to the conclusion that that last report was on gnome-vfs 2.18.0? i don't see anything about that in the bug report.

[lennart]

Hmm, I am sorry. This is *not* an Avahi bug. And I am pretty sure that it has been fixed by this commit in gnome-vfs:

http://svn.gnome.org/viewcvs/gnome-vfs/trunk/libgnomevfs/gnome-vfs-dns-sd.c

I have not been able to reproduce this with gnome-vfs with that patch applied, while I have been without this patch.

I am closing this bug now. Feel free to reopen this bug -- but only if you really believe this is really an Avahi bug and can provide some kind of proof. (useful stack trace with proper gnome-vfs version info).