Bug#985402: libgconf-2-4: found segmentation fault

[Bernhard Übelacker]

Hello Antonio,
this directory should contain a file: /etc/gconf/2/path

The content should most probably what is shown here:
   https://sources.debian.org/src/gconf/3.2.6-7/debian/default.path/
(And can be downloaded in the upper right corner.)

Kind regards,
Bernhard


Am 09.04.21 um 15:26 schrieb Antonio:

The path "/etc/gconf/2" is empty:

totale 8
drwxr-xr-x 2 root root 4096  1 mar 15.36 .
drwxr-xr-x 6 root root 4096  1 mar 15.36 ..

However, even if I remove it or remove "/etc/gconf" occurs the same 
problem.


I note if I remove the entire directory "usr/share/GConf/gsettings" then 
the bug does not occur, but it does not seem to be related to a specific 
file: just remains one file that the problem returns.

Bug#985402: libgconf-2-4: found segmentation fault

[Bernhard Übelacker]

Hello Antonio,
thank you for the detailed informations.



Am 01.04.21 um 19:15 schrieb Antonio:


$ gdb gsettings-data-convert



Starting program: /usr/bin/gsettings-data-convert



(gsettings-data-convert:4756): GConf-CRITICAL **: 19:00:31.514: 
gconf_engine_get_local_for_addresses: assertion 'addresses != NULL' failed




I guess the above line is causing the issue, which
results in "client->engine" being a null pointer [1] [2].

The interesting function for the addresses
seems to be get_writable_client [3].
It looks like upstream applied a patch to
exit the process immediately in the case of
addresses being a null pointer.

Therefore is just the question left why
get_writable_source_path/gconf_load_source_path
returns a null pointer...
Which leads to the question what the content
of this path might be:

/etc/gconf/2

Kind regards,
Bernhard




Thread 1 "gsettings-data-" received signal SIGSEGV, Segmentation fault.
gconf_engine_get_entry (conf=0x0, key=key@entry=0x555917d0 
"/system/pulseaudio/modules/combine/args0", locale=0x77b70b6e <_nl_C_name> 
"C", use_schema_default=use_schema_default@entry=1, err=err@entry=0x7fffde60) at 
gconf-dbus.c:1293
1293    gconf-dbus.c: File o directory non esistente.



(gdb) bt
#0  gconf_engine_get_entry (conf=0x0, key=key@entry=0x555917d0 
"/system/pulseaudio/modules/combine/args0", locale=0x77b70b6e <_nl_C_name> 
"C", use_schema_default=use_schema_default@entry=1, err=err@entry=0x7fffde60) at 
gconf-dbus.c:1293
#1  0x77f4d7a6 in get (client=client@entry=0xd2a0, key=0x555917d0 
"/system/pulseaudio/modules/combine/args0", use_default=0, 
error=error@entry=0x7fffde60) at gconf-client.c:1493
#2  0x77f4ee93 in gconf_client_get_full (client=client@entry=0xd2a0, 
key=key@entry=0x555917d0 "/system/pulseaudio/modules/combine/args0", 
use_schema_default=use_schema_default@entry=0, err=err@entry=0x7fffdef8, locale=0x0) 
at gconf-client.c:1543
#3  0x77f4efbf in gconf_client_get_without_default 
(client=client@entry=0xd2a0, key=key@entry=0x555917d0 
"/system/pulseaudio/modules/combine/args0", err=err@entry=0x7fffdef8) at 
gconf-client.c:1605
#4  0x715d in handle_file (filename=filename@entry=0x5556b490 
"/usr/share/GConf/gsettings/pulseaudio.convert") at gsettings-data-convert.c:214
#5  0x6912 in handle_dir (converted=0xc980, stored_mtime=0, 
dirname=0x5556a3e0 "/usr/share/GConf/gsettings") at 
gsettings-data-convert.c:436
#6  main (argc=, argv=) at 
gsettings-data-convert.c:670




[1] 
https://gitlab.gnome.org/Archive/gconf/-/blob/master/gconf/gconf-dbus.c#L1293
[2] 
https://gitlab.gnome.org/Archive/gconf/-/blob/master/gconf/gconf-client.c#L1491

[3] 
https://gitlab.gnome.org/Archive/gconf/-/blob/master/gsettings/gsettings-data-convert.c#L98
[4] 
https://gitlab.gnome.org/Archive/gconf/-/commit/98ff7acca7595f508b094506195aeffaf2e8b74c

Bug#985402: Fwd: Bug#985402: libgconf-2-4: found segmentation fault

[Antonio]

[ ! -f "/etc/gconf/2/path" ] && cp -a "/usr/share/gconf/default.path" 
"/etc/gconf/2/path"



Il 09/04/21 16:12, Antonio ha scritto:
I confirm that by downloading this file and copying it as 
"/etc/gconf/2/path" the bug is solved.

I had already noticed the check of this file via strace.

I think the post-installation script, of the package gconf2-common, 
should be changed so that if there is no file "/etc/gconf/2/path" then 
execute the copy from "/usr/share/gconf/default.path" (provided from 
this package, the same as what I downloaded):


[ -f "/etc/gconf/2/path" ] && cp -a "/usr/share/gconf/default.path" 
"/etc/gconf/2/path"


This would avoid bug for those who do not have this file (whatever the 
reason for his absence).


Thanks,
Bernhard

Bug#985402: libgconf-2-4: found segmentation fault

[Antonio]

I confirm that by downloading this file and copying it as 
"/etc/gconf/2/path" the bug is solved.

I had already noticed the check of this file via strace.

I think the post-installation script, of the package gconf2-common, 
should be changed so that if there is no file "/etc/gconf/2/path" then 
execute the copy from "/usr/share/gconf/default.path" (provided from 
this package, the same as what I downloaded):


[ -f "/etc/gconf/2/path" ] && cp -a "/usr/share/gconf/default.path" 
"/etc/gconf/2/path"


This would avoid bug for those who do not have this file (whatever the 
reason for his absence).


Thanks,
Bernhard


Il 09/04/21 15:48, Bernhard Übelacker ha scritto:

Hello Antonio,
this directory should contain a file: /etc/gconf/2/path

The content should most probably what is shown here:
https://sources.debian.org/src/gconf/3.2.6-7/debian/default.path/
(And can be downloaded in the upper right corner.)

Kind regards,
Bernhard


Am 09.04.21 um 15:26 schrieb Antonio:

The path "/etc/gconf/2" is empty:

totale 8
drwxr-xr-x 2 root root 4096  1 mar 15.36 .
drwxr-xr-x 6 root root 4096  1 mar 15.36 ..

However, even if I remove it or remove "/etc/gconf" occurs the same 
problem.


I note if I remove the entire directory "usr/share/GConf/gsettings" 
then the bug does not occur, but it does not seem to be related to a 
specific file: just remains one file that the problem returns.

Bug#985402: libgconf-2-4: found segmentation fault

[Antonio]

The path "/etc/gconf/2" is empty:

totale 8
drwxr-xr-x 2 root root 4096  1 mar 15.36 .
drwxr-xr-x 6 root root 4096  1 mar 15.36 ..

However, even if I remove it or remove "/etc/gconf" occurs the same problem.

I note if I remove the entire directory "usr/share/GConf/gsettings" then 
the bug does not occur, but it does not seem to be related to a specific 
file: just remains one file that the problem returns.



Il 09/04/21 15:03, Bernhard Übelacker ha scritto:

Hello Antonio,
thank you for the detailed informations.



Am 01.04.21 um 19:15 schrieb Antonio:


$ gdb gsettings-data-convert



Starting program: /usr/bin/gsettings-data-convert


(gsettings-data-convert:4756): GConf-CRITICAL **: 19:00:31.514: 
gconf_engine_get_local_for_addresses: assertion 'addresses != NULL' 
failed




I guess the above line is causing the issue, which
results in "client->engine" being a null pointer [1] [2].

The interesting function for the addresses
seems to be get_writable_client [3].
It looks like upstream applied a patch to
exit the process immediately in the case of
addresses being a null pointer.

Therefore is just the question left why
get_writable_source_path/gconf_load_source_path
returns a null pointer...
Which leads to the question what the content
of this path might be:

   /etc/gconf/2

Kind regards,
Bernhard




Thread 1 "gsettings-data-" received signal SIGSEGV, Segmentation fault.
gconf_engine_get_entry (conf=0x0, key=key@entry=0x555917d0 
"/system/pulseaudio/modules/combine/args0", locale=0x77b70b6e 
<_nl_C_name> "C", use_schema_default=use_schema_default@entry=1, 
err=err@entry=0x7fffde60) at gconf-dbus.c:1293

1293    gconf-dbus.c: File o directory non esistente.



(gdb) bt
#0  gconf_engine_get_entry (conf=0x0, key=key@entry=0x555917d0 
"/system/pulseaudio/modules/combine/args0", locale=0x77b70b6e 
<_nl_C_name> "C", use_schema_default=use_schema_default@entry=1, 
err=err@entry=0x7fffde60) at gconf-dbus.c:1293
#1  0x77f4d7a6 in get (client=client@entry=0xd2a0, 
key=0x555917d0 "/system/pulseaudio/modules/combine/args0", 
use_default=0, error=error@entry=0x7fffde60) at gconf-client.c:1493
#2  0x77f4ee93 in gconf_client_get_full 
(client=client@entry=0xd2a0, key=key@entry=0x555917d0 
"/system/pulseaudio/modules/combine/args0", 
use_schema_default=use_schema_default@entry=0, 
err=err@entry=0x7fffdef8, locale=0x0) at gconf-client.c:1543
#3  0x77f4efbf in gconf_client_get_without_default 
(client=client@entry=0xd2a0, key=key@entry=0x555917d0 
"/system/pulseaudio/modules/combine/args0", 
err=err@entry=0x7fffdef8) at gconf-client.c:1605
#4  0x715d in handle_file 
(filename=filename@entry=0x5556b490 
"/usr/share/GConf/gsettings/pulseaudio.convert") at 
gsettings-data-convert.c:214
#5  0x6912 in handle_dir (converted=0xc980, 
stored_mtime=0, dirname=0x5556a3e0 "/usr/share/GConf/gsettings") 
at gsettings-data-convert.c:436
#6  main (argc=, argv=) at 
gsettings-data-convert.c:670




[1] 
https://gitlab.gnome.org/Archive/gconf/-/blob/master/gconf/gconf-dbus.c#L1293
[2] 
https://gitlab.gnome.org/Archive/gconf/-/blob/master/gconf/gconf-client.c#L1491


[3] 
https://gitlab.gnome.org/Archive/gconf/-/blob/master/gsettings/gsettings-data-convert.c#L98
[4] 
https://gitlab.gnome.org/Archive/gconf/-/commit/98ff7acca7595f508b094506195aeffaf2e8b74c

Bug#985402: libgconf-2-4: found segmentation fault

[Bernhard Übelacker]

Hello Antonio,
was this line in dmesg maybe followed by a "Code:" line?
Could you provide that too?

Otherwise maybe you could install systemd-coredump and after
the next crash journal should contain more info about it and
collect a core for later inspection.

More details here: https://wiki.debian.org/HowToGetABacktrace

Kind regards,
Bernhard

Bug#985402: libgconf-2-4: found segmentation fault

[Antonio]

Salve Bernhard,
I did the tests you indicated me, here are the results:

_package:_
- gconf2

_file in autostart:_
- gsettings-data-convert.desktop

_called executable:_
- gsettings-data-convert

_log dmesg:_
[gio apr  1 18:58:26 2021] gsettings-data-[4466]: segfault at 48 ip 
7fc8059392bc sp 7fff007e3d90 error 4 in 
libgconf-2.so.4.1.5[7fc805922000+1b000]
[gio apr  1 18:58:26 2021] Code: 4d 89 c7 41 56 41 89 ce 41 55 49 89 d5 
41 54 49 89 f4 55 48 89 fd 48 83 ec 20 64 48 8b 04 25 28 00 00 00 48 89 
44 24 18 31 c0 <48> 83 7f 48 00 c7 04 24 01 00 00 00 c7 44 24 04 00 00 
00 00 74 0b


_test gdb:_

$ gdb gsettings-data-convert
GNU gdb (Debian 10.1-2) 10.1.90.20210103-git
Copyright (C) 2021 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later 


This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
Type "show copying" and "show warranty" for details.
This GDB was configured as "x86_64-linux-gnu".
Type "show configuration" for configuration details.
For bug reporting instructions, please see:
.
Find the GDB manual and other documentation resources online at:
    .

For help, type "help".
Type "apropos word" to search for commands related to "word"...
Reading symbols from gsettings-data-convert...
Reading symbols from 
/usr/lib/debug/.build-id/d2/00eb838d134772a161f2a3f6b63b1511ee35ea.debug...


(gdb) r
Starting program: /usr/bin/gsettings-data-convert
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".

(gsettings-data-convert:4756): GConf-CRITICAL **: 19:00:31.514: 
gconf_engine_get_local_for_addresses: assertion 'addresses != NULL' failed

[New Thread 0x773f7700 (LWP 4760)]
[New Thread 0x76bf6700 (LWP 4761)]
[New Thread 0x763f5700 (LWP 4762)]

Thread 1 "gsettings-data-" received signal SIGSEGV, Segmentation fault.
gconf_engine_get_entry (conf=0x0,
    key=key@entry=0x555917d0 
"/system/pulseaudio/modules/combine/args0",
    locale=0x77b70b6e <_nl_C_name> "C", 
use_schema_default=use_schema_default@entry=1,

    err=err@entry=0x7fffde60) at gconf-dbus.c:1293
1293    gconf-dbus.c: File o directory non esistente.

(gdb) bt
#0  gconf_engine_get_entry
    (conf=0x0, key=key@entry=0x555917d0 
"/system/pulseaudio/modules/combine/args0", locale=0x77b70b6e 
<_nl_C_name> "C", use_schema_default=use_schema_default@entry=1, 
err=err@entry=0x7fffde60)

    at gconf-dbus.c:1293
#1  0x77f4d7a6 in get
    (client=client@entry=0xd2a0, key=0x555917d0 
"/system/pulseaudio/modules/combine/args0", use_default=0, 
error=error@entry=0x7fffde60) at gconf-client.c:1493

#2  0x77f4ee93 in gconf_client_get_full
    (client=client@entry=0xd2a0, key=key@entry=0x555917d0 
"/system/pulseaudio/modules/combine/args0", 
use_schema_default=use_schema_default@entry=0, 
err=err@entry=0x7fffdef8, locale=0x0)

    at gconf-client.c:1543
#3  0x77f4efbf in gconf_client_get_without_default
    (client=client@entry=0xd2a0, key=key@entry=0x555917d0 
"/system/pulseaudio/modules/combine/args0", 
err=err@entry=0x7fffdef8) at gconf-client.c:1605

#4  0x715d in handle_file
    (filename=filename@entry=0x5556b490 
"/usr/share/GConf/gsettings/pulseaudio.convert")

    at gsettings-data-convert.c:214
#5  0x6912 in handle_dirPython Exception  
There is no member named keys.:


    (converted=0xc980, stored_mtime=0, dirname=0x5556a3e0 
"/usr/share/GConf/gsettings")

    at gsettings-data-convert.c:436
#6  main (argc=, argv=) at 
gsettings-data-convert.c:670


_Full test gdb:_

$ gdb -batch -n -ex 'set pagination off' -ex run -ex bt -ex 'bt full' 
-ex 'thread apply all bt full' --args gsettings-data-convert
Downloading separate debug info for 
/usr/lib/x86_64-linux-gnu/libgio-2.0.so.0...
Downloading separate debug info for 
/usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0...
Downloading separate debug info for 
/run/home/root/.cache/debuginfod_client/d0e0fbe8b2783580f652ad6c14f3ef21cc4d223b/debuginfo...
Downloading separate debug info for 
/usr/lib/x86_64-linux-gnu/libglib-2.0.so.0...

[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
Downloading separate debug info for 
/usr/lib/x86_64-linux-gnu/libgmodule-2.0.so.0...
Downloading separate debug info for 
/usr/lib/x86_64-linux-gnu/libdbus-glib-1.so.2...

Downloading separate debug info for /lib/x86_64-linux-gnu/libdbus-1.so.3...
Downloading separate debug info for /lib/x86_64-linux-gnu/libz.so.1...
Downloading separate debug info for 
/usr/lib/x86_64-linux-gnu/libmount.so.1...

Downloading separate debug info for /lib/x86_64-linux-gnu/libselinux.so.1...
Downloading separate debug info for 

Bug#985402: libgconf-2-4: found segmentation fault

[Antonio]

Package: libgconf-2-4
Severity: important

Dear Maintainer,
I found some error in journal:

kernel: gsettings-data-[1841]: segfault at 48 ip 7fdf53ffa2bc sp 
7ffcd6320700 error 4 in libgconf-2.so.4.1.5[7fdf53fe3000+1b000]


Thanks,
Antonio

-- System Information:
Debian Release: bullseye/sid
  APT prefers unstable
  APT policy: (700, 'unstable'), (500, 'stable-updates'), (500, 
'stable'), (100, 'experimental')

Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 5.11.6-custom (SMP w/4 CPU threads; PREEMPT)
Kernel taint flags: TAINT_WARN
Locale: LANG=it_IT.UTF-8, LC_CTYPE=it_IT.UTF-8 (charmap=ISO-8859-1) 
(ignored: LC_ALL set to it_IT), LANGUAGE=it

Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)

Versions of packages libgconf-2-4 depends on:
ii  gconf2-common 3.2.6-7
ii  libc6 2.31-9
ii  libdbus-1-3   1.12.20-2
ii  libdbus-glib-1-2  0.110-6
ii  libglib2.0-0  2.66.7-2

Versions of packages libgconf-2-4 recommends:
pn  gconf-service