Bug#1040297: gnome: Gnome fails to start on login and falls back to GDM3

[Simon McVittie]

On Wed, 05 Jul 2023 at 22:44:40 +0200, Bastian Venthur wrote:
> Start-Date: 2023-07-03  09:06:13

Unfortunately this upgrade was sufficiently large that it's hard to
spot which package might have triggered this. Nothing jumps out at me
as a particularly likely trigger. Maaaybe glibc, or the evolution family
of packages?

> Here are also two outputs of coredumpctl that appeared after a crash:

>                 Stack trace of thread 3960:
...
>                 #3  0x00007f134cbbb0ff g_log (libglib-2.0.so.0 + 0x5c0ff)
>                 #4  0x00007f134cbb96a2 g_malloc (libglib-2.0.so.0 + 0x5a6a2)
>                 #5  0x00007f134cbe97ce g_utf8_collate_key (libglib-2.0.so.0
> + 0x8a7ce)
>                 #6  0x00007f134ccee180 e_source_set_display_name
> (libedataserver-1.2.so.27 + 0x57180)

Well, this is messed up - something is setting the display name of an
ESource (a calendar or address book or something similar) to a value that
is, apparently, so long that allocating memory for its collation key (a
version that has been modified to sort in the correct locale-sensitive
order) will fail.

A display name that large is clearly absurd, so all I can think of is that
the `result_len` or `xfrm_len` in g_utf8_collate_key() (depending which code
path we're in) might have been calculated incorrectly?

>                 Stack trace of thread 3710:
...
>                 #7  0x00007f539ead20ff g_log (libglib-2.0.so.0 + 0x5c0ff)
>                 #8  0x00007f539ead06a2 g_malloc (libglib-2.0.so.0 + 0x5a6a2)
>                 #9  0x00007f539eb007ce g_utf8_collate_key (libglib-2.0.so.0
> + 0x8a7ce)
>                 #10 0x00007f539ee22d65 _shell_app_set_app_info
> (libgnome-shell.so + 0x22d65)

Similarly this one is setting up a collation key for the name of an app
(a fairly short string like "LibreOffice Writer", and again reaching
OOM as a result of that is clearly absurd.

Please could you try retracing these with debug symbols installed? You
can either install appropriate -dbgsym packages manually, or

    export DEBUGINFOD_URLS=https://debuginfod.debian.net
    coredumpctl gdb $PID

to download appropriate symbols automatically and cache them in
~/.cache/debuginfod_client. See https://wiki.debian.org/HowToGetABacktrace
for more details.

If you're setting this up manually, we would want to see debug symbols
for at least GLib (libglib2.0-0-dbgsym) and glibc (libc6-dbg), preferably
also gnome-shell-dbgsym and libedataserver-1.2-27-dbgsym.

Thanks,
    smcv