Flatpak depends on outdate and unsafe runtime org.freedesktop.Platform 21.08 about com.plexamp.plexamp

[Lamera]

@simonxciv Is there any progress on this issue?

[FlorianLaunay]

@simonxciv is it possible to upgrade to branch 23.08 by the next release ?

[hdonnay]

I tried building this on 23.08, but it coredumps. I can post the coredump somewhere if needed, but I can't really debug this because the libraries seem to be stripped.

[avLightless]

I tried building this on 23.08, but it coredumps. I can post the coredump somewhere if needed, but I can't really debug this because the libraries seem to be stripped.

Can confirm, tried building it with both 22.08 and 23.08.

[hdonnay]

So I decided to dig into this more.

I jumped into a debug sandbox and ran strace such that it would log for all forked processes:

% flatpak-builder --run build-dir com.plexamp.Plexamp.yaml strace -o strace -ff /app/bin/startplexamp
Passing the following arguments to Electron: --enable-gpu-rasterization --enable-zero-copy --enable-gpu-compositing --enable-native-gpu-memory-buffers --enable-oop-rasterization --disable-gpu-blocklist --enable-features=UseSkiaRenderer
Fontconfig error: Cannot load config file "/run/host/font-dirs.xml": No such file: /run/host/font-dirs.xml
LaunchProcess: failed to execvp:
xdg-settings
Gtk-Message: 18:18:53.249: Failed to load module "canberra-gtk-module"
Gtk-Message: 18:18:53.251: Failed to load module "canberra-gtk-module"
Fontconfig error: Cannot load config file "/run/host/font-dirs.xml": No such file: /run/host/font-dirs.xml
[6:1213/181853.266884:ERROR:bus.cc(398)] Failed to connect to the bus: Failed to connect to socket /run/dbus/system_bus_socket: No such file or directory
[6:1213/181853.266993:ERROR:bus.cc(398)] Failed to connect to the bus: Failed to connect to socket /run/dbus/system_bus_socket: No such file or directory
Main: restoring window state from /var/home/hank/.var/app/com.plexamp.Plexamp/config/Plexamp/window-state-plexamp-main.json
Started Media Service: false
Linux: Registering MPRIS service.
[6:1213/181854.063922:ERROR:bus.cc(398)] Failed to connect to the bus: Failed to connect to socket /run/dbus/system_bus_socket: No such file or directory
[6:1213/181854.064023:ERROR:bus.cc(398)] Failed to connect to the bus: Failed to connect to socket /run/dbus/system_bus_socket: No such file or directory
[6:1213/181854.064142:ERROR:bus.cc(398)] Failed to connect to the bus: Failed to connect to socket /run/dbus/system_bus_socket: No such file or directory
[6:1213/181854.064237:ERROR:bus.cc(398)] Failed to connect to the bus: Failed to connect to socket /run/dbus/system_bus_socket: No such file or directory
[6:1213/181854.064328:ERROR:bus.cc(398)] Failed to connect to the bus: Failed to connect to socket /run/dbus/system_bus_socket: No such file or directory
APPIMAGE env is not defined, current application is not an AppImage
Error: Render process (Plexamp) crashed (139) :(
Quitting...

I know the process segfaults, because that's what I can see in coredumpctl, so we need to see which process actually had the signal delivered:

% grep -e '--- SIGSEGV' strace.*
strace.114:--- SIGSEGV {si_signo=SIGSEGV, si_code=SEGV_MAPERR, si_addr=0x1000001b7} ---

It's process 114 on this run, so looking at the trace, I can see that it crashes after doing a read from fd 51:

read(51, "\32\23\n\16\335\366\203\311\204%\270]\n\322\312=:\207\2078GJ\0163\16j\31\360\246\177R\371", 32) = 32
--- SIGSEGV {si_signo=SIGSEGV, si_code=SEGV_MAPERR, si_addr=0x1000001b7} ---

Looking at the openat, socket, and connect calls made, it looks like this process is reading a cacert.pem and making HTTPS connections. For our specific fd, it's:

socket(AF_INET, SOCK_STREAM, IPPROTO_TCP) = 51
connect(51, {sa_family=AF_INET, sin_port=htons(443), sin_addr=inet_addr("104.18.41.153")}, 16) = -1 EINPROGRESS (Operation now in progress)

and the pem file:

openat(AT_FDCWD, "/app/bin/plexamp/resources/cacert.pem", O_RDONLY) = 73

The other file in that resources directory is a for an update check that lists plexamp.plex.tv. I have a hunch...

% dig +short plexamp.plex.tv
172.64.146.103
104.18.41.153

So this process looks to be reaching out for an update check. What if I just remove that file?
Seems to run fine. Can probably remove the whole update config, as Plexamp can't self-update anyway.

I'll send a PR with a fix soon.