slack: cannot upload files

[maximiliandaschner]

Description

Whenever I try to send a file on Slack, nothing happens.

Steps to Reproduce

Steps to reproduce the behavior

1. Run in bash LC_ALL=C firejail slack (LC_ALL=C to get a consistent
   output in English that can be understood by everybody)
2. Click on any contact
3. Click on the '+' button below the text box
4. Click on 'Upload from your computer'

Expected behavior

What you expected to happen

I should be able to choose a file that I want to send out.

Actual behavior

What actually happened

Nothing.

Behavior without a profile

What changed calling LC_ALL=C firejail --noprofile /path/to/program in a
terminal?

Still nothing.

Additional context

Any other detail that may help to understand/debug the problem

Everything works fine if I run slack without firejail.

Environment

• Name/version/arch of the Linux kernel (uname -srm): Linux 6.17.4-arch2-1 x86_64
• Name/version of the Linux distribution (e.g. "Ubuntu 20.04" or "Arch Linux"): Arch Linux
• Name/version of the relevant program(s)/package(s) (e.g. "firefox 134.0-1,
  mesa 1:24.3.3-2"): slack-desktop 4.46.101
• Version of Firejail (firejail --version): firejail version 0.9.76
• If you use a development version of firejail, also the commit from which it
  was compiled (git rev-parse HEAD):

Checklist

• The issues is caused by firejail (i.e. running the program by path (e.g. /usr/bin/vlc) "fixes" it).
• I can reproduce the issue without custom modifications (e.g. globals.local).
• The program has a profile. (If not, request one in https://github.com/netblue30/firejail/issues/1139)
• The profile (and redirect profile if exists) hasn't already been fixed upstream.
• I have performed a short search for similar issues (to avoid opening a duplicate).
• I'm aware of browser-allow-drm yes/browser-disable-u2f no in firejail.config to allow DRM/U2F in browsers.
• I used --profile=PROFILENAME to set the right profile. (Only relevant for AppImages)

Log

Output of LC_ALL=C firejail slack

Reading profile /etc/firejail/slack.profile
Reading profile /etc/firejail/allow-bin-sh.inc
Reading profile /etc/firejail/disable-shell.inc
Reading profile /etc/firejail/electron-common.profile
Reading profile /etc/firejail/blink-common.profile
Reading profile /etc/firejail/disable-common.inc
Reading profile /etc/firejail/disable-devel.inc
Reading profile /etc/firejail/disable-interpreters.inc
Reading profile /etc/firejail/disable-programs.inc
Reading profile /etc/firejail/whitelist-common.inc
Reading profile /etc/firejail/whitelist-var-common.inc
firejail version 0.9.76

Parent pid 51975, child pid 51976
12 programs installed in 16.93 ms
Private /etc installed in 43.72 ms
Warning: /sbin directory link was not blacklisted
Warning: /usr/sbin directory link was not blacklisted
Base filesystem installed in 28.27 ms
Child process initialized in 125.81 ms
(electron) Sending uncompressed crash reports is deprecated and will be removed in a future version of Electron. Set { compress: true } to opt-in to the new behavior. Crash reports w
[41:1022/215905.144929:ERROR:dbus/object_proxy.cc:573] Failed to call method: org.freedesktop.systemd1.Manager.StartTransientUnit: object_path= /org/freedesktop/systemd1: org.freedes
LaunchProcess: failed to execvp:
xdg-settings
[41:1022/215905.252615:ERROR:content/browser/browser_main_loop.cc:286] Gtk: gtk_widget_add_accelerator: assertion 'GTK_IS_ACCEL_GROUP (accel_group)' failed
[41:1022/215905.253211:ERROR:content/browser/browser_main_loop.cc:286] Gtk: gtk_widget_add_accelerator: assertion 'GTK_IS_ACCEL_GROUP (accel_group)' failed
[41:1022/215910.737732:ERROR:components/dbus/xdg/request.cc:169] Request ended (non-user cancelled).

Parent is shutting down, bye...

[kmk3]

Might be a duplicate of:

• File dialog crashes (gdk-pixbuf2 + glycin + bwrap) #6906

You can try the workaround there:

• File dialog crashes (gdk-pixbuf2 + glycin + bwrap) #6906 (comment)

What happens when adding the following to ~/.config/firejail/slack.local?

whitelist /usr/share/glycin-loaders
noblacklist /usr/bin/bwrap
noblacklist /proc/sys/kernel/overflowuid
noblacklist /proc/sys/kernel/overflowgid

ignore seccomp

If that does not work, you can comment lines in the following profiles until it
works to find out which lines are causing issues and post them in here:

• slack.profile
• electron-common.profile
• blink-common.profile