firefox: program stutters and bad performance

[lucasmz-dev]

Description

When using Firefox, it now stutters and has moments of bad performance

Steps to Reproduce

Steps to reproduce the behavior

1. Run firefox with firejail
2. See vsynctester.com for example and move the window around

Expected behavior

Consistent performance, on par with it being unsandboxed

Actual behavior

Stutters

Behavior without a profile

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

Works as expected

Additional context

Only started happening after F43

Environment

• Name/version/arch of the Linux kernel (uname -srm): 6.17.5
• Name/version of the Linux distribution (e.g. "Ubuntu 20.04" or "Arch Linux"): Fedora 43
• Name/version of the relevant program(s)/package(s) (e.g. "firefox 134.0-1,
  mesa 1:24.3.3-2"): firefox 144
• Version of Firejail (firejail --version): 0.9.77
• If you use a development version of firejail, also the commit from which it
  was compiled (git rev-parse HEAD): I do use Tavi's.. it should be somewhat close to nightly

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 /path/to/program

lucas@fedora:~$ firejail --ignore=globals.local firefox
Reading profile /etc/firejail/firefox.profile
Reading profile /home/lucas/.config/firejail/firefox.local
Reading profile /home/lucas/.config/firejail/globals.local
Reading profile /etc/firejail/disable-x11.inc
Reading profile /etc/firejail/whitelist-run-common.inc
Reading profile /etc/firejail/firefox-common.profile
Reading profile /etc/firejail/disable-common.inc
Reading profile /etc/firejail/disable-devel.inc
Reading profile /etc/firejail/disable-exec.inc
Reading profile /etc/firejail/disable-interpreters.inc
Reading profile /etc/firejail/disable-proc.inc
Reading profile /etc/firejail/disable-programs.inc
Reading profile /home/lucas/.config/firejail/disable-programs.local
Reading profile /etc/firejail/whitelist-common.inc
Reading profile /etc/firejail/whitelist-run-common.inc
Reading profile /etc/firejail/whitelist-runuser-common.inc
Reading profile /etc/firejail/whitelist-usr-share-common.inc
Reading profile /etc/firejail/whitelist-var-common.inc
firejail version 0.9.77

Seccomp list in: !chroot, check list: @default-keep, prelist: unknown,
Parent pid 9268, child pid 9272
Warning: An abstract unix socket for session D-BUS might still be available. Use --net or remove unix from --protocol set.
Private /etc installed in 129.17 ms
Warning: /sbin directory link was not blacklisted
Warning: /usr/sbin directory link was not blacklisted
Base filesystem installed in 177.70 ms
Seccomp list in: !chroot, check list: @default-keep, prelist: unknown,
Child process initialized in 433.74 ms
[Parent 42, Main Thread] WARNING: Could not load a pixbuf from icon theme.
This may indicate that pixbuf loaders or the mime database could not be found.: 'glib warning', file /builddir/build/BUILD/firefox-144.0-build/firefox-144.0/toolkit/xre/nsSigHandlers.cpp:201

(org.mozilla.firefox:42): Gtk-WARNING **: 20:47:49.427: Could not load a pixbuf from icon theme.
This may indicate that pixbuf loaders or the mime database could not be found.
[Parent 42, Main Thread] WARNING: Could not load a pixbuf from icon theme.
This may indicate that pixbuf loaders or the mime database could not be found.: 'glib warning', file /builddir/build/BUILD/firefox-144.0-build/firefox-144.0/toolkit/xre/nsSigHandlers.cpp:201

(org.mozilla.firefox:42): Gtk-WARNING **: 20:47:50.845: Could not load a pixbuf from icon theme.
This may indicate that pixbuf loaders or the mime database could not be found.

Output of LC_ALL=C firejail --debug /path/to/program

https://gist.github.com/lucasmz-dev/333e9f44545bcc5b62db84a18ca9e4d9

[kmk3]

Behavior without a profile

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

Basic debugging information is missing; please follow the bug report template:

• https://github.com/netblue30/firejail/issues/new?template=bug_report.md

[lucasmz-dev]

Fixed; Firefox works as expected

This issue is also accompanied by the icons from the window not showing up (like the close buttons)

[kmk3]

Fixed; Firefox works as expected

This issue is also accompanied by the icons from the window not showing up
(like the close buttons)

Fixed how?

Note that --noprofile is intended only for debugging; it just skips the
entire profile (see man firejail).

Since the problem is in the profiles, you can comment lines in them to find out
which lines are causing problems and then post them in here.

Relevant profiles:

• firefox.profile
• firefox-common.profile

[lucasmz-dev]

I tried messing a bit and nothing helped so I gave up but now I tried again messing with whitelist-common.inc and something's missing, but I don't know what... I don't know what pixbufs are!

[lucasmz-dev]

No... that was just be being confused with it actually opening a regular non-firejail next to it and arrghhh

[lucasmz-dev]

I'm guessing this is the issue:

(org.mozilla.firefox:41): Gtk-WARNING **: 04:51:22.262: Could not load a pixbuf from icon theme.
This may indicate that pixbuf loaders or the mime database could not be found.
[Parent 41, Main Thread] WARNING: Could not load a pixbuf from icon theme.
This may indicate that pixbuf loaders or the mime database could not be found.: 'glib warning', file /builddir/build/BUILD/firefox-144.0-build/firefox-144.0/toolkit/xre/nsSigHandlers.cpp:201

as this issue is accompanied by the missing buttons and it seems to kind of be affected by moving the window around so rendering i guess, but yeah i have no idea where pixbufs are even accessed or what they are