github-starred/firejail
2
0
Fork 0
mirror of https://github.com/netblue30/firejail.git synced 2026-05-15 14:16:14 -06:00
Code Issues 531 Projects Packages Wiki Activity Actions 6

[GH-ISSUE #6946] firefox: program stutters and bad performance #3435

New issue
Closed
opened 2026-05-05 09:59:52 -06:00 by gitea-mirror · 6 comments
gitea-mirror commented 2026-05-05 09:59:52 -06:00
Owner
Copy link

Originally created by @lucasmz-dev on GitHub (Oct 26, 2025).
Original GitHub issue: https://github.com/netblue30/firejail/issues/6946

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

Originally created by @lucasmz-dev on GitHub (Oct 26, 2025). Original GitHub issue: https://github.com/netblue30/firejail/issues/6946 <!-- See the following links for help with formatting: https://guides.github.com/features/mastering-markdown/ https://docs.github.com/en/github/writing-on-github/getting-started-with-writing-and-formatting-on-github/basic-writing-and-formatting-syntax --> ### 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 <!-- Note: Items are checked with an "x", like so: - [x] This is a checked item. --> - [x] The issues is caused by firejail (i.e. running the program by path (e.g. `/usr/bin/vlc`) "fixes" it). - [x] I can reproduce the issue without custom modifications (e.g. globals.local). - [x] The program has a profile. (If not, request one in `https://github.com/netblue30/firejail/issues/1139`) - [x] The profile (and redirect profile if exists) hasn't already been fixed [upstream](https://github.com/netblue30/firejail/tree/master/etc). - [x] I have performed a short search for similar issues (to avoid opening a duplicate). - [x] 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 <details> <summary>Output of <code>LC_ALL=C firejail /path/to/program</code></summary> <p> ``` 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. ``` </p> </details> <details> <summary>Output of <code>LC_ALL=C firejail --debug /path/to/program</code></summary> <p> <!-- If the output is too long, save it to a file (e.g. "fjdebug.txt") and attach it to the comment: https://docs.github.com/en/get-started/writing-on-github/working-with-advanced-formatting/attaching-files If that does not work, create a secret gist at https://gist.github.com/ and link it here. --> https://gist.github.com/lucasmz-dev/333e9f44545bcc5b62db84a18ca9e4d9 </p> </details>
gitea-mirror 2026-05-05 09:59:52 -06:00
  • closed this issue
  • added the
    needinfo
         label
gitea-mirror commented 2026-05-05 09:59:55 -06:00
Author
Owner
Copy link

@kmk3 commented on GitHub (Oct 27, 2025):

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:

<!-- gh-comment-id:3451286241 --> @kmk3 commented on GitHub (Oct 27, 2025): > 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>
gitea-mirror commented 2026-05-05 09:59:56 -06:00
Author
Owner
Copy link

@lucasmz-dev commented on GitHub (Oct 27, 2025):

Fixed; Firefox works as expected

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

<!-- gh-comment-id:3453723745 --> @lucasmz-dev commented on GitHub (Oct 27, 2025): Fixed; Firefox works as expected This issue is also accompanied by the icons from the window not showing up (like the close buttons)
gitea-mirror commented 2026-05-05 09:59:56 -06:00
Author
Owner
Copy link

@kmk3 commented on GitHub (Oct 28, 2025):

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
<!-- gh-comment-id:3456395782 --> @kmk3 commented on GitHub (Oct 28, 2025): > 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
gitea-mirror commented 2026-05-05 09:59:57 -06:00
Author
Owner
Copy link

@lucasmz-dev commented on GitHub (Nov 2, 2025):

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!

<!-- gh-comment-id:3477542194 --> @lucasmz-dev commented on GitHub (Nov 2, 2025): 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!
gitea-mirror commented 2026-05-05 09:59:58 -06:00
Author
Owner
Copy link

@lucasmz-dev commented on GitHub (Nov 2, 2025):

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

<!-- gh-comment-id:3477546365 --> @lucasmz-dev commented on GitHub (Nov 2, 2025): No... that was just be being confused with it actually opening a regular non-firejail next to it and arrghhh
gitea-mirror commented 2026-05-05 09:59:58 -06:00
Author
Owner
Copy link

@lucasmz-dev commented on GitHub (Nov 2, 2025):

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

<!-- gh-comment-id:3477547003 --> @lucasmz-dev commented on GitHub (Nov 2, 2025): 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
Sign in to join this conversation.
No Branch/Tag specified
Branches Tags
master
serialize_remounts_v2
landlock_v4
landlock
release-0.9.64
release-0.9.62
gitlab_ci
LTSbase
fred_ctests
docs
0.9.80
0.9.80-rc1
0.9.78
0.9.76
0.9.76-rc4
0.9.76-rc3
0.9.76-rc2
0.9.76-rc1
0.9.74
landlock-split
0.9.72
0.9.72rc1
0.9.70
0.9.68
0.9.68rc1
0.9.66
0.9.66rc1
0.9.64.4
0.9.64.2
0.9.64
0.9.64rc1
0.9.62.4
0.9.62.2
0.9.62
0.9.56.2-LTS
0.9.60
0.9.60-rc1
0.9.58.2
0.9.58
0.9.58-rc1
0.9.56-LTS-release
0.9.56-LTS
0.9.56
0.9.56-rc1
0.9.54
0.9.54-rc2
0.9.54-rc1
0.9.52
0.9.38.12
0.9.50
0.9.50-rc1
0.9.48
0.9.46
0.9.46-rc1
0.9.44.10
0.9.44.8
0.9.44.6
0.9.38.10
0.9.44.4
0.9.38.8
0.9.44.2
0.9.44
0.9.44-rc1
0.9.38.4
0.9.42
0.9.42-rc2
0.9.38.2
0.9.42-rc1
disable-globalcfg
0.9.40
0.9.40-rc1
0.9.38
0.9.38-rc1
0.9.36
0.9.36-rc1
0.9.34
0.9.34-rc1
0.9.32
0.9.32-rc1
0.9.30
0.9.30-rc1
Labels
Clear labels   
LTS merge

   
LTS merge

   
bug

   
bug

   
converted-to-discussion

   
doc-todo

   
documentation

   
duplicate

   
enhancement

   
file-transfer

   
firecfg

   
firejail-in-firejail

   
firetools

   
graphics

   
help wanted

   
information_old

   
installation

   
invalid

   
modif

   
moved

   
needinfo

   
networking

   
notabug

   
notourbug

   
old-version

   
overlayfs

   
packaging

   
profile-request

   
pull-request

Mirrored from GitHub Pull Request

  
question

   
question_old

   
removal

   
runtime-permissions

   
sandbox-ipc

   
security

   
stale

   
wiki

   
wiki

   
wontfix

   
wordpress

   
workaround
No labels
LTS merge
LTS merge
bug
bug
converted-to-discussion
doc-todo
documentation
duplicate
enhancement
file-transfer
firecfg
firejail-in-firejail
firetools
graphics
help wanted
information_old
installation
invalid
modif
moved
needinfo
networking
notabug
notourbug
old-version
overlayfs
packaging
profile-request
pull-request
question
question_old
removal
runtime-permissions
sandbox-ipc
security
stale
wiki
wiki
wontfix
wordpress
workaround
Milestone
Clear milestone
No items
No milestone
Projects
Clear projects
No items
No project
Assignees
Clear assignees
No assignees
1 participant
Notifications
Due date
The due date is invalid or out of range. Please use the format "yyyy-mm-dd".

No due date set.

Dependencies

No dependencies set.

Reference: github-starred/firejail#3435
No description provided.
Delete branch "%!s()"

Deleting a branch is permanent. Although the deleted branch may continue to exist for a short time before it actually gets removed, it CANNOT be undone in most cases. Continue?