[Bug 2072811] Re: Apparmor: New update broke flatpak with `apparmor="DENIED"`

Wed Jul 17 00:29:40 UTC 2024

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Title:
  Apparmor: New update broke flatpak with `apparmor="DENIED"`

Status in apparmor package in Ubuntu:
  Triaged
Status in apparmor source package in Noble:
  Fix Released
Status in apparmor source package in Oracular:
  Triaged

Bug description:
  The recent apparmor update appear to have broken some flatpak's ability to save file, e.g.:
  - org.keepassxc.KeePassXC
  - org.ksnip.ksnip

  It seems update introduced a new profile ("/etc/apparmor.d/bwrap-
  userns-restrict"), which is causing the issue below.

  **** To reproduce ****

  (I'm using KeepassXC as example, but same issue for ksnip):

  1. Install and run KeepassXC

  ```bash
  flatpak install org.keepassxc.KeePassXC
  flatpak run org.keepassxc.KeePassXC
  ```

  2. Got error: "Access error for config file
  /home/****/.var/app/org.keepassxc.KeePassXC/config/keepassxc/keepassxc.ini"

  Looking at `journalctl -f`, I see these apparmor DENIED entries:

  ```txt
  Jul 12 09:44:36 ubuntu2404 systemd[2144]: Started app-flatpak-org.keepassxc.KeePassXC-4010.scope.
  Jul 12 09:44:37 ubuntu2404 kernel: kauditd_printk_skb: 6 callbacks suppressed
  Jul 12 09:44:37 ubuntu2404 kernel: audit: type=1400 audit(1720741477.106:310): apparmor="DENIED" operation="link" class="file" info="Failed name lookup - deleted entry" error=-2 profile="bwrap" name="/home/****/.var/app/org.keepassxc.KeePassXC/config/keepassxc/#317211" pid=4021 comm="keepassxc" requested_mask="l" denied_mask="l" fsuid=1000 ouid=1000
  Jul 12 09:44:37 ubuntu2404 kernel: audit: type=1400 audit(1720741477.106:311): apparmor="DENIED" operation="link" class="file" profile="bwrap" name="/home/****/.var/app/org.keepassxc.KeePassXC/config/keepassxc/keepassxc.ini" pid=4021 comm="keepassxc" requested_mask="l" denied_mask="l" fsuid=1000 ouid=1000 target="/home/****/.var/app/org.keepassxc.KeePassXC/config/keepassxc/#317211"
  Jul 12 09:44:37 ubuntu2404 kernel: audit: type=1400 audit(1720741477.106:312): apparmor="DENIED" operation="link" class="file" info="Failed name lookup - deleted entry" error=-2 profile="unpriv_bwrap" name="/home/****/.var/app/org.keepassxc.KeePassXC/config/keepassxc/#317211" pid=4021 comm="keepassxc" requested_mask="l" denied_mask="l" fsuid=1000 ouid=1000
  Jul 12 09:44:37 ubuntu2404 kernel: audit: type=1400 audit(1720741477.106:313): apparmor="DENIED" operation="link" class="file" profile="unpriv_bwrap" name="/home/****/.var/app/org.keepassxc.KeePassXC/config/keepassxc/keepassxc.ini" pid=4021 comm="keepassxc" requested_mask="l" denied_mask="l" fsuid=1000 ouid=1000 target="/home/****/.var/app/org.keepassxc.KeePassXC/config/keepassxc/#317211"
  Jul 12 09:44:37 ubuntu2404 kernel: audit: type=1400 audit(1720741477.341:314): apparmor="DENIED" operation="link" class="file" info="Failed name lookup - deleted entry" error=-2 profile="bwrap" name="/home/****/.var/app/org.keepassxc.KeePassXC/config/keepassxc/#317214" pid=4021 comm="keepassxc" requested_mask="l" denied_mask="l" fsuid=1000 ouid=1000
  Jul 12 09:44:37 ubuntu2404 kernel: audit: type=1400 audit(1720741477.341:315): apparmor="DENIED" operation="link" class="file" profile="bwrap" name="/home/****/.var/app/org.keepassxc.KeePassXC/config/keepassxc/keepassxc.ini" pid=4021 comm="keepassxc" requested_mask="l" denied_mask="l" fsuid=1000 ouid=1000 target="/home/****/.var/app/org.keepassxc.KeePassXC/config/keepassxc/#317214"
  Jul 12 09:44:37 ubuntu2404 kernel: audit: type=1400 audit(1720741477.341:316): apparmor="DENIED" operation="link" class="file" info="Failed name lookup - deleted entry" error=-2 profile="unpriv_bwrap" name="/home/****/.var/app/org.keepassxc.KeePassXC/config/keepassxc/#317214" pid=4021 comm="keepassxc" requested_mask="l" denied_mask="l" fsuid=1000 ouid=1000
  Jul 12 09:44:37 ubuntu2404 kernel: audit: type=1400 audit(1720741477.341:317): apparmor="DENIED" operation="link" class="file" profile="unpriv_bwrap" name="/home/****/.var/app/org.keepassxc.KeePassXC/config/keepassxc/keepassxc.ini" pid=4021 comm="keepassxc" requested_mask="l" denied_mask="l" fsuid=1000 ouid=1000 target="/home/****/.var/app/org.keepassxc.KeePassXC/config/keepassxc/#317214"
  Jul 12 09:44:38 ubuntu2404 kernel: audit: type=1400 audit(1720741478.704:318): apparmor="DENIED" operation="link" class="file" info="Failed name lookup - deleted entry" error=-2 profile="bwrap" name="/home/****/.var/app/org.keepassxc.KeePassXC/config/keepassxc/#317217" pid=4021 comm="keepassxc" requested_mask="l" denied_mask="l" fsuid=1000 ouid=1000
  Jul 12 09:44:38 ubuntu2404 kernel: audit: type=1400 audit(1720741478.704:319): apparmor="DENIED" operation="link" class="file" profile="bwrap" name="/home/****/.var/app/org.keepassxc.KeePassXC/config/keepassxc/keepassxc.ini" pid=4021 comm="keepassxc" requested_mask="l" denied_mask="l" fsuid=1000 ouid=1000 target="/home/****/.var/app/org.keepassxc.KeePassXC/config/keepassxc/#317217"
  ```

  **** Workaround ****

  For now, work-around is by disabling "/etc/apparmor.d/bwrap-userns-
  restrict" profile.

  ```bash
  sudo aa-disable /usr/bin/bwrap
  ```

  **** Version info ****
  $ lsb_release -rd
  No LSB modules are available.
  Description:	Ubuntu 24.04 LTS
  Release:	24.04

  $ apt-cache policy apparmor
  apparmor:
    Installed: 4.0.1-0ubuntu0.24.04.2
    Candidate: 4.0.1-0ubuntu0.24.04.2
    Version table:
   *** 4.0.1-0ubuntu0.24.04.2 500 (phased 70%)
          500 http://au.archive.ubuntu.com/ubuntu noble-updates/main amd64 Packages
          100 /var/lib/dpkg/status
       4.0.0-beta3-0ubuntu3 500
          500 http://au.archive.ubuntu.com/ubuntu noble/main amd64 Packages

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