Public bug reported: evince-thumbnailer crashes every time GNOME Files tries to generate a PDF thumbnail. The AppArmor profile for /usr/bin/evince-thumbnailer does not allow executing /usr/bin/bwrap, which libglycin (used by gdk-pixbuf) needs to spawn its sandboxed image loaders. glycin then aborts the process.
Package versions: evince 49~alpha-2ubuntu2.1 glycin 2.1.5+ds-0ubuntu0.2 gdk-pixbuf 2.44.5+dfsg-4ubuntu1 kernel 7.0.0-43.43 Steps to reproduce: 1. Open a folder containing a PDF without a cached thumbnail in Files. 2. evince-thumbnailer crashes; no thumbnail is produced. Command line of the crashing process: evince-thumbnailer -s 512 file:///tmp/gnome-desktop-file-to-thumbnail.pdf /tmp/gnome-desktop-thumbnailer.png AppArmor denials at the time of the crash: apparmor="DENIED" operation="exec" class="file" profile="/usr/bin/evince-thumbnailer" name="/usr/bin/bwrap" comm="blocking-1" requested_mask="x" denied_mask="x" fsuid=1001 ouid=0 apparmor="DENIED" operation="file_perm" class="net" profile="/usr/bin/evince-thumbnailer" comm="blocking-1" family="unix" sock_type="seqpacket" protocol=0 requested="send receive" denied="send receive" addr=none peer_addr=none peer="bwrap" apparmor="DENIED" operation="file_perm" class="net" profile="/usr/bin/evince-thumbnailer" comm="blocking-1" family="unix" sock_type="seqpacket" protocol=0 requested="send receive" denied="send receive" addr=none peer_addr=none peer="unpriv_bwrap" Crash (coredumpctl): signal 11 (SEGV), thread "blocking-1" #0 __GI_abort (libc.so.6 + 0x2896e) #1 n/a (libglycin-2.so.0 + 0x3ceba) #2 n/a (libglycin-2.so.0 + 0x3cee9) #3 n/a (libglycin-2.so.0 + 0x28a6e0) #4 n/a (libglycin-2.so.0 + 0x2a1f87) #5 n/a (libglycin-2.so.0 + 0x6d5d1) #6 n/a (libglycin-2.so.0 + 0x172187) #7 n/a (libglycin-2.so.0 + 0x172f98) #8 n/a (libglycin-2.so.0 + 0x28f394) #9 start_thread (libc.so.6 + 0xa3dfa) #10 __clone (libc.so.6 + 0x1373d4) Expected: thumbnail is generated. Actual: thumbnailer aborts inside libglycin after the bwrap exec is denied. Suggested fix: update the evince-thumbnailer AppArmor profile to permit glycin's bwrap-based loader sandbox (exec of /usr/bin/bwrap plus the unix seqpacket communication with the bwrap / unpriv_bwrap profiles). Similar issue in another confined app after gdk-pixbuf switched to glycin: https://gitlab.torproject.org/tpo/applications/torbrowser-launcher/-/issues/50 ProblemType: Bug DistroRelease: Ubuntu 26.04 Package: evince 49~alpha-2ubuntu2.1 ProcVersionSignature: Ubuntu 7.0.0-43.43-generic 7.0.14 Uname: Linux 7.0.0-43-generic x86_64 ApportVersion: 2.34.1-0ubuntu0.1 Architecture: amd64 CasperMD5CheckResult: unknown CurrentDesktop: ubuntu:GNOME Date: Tue Nov 10 10:58:03 2026 ProcEnviron: LANG=en_US.UTF-8 PATH=(custom, no user) SHELL=/usr/bin/zsh TERM=xterm-256color XDG_RUNTIME_DIR=<set> SourcePackage: evince UpgradeStatus: Upgraded to resolute on 2026-11-05 (5 days ago) ** Affects: evince (Ubuntu) Importance: Undecided Status: New ** Tags: amd64 apparmor apport-bug resolute wayland-session -- You received this bug notification because you are a member of Ubuntu Desktop Bugs, which is subscribed to evince in Ubuntu. https://bugs.launchpad.net/bugs/2173856 Title: evince-thumbnailer crashes: AppArmor profile denies exec of /usr/bin/bwrap needed by glycin (gdk-pixbuf) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/evince/+bug/2173856/+subscriptions -- desktop-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/desktop-bugs
