Steps i can reproduce: wget https://bugs.launchpad.net/ubuntu/+source/os- prober/+bug/1826294/+attachment/5652492/+files/reproducer.sh
chmod +x reproducer.sh sudo journalctl -f -e & clear sudo ./reproducer.sh -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to rsyslog in Ubuntu. https://bugs.launchpad.net/bugs/1826294 Title: os-prober exits prematurely with "logger: socket /dev/log: Protocol wrong type for socket" Status in AppArmor Profiles: New Status in os-prober package in Ubuntu: New Status in rsyslog package in Ubuntu: New Bug description: Failure occurs on Ubuntu 16.04 with the apparmor- profiles-2.10.95-0ubuntu2.10 package installed. Running update-grub will run /usr/bin/os-prober, which spews about a dozen of the following line to stderr: logger: socket /dev/log: Protocol wrong type for socket … but fails to report the existence of some installed operating systems as expected. Furthermore, /var/log/messages contains: kernel: audit: type=1400 audit(1556043066.679:11460): apparmor="ALLOWED" operation="sendmsg" info="Failed name lookup - disconnected path" error=-13 profile="syslog-ng" name="dev/log" pid=28566 comm="logger" requested_mask="r" denied_mask="r" fsuid=0 ouid=0 Here is a stripped-down skeleton of the /usr/bin/os-prober script, which demonstrates the problem: #!/bin/sh set -e -x newns () { [ "$OS_PROBER_NEWNS" ] || exec /usr/lib/os-prober/newns "$0" "$@" } log() { logger -t "$(basename "$0")" "$@" } debug() { log "debug: $@" } ls -l /dev/log debug "Hello world" newns "$@" The expected behavior is that it should write "debug: os-prober- testcase Hello world" to /var/log/messages twice. However, it only succeeds in writing "Hello world" once. After the script respawns itself with /usr/lib/os-prober/newns (which is like `unshare -m`), the second attempt to write to /dev/log fails as described above. Since the os-prober Bash script runs with the -e flag, any error, even just a logging error, causes the script to terminate prematurely. (Arguably, the log() function should call `logger -t "$(basename "$0")" "$@" || :` so that logging failures aren't fatal.) The fix, for me, is to edit /etc/apparmor.d/sbin.syslog-ng, and change profile syslog-ng /{usr/,}sbin/syslog-ng flags=(complain) {\ … } to profile syslog-ng /{usr/,}sbin/syslog-ng flags=(complain,attach_disconnected) { … } … then run `aa-complain sbin.syslog-ng` and `service syslog-ng restart`, before running update-grub again. I assume that similar fixes would be required for the other logging daemons. To manage notifications about this bug go to: https://bugs.launchpad.net/apparmor-profiles/+bug/1826294/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
