I have declared also the bug in Ansible collection repo, however this is clearly a UFW bug: https://github.com/ansible-collections/community.general/issues/4769
** Bug watch added: github.com/ansible-collections/community.general/issues #4769 https://github.com/ansible-collections/community.general/issues/4769 -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to ufw in Ubuntu. https://bugs.launchpad.net/bugs/1204579 Title: ufw doesn't support concurrent updates Status in ufw: Fix Released Status in ufw package in Ubuntu: Fix Released Status in ufw source package in Bionic: Fix Released Status in ufw source package in Cosmic: Fix Released Status in ufw source package in Disco: Fix Released Status in ufw package in Debian: Fix Released Bug description: [Impact] ufw prior to 0.36 did not support locking or use xtables locking which can lead to problems when using ufw as a dynamic firewall. [Test Case] $ sudo apt-get install python-minimal # for the test script $ sudo ./test_ufw_threads.py # this runs for many seconds A patched ufw will complete with no errors. With an unpatched ufw, there will be many errors like: $ sudo ./test_ufw_threads.py ... ERROR: initcaps [Errno 2] iptables: Chain already exists. ERROR: initcaps [Errno 2] iptables: Chain already exists. [Regression Potential] ufw 0.36 implements a global exclusive lock before doing any kernel or file writes. Risk of regression includes the lock file not being released due to coding error. The locking is done via fcntl.lockf and ufw releases it in a finally clause that is careful to always release it. [Other Info] This locking code has been in production in the ufw snap for years and is known to work is static environments as well as in dynamic environments (IPS/fail2ban/etc). = Original description = On a server under Ubuntu 12.04 I automatically update firewall rules and I unfortunately noticed that if 2 rules are processed at the same time it leads to an inconsistent result between iptables and ufw status. In fact it can be reproduced using the python script in attachment. Before executing this script I didn't have any rules matching the ip 192.168.254.1 on my computer. After a launch iptables takes into acount 464 rules. sudo iptables -L -n | grep 192.168.254.1 | wc -l 464 It should be 500 rules but the script stressed a lot my system and all rules can't be processed by iptables sudo ./test_ufw_threads.py iptables: Resource temporarily unavailable. iptables: Resource temporarily unavailable. iptables: Resource temporarily unavailable. [...] Anyway, ufw stores only the last updates (in /lib/ufw/user.rules): sudo ufw status État : actif Vers Action Depuis ---- ------ ------ 192.168.254.1 1234/tcp ALLOW 192.168.46.9 192.168.254.1 1234/tcp ALLOW 192.168.22.10 192.168.254.1 1234/tcp ALLOW 192.168.32.10 192.168.254.1 1234/tcp ALLOW 192.168.5.10 192.168.254.1 1234/tcp ALLOW 192.168.43.9 192.168.254.1 1234/tcp ALLOW 192.168.40.10 192.168.254.1 1234/tcp ALLOW 192.168.46.10 192.168.254.1 1234/tcp ALLOW 192.168.48.10 192.168.254.1 1234/tcp ALLOW 192.168.42.10 192.168.254.1 1234/tcp ALLOW 192.168.43.10 So I can't delete other rules using ufw, I had to directly use iptables. In this case I can only delete 10 rules using ufw. Could you please handle some kind of lock? To manage notifications about this bug go to: https://bugs.launchpad.net/ufw/+bug/1204579/+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
