Comment 0 for bug 1204579

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 120 rules but only 51 are unique.

sudo iptables -L | grep 192.168.254.1 | wc -l
120

sudo iptables -L | grep 192.168.254.1| sort | uniq | wc -l
51

It should be 500 uniques 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 192.168.49.7
192.168.254.1 1234/tcp ALLOW 192.168.49.6
192.168.254.1 1234/tcp ALLOW 192.168.49.8
192.168.254.1 1234/tcp ALLOW 192.168.49.9
192.168.254.1 1234/tcp ALLOW 192.168.49.10

So I can't delete other rules using ufw, I had to directly use iptables.
In this case I can only delete 5 rules using ufw.
Could you please handle some kind of lock?