Hello Alfonso, or anyone else affected, Accepted resolvconf into xenial-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/resolvconf/1.78ubuntu7 in a few hours, and then in the -proposed repository.
Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation on how to enable and use -proposed.Your feedback will aid us getting this update out to other Ubuntu users. If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested and change the tag from verification-needed-xenial to verification-done-xenial. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed-xenial. In either case, details of your testing will help us make a better decision. Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance! ** Changed in: resolvconf (Ubuntu Xenial) Status: In Progress => Fix Committed ** Tags added: verification-needed verification-needed-xenial -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to resolvconf in Ubuntu. https://bugs.launchpad.net/bugs/1825194 Title: [SRU] resolvconf is racy, which leads to broken resolv.conf in parallel calls Status in resolvconf package in Ubuntu: Fix Released Status in resolvconf source package in Xenial: Fix Committed Bug description: [Impact] The bug can lead to non-working DNS. This is a critical bug that needs to be fixed in the stable release. The patch fixes the bug by using a file lock via the flock command. [Test case] This script should eventually stop with the current version, thing that should not happen after applying the patch: while true; do printf "\n" | sudo resolvconf -a NetworkManager printf "nameserver 8.8.8.8\n" | sudo resolvconf -a networkd wait printf "nameserver 8.8.8.8\n" | sudo resolvconf -a NetworkManager & printf "\n" | sudo resolvconf -a networkd wait ping -c 1 www.google.com || break done [Regression Potential] The patch is small and what it does is straightforward. It has also been thoroughly tested. However, the effect if something is wrong would be not being able to resolve DNS names, which is disastrous, so it needs to be very well tested for the SRU. [Other Info] It has been found that simultaneous calls to resolvconf can lead to inconsistent content in resolv.conf. For instance, no nameservers while NetworkManager has one in its record (see LP: #1824395): $ cat /run/resolvconf/resolv.conf # Dynamic resolv.conf(5) file for glibc resolver(3) generated by resolvconf(8) # DO NOT EDIT THIS FILE BY HAND -- YOUR CHANGES WILL BE OVERWRITTEN $ cat /run/resolvconf/interface/NetworkManager nameserver 192.168.1.6 nameserver 192.168.1.2 This can happen easily when calling "netplan apply", which can re- start both networkd and NM. resolvconf is called at that point by the "systemd-networkd-resolvconf-update.service" service, and also directly by NetworkManager, which leads to the situation described above. This is not surprising as there is nothing preventing different instances of resolvconf to access the same files. This sort of situation can be reproduced by running in a loop commands like: $ printf "\n" | sudo resolvconf -a NetworkManager & printf "\n" | sudo resolvconf -a networkd $ printf "nameserver 80.58.61.250\n" | sudo resolvconf -a NetworkManager & printf "\n" | sudo resolvconf -a networkd Eventually, this leads to a resolv.conf that is not consistent with the last run command. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/resolvconf/+bug/1825194/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : [email protected] Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
