Thanks for the confirmation Paul, and thanks to all for the assistance with testing and isolation.
We will be deploying this fix (the 'retpoline' patch set) in the next version of the linux-aws kernel (4.4.0-1051.60) and the Xenial generic kernel (4.4.0-113.136). We'll post here once those builds land in the -proposed archive. -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux-aws in Ubuntu. https://bugs.launchpad.net/bugs/1746806 Title: sssd appears to crash AWS c5 and m5 instances, cause 100% CPU Status in cloud-images: New Status in linux package in Ubuntu: Confirmed Status in linux-aws package in Ubuntu: Confirmed Status in linux source package in Xenial: In Progress Status in linux-aws source package in Xenial: In Progress Bug description: After upgrading to the Ubuntu EC2 AMI from 20180126 (specifically ami-79873901 in us-west-2) we have seen sssd hard locking c5 and m5 EC2 instances after starting the service and CPU goes to 100%. We do not experience this issue with t2 or c4 instance types and we do not see this issue on any instance types using Ubuntu Cloud images from 20180109 or before. I have verified that this is kernel related as I booted an image that we created using the Ubuntu cloud image from 20180109 which works fine on a c5. I then did a "apt update && apt install --only-upgrade linux-aws && systemctl disable sssd", rebooted the server, verified I was on the new kernel and started sssd with "systemctl start sssd" and the EC2 instance froze and Cloudwatch CPU usage for that instance went to 100%. I haven't been able to find much in the syslog, kern.log, journalctl logs, etc. The only thing I have been able to find is that when this happens I tend to see "^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@" in the syslog and sssd log files. I have attached several log files and the output of a "apport-bug /usr/sbin/sssd". Let me know if you need anything else to help track this down. Thanks, Paul To manage notifications about this bug go to: https://bugs.launchpad.net/cloud-images/+bug/1746806/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
