I have the same problem of the enter in the password field send many enters.
It happens to me in ubuntu 16.04.5 - 4.4.0-142
Tested that in 4.4.0-141 don't happen.
Also commented in this issue: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1813873 (the one that current issue is marked as duplicated of) that kernel 4.4.0-143 has a fix for this.
I tested the kernel 4.4.0-143, and i can't reproduce the issue, so looks like fixed.
I have the same problem of the enter in the password field send many enters.
It happens to me in ubuntu 16.04.5 - 4.4.0-142
Tested that in 4.4.0-141 don't happen.
Also commented in this issue: https:/ /bugs.launchpad .net/ubuntu/ +source/ linux/+ bug/1813873
(the one that current issue is marked as duplicated of)
that kernel 4.4.0-143 has a fix for this.
I tested the kernel 4.4.0-143, and i can't reproduce the issue, so looks like fixed.