It turns out that 3.19.3 stable is affected. The /etc/schroot/setup.d/10mount script has a bug in it that causes schroot sessions to not be restored when booting a non-Ubuntu kernel. After I manually fixed that bug, I was able to trigger the BUG on the 3.19.3 stable kernel.
To reproduce this issue, there needs to be two schroot sessions:
It turns out that 3.19.3 stable is affected. The /etc/schroot/ setup.d/ 10mount script has a bug in it that causes schroot sessions to not be restored when booting a non-Ubuntu kernel. After I manually fixed that bug, I was able to trigger the BUG on the 3.19.3 stable kernel.
To reproduce this issue, there needs to be two schroot sessions:
$ schroot -bn test1 -c vivid-amd64
$ schroot -bn test2 -c vivid-amd64
Reboot and attempt to log in as a used with an encrypted home directory to hit the BUG.