Linux Kernels 5.1, 5.2 - Critical bug found, may lead to data loss
May 22nd, 2019: Fixed in version 5.1.4
May 21st, 2019: A critical bug has been found in Linux 5.1. (edit: and possibly 5.2)
It is related to TRIM commands issued on SSDs.
It is unclear who is affected exactly, as information given on sources doesn't match well. It may only affect installs using encryption. It may only affect certain models of SSDs. Testing is underway. However, if you use an SSD, you are unsure if you are affected or not and you do not want to take any chance, we strongly recommend that you avoid using the 5.1 and 5.2 kernel for now.