Comment 30 for bug 1799237

I performed bisect on my own and it seems that following commit causes the problem:
1920d4a1d4ff27ebfd34a99eca67c3c470c8c524 (x86/speculation/l1tf: Invert all not present mappings).

In upstream kernel there is a commit fixing this:
f19f5c49bbc3ffcc9126cc245fc1b24cc29f4a37

The mprotect issue is observed on Ubuntu 4.15.0-36. However, when I apply f19f5c49bbc3ffcc9126cc245fc1b24cc29f4a37 to Ubuntu 4.15.0-36, the issue is gone.