Comment 2 for bug 1719733

Seems likely related to:
  https://github.com/coreos/bugs/issues/2152

There are three overlayfs commits that add ESTALE returns in 4.13. Two of them only affect mount time, and the third is torvalds/linux@b9ac5c2. Other 4.13 overlayfs changes may have introduced new calls to existing functions returning ESTALE, but I haven't checked.
aka, might be an issue *only* in 4.13
https://patchwork.kernel.org/patch/9955803/