On Tue, Mar 24, 2020 at 09:49:48PM -0400, Qian Cai wrote: > It does not catch anything at all with the patch, You mean, oops happens, but neither WARN_ON() is triggered? Lovely... Just to make sure: could you slap the same couple of lines just before if (unlikely(!d_can_lookup(nd->path.dentry))) { in link_path_walk(), just to check if I have misread the trace you've got? Does that (+ other two inserts) end up with 1) some of these WARN_ON() triggered when oops happens or 2) oops is happening, but neither WARN_ON() triggers or 3) oops not happening / becoming harder to hit?