On Sun, 24 Oct 2021 at 07:38, Mike Rapoport <rppt@xxxxxxxxxx> wrote: > > On Sat, Oct 23, 2021 at 11:46:18PM +0100, Matthew Wilcox wrote: > > On Sat, Oct 23, 2021 at 10:03:11AM -0700, Kees Cook wrote: > > > On October 23, 2021 8:27:28 AM PDT, Mike Rapoport <rppt@xxxxxxxxxx> wrote: > > > >and my first reaction was to send a revert the untested commit 110860541f44 > > > >("mm/secretmem: use refcount_t instead of atomic_t"). > > > > I think you should. This isn't a real problem. > > Do you mean that creation of 4 billion of file descriptors is not feasible? FWIW I think refcount is at least capable of catching the issue I described with the counter temporarily going below its true value. With refcount it can be caught during fuzzing as refcount reaching 0 and then being incremented again. Basically this warning, but a true positive.