On Fri, Sep 16, 2022 at 03:46:07PM +0100, Matthew Wilcox wrote: > On Fri, Sep 16, 2022 at 06:59:57AM -0700, Kees Cook wrote: > > The check_object_size() checks under CONFIG_HARDENED_USERCOPY need to be > > more defensive against running from interrupt context. Use a best-effort > > check for VMAP areas when running in interrupt context > > I had something more like this in mind: Yeah, I like -EAGAIN. I'd like to keep the interrupt test to choose lock vs trylock, otherwise it's trivial to bypass the hardening test by having all the other CPUs beating on the spinlock. Thanks! -Kees -- Kees Cook