On Tue, Jan 17, 2023 at 5:35 PM Jann Horn <jannh@xxxxxxxxxx> wrote: > > KASAN (except in HW_TAGS mode) tracks memory state based on virtual > addresses. The mappings of kernel stack pages in the linear mapping are > currently marked as fully accessible. > Since stack corruption issues can cause some very gnarly errors, let's be > extra careful and tell KASAN to forbid accesses to stack memory through the > linear mapping. > > Signed-off-by: Jann Horn <jannh@xxxxxxxxxx> > --- > I wrote this after seeing > https://lore.kernel.org/all/Y8W5rjKdZ9erIF14@xxxxxxxxxxxxxxxxxxxx/ > and wondering about possible ways that this kind of stack corruption > could be sneaking past KASAN. > That's proooobably not the explanation, but still... Hi Jann, if you decide to keep KASAN poisoning after addressing Dmitry's comments, please add a KASAN KUnit test for this. Thank you!
