On Mon, Dec 13, 2021 at 10:54:19PM +0100, andrey.konovalov@xxxxxxxxx wrote: > From: Andrey Konovalov <andreyknvl@xxxxxxxxxx> > > Once tag-based KASAN modes start tagging vmalloc() allocations, > kernel stacks start getting tagged if CONFIG_VMAP_STACK is enabled. > > Reset the tag of kernel stack pointers after allocation in > arch_alloc_vmap_stack(). > > For SW_TAGS KASAN, when CONFIG_KASAN_STACK is enabled, the > instrumentation can't handle the SP register being tagged. > > For HW_TAGS KASAN, there's no instrumentation-related issues. However, > the impact of having a tagged SP register needs to be properly evaluated, > so keep it non-tagged for now. > > Note, that the memory for the stack allocation still gets tagged to > catch vmalloc-into-stack out-of-bounds accesses. > > Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx> Acked-by: Catalin Marinas <catalin.marinas@xxxxxxx>
