Messages in this thread | ![/](/images/icornerl.gif) | | Date | Tue, 14 Dec 2021 13:25:19 +0000 | From | Catalin Marinas <> | Subject | Re: [PATCH mm v3 23/38] kasan, arm64: reset pointer tags of vmapped stacks |
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On Mon, Dec 13, 2021 at 10:54:19PM +0100, andrey.konovalov@linux.dev wrote: > From: Andrey Konovalov <andreyknvl@google.com> > > 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@google.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
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