On Fri, Sep 15, 2023 at 10:59:27AM +0000, Matteo Rizzo wrote: > From: Jann Horn <jannh@xxxxxxxxxx> > > SLAB_VIRTUAL is a mitigation for the SLUB allocator which prevents reuse > of virtual addresses across different slab caches and therefore makes > some types of use-after-free bugs unexploitable. > > SLAB_VIRTUAL is incompatible with KASAN and we believe it's not worth > adding support for it. This is because SLAB_VIRTUAL and KASAN are aimed > at two different use cases: KASAN is meant for catching bugs as early as > possible in debug/fuzz/testing builds, and it's not meant to be used in > production. SLAB_VIRTUAL on the other hand is an exploit mitigation that > doesn't attempt to highlight bugs but instead tries to make them > unexploitable. It doesn't make sense to enable it in debugging builds or > during fuzzing, and instead we expect that it will be enabled in > production kernels. > > SLAB_VIRTUAL is not currently compatible with KFENCE, removing this > limitation is future work. > > Signed-off-by: Jann Horn <jannh@xxxxxxxxxx> Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx> -- Kees Cook
