On Fri, 03 Apr 2015 17:47:47 +0300 Andrey Ryabinin <a.ryabi...@samsung.com> wrote:
> Mempools keep allocated objects in reserved for situations > when ordinary allocation may not be possible to satisfy. > These objects shouldn't be accessed before they leave > the pool. > This patch poison elements when get into the pool > and unpoison when they leave it. This will let KASan > to detect use-after-free of mempool's elements. > > ... > > +static void kasan_poison_element(mempool_t *pool, void *element) > +{ > + if (pool->alloc == mempool_alloc_slab) > + kasan_slab_free(pool->pool_data, element); > + if (pool->alloc == mempool_kmalloc) > + kasan_kfree(element); > + if (pool->alloc == mempool_alloc_pages) > + kasan_free_pages(element, (unsigned long)pool->pool_data); > +} We recently discovered that mempool pages (from alloc_pages, not slab) can be in highmem. But kasan apepars to handle highmem pages (by baling out) so we should be OK with that. Can kasan be taught to use kmap_atomic() or is it more complicated than that? It probably isn't worthwhile - highmem pages don'[t get used by the kernel much and most bugs will be found using 64-bit testing anyway. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/