From b2b23ba03cb9059d11b270cc280dcdfa6dbbdf53 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Fri, 28 Oct 2022 08:53:01 -0700 Subject: mempool: do not use ksize() for poisoning Nothing appears to be using ksize() within the kmalloc-backed mempools except the mempool poisoning logic. Use the actual pool size instead of the ksize() to avoid needing any special handling of the memory as needed by KASAN, UBSAN_BOUNDS, nor FORTIFY_SOURCE. [vbabka@suse.cz: for slab mempools pool_data is not object size] Link: https://lkml.kernel.org/r/13c4bd6e-09d3-efce-43a5-5a99be8bc96b@suse.cz Link: https://lkml.kernel.org/r/20221028154823.you.615-kees@kernel.org Signed-off-by: Kees Cook Signed-off-by: Vlastimil Babka Suggested-by: Vlastimil Babka Link: https://lore.kernel.org/lkml/f4fc52c4-7c18-1d76-0c7a-4058ea2486b9@suse.cz/ Acked-by: Vlastimil Babka Reviewed-by: Andrey Konovalov Cc: David Rientjes Cc: Marco Elver Cc: Vincenzo Frascino Reported-by: Anders Roxell Link: https://lore.kernel.org/all/20221031105514.GB69385@mutt/ Cc: Matthew Wilcox Signed-off-by: Andrew Morton --- mm/mempool.c | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-) (limited to 'mm/mempool.c') diff --git a/mm/mempool.c b/mm/mempool.c index 96488b13a1ef..734bcf5afbb7 100644 --- a/mm/mempool.c +++ b/mm/mempool.c @@ -57,8 +57,10 @@ static void __check_element(mempool_t *pool, void *element, size_t size) static void check_element(mempool_t *pool, void *element) { /* Mempools backed by slab allocator */ - if (pool->free == mempool_free_slab || pool->free == mempool_kfree) { - __check_element(pool, element, ksize(element)); + if (pool->free == mempool_kfree) { + __check_element(pool, element, (size_t)pool->pool_data); + } else if (pool->free == mempool_free_slab) { + __check_element(pool, element, kmem_cache_size(pool->pool_data)); } else if (pool->free == mempool_free_pages) { /* Mempools backed by page allocator */ int order = (int)(long)pool->pool_data; @@ -80,8 +82,10 @@ static void __poison_element(void *element, size_t size) static void poison_element(mempool_t *pool, void *element) { /* Mempools backed by slab allocator */ - if (pool->alloc == mempool_alloc_slab || pool->alloc == mempool_kmalloc) { - __poison_element(element, ksize(element)); + if (pool->alloc == mempool_kmalloc) { + __poison_element(element, (size_t)pool->pool_data); + } else if (pool->alloc == mempool_alloc_slab) { + __poison_element(element, kmem_cache_size(pool->pool_data)); } else if (pool->alloc == mempool_alloc_pages) { /* Mempools backed by page allocator */ int order = (int)(long)pool->pool_data; @@ -111,8 +115,10 @@ static __always_inline void kasan_poison_element(mempool_t *pool, void *element) static void kasan_unpoison_element(mempool_t *pool, void *element) { - if (pool->alloc == mempool_alloc_slab || pool->alloc == mempool_kmalloc) - kasan_unpoison_range(element, __ksize(element)); + if (pool->alloc == mempool_kmalloc) + kasan_unpoison_range(element, (size_t)pool->pool_data); + else if (pool->alloc == mempool_alloc_slab) + kasan_unpoison_range(element, kmem_cache_size(pool->pool_data)); else if (pool->alloc == mempool_alloc_pages) kasan_unpoison_pages(element, (unsigned long)pool->pool_data, false); -- cgit v1.2.3