diff options
Diffstat (limited to 'mm/slab.c')
| -rw-r--r-- | mm/slab.c | 36 |
1 files changed, 27 insertions, 9 deletions
diff --git a/mm/slab.c b/mm/slab.c index 226906294183..cd86f15071ad 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -1281,7 +1281,7 @@ void __init kmem_cache_init(void) create_boot_cache(kmem_cache, "kmem_cache", offsetof(struct kmem_cache, node) + nr_node_ids * sizeof(struct kmem_cache_node *), - SLAB_HWCACHE_ALIGN); + SLAB_HWCACHE_ALIGN, 0, 0); list_add(&kmem_cache->list, &slab_caches); slab_state = PARTIAL; @@ -1291,7 +1291,8 @@ void __init kmem_cache_init(void) */ kmalloc_caches[INDEX_NODE] = create_kmalloc_cache( kmalloc_info[INDEX_NODE].name, - kmalloc_size(INDEX_NODE), ARCH_KMALLOC_FLAGS); + kmalloc_size(INDEX_NODE), ARCH_KMALLOC_FLAGS, + 0, kmalloc_size(INDEX_NODE)); slab_state = PARTIAL_NODE; setup_kmalloc_cache_index_table(); @@ -4385,13 +4386,15 @@ module_init(slab_proc_init); #ifdef CONFIG_HARDENED_USERCOPY /* - * Rejects objects that are incorrectly sized. + * Rejects incorrectly sized objects and objects that are to be copied + * to/from userspace but do not fall entirely within the containing slab + * cache's usercopy region. * * Returns NULL if check passes, otherwise const char * to name of cache * to indicate an error. */ -const char *__check_heap_object(const void *ptr, unsigned long n, - struct page *page) +void __check_heap_object(const void *ptr, unsigned long n, struct page *page, + bool to_user) { struct kmem_cache *cachep; unsigned int objnr; @@ -4405,11 +4408,26 @@ const char *__check_heap_object(const void *ptr, unsigned long n, /* Find offset within object. */ offset = ptr - index_to_obj(cachep, page, objnr) - obj_offset(cachep); - /* Allow address range falling entirely within object size. */ - if (offset <= cachep->object_size && n <= cachep->object_size - offset) - return NULL; + /* Allow address range falling entirely within usercopy region. */ + if (offset >= cachep->useroffset && + offset - cachep->useroffset <= cachep->usersize && + n <= cachep->useroffset - offset + cachep->usersize) + return; + + /* + * If the copy is still within the allocated object, produce + * a warning instead of rejecting the copy. This is intended + * to be a temporary method to find any missing usercopy + * whitelists. + */ + if (usercopy_fallback && + offset <= cachep->object_size && + n <= cachep->object_size - offset) { + usercopy_warn("SLAB object", cachep->name, to_user, offset, n); + return; + } - return cachep->name; + usercopy_abort("SLAB object", cachep->name, to_user, offset, n); } #endif /* CONFIG_HARDENED_USERCOPY */ |