From 47adccce3e8a31d315f47183ab1185862b2fc5d4 Mon Sep 17 00:00:00 2001 From: Dmitry Vyukov Date: Tue, 6 Feb 2018 15:36:23 -0800 Subject: kasan: detect invalid frees for large objects Patch series "kasan: detect invalid frees". KASAN detects double-frees, but does not detect invalid-frees (when a pointer into a middle of heap object is passed to free). We recently had a very unpleasant case in crypto code which freed an inner object inside of a heap allocation. This left unnoticed during free, but totally corrupted heap and later lead to a bunch of random crashes all over kernel code. Detect invalid frees. This patch (of 5): Detect frees of pointers into middle of large heap objects. I dropped const from kasan_kfree_large() because it starts propagating through a bunch of functions in kasan_report.c, slab/slub nearest_obj(), all of their local variables, fixup_red_left(), etc. Link: http://lkml.kernel.org/r/1b45b4fe1d20fc0de1329aab674c1dd973fee723.1514378558.git.dvyukov@google.com Signed-off-by: Dmitry Vyukov Cc: Andrey Ryabinin a Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/kasan.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'include/linux') diff --git a/include/linux/kasan.h b/include/linux/kasan.h index e3eb834c9a35..fc9e642533f8 100644 --- a/include/linux/kasan.h +++ b/include/linux/kasan.h @@ -56,7 +56,7 @@ void kasan_poison_object_data(struct kmem_cache *cache, void *object); void kasan_init_slab_obj(struct kmem_cache *cache, const void *object); void kasan_kmalloc_large(const void *ptr, size_t size, gfp_t flags); -void kasan_kfree_large(const void *ptr); +void kasan_kfree_large(void *ptr); void kasan_poison_kfree(void *ptr); void kasan_kmalloc(struct kmem_cache *s, const void *object, size_t size, gfp_t flags); @@ -108,7 +108,7 @@ static inline void kasan_init_slab_obj(struct kmem_cache *cache, const void *object) {} static inline void kasan_kmalloc_large(void *ptr, size_t size, gfp_t flags) {} -static inline void kasan_kfree_large(const void *ptr) {} +static inline void kasan_kfree_large(void *ptr) {} static inline void kasan_poison_kfree(void *ptr) {} static inline void kasan_kmalloc(struct kmem_cache *s, const void *object, size_t size, gfp_t flags) {} -- cgit