SLAB support for KASAN

index c32f3b0..90ad74f 100644
@@ -65,11 +65,34 @@ static noinline void __init kmalloc_node_oob_right(void)
 	kfree(ptr);
 }
 
-static noinline void __init kmalloc_large_oob_right(void)
+#ifdef CONFIG_SLUB
+static noinline void __init kmalloc_pagealloc_oob_right(void)
 {
 	char *ptr;
 	size_t size = KMALLOC_MAX_CACHE_SIZE + 10;
 
+	/* Allocate a chunk that does not fit into a SLUB cache to trigger
+	 * the page allocator fallback.
+	 */
+	pr_info("kmalloc pagealloc allocation: out-of-bounds to right\n");
+	ptr = kmalloc(size, GFP_KERNEL);
+	if (!ptr) {
+		pr_err("Allocation failed\n");
+		return;
+	}
+
+	ptr[size] = 0;
+	kfree(ptr);
+}
+#endif
+
+static noinline void __init kmalloc_large_oob_right(void)
+{
+	char *ptr;
+	size_t size = KMALLOC_MAX_CACHE_SIZE - 256;
+	/* Allocate a chunk that is large enough, but still fits into a slab
+	 * and does not trigger the page allocator fallback in SLUB.
+	 */
 	pr_info("kmalloc large allocation: out-of-bounds to right\n");
 	ptr = kmalloc(size, GFP_KERNEL);
 	if (!ptr) {

@@ -324,6 +347,9 @@ static int __init kmalloc_tests_init(void)
 	kmalloc_oob_right();
 	kmalloc_oob_left();
 	kmalloc_node_oob_right();
+#ifdef CONFIG_SLUB
+	kmalloc_pagealloc_oob_right();
+#endif
 	kmalloc_large_oob_right();
 	kmalloc_oob_krealloc_more();
 	kmalloc_oob_krealloc_less();

index 4b9f85c..4405a35 100644
@@ -46,6 +46,9 @@ void kasan_unpoison_shadow(const void *address, size_t size);
 void kasan_alloc_pages(struct page *page, unsigned int order);
 void kasan_free_pages(struct page *page, unsigned int order);
 
+void kasan_cache_create(struct kmem_cache *cache, size_t *size,
+			unsigned long *flags);
+
 void kasan_poison_slab(struct page *page);
 void kasan_unpoison_object_data(struct kmem_cache *cache, void *object);
 void kasan_poison_object_data(struct kmem_cache *cache, void *object);

@@ -59,6 +62,11 @@ void kasan_krealloc(const void *object, size_t new_size);
 void kasan_slab_alloc(struct kmem_cache *s, void *object);
 void kasan_slab_free(struct kmem_cache *s, void *object);
 
+struct kasan_cache {
+	int alloc_meta_offset;
+	int free_meta_offset;
+};
+
 int kasan_module_alloc(void *addr, size_t size);
 void kasan_free_shadow(const struct vm_struct *vm);
 

@@ -72,6 +80,10 @@ static inline void kasan_disable_current(void) {}
 static inline void kasan_alloc_pages(struct page *page, unsigned int order) {}
 static inline void kasan_free_pages(struct page *page, unsigned int order) {}
 
+static inline void kasan_cache_create(struct kmem_cache *cache,
+				      size_t *size,
+				      unsigned long *flags) {}
+
 static inline void kasan_poison_slab(struct page *page) {}
 static inline void kasan_unpoison_object_data(struct kmem_cache *cache,
 					void *object) {}

index 3627d5c..840e652 100644
@@ -92,6 +92,12 @@
 # define SLAB_ACCOUNT		0x00000000UL
 #endif
 
+#ifdef CONFIG_KASAN
+#define SLAB_KASAN		0x08000000UL
+#else
+#define SLAB_KASAN		0x00000000UL
+#endif
+
 /* The following flags affect the page allocator grouping pages by mobility */
 #define SLAB_RECLAIM_ACCOUNT	0x00020000UL		/* Objects are reclaimable */
 #define SLAB_TEMPORARY		SLAB_RECLAIM_ACCOUNT	/* Objects are short-lived */

index cf139d3..f57232c 100644
@@ -73,8 +73,22 @@ struct kmem_cache {
 #ifdef CONFIG_MEMCG
 	struct memcg_cache_params memcg_params;
 #endif
+#ifdef CONFIG_KASAN
+	struct kasan_cache kasan_info;
+#endif
 
 	struct kmem_cache_node *node[MAX_NUMNODES];
 };
 
+static inline void *nearest_obj(struct kmem_cache *cache, struct page *page,
+				void *x) {
+	void *object = x - (x - page->s_mem) % cache->size;
+	void *last_object = page->s_mem + (cache->num - 1) * cache->size;
+
+	if (unlikely(object > last_object))
+		return last_object;
+	else
+		return object;
+}
+
 #endif	/* _LINUX_SLAB_DEF_H */

index b7e57927..c6970a0 100644
@@ -129,4 +129,15 @@ static inline void *virt_to_obj(struct kmem_cache *s,
 void object_err(struct kmem_cache *s, struct page *page,
 		u8 *object, char *reason);
 
+static inline void *nearest_obj(struct kmem_cache *cache, struct page *page,
+				void *x) {
+	void *object = x - (x - page_address(page)) % cache->size;
+	void *last_object = page_address(page) +
+		(page->objects - 1) * cache->size;
+	if (unlikely(object > last_object))
+		return last_object;
+	else
+		return object;
+}
+
 #endif /* _LINUX_SLUB_DEF_H */

111 lines not on this page · raw message

index 4f6c62e..7b9e4ab9 100644
@@ -54,6 +54,40 @@ struct kasan_global {
 #endif
 };
 
+/**
+ * Structures to keep alloc and free tracks *
+ */
+
+enum kasan_state {
+	KASAN_STATE_INIT,
+	KASAN_STATE_ALLOC,
+	KASAN_STATE_FREE
+};
+
+struct kasan_track {
+	u64 cpu : 6;			/* for NR_CPUS = 64 */
+	u64 pid : 16;			/* 65536 processes */
+	u64 when : 42;			/* ~140 years */
+};
+
+struct kasan_alloc_meta {
+	u32 state : 2;	/* enum kasan_state */
+	u32 alloc_size : 30;
+	struct kasan_track track;
+};
+
+struct kasan_free_meta {
+	/* Allocator freelist pointer, unused by KASAN. */
+	void **freelist;
+	struct kasan_track track;
+};
+
+struct kasan_alloc_meta *get_alloc_info(struct kmem_cache *cache,
+					const void *object);
+struct kasan_free_meta *get_free_info(struct kmem_cache *cache,
+					const void *object);
+
+
 static inline const void *kasan_shadow_to_mem(const void *shadow_addr)
 {
 	return (void *)(((unsigned long)shadow_addr - KASAN_SHADOW_OFFSET)

85 lines not on this page · raw message

127 lines not on this page · raw message

index b50aef0..6307b21 100644
@@ -35,7 +35,7 @@ struct kmem_cache *kmem_cache;
  */
 #define SLAB_NEVER_MERGE (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \
 		SLAB_TRACE | SLAB_DESTROY_BY_RCU | SLAB_NOLEAKTRACE | \
-		SLAB_FAILSLAB)
+		SLAB_FAILSLAB | SLAB_KASAN)
 
 #define SLAB_MERGE_SAME (SLAB_RECLAIM_ACCOUNT | SLAB_CACHE_DMA | \
 			 SLAB_NOTRACK | SLAB_ACCOUNT)

index 4405a35..bf71ab0 100644
@@ -53,13 +53,14 @@ void kasan_poison_slab(struct page *page);
 void kasan_unpoison_object_data(struct kmem_cache *cache, void *object);
 void kasan_poison_object_data(struct kmem_cache *cache, void *object);
 
-void kasan_kmalloc_large(const void *ptr, size_t size);
+void kasan_kmalloc_large(const void *ptr, size_t size, gfp_t flags);
 void kasan_kfree_large(const void *ptr);
 void kasan_kfree(void *ptr);
-void kasan_kmalloc(struct kmem_cache *s, const void *object, size_t size);
-void kasan_krealloc(const void *object, size_t new_size);
+void kasan_kmalloc(struct kmem_cache *s, const void *object, size_t size,
+		  gfp_t flags);
+void kasan_krealloc(const void *object, size_t new_size, gfp_t flags);
 
-void kasan_slab_alloc(struct kmem_cache *s, void *object);
+void kasan_slab_alloc(struct kmem_cache *s, void *object, gfp_t flags);
 void kasan_slab_free(struct kmem_cache *s, void *object);
 
 struct kasan_cache {

@@ -90,14 +91,16 @@ static inline void kasan_unpoison_object_data(struct kmem_cache *cache,
 static inline void kasan_poison_object_data(struct kmem_cache *cache,
 					void *object) {}
 
-static inline void kasan_kmalloc_large(void *ptr, size_t size) {}
+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(void *ptr) {}
 static inline void kasan_kmalloc(struct kmem_cache *s, const void *object,
-				size_t size) {}
-static inline void kasan_krealloc(const void *object, size_t new_size) {}
+				size_t size, gfp_t flags) {}
+static inline void kasan_krealloc(const void *object, size_t new_size,
+				 gfp_t flags) {}
 
-static inline void kasan_slab_alloc(struct kmem_cache *s, void *object) {}
+static inline void kasan_slab_alloc(struct kmem_cache *s, void *object,
+				   gfp_t flags) {}
 static inline void kasan_slab_free(struct kmem_cache *s, void *object) {}
 
 static inline int kasan_module_alloc(void *addr, size_t size) { return 0; }

index 84305c2..787224a 100644
@@ -414,9 +414,9 @@ struct kasan_free_meta *get_free_info(struct kmem_cache *cache,
 }
 #endif
 
-void kasan_slab_alloc(struct kmem_cache *cache, void *object)
+void kasan_slab_alloc(struct kmem_cache *cache, void *object, gfp_t flags)
 {
-	kasan_kmalloc(cache, object, cache->object_size);
+	kasan_kmalloc(cache, object, cache->object_size, flags);
 }
 
 void kasan_slab_free(struct kmem_cache *cache, void *object)

@@ -431,7 +431,8 @@ void kasan_slab_free(struct kmem_cache *cache, void *object)
 	kasan_poison_shadow(object, rounded_up_size, KASAN_KMALLOC_FREE);
 }
 
-void kasan_kmalloc(struct kmem_cache *cache, const void *object, size_t size)
+void kasan_kmalloc(struct kmem_cache *cache, const void *object, size_t size,
+		   gfp_t flags)
 {
 	unsigned long redzone_start;
 	unsigned long redzone_end;

@@ -460,7 +461,7 @@ void kasan_kmalloc(struct kmem_cache *cache, const void *object, size_t size)
 }
 EXPORT_SYMBOL(kasan_kmalloc);
 
-void kasan_kmalloc_large(const void *ptr, size_t size)
+void kasan_kmalloc_large(const void *ptr, size_t size, gfp_t flags)
 {
 	struct page *page;
 	unsigned long redzone_start;

@@ -479,7 +480,7 @@ void kasan_kmalloc_large(const void *ptr, size_t size)
 		KASAN_PAGE_REDZONE);
 }
 
-void kasan_krealloc(const void *object, size_t size)
+void kasan_krealloc(const void *object, size_t size, gfp_t flags)
 {
 	struct page *page;
 

@@ -489,9 +490,9 @@ void kasan_krealloc(const void *object, size_t size)
 	page = virt_to_head_page(object);
 
 	if (unlikely(!PageSlab(page)))
-		kasan_kmalloc_large(object, size);
+		kasan_kmalloc_large(object, size, flags);
 	else
-		kasan_kmalloc(page->slab_cache, object, size);
+		kasan_kmalloc(page->slab_cache, object, size, flags);
 }
 
 void kasan_kfree(void *ptr)

index 004d42b..b47c8a7 100644
@@ -112,12 +112,12 @@ static void kasan_poison_element(mempool_t *pool, void *element)
 		kasan_free_pages(element, (unsigned long)pool->pool_data);
 }
 
-static void kasan_unpoison_element(mempool_t *pool, void *element)
+static void kasan_unpoison_element(mempool_t *pool, void *element, gfp_t flags)
 {
 	if (pool->alloc == mempool_alloc_slab)
-		kasan_slab_alloc(pool->pool_data, element);
+		kasan_slab_alloc(pool->pool_data, element, flags);
 	if (pool->alloc == mempool_kmalloc)
-		kasan_krealloc(element, (size_t)pool->pool_data);
+		kasan_krealloc(element, (size_t)pool->pool_data, flags);
 	if (pool->alloc == mempool_alloc_pages)
 		kasan_alloc_pages(element, (unsigned long)pool->pool_data);
 }

@@ -130,13 +130,13 @@ static void add_element(mempool_t *pool, void *element)
 	pool->elements[pool->curr_nr++] = element;
 }
 
-static void *remove_element(mempool_t *pool)
+static void *remove_element(mempool_t *pool, gfp_t flags)
 {
 	void *element = pool->elements[--pool->curr_nr];
 
 	BUG_ON(pool->curr_nr < 0);
 	check_element(pool, element);
-	kasan_unpoison_element(pool, element);
+	kasan_unpoison_element(pool, element, flags);
 	return element;
 }
 

@@ -154,7 +154,7 @@ void mempool_destroy(mempool_t *pool)
 		return;
 
 	while (pool->curr_nr) {
-		void *element = remove_element(pool);
+		void *element = remove_element(pool, GFP_KERNEL);
 		pool->free(element, pool->pool_data);
 	}
 	kfree(pool->elements);

@@ -250,7 +250,7 @@ int mempool_resize(mempool_t *pool, int new_min_nr)
 	spin_lock_irqsave(&pool->lock, flags);
 	if (new_min_nr <= pool->min_nr) {
 		while (new_min_nr < pool->curr_nr) {
-			element = remove_element(pool);
+			element = remove_element(pool, GFP_KERNEL);
 			spin_unlock_irqrestore(&pool->lock, flags);
 			pool->free(element, pool->pool_data);
 			spin_lock_irqsave(&pool->lock, flags);

@@ -336,7 +336,7 @@ repeat_alloc:
 
 	spin_lock_irqsave(&pool->lock, flags);
 	if (likely(pool->curr_nr)) {
-		element = remove_element(pool);
+		element = remove_element(pool, gfp_temp);
 		spin_unlock_irqrestore(&pool->lock, flags);
 		/* paired with rmb in mempool_free(), read comment there */
 		smp_wmb();

index 739b89d..0ec7aa3 100644
@@ -3417,7 +3417,7 @@ void *kmem_cache_alloc(struct kmem_cache *cachep, gfp_t flags)
 {
 	void *ret = slab_alloc(cachep, flags, _RET_IP_);
 	if (ret)
-		kasan_slab_alloc(cachep, ret);
+		kasan_slab_alloc(cachep, ret, flags);
 
 	trace_kmem_cache_alloc(_RET_IP_, ret,
 			       cachep->object_size, cachep->size, flags);

@@ -3448,7 +3448,7 @@ kmem_cache_alloc_trace(struct kmem_cache *cachep, gfp_t flags, size_t size)
 	ret = slab_alloc(cachep, flags, _RET_IP_);
 
 	if (ret)
-		kasan_kmalloc(cachep, ret, size);
+		kasan_kmalloc(cachep, ret, size, flags);
 	trace_kmalloc(_RET_IP_, ret,
 		      size, cachep->size, flags);
 	return ret;

@@ -3473,7 +3473,7 @@ void *kmem_cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid)
 	void *ret = slab_alloc_node(cachep, flags, nodeid, _RET_IP_);
 
 	if (ret)
-		kasan_slab_alloc(cachep, ret);
+		kasan_slab_alloc(cachep, ret, flags);
 	trace_kmem_cache_alloc_node(_RET_IP_, ret,
 				    cachep->object_size, cachep->size,
 				    flags, nodeid);

@@ -3493,7 +3493,7 @@ void *kmem_cache_alloc_node_trace(struct kmem_cache *cachep,
 	ret = slab_alloc_node(cachep, flags, nodeid, _RET_IP_);
 
 	if (ret)
-		kasan_kmalloc(cachep, ret, size);
+		kasan_kmalloc(cachep, ret, size, flags);
 	trace_kmalloc_node(_RET_IP_, ret,
 			   size, cachep->size,
 			   flags, nodeid);

@@ -3513,7 +3513,7 @@ __do_kmalloc_node(size_t size, gfp_t flags, int node, unsigned long caller)
 		return cachep;
 	ret = kmem_cache_alloc_node_trace(cachep, flags, node, size);
 	if (ret)
-		kasan_kmalloc(cachep, ret, size);
+		kasan_kmalloc(cachep, ret, size, flags);
 
 	return ret;
 }

@@ -3550,7 +3550,7 @@ static __always_inline void *__do_kmalloc(size_t size, gfp_t flags,
 	ret = slab_alloc(cachep, flags, caller);
 
 	if (ret)
-		kasan_kmalloc(cachep, ret, size);
+		kasan_kmalloc(cachep, ret, size, flags);
 	trace_kmalloc(caller, ret,
 		      size, cachep->size, flags);
 

@@ -4278,7 +4278,7 @@ size_t ksize(const void *objp)
 	/* We assume that ksize callers could use whole allocated area,
 	 * so we need to unpoison this area.
 	 */
-	kasan_krealloc(objp, size);
+	kasan_krealloc(objp, size, GFP_NOWAIT);
 
 	return size;
 }

index 6307b21..02ea7d6 100644
@@ -1008,7 +1008,7 @@ void *kmalloc_order(size_t size, gfp_t flags, unsigned int order)
 	page = alloc_kmem_pages(flags, order);
 	ret = page ? page_address(page) : NULL;
 	kmemleak_alloc(ret, size, 1, flags);
-	kasan_kmalloc_large(ret, size);
+	kasan_kmalloc_large(ret, size, flags);
 	return ret;
 }
 EXPORT_SYMBOL(kmalloc_order);

@@ -1189,7 +1189,7 @@ static __always_inline void *__do_krealloc(const void *p, size_t new_size,
 		ks = ksize(p);
 
 	if (ks >= new_size) {
-		kasan_krealloc((void *)p, new_size);
+		kasan_krealloc((void *)p, new_size, flags);
 		return (void *)p;
 	}
 

index 2e1355a..28901ca 100644
@@ -1272,7 +1272,7 @@ static inline void dec_slabs_node(struct kmem_cache *s, int node,
 static inline void kmalloc_large_node_hook(void *ptr, size_t size, gfp_t flags)
 {
 	kmemleak_alloc(ptr, size, 1, flags);
-	kasan_kmalloc_large(ptr, size);
+	kasan_kmalloc_large(ptr, size, flags);
 }
 
 static inline void kfree_hook(const void *x)

@@ -1306,7 +1306,7 @@ static inline void slab_post_alloc_hook(struct kmem_cache *s, gfp_t flags,
 		kmemcheck_slab_alloc(s, flags, object, slab_ksize(s));
 		kmemleak_alloc_recursive(object, s->object_size, 1,
 					 s->flags, flags);
-		kasan_slab_alloc(s, object);
+		kasan_slab_alloc(s, object, flags);
 	}
 	memcg_kmem_put_cache(s);
 }

@@ -2590,7 +2590,7 @@ void *kmem_cache_alloc_trace(struct kmem_cache *s, gfp_t gfpflags, size_t size)
 {
 	void *ret = slab_alloc(s, gfpflags, _RET_IP_);
 	trace_kmalloc(_RET_IP_, ret, size, s->size, gfpflags);
-	kasan_kmalloc(s, ret, size);
+	kasan_kmalloc(s, ret, size, gfpflags);
 	return ret;
 }
 EXPORT_SYMBOL(kmem_cache_alloc_trace);

@@ -2618,7 +2618,7 @@ void *kmem_cache_alloc_node_trace(struct kmem_cache *s,
 	trace_kmalloc_node(_RET_IP_, ret,
 			   size, s->size, gfpflags, node);
 
-	kasan_kmalloc(s, ret, size);
+	kasan_kmalloc(s, ret, size, gfpflags);
 	return ret;
 }
 EXPORT_SYMBOL(kmem_cache_alloc_node_trace);

@@ -3162,7 +3162,8 @@ static void early_kmem_cache_node_alloc(int node)
 	init_object(kmem_cache_node, n, SLUB_RED_ACTIVE);
 	init_tracking(kmem_cache_node, n);
 #endif
-	kasan_kmalloc(kmem_cache_node, n, sizeof(struct kmem_cache_node));
+	kasan_kmalloc(kmem_cache_node, n, sizeof(struct kmem_cache_node),
+		      GFP_KERNEL);
 	init_kmem_cache_node(n);
 	inc_slabs_node(kmem_cache_node, node, page->objects);
 

@@ -3535,7 +3536,7 @@ void *__kmalloc(size_t size, gfp_t flags)
 
 	trace_kmalloc(_RET_IP_, ret, size, s->size, flags);
 
-	kasan_kmalloc(s, ret, size);
+	kasan_kmalloc(s, ret, size, flags);
 
 	return ret;
 }

@@ -3580,7 +3581,7 @@ void *__kmalloc_node(size_t size, gfp_t flags, int node)
 
 	trace_kmalloc_node(_RET_IP_, ret, size, s->size, flags, node);
 
-	kasan_kmalloc(s, ret, size);
+	kasan_kmalloc(s, ret, size, flags);
 
 	return ret;
 }

@@ -3609,7 +3610,7 @@ size_t ksize(const void *object)
 	size_t size = __ksize(object);
 	/* We assume that ksize callers could use whole allocated area,
 	   so we need unpoison this area. */
-	kasan_krealloc(object, size);
+	kasan_krealloc(object, size, GFP_NOWAIT);
 	return size;
 }
 EXPORT_SYMBOL(ksize);

index c4bd0e2..b470421 100644
@@ -456,7 +456,7 @@
 		*(.entry.text)						\
 		VMLINUX_SYMBOL(__entry_text_end) = .;
 
-#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+#if defined(CONFIG_FUNCTION_GRAPH_TRACER) || defined(CONFIG_KASAN)
 #define IRQENTRY_TEXT							\
 		ALIGN_FUNCTION();					\
 		VMLINUX_SYMBOL(__irqentry_text_start) = .;		\

@@ -466,6 +466,16 @@
 #define IRQENTRY_TEXT
 #endif
 
+#if defined(CONFIG_FUNCTION_GRAPH_TRACER) || defined(CONFIG_KASAN)
+#define SOFTIRQENTRY_TEXT						\
+		ALIGN_FUNCTION();					\
+		VMLINUX_SYMBOL(__softirqentry_text_start) = .;		\
+		*(.softirqentry.text)					\
+		VMLINUX_SYMBOL(__softirqentry_text_end) = .;
+#else
+#define SOFTIRQENTRY_TEXT
+#endif
+
 /* Section used for early init (in .S files) */
 #define HEAD_TEXT  *(.head.text)
 

index 81de712..ba23a56 100644
@@ -797,16 +797,6 @@ ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth,
  */
 #define __notrace_funcgraph		notrace
 
-/*
- * We want to which function is an entrypoint of a hardirq.
- * That will help us to put a signal on output.
- */
-#define __irq_entry		 __attribute__((__section__(".irqentry.text")))
-
-/* Limits of hardirq entrypoints */
-extern char __irqentry_text_start[];
-extern char __irqentry_text_end[];
-
 #define FTRACE_NOTRACE_DEPTH 65536
 #define FTRACE_RETFUNC_DEPTH 50
 #define FTRACE_RETSTACK_ALLOC_SIZE 32

@@ -843,7 +833,6 @@ static inline void unpause_graph_tracing(void)
 #else /* !CONFIG_FUNCTION_GRAPH_TRACER */
 
 #define __notrace_funcgraph
-#define __irq_entry
 #define INIT_FTRACE_GRAPH
 
 static inline void ftrace_graph_init_task(struct task_struct *t) { }

index 0e95fcc..1dcecaf 100644
@@ -673,4 +673,24 @@ extern int early_irq_init(void);
 extern int arch_probe_nr_irqs(void);
 extern int arch_early_irq_init(void);
 
+#if defined(CONFIG_FUNCTION_GRAPH_TRACER) || defined(CONFIG_KASAN)
+/*
+ * We want to know which function is an entrypoint of a hardirq or a softirq.
+ */
+#define __irq_entry		 __attribute__((__section__(".irqentry.text")))
+#define __softirq_entry  \
+	__attribute__((__section__(".softirqentry.text")))
+
+/* Limits of hardirq entrypoints */
+extern char __irqentry_text_start[];
+extern char __irqentry_text_end[];
+/* Limits of softirq entrypoints */
+extern char __softirqentry_text_start[];
+extern char __softirqentry_text_end[];
+
+#else
+#define __irq_entry
+#define __softirq_entry
+#endif
+
 #endif

index 479e443..359be4f 100644
@@ -227,7 +227,7 @@ static inline bool lockdep_softirq_start(void) { return false; }
 static inline void lockdep_softirq_end(bool in_hardirq) { }
 #endif
 
-asmlinkage __visible void __do_softirq(void)
+asmlinkage __visible void __softirq_entry __do_softirq(void)
 {
 	unsigned long end = jiffies + MAX_SOFTIRQ_TIME;
 	unsigned long old_flags = current->flags;

index a663cbb..3e6f7d4 100644
@@ -8,6 +8,7 @@
  */
 #include <linux/uaccess.h>
 #include <linux/ftrace.h>
+#include <linux/interrupt.h>
 #include <linux/slab.h>
 #include <linux/fs.h>
 

new file mode 100644
index 0000000..b6cbe05
@@ -0,0 +1,32 @@
+/*
+ * A generic stack depot implementation
+ *
+ * Author: Alexander Potapenko <[email protected]>
+ * Copyright (C) 2016 Google, Inc.
+ *
+ * Based on code by Dmitry Chernenkov.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#ifndef _LINUX_STACKDEPOT_H
+#define _LINUX_STACKDEPOT_H
+
+typedef u32 depot_stack_handle;
+
+struct stack_trace;
+
+depot_stack_handle depot_save_stack(struct stack_trace *trace, gfp_t flags);
+
+void depot_fetch_stack(depot_stack_handle handle, struct stack_trace *trace);
+
+#endif

274 lines not on this page · raw message

92 lines not on this page · raw message

index 7b9e4ab9..b4e5942 100644
@@ -2,6 +2,7 @@
 #define __MM_KASAN_KASAN_H
 
 #include <linux/kasan.h>
+#include <linux/stackdepot.h>
 
 #define KASAN_SHADOW_SCALE_SIZE (1UL << KASAN_SHADOW_SCALE_SHIFT)
 #define KASAN_SHADOW_MASK       (KASAN_SHADOW_SCALE_SIZE - 1)

@@ -64,10 +65,13 @@ enum kasan_state {
 	KASAN_STATE_FREE
 };
 
+#define KASAN_STACK_DEPTH 64
+
 struct kasan_track {
 	u64 cpu : 6;			/* for NR_CPUS = 64 */
 	u64 pid : 16;			/* 65536 processes */
 	u64 when : 42;			/* ~140 years */
+	depot_stack_handle stack : sizeof(depot_stack_handle);
 };
 
 struct kasan_alloc_meta {

index 2bf7218..4af52bb 100644
@@ -18,6 +18,7 @@
 #include <linux/printk.h>
 #include <linux/sched.h>
 #include <linux/slab.h>
+#include <linux/stackdepot.h>
 #include <linux/stacktrace.h>
 #include <linux/string.h>
 #include <linux/types.h>

@@ -119,6 +120,14 @@ static void print_track(struct kasan_track *track)
 {
 	pr_err("PID = %lu, CPU = %lu, timestamp = %lu\n", track->pid,
 	       track->cpu, track->when);
+	if (track->stack) {
+		struct stack_trace trace;
+
+		depot_fetch_stack(track->stack, &trace);
+		print_stack_trace(&trace, 0);
+	} else {
+		pr_err("(stack is not available)\n");
+	}
 }
 
 static void print_object(struct kmem_cache *cache, void *object)

index 90ad74f..82169fb 100644
@@ -294,6 +294,8 @@ static noinline void __init kmalloc_uaf2(void)
 	}
 
 	ptr1[40] = 'x';
+	if (ptr1 == ptr2)
+		pr_err("Could not detect use-after-free: ptr1 == ptr2\n");
 	kfree(ptr2);
 }
 

index bf71ab0..355e722 100644
@@ -44,24 +44,29 @@ static inline void kasan_disable_current(void)
 void kasan_unpoison_shadow(const void *address, size_t size);
 
 void kasan_alloc_pages(struct page *page, unsigned int order);
-void kasan_free_pages(struct page *page, unsigned int order);
+void kasan_poison_free_pages(struct page *page, unsigned int order);
 
 void kasan_cache_create(struct kmem_cache *cache, size_t *size,
 			unsigned long *flags);
+void kasan_cache_shrink(struct kmem_cache *cache);
+void kasan_cache_destroy(struct kmem_cache *cache);
 
 void kasan_poison_slab(struct page *page);
 void kasan_unpoison_object_data(struct kmem_cache *cache, void *object);
 void kasan_poison_object_data(struct kmem_cache *cache, 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(void *ptr);
+void kasan_poison_kfree_large(const void *ptr);
+void kasan_poison_kfree(void *ptr);
 void kasan_kmalloc(struct kmem_cache *s, const void *object, size_t size,
 		  gfp_t flags);
 void kasan_krealloc(const void *object, size_t new_size, gfp_t flags);
 
 void kasan_slab_alloc(struct kmem_cache *s, void *object, gfp_t flags);
-void kasan_slab_free(struct kmem_cache *s, void *object);
+/* kasan_slab_free() returns true if the object has been put into quarantine.
+ */
+bool kasan_slab_free(struct kmem_cache *s, void *object);
+void kasan_poison_slab_free(struct kmem_cache *s, void *object);
 
 struct kasan_cache {
 	int alloc_meta_offset;

@@ -79,11 +84,14 @@ static inline void kasan_enable_current(void) {}
 static inline void kasan_disable_current(void) {}
 
 static inline void kasan_alloc_pages(struct page *page, unsigned int order) {}
-static inline void kasan_free_pages(struct page *page, unsigned int order) {}
+static inline void kasan_poison_free_pages(struct page *page,
+						unsigned int order) {}
 
 static inline void kasan_cache_create(struct kmem_cache *cache,
 				      size_t *size,
 				      unsigned long *flags) {}
+static inline void kasan_cache_shrink(struct kmem_cache *cache) {}
+static inline void kasan_cache_destroy(struct kmem_cache *cache) {}
 
 static inline void kasan_poison_slab(struct page *page) {}
 static inline void kasan_unpoison_object_data(struct kmem_cache *cache,

@@ -92,8 +100,8 @@ static inline void kasan_poison_object_data(struct kmem_cache *cache,
 					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(void *ptr) {}
+static inline void kasan_poison_kfree_large(const 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) {}
 static inline void kasan_krealloc(const void *object, size_t new_size,

@@ -101,7 +109,13 @@ static inline void kasan_krealloc(const void *object, size_t new_size,
 
 static inline void kasan_slab_alloc(struct kmem_cache *s, void *object,
 				   gfp_t flags) {}
-static inline void kasan_slab_free(struct kmem_cache *s, void *object) {}
+/* kasan_slab_free() returns true if the object has been put into quarantine.
+ */
+static inline bool kasan_slab_free(struct kmem_cache *s, void *object)
+{
+	return false;
+}
+static inline void kasan_poison_slab_free(struct kmem_cache *s, void *object) {}
 
 static inline int kasan_module_alloc(void *addr, size_t size) { return 0; }
 static inline void kasan_free_shadow(const struct vm_struct *vm) {}

index 82169fb..799c98e 100644
@@ -344,6 +344,32 @@ static noinline void __init kasan_stack_oob(void)
 	*(volatile char *)p;
 }
 
+#ifdef CONFIG_SLAB
+static noinline void __init kasan_quarantine_cache(void)
+{
+	struct kmem_cache *cache = kmem_cache_create(
+			"test", 137, 8, GFP_KERNEL, NULL);
+	int i;
+
+	for (i = 0; i <  100; i++) {
+		void *p = kmem_cache_alloc(cache, GFP_KERNEL);
+
+		kmem_cache_free(cache, p);
+		p = kmalloc(sizeof(u64), GFP_KERNEL);
+		kfree(p);
+	}
+	kmem_cache_shrink(cache);
+	for (i = 0; i <  100; i++) {
+		u64 *p = kmem_cache_alloc(cache, GFP_KERNEL);
+
+		kmem_cache_free(cache, p);
+		p = kmalloc(sizeof(u64), GFP_KERNEL);
+		kfree(p);
+	}
+	kmem_cache_destroy(cache);
+}
+#endif
+
 static int __init kmalloc_tests_init(void)
 {
 	kmalloc_oob_right();

@@ -367,6 +393,9 @@ static int __init kmalloc_tests_init(void)
 	kmem_cache_oob();
 	kasan_stack_oob();
 	kasan_global_oob();
+#ifdef CONFIG_SLAB
+	kasan_quarantine_cache();
+#endif
 	return -EAGAIN;
 }
 

116 lines not on this page · raw message

index b4e5942..37e0b3a 100644
@@ -62,6 +62,7 @@ struct kasan_global {
 enum kasan_state {
 	KASAN_STATE_INIT,
 	KASAN_STATE_ALLOC,
+	KASAN_STATE_QUARANTINE,
 	KASAN_STATE_FREE
 };
 

@@ -81,8 +82,10 @@ struct kasan_alloc_meta {
 };
 
 struct kasan_free_meta {
-	/* Allocator freelist pointer, unused by KASAN. */
-	void **freelist;
+	/* This field is used while the object is in the quarantine.
+	 * Otherwise it might be used for the allocator freelist.
+	 */
+	void **quarantine_link;
 	struct kasan_track track;
 };
 

@@ -106,4 +109,8 @@ static inline bool kasan_report_enabled(void)
 void kasan_report(unsigned long addr, size_t size,
 		bool is_write, unsigned long ip);
 
+void quarantine_put(struct kasan_free_meta *info, struct kmem_cache *cache);
+void quarantine_reduce(void);
+void quarantine_remove_cache(struct kmem_cache *cache);
+
 #endif

306 lines not on this page · raw message

index 4af52bb..a398ad4 100644
@@ -149,7 +149,8 @@ static void print_object(struct kmem_cache *cache, void *object)
 		print_track(&alloc_info->track);
 		break;
 	case KASAN_STATE_FREE:
-		pr_err("Object freed, allocated with size %u bytes\n",
+	case KASAN_STATE_QUARANTINE:
+		pr_err("Object freed, allocated with size %lu bytes\n",
 		       alloc_info->alloc_size);
 		free_info = get_free_info(cache, object);
 		pr_err("Allocation:\n");

index b47c8a7..4beeeef 100644
@@ -105,11 +105,12 @@ static inline void poison_element(mempool_t *pool, void *element)
 static void kasan_poison_element(mempool_t *pool, void *element)
 {
 	if (pool->alloc == mempool_alloc_slab)
-		kasan_slab_free(pool->pool_data, element);
+		kasan_poison_slab_free(pool->pool_data, element);
 	if (pool->alloc == mempool_kmalloc)
-		kasan_kfree(element);
+		kasan_poison_kfree(element);
 	if (pool->alloc == mempool_alloc_pages)
-		kasan_free_pages(element, (unsigned long)pool->pool_data);
+		kasan_poison_free_pages(element,
+					(unsigned long)pool->pool_data);
 }
 
 static void kasan_unpoison_element(mempool_t *pool, void *element, gfp_t flags)

index 838ca8bb..a79ae81 100644
@@ -980,7 +980,7 @@ static bool free_pages_prepare(struct page *page, unsigned int order)
 
 	trace_mm_page_free(page, order);
 	kmemcheck_free_shadow(page, order);
-	kasan_free_pages(page, order);
+	kasan_poison_free_pages(page, order);
 
 	if (PageAnon(page))
 		page->mapping = NULL;

index 0ec7aa3..8e1add8 100644
@@ -3374,9 +3374,21 @@ free_done:
 static inline void __cache_free(struct kmem_cache *cachep, void *objp,
 				unsigned long caller)
 {
+#ifdef CONFIG_KASAN
+	if (kasan_slab_free(cachep, objp))
+		/* The object has been put into the quarantine, don't touch it
+		 * for now.
+		 */
+		return;
+#endif
+	___cache_free(cachep, objp, caller);
+}
+
+void ___cache_free(struct kmem_cache *cachep, void *objp,
+		unsigned long caller)
+{
 	struct array_cache *ac;
 
-	kasan_slab_free(cachep, objp);
 	ac = cpu_cache_get(cachep);
 
 	check_irq_off();

index 834ad24..4ddebfe 100644
@@ -372,4 +372,8 @@ void *slab_next(struct seq_file *m, void *p, loff_t *pos);
 void slab_stop(struct seq_file *m, void *p);
 int memcg_slab_show(struct seq_file *m, void *p);
 
+#ifdef CONFIG_KASAN
+void ___cache_free(struct kmem_cache *cache, void *x, unsigned long addr);
+#endif
+
 #endif /* MM_SLAB_H */

index 02ea7d6..0937afd 100644
@@ -710,6 +710,7 @@ void kmem_cache_destroy(struct kmem_cache *s)
 	get_online_cpus();
 	get_online_mems();
 
+	kasan_cache_destroy(s);
 	mutex_lock(&slab_mutex);
 
 	s->refcount--;

@@ -748,6 +749,7 @@ int kmem_cache_shrink(struct kmem_cache *cachep)
 
 	get_online_cpus();
 	get_online_mems();
+	kasan_cache_shrink(cachep);
 	ret = __kmem_cache_shrink(cachep, false);
 	put_online_mems();
 	put_online_cpus();

index 28901ca..01ca8a1 100644
@@ -1278,7 +1278,7 @@ static inline void kmalloc_large_node_hook(void *ptr, size_t size, gfp_t flags)
 static inline void kfree_hook(const void *x)
 {
 	kmemleak_free(x);
-	kasan_kfree_large(x);
+	kasan_poison_kfree_large(x);
 }
 
 static inline struct kmem_cache *slab_pre_alloc_hook(struct kmem_cache *s,

@@ -1333,7 +1333,7 @@ static inline void slab_free_hook(struct kmem_cache *s, void *x)
 	if (!(s->flags & SLAB_DEBUG_OBJECTS))
 		debug_check_no_obj_freed(x, s->object_size);
 
-	kasan_slab_free(s, x);
+	kasan_poison_slab_free(s, x);
 }
 
 static inline void slab_free_freelist_hook(struct kmem_cache *s,