kasan: detect invalid frees
Detect frees of pointers into middle of heap objects.
Link: http://lkml.kernel.org/r/cb569193190356beb018a03bb8d6fbae67e7adbc.1514378558.git.dvyukov@google.com
Signed-off-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>a
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/lib/test_kasan.c b/lib/test_kasan.c
index e9c5d76..a808d81 100644
--- a/lib/test_kasan.c
+++ b/lib/test_kasan.c
@@ -523,6 +523,54 @@ static noinline void __init kasan_alloca_oob_right(void)
*(volatile char *)p;
}
+static noinline void __init kmem_cache_double_free(void)
+{
+ char *p;
+ size_t size = 200;
+ struct kmem_cache *cache;
+
+ cache = kmem_cache_create("test_cache", size, 0, 0, NULL);
+ if (!cache) {
+ pr_err("Cache allocation failed\n");
+ return;
+ }
+ pr_info("double-free on heap object\n");
+ p = kmem_cache_alloc(cache, GFP_KERNEL);
+ if (!p) {
+ pr_err("Allocation failed\n");
+ kmem_cache_destroy(cache);
+ return;
+ }
+
+ kmem_cache_free(cache, p);
+ kmem_cache_free(cache, p);
+ kmem_cache_destroy(cache);
+}
+
+static noinline void __init kmem_cache_invalid_free(void)
+{
+ char *p;
+ size_t size = 200;
+ struct kmem_cache *cache;
+
+ cache = kmem_cache_create("test_cache", size, 0, SLAB_TYPESAFE_BY_RCU,
+ NULL);
+ if (!cache) {
+ pr_err("Cache allocation failed\n");
+ return;
+ }
+ pr_info("invalid-free of heap object\n");
+ p = kmem_cache_alloc(cache, GFP_KERNEL);
+ if (!p) {
+ pr_err("Allocation failed\n");
+ kmem_cache_destroy(cache);
+ return;
+ }
+
+ kmem_cache_free(cache, p + 1);
+ kmem_cache_destroy(cache);
+}
+
static int __init kmalloc_tests_init(void)
{
/*
@@ -560,6 +608,8 @@ static int __init kmalloc_tests_init(void)
ksize_unpoisons_memory();
copy_user_test();
use_after_scope_test();
+ kmem_cache_double_free();
+ kmem_cache_invalid_free();
kasan_restore_multi_shot(multishot);
