diff options
Diffstat (limited to 'lib/test_kasan.c')
| -rw-r--r-- | lib/test_kasan.c | 138 |
1 files changed, 137 insertions, 1 deletions
diff --git a/lib/test_kasan.c b/lib/test_kasan.c index c32f3b0048dc..0e70ecc12fe2 100644 --- a/lib/test_kasan.c +++ b/lib/test_kasan.c @@ -12,10 +12,19 @@ #define pr_fmt(fmt) "kasan test: %s " fmt, __func__ #include <linux/kernel.h> +#include <linux/mman.h> +#include <linux/mm.h> #include <linux/printk.h> #include <linux/slab.h> #include <linux/string.h> +#include <linux/uaccess.h> #include <linux/module.h> +#include <linux/kasan.h> + +/* + * Note: test functions are marked noinline so that their names appear in + * reports. + */ static noinline void __init kmalloc_oob_right(void) { @@ -65,11 +74,34 @@ 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) { @@ -271,6 +303,8 @@ 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); } @@ -319,11 +353,107 @@ static noinline void __init kasan_stack_oob(void) *(volatile char *)p; } +static noinline void __init ksize_unpoisons_memory(void) +{ + char *ptr; + size_t size = 123, real_size = size; + + pr_info("ksize() unpoisons the whole allocated chunk\n"); + ptr = kmalloc(size, GFP_KERNEL); + if (!ptr) { + pr_err("Allocation failed\n"); + return; + } + real_size = ksize(ptr); + /* This access doesn't trigger an error. */ + ptr[size] = 'x'; + /* This one does. */ + ptr[real_size] = 'y'; + kfree(ptr); +} + +static noinline void __init copy_user_test(void) +{ + char *kmem; + char __user *usermem; + size_t size = 10; + int unused; + + kmem = kmalloc(size, GFP_KERNEL); + if (!kmem) + return; + + usermem = (char __user *)vm_mmap(NULL, 0, PAGE_SIZE, + PROT_READ | PROT_WRITE | PROT_EXEC, + MAP_ANONYMOUS | MAP_PRIVATE, 0); + if (IS_ERR(usermem)) { + pr_err("Failed to allocate user memory\n"); + kfree(kmem); + return; + } + + pr_info("out-of-bounds in copy_from_user()\n"); + unused = copy_from_user(kmem, usermem, size + 1); + + pr_info("out-of-bounds in copy_to_user()\n"); + unused = copy_to_user(usermem, kmem, size + 1); + + pr_info("out-of-bounds in __copy_from_user()\n"); + unused = __copy_from_user(kmem, usermem, size + 1); + + pr_info("out-of-bounds in __copy_to_user()\n"); + unused = __copy_to_user(usermem, kmem, size + 1); + + pr_info("out-of-bounds in __copy_from_user_inatomic()\n"); + unused = __copy_from_user_inatomic(kmem, usermem, size + 1); + + pr_info("out-of-bounds in __copy_to_user_inatomic()\n"); + unused = __copy_to_user_inatomic(usermem, kmem, size + 1); + + pr_info("out-of-bounds in strncpy_from_user()\n"); + unused = strncpy_from_user(kmem, usermem, size + 1); + + vm_munmap((unsigned long)usermem, PAGE_SIZE); + kfree(kmem); +} + +static noinline void __init use_after_scope_test(void) +{ + volatile char *volatile p; + + pr_info("use-after-scope on int\n"); + { + int local = 0; + + p = (char *)&local; + } + p[0] = 1; + p[3] = 1; + + pr_info("use-after-scope on array\n"); + { + char local[1024] = {0}; + + p = local; + } + p[0] = 1; + p[1023] = 1; +} + static int __init kmalloc_tests_init(void) { + /* + * Temporarily enable multi-shot mode. Otherwise, we'd only get a + * report for the first case. + */ + bool multishot = kasan_save_enable_multi_shot(); + 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(); @@ -339,6 +469,12 @@ static int __init kmalloc_tests_init(void) kmem_cache_oob(); kasan_stack_oob(); kasan_global_oob(); + ksize_unpoisons_memory(); + copy_user_test(); + use_after_scope_test(); + + kasan_restore_multi_shot(multishot); + return -EAGAIN; } |