From 73228c7ecc5e40c0851c4703c5ec6ed38123e989 Mon Sep 17 00:00:00 2001 From: Patricia Alfonso Date: Tue, 13 Oct 2020 16:55:06 -0700 Subject: KASAN: port KASAN Tests to KUnit Transfer all previous tests for KASAN to KUnit so they can be run more easily. Using kunit_tool, developers can run these tests with their other KUnit tests and see "pass" or "fail" with the appropriate KASAN report instead of needing to parse each KASAN report to test KASAN functionalities. All KASAN reports are still printed to dmesg. Stack tests do not work properly when KASAN_STACK is enabled so those tests use a check for "if IS_ENABLED(CONFIG_KASAN_STACK)" so they only run if stack instrumentation is enabled. If KASAN_STACK is not enabled, KUnit will print a statement to let the user know this test was not run with KASAN_STACK enabled. copy_user_test and kasan_rcu_uaf cannot be run in KUnit so there is a separate test file for those tests, which can be run as before as a module. [trishalfonso@google.com: v14] Link: https://lkml.kernel.org/r/20200915035828.570483-4-davidgow@google.com Signed-off-by: Patricia Alfonso Signed-off-by: David Gow Signed-off-by: Andrew Morton Tested-by: Andrey Konovalov Reviewed-by: Brendan Higgins Reviewed-by: Andrey Konovalov Reviewed-by: Dmitry Vyukov Cc: Andrey Ryabinin Cc: Ingo Molnar Cc: Juri Lelli Cc: Peter Zijlstra Cc: Shuah Khan Cc: Vincent Guittot Link: https://lkml.kernel.org/r/20200910070331.3358048-4-davidgow@google.com Signed-off-by: Linus Torvalds --- lib/test_kasan_module.c | 111 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 111 insertions(+) create mode 100644 lib/test_kasan_module.c (limited to 'lib/test_kasan_module.c') diff --git a/lib/test_kasan_module.c b/lib/test_kasan_module.c new file mode 100644 index 000000000000..2d68db6ae67b --- /dev/null +++ b/lib/test_kasan_module.c @@ -0,0 +1,111 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * + * Copyright (c) 2014 Samsung Electronics Co., Ltd. + * Author: Andrey Ryabinin + */ + +#define pr_fmt(fmt) "kasan test: %s " fmt, __func__ + +#include +#include +#include +#include +#include + +#include "../mm/kasan/kasan.h" + +#define OOB_TAG_OFF (IS_ENABLED(CONFIG_KASAN_GENERIC) ? 0 : KASAN_SHADOW_SCALE_SIZE) + +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 + OOB_TAG_OFF); + + pr_info("out-of-bounds in copy_to_user()\n"); + unused = copy_to_user(usermem, kmem, size + 1 + OOB_TAG_OFF); + + pr_info("out-of-bounds in __copy_from_user()\n"); + unused = __copy_from_user(kmem, usermem, size + 1 + OOB_TAG_OFF); + + pr_info("out-of-bounds in __copy_to_user()\n"); + unused = __copy_to_user(usermem, kmem, size + 1 + OOB_TAG_OFF); + + pr_info("out-of-bounds in __copy_from_user_inatomic()\n"); + unused = __copy_from_user_inatomic(kmem, usermem, size + 1 + OOB_TAG_OFF); + + pr_info("out-of-bounds in __copy_to_user_inatomic()\n"); + unused = __copy_to_user_inatomic(usermem, kmem, size + 1 + OOB_TAG_OFF); + + pr_info("out-of-bounds in strncpy_from_user()\n"); + unused = strncpy_from_user(kmem, usermem, size + 1 + OOB_TAG_OFF); + + vm_munmap((unsigned long)usermem, PAGE_SIZE); + kfree(kmem); +} + +static struct kasan_rcu_info { + int i; + struct rcu_head rcu; +} *global_rcu_ptr; + +static noinline void __init kasan_rcu_reclaim(struct rcu_head *rp) +{ + struct kasan_rcu_info *fp = container_of(rp, + struct kasan_rcu_info, rcu); + + kfree(fp); + fp->i = 1; +} + +static noinline void __init kasan_rcu_uaf(void) +{ + struct kasan_rcu_info *ptr; + + pr_info("use-after-free in kasan_rcu_reclaim\n"); + ptr = kmalloc(sizeof(struct kasan_rcu_info), GFP_KERNEL); + if (!ptr) { + pr_err("Allocation failed\n"); + return; + } + + global_rcu_ptr = rcu_dereference_protected(ptr, NULL); + call_rcu(&global_rcu_ptr->rcu, kasan_rcu_reclaim); +} + + +static int __init test_kasan_module_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(); + + copy_user_test(); + kasan_rcu_uaf(); + + kasan_restore_multi_shot(multishot); + return -EAGAIN; +} + +module_init(test_kasan_module_init); +MODULE_LICENSE("GPL"); -- cgit v1.2.3