diff --git a/mm/kasan/Makefile b/mm/kasan/Makefile index b88543e5c0cc..1a958e7c8a46 100644 --- a/mm/kasan/Makefile +++ b/mm/kasan/Makefile @@ -46,7 +46,6 @@ endif CFLAGS_kasan_test_c.o := $(CFLAGS_KASAN_TEST) RUSTFLAGS_kasan_test_rust.o := $(RUSTFLAGS_KASAN) -CFLAGS_kasan_test_module.o := $(CFLAGS_KASAN_TEST) obj-y := common.o report.o obj-$(CONFIG_KASAN_GENERIC) += init.o generic.o report_generic.o shadow.o quarantine.o @@ -59,4 +58,3 @@ ifdef CONFIG_RUST endif obj-$(CONFIG_KASAN_KUNIT_TEST) += kasan_test.o -obj-$(CONFIG_KASAN_MODULE_TEST) += kasan_test_module.o diff --git a/mm/kasan/kasan_test_c.c b/mm/kasan/kasan_test_c.c index fe132ce3c2b3..fd5058c5d0f7 100644 --- a/mm/kasan/kasan_test_c.c +++ b/mm/kasan/kasan_test_c.c @@ -1963,6 +1963,52 @@ static void copy_to_kernel_nofault_oob(struct kunit *test) kfree(ptr); } +static void copy_user_test_oob(struct kunit *test) +{ + char *kmem; + char __user *usermem; + unsigned long useraddr; + size_t size = 128 - KASAN_GRANULE_SIZE; + int __maybe_unused unused; + + kmem = kunit_kmalloc(test, size, GFP_KERNEL); + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, kmem); + + useraddr = kunit_vm_mmap(test, NULL, 0, PAGE_SIZE, + PROT_READ | PROT_WRITE | PROT_EXEC, + MAP_ANONYMOUS | MAP_PRIVATE, 0); + KUNIT_ASSERT_NE_MSG(test, useraddr, 0, + "Could not create userspace mm"); + KUNIT_ASSERT_LT_MSG(test, useraddr, (unsigned long)TASK_SIZE, + "Failed to allocate user memory"); + + OPTIMIZER_HIDE_VAR(size); + usermem = (char __user *)useraddr; + + KUNIT_EXPECT_KASAN_FAIL(test, + unused = copy_from_user(kmem, usermem, size + 1)); + KUNIT_EXPECT_KASAN_FAIL(test, + unused = copy_to_user(usermem, kmem, size + 1)); + KUNIT_EXPECT_KASAN_FAIL(test, + unused = __copy_from_user(kmem, usermem, size + 1)); + KUNIT_EXPECT_KASAN_FAIL(test, + unused = __copy_to_user(usermem, kmem, size + 1)); + KUNIT_EXPECT_KASAN_FAIL(test, + unused = __copy_from_user_inatomic(kmem, usermem, size + 1)); + KUNIT_EXPECT_KASAN_FAIL(test, + unused = __copy_to_user_inatomic(usermem, kmem, size + 1)); + + /* + * Prepare a long string in usermem to avoid the strncpy_from_user test + * bailing out on '\0' before it reaches out-of-bounds. + */ + memset(kmem, 'a', size); + KUNIT_EXPECT_EQ(test, copy_to_user(usermem, kmem, size), 0); + + KUNIT_EXPECT_KASAN_FAIL(test, + unused = strncpy_from_user(kmem, usermem, size + 1)); +} + static struct kunit_case kasan_kunit_test_cases[] = { KUNIT_CASE(kmalloc_oob_right), KUNIT_CASE(kmalloc_oob_left), @@ -2037,6 +2083,7 @@ static struct kunit_case kasan_kunit_test_cases[] = { KUNIT_CASE(match_all_mem_tag), KUNIT_CASE(copy_to_kernel_nofault_oob), KUNIT_CASE(rust_uaf), + KUNIT_CASE(copy_user_test_oob), {} }; diff --git a/mm/kasan/kasan_test_module.c b/mm/kasan/kasan_test_module.c deleted file mode 100644 index 27ec22767e42..000000000000 --- a/mm/kasan/kasan_test_module.c +++ /dev/null @@ -1,81 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0-only -/* - * - * Copyright (c) 2014 Samsung Electronics Co., Ltd. - * Author: Andrey Ryabinin - */ - -#define pr_fmt(fmt) "kasan: test: " fmt - -#include -#include -#include -#include -#include - -#include "kasan.h" - -static noinline void __init copy_user_test(void) -{ - char *kmem; - char __user *usermem; - size_t size = 128 - KASAN_GRANULE_SIZE; - int __maybe_unused 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; - } - - OPTIMIZER_HIDE_VAR(size); - - 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 int __init kasan_test_module_init(void) -{ - /* - * Temporarily enable multi-shot mode. Otherwise, KASAN would only - * report the first detected bug and panic the kernel if panic_on_warn - * is enabled. - */ - bool multishot = kasan_save_enable_multi_shot(); - - copy_user_test(); - - kasan_restore_multi_shot(multishot); - return -EAGAIN; -} - -module_init(kasan_test_module_init); -MODULE_LICENSE("GPL"); diff --git a/mm/maccess.c b/mm/maccess.c index 3ca55ec63a6a..8f0906180a94 100644 --- a/mm/maccess.c +++ b/mm/maccess.c @@ -82,6 +82,7 @@ long copy_to_kernel_nofault(void *dst, const void *src, size_t size) pagefault_enable(); return -EFAULT; } +EXPORT_SYMBOL_GPL(copy_to_kernel_nofault); long strncpy_from_kernel_nofault(char *dst, const void *unsafe_addr, long count) {