+ kasan-migrate-copy_user_test-to-kunit.patch added to mm-unstable branch

[Andrew Morton <akpm@linux-foundation.org>]

The patch titled
     Subject: kasan: migrate copy_user_test to kunit
has been added to the -mm mm-unstable branch.  Its filename is
     kasan-migrate-copy_user_test-to-kunit.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/kasan-migrate-copy_user_test-to-kunit.patch

This patch will later appear in the mm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------
From: Sabyrzhan Tasbolatov <snovitoll@gmail.com>
Subject: kasan: migrate copy_user_test to kunit
Date: Wed, 16 Oct 2024 18:18:01 +0500

Migrate the copy_user_test to the KUnit framework to verify out-of-bound
detection via KASAN reports in copy_from_user(), copy_to_user() and their
static functions.

This is the last migrated test in kasan_test_module.c, therefore delete
the file.

Link: https://lkml.kernel.org/r/20241016131802.3115788-3-snovitoll@gmail.com
Signed-off-by: Sabyrzhan Tasbolatov <snovitoll@gmail.com>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Alex Shi <alexs@kernel.org>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Hu Haowen <2023002089@link.tyut.edu.cn>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Marco Elver <elver@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Yanteng Si <siyanteng@loongson.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/kasan/Makefile            |    2 
 mm/kasan/kasan_test_c.c      |   47 +++++++++++++++++++
 mm/kasan/kasan_test_module.c |   81 ---------------------------------
 3 files changed, 47 insertions(+), 83 deletions(-)

--- a/mm/kasan/kasan_test_c.c~kasan-migrate-copy_user_test-to-kunit
+++ a/mm/kasan/kasan_test_c.c
@@ -1989,6 +1989,52 @@ static void copy_to_kernel_nofault_oob(s
 	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),
@@ -2064,6 +2110,7 @@ static struct kunit_case kasan_kunit_tes
 	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 a/mm/kasan/kasan_test_module.c
deleted file mode 100644
--- 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 <a.ryabinin@samsung.com>
- */
-
-#define pr_fmt(fmt) "kasan: test: " fmt
-
-#include <linux/mman.h>
-#include <linux/module.h>
-#include <linux/printk.h>
-#include <linux/slab.h>
-#include <linux/uaccess.h>
-
-#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");
--- a/mm/kasan/Makefile~kasan-migrate-copy_user_test-to-kunit
+++ a/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
_

Patches currently in -mm which might be from snovitoll@gmail.com are

x86-traps-move-kmsan-check-after-instrumentation_begin.patch
mm-kasan-kmsan-copy_from-to_kernel_nofault.patch
kasan-move-checks-to-do_strncpy_from_user.patch
kasan-migrate-copy_user_test-to-kunit.patch
kasan-delete-config_kasan_module_test.patch