| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <202007211207.5BAA9D8D@keescook>
Date: Tue, 21 Jul 2020 12:09:30 -0700
From: Kees Cook <keescook@...omium.org>
To: Vitor Massaru Iha <vitor@...saru.org>
Cc: kunit-dev@...glegroups.com, linux-kselftest@...r.kernel.org,
linux-kernel@...r.kernel.org, brendanhiggins@...gle.com,
davidgow@...gle.com, skhan@...uxfoundation.org,
linux-kernel-mentees@...ts.linuxfoundation.org
Subject: Re: [PATCH v3] lib: Convert test_user_copy to KUnit test
On Tue, Jul 21, 2020 at 02:46:54PM -0300, Vitor Massaru Iha wrote:
> This adds the conversion of the runtime tests of test_user_copy fuctions,
> from `lib/test_user_copy.c`to KUnit tests.
>
> Signed-off-by: Vitor Massaru Iha <vitor@...saru.org>
> ---
> v2:
> * splitted patch in 3:
> - Allows to install and load modules in root filesystem;
> - Provides an userspace memory context when tests are compiled
> as module;
> - Convert test_user_copy to KUnit test;
> * removed entry for CONFIG_TEST_USER_COPY;
> * replaced pr_warn to KUNIT_EXPECT_FALSE_MSG in test macro to
> decrease the diff;
> v3:
> * rebased with last kunit branch
> * Please apply this commit from kunit-fixes:
> 3f37d14b8a3152441f36b6bc74000996679f0998
> And these from patchwork:
> https://patchwork.kernel.org/patch/11676331/
> https://patchwork.kernel.org/patch/11676335/
> ---
> lib/Kconfig.debug | 28 ++++++++------
> lib/Makefile | 2 +-
> lib/{test_user_copy.c => user_copy_kunit.c} | 42 +++++++++------------
> 3 files changed, 35 insertions(+), 37 deletions(-)
> rename lib/{test_user_copy.c => user_copy_kunit.c} (91%)
>
> diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
> index 9ad9210d70a1..f699a3624ae7 100644
> --- a/lib/Kconfig.debug
> +++ b/lib/Kconfig.debug
> @@ -2078,18 +2078,6 @@ config TEST_VMALLOC
>
> If unsure, say N.
>
> -config TEST_USER_COPY
> - tristate "Test user/kernel boundary protections"
> - depends on m
> - help
> - This builds the "test_user_copy" module that runs sanity checks
> - on the copy_to/from_user infrastructure, making sure basic
> - user/kernel boundary testing is working. If it fails to load,
> - a regression has been detected in the user/kernel memory boundary
> - protections.
> -
> - If unsure, say N.
> -
> config TEST_BPF
> tristate "Test BPF filter functionality"
> depends on m && NET
> @@ -2154,6 +2142,22 @@ config SYSCTL_KUNIT_TEST
>
> If unsure, say N.
>
> +config USER_COPY_KUNIT
> + tristate "KUnit Test for user/kernel boundary protections"
> + depends on KUNIT
> + depends on m
> + help
> + This builds the "user_copy_kunit" module that runs sanity checks
> + on the copy_to/from_user infrastructure, making sure basic
> + user/kernel boundary testing is working. If it fails to load,
> + a regression has been detected in the user/kernel memory boundary
> + protections.
> +
> + For more information on KUnit and unit tests in general please refer
> + to the KUnit documentation in Documentation/dev-tools/kunit/.
> +
> + If unsure, say N.
> +
> config LIST_KUNIT_TEST
> tristate "KUnit Test for Kernel Linked-list structures" if !KUNIT_ALL_TESTS
> depends on KUNIT
> diff --git a/lib/Makefile b/lib/Makefile
> index b1c42c10073b..8c145f85accc 100644
> --- a/lib/Makefile
> +++ b/lib/Makefile
> @@ -78,7 +78,6 @@ obj-$(CONFIG_TEST_VMALLOC) += test_vmalloc.o
> obj-$(CONFIG_TEST_OVERFLOW) += test_overflow.o
> obj-$(CONFIG_TEST_RHASHTABLE) += test_rhashtable.o
> obj-$(CONFIG_TEST_SORT) += test_sort.o
> -obj-$(CONFIG_TEST_USER_COPY) += test_user_copy.o
> obj-$(CONFIG_TEST_STATIC_KEYS) += test_static_keys.o
> obj-$(CONFIG_TEST_STATIC_KEYS) += test_static_key_base.o
> obj-$(CONFIG_TEST_PRINTF) += test_printf.o
> @@ -318,3 +317,4 @@ obj-$(CONFIG_OBJAGG) += objagg.o
> # KUnit tests
> obj-$(CONFIG_LIST_KUNIT_TEST) += list-test.o
> obj-$(CONFIG_LINEAR_RANGES_TEST) += test_linear_ranges.o
> +obj-$(CONFIG_USER_COPY_KUNIT) += user_copy_kunit.o
> diff --git a/lib/test_user_copy.c b/lib/user_copy_kunit.c
> similarity index 91%
> rename from lib/test_user_copy.c
> rename to lib/user_copy_kunit.c
> index 5ff04d8fe971..a10ddd15b4cd 100644
> --- a/lib/test_user_copy.c
> +++ b/lib/user_copy_kunit.c
> @@ -16,6 +16,7 @@
> #include <linux/slab.h>
> #include <linux/uaccess.h>
> #include <linux/vmalloc.h>
> +#include <kunit/test.h>
>
> /*
> * Several 32-bit architectures support 64-bit {get,put}_user() calls.
> @@ -35,7 +36,7 @@
> ({ \
> int cond = (condition); \
> if (cond) \
> - pr_warn("[%d] " msg "\n", __LINE__, ##__VA_ARGS__); \
> + KUNIT_EXPECT_FALSE_MSG(test, cond, msg, ##__VA_ARGS__); \
I'm surprised any of this compiles with both a macro and arg named
"test". :) Can you change the arg to something with more clarity?
"context" or "kunit" seems better.
> cond; \
> })
>
> @@ -44,7 +45,7 @@ static bool is_zeroed(void *from, size_t size)
> return memchr_inv(from, 0x0, size) == NULL;
> }
>
> -static int test_check_nonzero_user(char *kmem, char __user *umem, size_t size)
> +static int test_check_nonzero_user(struct kunit *test, char *kmem, char __user *umem, size_t size)
> {
> int ret = 0;
> size_t start, end, i, zero_start, zero_end;
> @@ -102,7 +103,7 @@ static int test_check_nonzero_user(char *kmem, char __user *umem, size_t size)
> return ret;
> }
>
> -static int test_copy_struct_from_user(char *kmem, char __user *umem,
> +static int test_copy_struct_from_user(struct kunit *test, char *kmem, char __user *umem,
> size_t size)
> {
> int ret = 0;
> @@ -177,7 +178,7 @@ static int test_copy_struct_from_user(char *kmem, char __user *umem,
> return ret;
> }
>
> -static int __init test_user_copy_init(void)
> +static void user_copy_test(struct kunit *test)
> {
> int ret = 0;
> char *kmem;
> @@ -192,16 +193,14 @@ static int __init test_user_copy_init(void)
> #endif
>
> kmem = kmalloc(PAGE_SIZE * 2, GFP_KERNEL);
> - if (!kmem)
> - return -ENOMEM;
> + KUNIT_EXPECT_FALSE_MSG(test, kmem == NULL, "kmalloc failed");
This would need to be an ASSERT, yes?
>
> user_addr = vm_mmap(NULL, 0, PAGE_SIZE * 2,
> PROT_READ | PROT_WRITE | PROT_EXEC,
> MAP_ANONYMOUS | MAP_PRIVATE, 0);
> if (user_addr >= (unsigned long)(TASK_SIZE)) {
> - pr_warn("Failed to allocate user memory\n");
> kfree(kmem);
> - return -ENOMEM;
> + KUNIT_FAIL(test, "Failed to allocate user memory");
> }
Why FAIL instead of ASSERT?
>
> usermem = (char __user *)user_addr;
> @@ -245,9 +244,9 @@ static int __init test_user_copy_init(void)
> #undef test_legit
>
> /* Test usage of check_nonzero_user(). */
> - ret |= test_check_nonzero_user(kmem, usermem, 2 * PAGE_SIZE);
> + ret |= test_check_nonzero_user(test, kmem, usermem, 2 * PAGE_SIZE);
> /* Test usage of copy_struct_from_user(). */
> - ret |= test_copy_struct_from_user(kmem, usermem, 2 * PAGE_SIZE);
> + ret |= test_copy_struct_from_user(test, kmem, usermem, 2 * PAGE_SIZE);
>
> /*
> * Invalid usage: none of these copies should succeed.
> @@ -309,23 +308,18 @@ static int __init test_user_copy_init(void)
>
> vm_munmap(user_addr, PAGE_SIZE * 2);
> kfree(kmem);
> -
> - if (ret == 0) {
> - pr_info("tests passed.\n");
> - return 0;
> - }
> -
> - return -EINVAL;
Does KUnit provide a end-of-test summary now?
> }
>
> -module_init(test_user_copy_init);
> -
> -static void __exit test_user_copy_exit(void)
> -{
> - pr_info("unloaded.\n");
> -}
> +static struct kunit_case user_copy_test_cases[] = {
> + KUNIT_CASE(user_copy_test),
> + {}
> +};
>
> -module_exit(test_user_copy_exit);
> +static struct kunit_suite user_copy_test_suite = {
> + .name = "user_copy",
> + .test_cases = user_copy_test_cases,
> +};
>
> +kunit_test_suites(&user_copy_test_suite);
> MODULE_AUTHOR("Kees Cook <keescook@...omium.org>");
> MODULE_LICENSE("GPL");
>
> base-commit: d43c7fb05765152d4d4a39a8ef957c4ea14d8847
> --
> 2.26.2
>
Otherwise, yes, looking good.
--
Kees Cook
Powered by blists - more mailing lists