| Message ID | 20240519191254.651865-2-keescook@chromium.org |
|---|---|
| State | New |
| Headers | show |
| Series | usercopy: Convert test_user_copy to KUnit test | expand |
On Mon, 20 May 2024 at 03:12, Kees Cook <keescook@chromium.org> wrote: > > Convert the runtime tests of hardened usercopy to standard KUnit tests. > > Co-developed-by: Vitor Massaru Iha <vitor@massaru.org> > Signed-off-by: Vitor Massaru Iha <vitor@massaru.org> > Link: https://lore.kernel.org/r/20200721174654.72132-1-vitor@massaru.org > Signed-off-by: Kees Cook <keescook@chromium.org> > --- This fails here on i386: > # usercopy_test_invalid: EXPECTATION FAILED at lib/usercopy_kunit.c:278 > Expected val_u64 == 0, but > val_u64 == -60129542144 (0xfffffff200000000) It also seems to be hanging somewhere in usercopy_test_invalid on my m68k/qemu setup: ./tools/testing/kunit/kunit.py run --build_dir=.kunit-m68k --arch m68k usercopy Otherwise, it looks fine. Maybe it'd make sense to split some of the tests up a bit more, but it's a matter of taste (and only really an advantage for debugging hangs where more detailed progress is nice). With those architecture-specific hangs either fixed, or documented (if they're actual problems, not issues with the test), this is: Reviewed-by: David Gow <davidgow@google.com> Cheers, -- David > MAINTAINERS | 1 + > lib/Kconfig.debug | 21 +- > lib/Makefile | 2 +- > lib/{test_user_copy.c => usercopy_kunit.c} | 252 ++++++++++----------- > 4 files changed, 133 insertions(+), 143 deletions(-) > rename lib/{test_user_copy.c => usercopy_kunit.c} (52%) > > diff --git a/MAINTAINERS b/MAINTAINERS > index 7c121493f43d..73995b807e5a 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -11761,6 +11761,7 @@ F: arch/*/configs/hardening.config > F: include/linux/overflow.h > F: include/linux/randomize_kstack.h > F: kernel/configs/hardening.config > +F: lib/usercopy_kunit.c > F: mm/usercopy.c > K: \b(add|choose)_random_kstack_offset\b > K: \b__check_(object_size|heap_object)\b > diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug > index c63a5fbf1f1c..fd974480aa45 100644 > --- a/lib/Kconfig.debug > +++ b/lib/Kconfig.debug > @@ -2460,18 +2460,6 @@ 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 > @@ -2779,6 +2767,15 @@ config SIPHASH_KUNIT_TEST > This is intended to help people writing architecture-specific > optimized versions. If unsure, say N. > > +config USERCOPY_KUNIT_TEST > + tristate "KUnit Test for user/kernel boundary protections" > + depends on KUNIT > + default KUNIT_ALL_TESTS > + help > + This builds the "usercopy_kunit" module that runs sanity checks > + on the copy_to/from_user infrastructure, making sure basic > + user/kernel boundary testing is working. > + FYI: Checkpatch is whinging that this help text isn't detailed enough. (I'm not sure what else you could add, though...) > config TEST_UDELAY > tristate "udelay test driver" > help > diff --git a/lib/Makefile b/lib/Makefile > index ffc6b2341b45..6287bd6be5d7 100644 > --- a/lib/Makefile > +++ b/lib/Makefile > @@ -78,7 +78,6 @@ obj-$(CONFIG_TEST_LKM) += test_module.o > obj-$(CONFIG_TEST_VMALLOC) += test_vmalloc.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_DYNAMIC_DEBUG) += test_dynamic_debug.o > @@ -406,6 +405,7 @@ obj-$(CONFIG_FORTIFY_KUNIT_TEST) += fortify_kunit.o > obj-$(CONFIG_STRCAT_KUNIT_TEST) += strcat_kunit.o > obj-$(CONFIG_STRSCPY_KUNIT_TEST) += strscpy_kunit.o > obj-$(CONFIG_SIPHASH_KUNIT_TEST) += siphash_kunit.o > +obj-$(CONFIG_USERCOPY_KUNIT_TEST) += usercopy_kunit.o > > obj-$(CONFIG_GENERIC_LIB_DEVMEM_IS_ALLOWED) += devmem_is_allowed.o > > diff --git a/lib/test_user_copy.c b/lib/usercopy_kunit.c > similarity index 52% > rename from lib/test_user_copy.c > rename to lib/usercopy_kunit.c > index 5ff04d8fe971..515df08b3190 100644 > --- a/lib/test_user_copy.c > +++ b/lib/usercopy_kunit.c > @@ -15,7 +15,7 @@ > #include <linux/sched.h> > #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. > @@ -31,11 +31,17 @@ > # define TEST_U64 > #endif > > +struct usercopy_test_priv { > + char *kmem; > + char __user *umem; > + size_t size; > +}; > + > #define test(condition, msg, ...) \ > ({ \ > int cond = (condition); \ > if (cond) \ > - pr_warn("[%d] " msg "\n", __LINE__, ##__VA_ARGS__); \ > + KUNIT_EXPECT_FALSE_MSG(test, cond, msg, ##__VA_ARGS__); \ > cond; \ > }) > > @@ -44,13 +50,16 @@ 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) > +/* Test usage of check_nonzero_user(). */ > +static void usercopy_test_check_nonzero_user(struct kunit *test) > { > - int ret = 0; > size_t start, end, i, zero_start, zero_end; > + struct usercopy_test_priv *priv = test->priv; > + char __user *umem = priv->umem; > + char *kmem = priv->kmem; > + size_t size = priv->size; > > - if (test(size < 2 * PAGE_SIZE, "buffer too small")) > - return -EINVAL; > + KUNIT_ASSERT_GE_MSG(test, size, 2 * PAGE_SIZE, "buffer too small"); > > /* > * We want to cross a page boundary to exercise the code more > @@ -84,8 +93,8 @@ static int test_check_nonzero_user(char *kmem, char __user *umem, size_t size) > for (i = zero_end; i < size; i += 2) > kmem[i] = 0xff; > > - ret |= test(copy_to_user(umem, kmem, size), > - "legitimate copy_to_user failed"); > + KUNIT_EXPECT_EQ_MSG(test, copy_to_user(umem, kmem, size), 0, > + "legitimate copy_to_user failed"); > > for (start = 0; start <= size; start++) { > for (end = start; end <= size; end++) { > @@ -93,35 +102,32 @@ static int test_check_nonzero_user(char *kmem, char __user *umem, size_t size) > int retval = check_zeroed_user(umem + start, len); > int expected = is_zeroed(kmem + start, len); > > - ret |= test(retval != expected, > - "check_nonzero_user(=%d) != memchr_inv(=%d) mismatch (start=%zu, end=%zu)", > - retval, expected, start, end); > + KUNIT_EXPECT_EQ_MSG(test, retval, expected, > + "check_nonzero_user(=%d) != memchr_inv(=%d) mismatch (start=%zu, end=%zu)", > + retval, expected, start, end); > } > } > - > - return ret; > } > > -static int test_copy_struct_from_user(char *kmem, char __user *umem, > - size_t size) > +/* Test usage of copy_struct_from_user(). */ > +static void usercopy_test_copy_struct_from_user(struct kunit *test) > { > - int ret = 0; > char *umem_src = NULL, *expected = NULL; > + struct usercopy_test_priv *priv = test->priv; > + char __user *umem = priv->umem; > + char *kmem = priv->kmem; > + size_t size = priv->size; > size_t ksize, usize; > > - umem_src = kmalloc(size, GFP_KERNEL); > - ret = test(umem_src == NULL, "kmalloc failed"); > - if (ret) > - goto out_free; > + umem_src = kunit_kmalloc(test, size, GFP_KERNEL); > + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, umem_src); > > - expected = kmalloc(size, GFP_KERNEL); > - ret = test(expected == NULL, "kmalloc failed"); > - if (ret) > - goto out_free; > + expected = kunit_kmalloc(test, size, GFP_KERNEL); > + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, expected); > > /* Fill umem with a fixed byte pattern. */ > memset(umem_src, 0x3e, size); > - ret |= test(copy_to_user(umem, umem_src, size), > + KUNIT_ASSERT_EQ_MSG(test, copy_to_user(umem, umem_src, size), 0, > "legitimate copy_to_user failed"); > > /* Check basic case -- (usize == ksize). */ > @@ -131,9 +137,9 @@ static int test_copy_struct_from_user(char *kmem, char __user *umem, > memcpy(expected, umem_src, ksize); > > memset(kmem, 0x0, size); > - ret |= test(copy_struct_from_user(kmem, ksize, umem, usize), > + KUNIT_EXPECT_EQ_MSG(test, copy_struct_from_user(kmem, ksize, umem, usize), 0, > "copy_struct_from_user(usize == ksize) failed"); > - ret |= test(memcmp(kmem, expected, ksize), > + KUNIT_EXPECT_EQ_MSG(test, memcmp(kmem, expected, ksize), 0, > "copy_struct_from_user(usize == ksize) gives unexpected copy"); > > /* Old userspace case -- (usize < ksize). */ > @@ -144,9 +150,9 @@ static int test_copy_struct_from_user(char *kmem, char __user *umem, > memset(expected + usize, 0x0, ksize - usize); > > memset(kmem, 0x0, size); > - ret |= test(copy_struct_from_user(kmem, ksize, umem, usize), > + KUNIT_EXPECT_EQ_MSG(test, copy_struct_from_user(kmem, ksize, umem, usize), 0, > "copy_struct_from_user(usize < ksize) failed"); > - ret |= test(memcmp(kmem, expected, ksize), > + KUNIT_EXPECT_EQ_MSG(test, memcmp(kmem, expected, ksize), 0, > "copy_struct_from_user(usize < ksize) gives unexpected copy"); > > /* New userspace (-E2BIG) case -- (usize > ksize). */ > @@ -154,7 +160,7 @@ static int test_copy_struct_from_user(char *kmem, char __user *umem, > usize = size; > > memset(kmem, 0x0, size); > - ret |= test(copy_struct_from_user(kmem, ksize, umem, usize) != -E2BIG, > + KUNIT_EXPECT_EQ_MSG(test, copy_struct_from_user(kmem, ksize, umem, usize), -E2BIG, > "copy_struct_from_user(usize > ksize) didn't give E2BIG"); > > /* New userspace (success) case -- (usize > ksize). */ > @@ -162,78 +168,46 @@ static int test_copy_struct_from_user(char *kmem, char __user *umem, > usize = size; > > memcpy(expected, umem_src, ksize); > - ret |= test(clear_user(umem + ksize, usize - ksize), > + KUNIT_EXPECT_EQ_MSG(test, clear_user(umem + ksize, usize - ksize), 0, > "legitimate clear_user failed"); > > memset(kmem, 0x0, size); > - ret |= test(copy_struct_from_user(kmem, ksize, umem, usize), > + KUNIT_EXPECT_EQ_MSG(test, copy_struct_from_user(kmem, ksize, umem, usize), 0, > "copy_struct_from_user(usize > ksize) failed"); > - ret |= test(memcmp(kmem, expected, ksize), > + KUNIT_EXPECT_EQ_MSG(test, memcmp(kmem, expected, ksize), 0, > "copy_struct_from_user(usize > ksize) gives unexpected copy"); > - > -out_free: > - kfree(expected); > - kfree(umem_src); > - return ret; > } > > -static int __init test_user_copy_init(void) > +/* > + * Legitimate usage: none of these copies should fail. > + */ > +static void usercopy_test_valid(struct kunit *test) > { > - int ret = 0; > - char *kmem; > - char __user *usermem; > - char *bad_usermem; > - unsigned long user_addr; > - u8 val_u8; > - u16 val_u16; > - u32 val_u32; > -#ifdef TEST_U64 > - u64 val_u64; > -#endif > - > - kmem = kmalloc(PAGE_SIZE * 2, GFP_KERNEL); > - if (!kmem) > - return -ENOMEM; > - > - 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; > - } > + struct usercopy_test_priv *priv = test->priv; > + char __user *usermem = priv->umem; > + char *kmem = priv->kmem; > > - usermem = (char __user *)user_addr; > - bad_usermem = (char *)user_addr; > - > - /* > - * Legitimate usage: none of these copies should fail. > - */ > memset(kmem, 0x3a, PAGE_SIZE * 2); > - ret |= test(copy_to_user(usermem, kmem, PAGE_SIZE), > - "legitimate copy_to_user failed"); > + KUNIT_EXPECT_EQ_MSG(test, 0, copy_to_user(usermem, kmem, PAGE_SIZE), > + "legitimate copy_to_user failed"); > memset(kmem, 0x0, PAGE_SIZE); > - ret |= test(copy_from_user(kmem, usermem, PAGE_SIZE), > - "legitimate copy_from_user failed"); > - ret |= test(memcmp(kmem, kmem + PAGE_SIZE, PAGE_SIZE), > - "legitimate usercopy failed to copy data"); > - > -#define test_legit(size, check) \ > - do { \ > - val_##size = check; \ > - ret |= test(put_user(val_##size, (size __user *)usermem), \ > - "legitimate put_user (" #size ") failed"); \ > - val_##size = 0; \ > - ret |= test(get_user(val_##size, (size __user *)usermem), \ > - "legitimate get_user (" #size ") failed"); \ > - ret |= test(val_##size != check, \ > - "legitimate get_user (" #size ") failed to do copy"); \ > - if (val_##size != check) { \ > - pr_info("0x%llx != 0x%llx\n", \ > - (unsigned long long)val_##size, \ > - (unsigned long long)check); \ > - } \ > + KUNIT_EXPECT_EQ_MSG(test, 0, copy_from_user(kmem, usermem, PAGE_SIZE), > + "legitimate copy_from_user failed"); > + KUNIT_EXPECT_EQ_MSG(test, 0, memcmp(kmem, kmem + PAGE_SIZE, PAGE_SIZE), > + "legitimate usercopy failed to copy data"); > + > +#define test_legit(size, check) \ > + do { \ > + size val_##size = (check); \ > + KUNIT_EXPECT_EQ_MSG(test, 0, \ > + put_user(val_##size, (size __user *)usermem), \ > + "legitimate put_user (" #size ") failed"); \ > + val_##size = 0; \ > + KUNIT_EXPECT_EQ_MSG(test, 0, \ > + get_user(val_##size, (size __user *)usermem), \ > + "legitimate get_user (" #size ") failed"); \ > + KUNIT_EXPECT_EQ_MSG(test, val_##size, check, \ > + "legitimate get_user (" #size ") failed to do copy"); \ > } while (0) > > test_legit(u8, 0x5a); > @@ -243,27 +217,29 @@ static int __init test_user_copy_init(void) > test_legit(u64, 0x5a5b5c5d6a6b6c6d); > #endif > #undef test_legit > +} > > - /* Test usage of check_nonzero_user(). */ > - ret |= test_check_nonzero_user(kmem, usermem, 2 * PAGE_SIZE); > - /* Test usage of copy_struct_from_user(). */ > - ret |= test_copy_struct_from_user(kmem, usermem, 2 * PAGE_SIZE); > - > - /* > - * Invalid usage: none of these copies should succeed. > - */ > +/* > + * Invalid usage: none of these copies should succeed. > + */ > +static void usercopy_test_invalid(struct kunit *test) > +{ > + struct usercopy_test_priv *priv = test->priv; > + char __user *usermem = priv->umem; > + char *bad_usermem = (char *)usermem; > + char *kmem = priv->kmem; > > /* Prepare kernel memory with check values. */ > memset(kmem, 0x5a, PAGE_SIZE); > memset(kmem + PAGE_SIZE, 0, PAGE_SIZE); > > /* Reject kernel-to-kernel copies through copy_from_user(). */ > - ret |= test(!copy_from_user(kmem, (char __user *)(kmem + PAGE_SIZE), > - PAGE_SIZE), > + KUNIT_EXPECT_NE_MSG(test, copy_from_user(kmem, (char __user *)(kmem + PAGE_SIZE), > + PAGE_SIZE), 0, > "illegal all-kernel copy_from_user passed"); > > /* Destination half of buffer should have been zeroed. */ > - ret |= test(memcmp(kmem + PAGE_SIZE, kmem, PAGE_SIZE), > + KUNIT_EXPECT_EQ_MSG(test, memcmp(kmem + PAGE_SIZE, kmem, PAGE_SIZE), 0, > "zeroing failure for illegal all-kernel copy_from_user"); > > #if 0 > @@ -273,29 +249,25 @@ static int __init test_user_copy_init(void) > * to be tested in LKDTM instead, since this test module does not > * expect to explode. > */ > - ret |= test(!copy_from_user(bad_usermem, (char __user *)kmem, > - PAGE_SIZE), > + KUNIT_EXPECT_NE_MSG(test, copy_from_user(bad_usermem, (char __user *)kmem, > + PAGE_SIZE), 0, > "illegal reversed copy_from_user passed"); > #endif > - ret |= test(!copy_to_user((char __user *)kmem, kmem + PAGE_SIZE, > - PAGE_SIZE), > + KUNIT_EXPECT_NE_MSG(test, copy_to_user((char __user *)kmem, kmem + PAGE_SIZE, > + PAGE_SIZE), 0, > "illegal all-kernel copy_to_user passed"); > - ret |= test(!copy_to_user((char __user *)kmem, bad_usermem, > - PAGE_SIZE), > + KUNIT_EXPECT_NE_MSG(test, copy_to_user((char __user *)kmem, bad_usermem, > + PAGE_SIZE), 0, > "illegal reversed copy_to_user passed"); > > #define test_illegal(size, check) \ > do { \ > - val_##size = (check); \ > - ret |= test(!get_user(val_##size, (size __user *)kmem), \ > + size val_##size = (check); \ > + KUNIT_EXPECT_NE_MSG(test, get_user(val_##size, (size __user *)kmem), 0, \ > "illegal get_user (" #size ") passed"); \ > - ret |= test(val_##size != (size)0, \ > + KUNIT_EXPECT_EQ_MSG(test, val_##size, 0, \ > "zeroing failure for illegal get_user (" #size ")"); \ > - if (val_##size != (size)0) { \ > - pr_info("0x%llx != 0\n", \ > - (unsigned long long)val_##size); \ > - } \ > - ret |= test(!put_user(val_##size, (size __user *)kmem), \ > + KUNIT_EXPECT_NE_MSG(test, put_user(val_##size, (size __user *)kmem), 0, \ > "illegal put_user (" #size ") passed"); \ > } while (0) > > @@ -306,26 +278,46 @@ static int __init test_user_copy_init(void) > test_illegal(u64, 0x5a5b5c5d6a6b6c6d); > #endif > #undef test_illegal > +} > > - vm_munmap(user_addr, PAGE_SIZE * 2); > - kfree(kmem); > +static int usercopy_test_init(struct kunit *test) > +{ > + struct usercopy_test_priv *priv; > + unsigned long user_addr; > > - if (ret == 0) { > - pr_info("tests passed.\n"); > - return 0; > - } > + priv = kunit_kzalloc(test, sizeof(*priv), GFP_KERNEL); > + if (!priv) > + return -ENOMEM; > + test->priv = priv; > + priv->size = PAGE_SIZE * 2; > > - return -EINVAL; > -} > + priv->kmem = kunit_kmalloc(test, priv->size, GFP_KERNEL); > + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, priv->kmem); > > -module_init(test_user_copy_init); > + user_addr = kunit_vm_mmap(test, NULL, 0, priv->size, > + PROT_READ | PROT_WRITE | PROT_EXEC, > + MAP_ANONYMOUS | MAP_PRIVATE, 0); > + KUNIT_ASSERT_LT_MSG(test, user_addr, (unsigned long)TASK_SIZE, > + "Failed to allocate user memory"); > + priv->umem = (char __user *)user_addr; > > -static void __exit test_user_copy_exit(void) > -{ > - pr_info("unloaded.\n"); > + return 0; > } > > -module_exit(test_user_copy_exit); > - > +static struct kunit_case usercopy_test_cases[] = { > + KUNIT_CASE(usercopy_test_valid), > + KUNIT_CASE(usercopy_test_invalid), > + KUNIT_CASE(usercopy_test_check_nonzero_user), > + KUNIT_CASE(usercopy_test_copy_struct_from_user), > + {} > +}; > + > +static struct kunit_suite usercopy_test_suite = { > + .name = "usercopy", > + .init = usercopy_test_init, > + .test_cases = usercopy_test_cases, > +}; > + > +kunit_test_suites(&usercopy_test_suite); > MODULE_AUTHOR("Kees Cook <keescook@chromium.org>"); > MODULE_LICENSE("GPL"); > -- > 2.34.1 >
On Wed, May 29, 2024 at 01:17:35PM +0100, Ivan Orlov wrote: > On 5/19/24 20:12, Kees Cook wrote: > > #define test(condition, msg, ...) \ > > ({ \ > > int cond = (condition); \ > > if (cond) \ > > - pr_warn("[%d] " msg "\n", __LINE__, ##__VA_ARGS__); \ > > + KUNIT_EXPECT_FALSE_MSG(test, cond, msg, ##__VA_ARGS__); \ > > cond; \ > > }) > It looks like the 'test' macro is not used anymore, so probably it should be > removed. Oops, yes. Thanks! > > +static int usercopy_test_init(struct kunit *test) > > +{ > > + struct usercopy_test_priv *priv; > > + unsigned long user_addr; > > - if (ret == 0) { > > - pr_info("tests passed.\n"); > > - return 0; > > - } > > + priv = kunit_kzalloc(test, sizeof(*priv), GFP_KERNEL); > > + if (!priv) > > + return -ENOMEM; > > Should the check be done with KUNIT_ASSERT_NOT_ERR_OR_NULL here as well, as > it is done with priv->kmem? Yes, that's much more idiomatic. I'll adjust this too. > Other than that, > > Tested-by: Ivan Orlov <ivan.orlov0322@gmail.com> Thanks!
On Sat, Jun 08, 2024 at 04:44:10PM +0800, David Gow wrote: > On Mon, 20 May 2024 at 03:12, Kees Cook <keescook@chromium.org> wrote: > > > > Convert the runtime tests of hardened usercopy to standard KUnit tests. > > > > Co-developed-by: Vitor Massaru Iha <vitor@massaru.org> > > Signed-off-by: Vitor Massaru Iha <vitor@massaru.org> > > Link: https://lore.kernel.org/r/20200721174654.72132-1-vitor@massaru.org > > Signed-off-by: Kees Cook <keescook@chromium.org> > > --- > > This fails here on i386: > > # usercopy_test_invalid: EXPECTATION FAILED at lib/usercopy_kunit.c:278 > > Expected val_u64 == 0, but > > val_u64 == -60129542144 (0xfffffff200000000) Hunh. I can reproduce this with "--arch=i386" but not under UML with SUBARCH=i386. But perhaps it's a difference in the get_user() implementations between the two. And this looks like a bug in the get_user() failure path on i386. I will investigate... > It also seems to be hanging somewhere in usercopy_test_invalid on my > m68k/qemu setup: > ./tools/testing/kunit/kunit.py run --build_dir=.kunit-m68k --arch m68k usercopy Oh, that's weird. I'll need to get an m68k environment set up... > Otherwise, it looks fine. Maybe it'd make sense to split some of the > tests up a bit more, but it's a matter of taste (and only really an > advantage for debugging hangs where more detailed progress is nice). Yeah. I can do this in follow-up patches, perhaps. > With those architecture-specific hangs either fixed, or documented (if > they're actual problems, not issues with the test), this is: > > Reviewed-by: David Gow <davidgow@google.com> Thanks!
diff --git a/MAINTAINERS b/MAINTAINERS index 7c121493f43d..73995b807e5a 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -11761,6 +11761,7 @@ F: arch/*/configs/hardening.config F: include/linux/overflow.h F: include/linux/randomize_kstack.h F: kernel/configs/hardening.config +F: lib/usercopy_kunit.c F: mm/usercopy.c K: \b(add|choose)_random_kstack_offset\b K: \b__check_(object_size|heap_object)\b diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index c63a5fbf1f1c..fd974480aa45 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -2460,18 +2460,6 @@ 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 @@ -2779,6 +2767,15 @@ config SIPHASH_KUNIT_TEST This is intended to help people writing architecture-specific optimized versions. If unsure, say N. +config USERCOPY_KUNIT_TEST + tristate "KUnit Test for user/kernel boundary protections" + depends on KUNIT + default KUNIT_ALL_TESTS + help + This builds the "usercopy_kunit" module that runs sanity checks + on the copy_to/from_user infrastructure, making sure basic + user/kernel boundary testing is working. + config TEST_UDELAY tristate "udelay test driver" help diff --git a/lib/Makefile b/lib/Makefile index ffc6b2341b45..6287bd6be5d7 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -78,7 +78,6 @@ obj-$(CONFIG_TEST_LKM) += test_module.o obj-$(CONFIG_TEST_VMALLOC) += test_vmalloc.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_DYNAMIC_DEBUG) += test_dynamic_debug.o @@ -406,6 +405,7 @@ obj-$(CONFIG_FORTIFY_KUNIT_TEST) += fortify_kunit.o obj-$(CONFIG_STRCAT_KUNIT_TEST) += strcat_kunit.o obj-$(CONFIG_STRSCPY_KUNIT_TEST) += strscpy_kunit.o obj-$(CONFIG_SIPHASH_KUNIT_TEST) += siphash_kunit.o +obj-$(CONFIG_USERCOPY_KUNIT_TEST) += usercopy_kunit.o obj-$(CONFIG_GENERIC_LIB_DEVMEM_IS_ALLOWED) += devmem_is_allowed.o diff --git a/lib/test_user_copy.c b/lib/usercopy_kunit.c similarity index 52% rename from lib/test_user_copy.c rename to lib/usercopy_kunit.c index 5ff04d8fe971..515df08b3190 100644 --- a/lib/test_user_copy.c +++ b/lib/usercopy_kunit.c @@ -15,7 +15,7 @@ #include <linux/sched.h> #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. @@ -31,11 +31,17 @@ # define TEST_U64 #endif +struct usercopy_test_priv { + char *kmem; + char __user *umem; + size_t size; +}; + #define test(condition, msg, ...) \ ({ \ int cond = (condition); \ if (cond) \ - pr_warn("[%d] " msg "\n", __LINE__, ##__VA_ARGS__); \ + KUNIT_EXPECT_FALSE_MSG(test, cond, msg, ##__VA_ARGS__); \ cond; \ }) @@ -44,13 +50,16 @@ 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) +/* Test usage of check_nonzero_user(). */ +static void usercopy_test_check_nonzero_user(struct kunit *test) { - int ret = 0; size_t start, end, i, zero_start, zero_end; + struct usercopy_test_priv *priv = test->priv; + char __user *umem = priv->umem; + char *kmem = priv->kmem; + size_t size = priv->size; - if (test(size < 2 * PAGE_SIZE, "buffer too small")) - return -EINVAL; + KUNIT_ASSERT_GE_MSG(test, size, 2 * PAGE_SIZE, "buffer too small"); /* * We want to cross a page boundary to exercise the code more @@ -84,8 +93,8 @@ static int test_check_nonzero_user(char *kmem, char __user *umem, size_t size) for (i = zero_end; i < size; i += 2) kmem[i] = 0xff; - ret |= test(copy_to_user(umem, kmem, size), - "legitimate copy_to_user failed"); + KUNIT_EXPECT_EQ_MSG(test, copy_to_user(umem, kmem, size), 0, + "legitimate copy_to_user failed"); for (start = 0; start <= size; start++) { for (end = start; end <= size; end++) { @@ -93,35 +102,32 @@ static int test_check_nonzero_user(char *kmem, char __user *umem, size_t size) int retval = check_zeroed_user(umem + start, len); int expected = is_zeroed(kmem + start, len); - ret |= test(retval != expected, - "check_nonzero_user(=%d) != memchr_inv(=%d) mismatch (start=%zu, end=%zu)", - retval, expected, start, end); + KUNIT_EXPECT_EQ_MSG(test, retval, expected, + "check_nonzero_user(=%d) != memchr_inv(=%d) mismatch (start=%zu, end=%zu)", + retval, expected, start, end); } } - - return ret; } -static int test_copy_struct_from_user(char *kmem, char __user *umem, - size_t size) +/* Test usage of copy_struct_from_user(). */ +static void usercopy_test_copy_struct_from_user(struct kunit *test) { - int ret = 0; char *umem_src = NULL, *expected = NULL; + struct usercopy_test_priv *priv = test->priv; + char __user *umem = priv->umem; + char *kmem = priv->kmem; + size_t size = priv->size; size_t ksize, usize; - umem_src = kmalloc(size, GFP_KERNEL); - ret = test(umem_src == NULL, "kmalloc failed"); - if (ret) - goto out_free; + umem_src = kunit_kmalloc(test, size, GFP_KERNEL); + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, umem_src); - expected = kmalloc(size, GFP_KERNEL); - ret = test(expected == NULL, "kmalloc failed"); - if (ret) - goto out_free; + expected = kunit_kmalloc(test, size, GFP_KERNEL); + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, expected); /* Fill umem with a fixed byte pattern. */ memset(umem_src, 0x3e, size); - ret |= test(copy_to_user(umem, umem_src, size), + KUNIT_ASSERT_EQ_MSG(test, copy_to_user(umem, umem_src, size), 0, "legitimate copy_to_user failed"); /* Check basic case -- (usize == ksize). */ @@ -131,9 +137,9 @@ static int test_copy_struct_from_user(char *kmem, char __user *umem, memcpy(expected, umem_src, ksize); memset(kmem, 0x0, size); - ret |= test(copy_struct_from_user(kmem, ksize, umem, usize), + KUNIT_EXPECT_EQ_MSG(test, copy_struct_from_user(kmem, ksize, umem, usize), 0, "copy_struct_from_user(usize == ksize) failed"); - ret |= test(memcmp(kmem, expected, ksize), + KUNIT_EXPECT_EQ_MSG(test, memcmp(kmem, expected, ksize), 0, "copy_struct_from_user(usize == ksize) gives unexpected copy"); /* Old userspace case -- (usize < ksize). */ @@ -144,9 +150,9 @@ static int test_copy_struct_from_user(char *kmem, char __user *umem, memset(expected + usize, 0x0, ksize - usize); memset(kmem, 0x0, size); - ret |= test(copy_struct_from_user(kmem, ksize, umem, usize), + KUNIT_EXPECT_EQ_MSG(test, copy_struct_from_user(kmem, ksize, umem, usize), 0, "copy_struct_from_user(usize < ksize) failed"); - ret |= test(memcmp(kmem, expected, ksize), + KUNIT_EXPECT_EQ_MSG(test, memcmp(kmem, expected, ksize), 0, "copy_struct_from_user(usize < ksize) gives unexpected copy"); /* New userspace (-E2BIG) case -- (usize > ksize). */ @@ -154,7 +160,7 @@ static int test_copy_struct_from_user(char *kmem, char __user *umem, usize = size; memset(kmem, 0x0, size); - ret |= test(copy_struct_from_user(kmem, ksize, umem, usize) != -E2BIG, + KUNIT_EXPECT_EQ_MSG(test, copy_struct_from_user(kmem, ksize, umem, usize), -E2BIG, "copy_struct_from_user(usize > ksize) didn't give E2BIG"); /* New userspace (success) case -- (usize > ksize). */ @@ -162,78 +168,46 @@ static int test_copy_struct_from_user(char *kmem, char __user *umem, usize = size; memcpy(expected, umem_src, ksize); - ret |= test(clear_user(umem + ksize, usize - ksize), + KUNIT_EXPECT_EQ_MSG(test, clear_user(umem + ksize, usize - ksize), 0, "legitimate clear_user failed"); memset(kmem, 0x0, size); - ret |= test(copy_struct_from_user(kmem, ksize, umem, usize), + KUNIT_EXPECT_EQ_MSG(test, copy_struct_from_user(kmem, ksize, umem, usize), 0, "copy_struct_from_user(usize > ksize) failed"); - ret |= test(memcmp(kmem, expected, ksize), + KUNIT_EXPECT_EQ_MSG(test, memcmp(kmem, expected, ksize), 0, "copy_struct_from_user(usize > ksize) gives unexpected copy"); - -out_free: - kfree(expected); - kfree(umem_src); - return ret; } -static int __init test_user_copy_init(void) +/* + * Legitimate usage: none of these copies should fail. + */ +static void usercopy_test_valid(struct kunit *test) { - int ret = 0; - char *kmem; - char __user *usermem; - char *bad_usermem; - unsigned long user_addr; - u8 val_u8; - u16 val_u16; - u32 val_u32; -#ifdef TEST_U64 - u64 val_u64; -#endif - - kmem = kmalloc(PAGE_SIZE * 2, GFP_KERNEL); - if (!kmem) - return -ENOMEM; - - 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; - } + struct usercopy_test_priv *priv = test->priv; + char __user *usermem = priv->umem; + char *kmem = priv->kmem; - usermem = (char __user *)user_addr; - bad_usermem = (char *)user_addr; - - /* - * Legitimate usage: none of these copies should fail. - */ memset(kmem, 0x3a, PAGE_SIZE * 2); - ret |= test(copy_to_user(usermem, kmem, PAGE_SIZE), - "legitimate copy_to_user failed"); + KUNIT_EXPECT_EQ_MSG(test, 0, copy_to_user(usermem, kmem, PAGE_SIZE), + "legitimate copy_to_user failed"); memset(kmem, 0x0, PAGE_SIZE); - ret |= test(copy_from_user(kmem, usermem, PAGE_SIZE), - "legitimate copy_from_user failed"); - ret |= test(memcmp(kmem, kmem + PAGE_SIZE, PAGE_SIZE), - "legitimate usercopy failed to copy data"); - -#define test_legit(size, check) \ - do { \ - val_##size = check; \ - ret |= test(put_user(val_##size, (size __user *)usermem), \ - "legitimate put_user (" #size ") failed"); \ - val_##size = 0; \ - ret |= test(get_user(val_##size, (size __user *)usermem), \ - "legitimate get_user (" #size ") failed"); \ - ret |= test(val_##size != check, \ - "legitimate get_user (" #size ") failed to do copy"); \ - if (val_##size != check) { \ - pr_info("0x%llx != 0x%llx\n", \ - (unsigned long long)val_##size, \ - (unsigned long long)check); \ - } \ + KUNIT_EXPECT_EQ_MSG(test, 0, copy_from_user(kmem, usermem, PAGE_SIZE), + "legitimate copy_from_user failed"); + KUNIT_EXPECT_EQ_MSG(test, 0, memcmp(kmem, kmem + PAGE_SIZE, PAGE_SIZE), + "legitimate usercopy failed to copy data"); + +#define test_legit(size, check) \ + do { \ + size val_##size = (check); \ + KUNIT_EXPECT_EQ_MSG(test, 0, \ + put_user(val_##size, (size __user *)usermem), \ + "legitimate put_user (" #size ") failed"); \ + val_##size = 0; \ + KUNIT_EXPECT_EQ_MSG(test, 0, \ + get_user(val_##size, (size __user *)usermem), \ + "legitimate get_user (" #size ") failed"); \ + KUNIT_EXPECT_EQ_MSG(test, val_##size, check, \ + "legitimate get_user (" #size ") failed to do copy"); \ } while (0) test_legit(u8, 0x5a); @@ -243,27 +217,29 @@ static int __init test_user_copy_init(void) test_legit(u64, 0x5a5b5c5d6a6b6c6d); #endif #undef test_legit +} - /* Test usage of check_nonzero_user(). */ - ret |= test_check_nonzero_user(kmem, usermem, 2 * PAGE_SIZE); - /* Test usage of copy_struct_from_user(). */ - ret |= test_copy_struct_from_user(kmem, usermem, 2 * PAGE_SIZE); - - /* - * Invalid usage: none of these copies should succeed. - */ +/* + * Invalid usage: none of these copies should succeed. + */ +static void usercopy_test_invalid(struct kunit *test) +{ + struct usercopy_test_priv *priv = test->priv; + char __user *usermem = priv->umem; + char *bad_usermem = (char *)usermem; + char *kmem = priv->kmem; /* Prepare kernel memory with check values. */ memset(kmem, 0x5a, PAGE_SIZE); memset(kmem + PAGE_SIZE, 0, PAGE_SIZE); /* Reject kernel-to-kernel copies through copy_from_user(). */ - ret |= test(!copy_from_user(kmem, (char __user *)(kmem + PAGE_SIZE), - PAGE_SIZE), + KUNIT_EXPECT_NE_MSG(test, copy_from_user(kmem, (char __user *)(kmem + PAGE_SIZE), + PAGE_SIZE), 0, "illegal all-kernel copy_from_user passed"); /* Destination half of buffer should have been zeroed. */ - ret |= test(memcmp(kmem + PAGE_SIZE, kmem, PAGE_SIZE), + KUNIT_EXPECT_EQ_MSG(test, memcmp(kmem + PAGE_SIZE, kmem, PAGE_SIZE), 0, "zeroing failure for illegal all-kernel copy_from_user"); #if 0 @@ -273,29 +249,25 @@ static int __init test_user_copy_init(void) * to be tested in LKDTM instead, since this test module does not * expect to explode. */ - ret |= test(!copy_from_user(bad_usermem, (char __user *)kmem, - PAGE_SIZE), + KUNIT_EXPECT_NE_MSG(test, copy_from_user(bad_usermem, (char __user *)kmem, + PAGE_SIZE), 0, "illegal reversed copy_from_user passed"); #endif - ret |= test(!copy_to_user((char __user *)kmem, kmem + PAGE_SIZE, - PAGE_SIZE), + KUNIT_EXPECT_NE_MSG(test, copy_to_user((char __user *)kmem, kmem + PAGE_SIZE, + PAGE_SIZE), 0, "illegal all-kernel copy_to_user passed"); - ret |= test(!copy_to_user((char __user *)kmem, bad_usermem, - PAGE_SIZE), + KUNIT_EXPECT_NE_MSG(test, copy_to_user((char __user *)kmem, bad_usermem, + PAGE_SIZE), 0, "illegal reversed copy_to_user passed"); #define test_illegal(size, check) \ do { \ - val_##size = (check); \ - ret |= test(!get_user(val_##size, (size __user *)kmem), \ + size val_##size = (check); \ + KUNIT_EXPECT_NE_MSG(test, get_user(val_##size, (size __user *)kmem), 0, \ "illegal get_user (" #size ") passed"); \ - ret |= test(val_##size != (size)0, \ + KUNIT_EXPECT_EQ_MSG(test, val_##size, 0, \ "zeroing failure for illegal get_user (" #size ")"); \ - if (val_##size != (size)0) { \ - pr_info("0x%llx != 0\n", \ - (unsigned long long)val_##size); \ - } \ - ret |= test(!put_user(val_##size, (size __user *)kmem), \ + KUNIT_EXPECT_NE_MSG(test, put_user(val_##size, (size __user *)kmem), 0, \ "illegal put_user (" #size ") passed"); \ } while (0) @@ -306,26 +278,46 @@ static int __init test_user_copy_init(void) test_illegal(u64, 0x5a5b5c5d6a6b6c6d); #endif #undef test_illegal +} - vm_munmap(user_addr, PAGE_SIZE * 2); - kfree(kmem); +static int usercopy_test_init(struct kunit *test) +{ + struct usercopy_test_priv *priv; + unsigned long user_addr; - if (ret == 0) { - pr_info("tests passed.\n"); - return 0; - } + priv = kunit_kzalloc(test, sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + test->priv = priv; + priv->size = PAGE_SIZE * 2; - return -EINVAL; -} + priv->kmem = kunit_kmalloc(test, priv->size, GFP_KERNEL); + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, priv->kmem); -module_init(test_user_copy_init); + user_addr = kunit_vm_mmap(test, NULL, 0, priv->size, + PROT_READ | PROT_WRITE | PROT_EXEC, + MAP_ANONYMOUS | MAP_PRIVATE, 0); + KUNIT_ASSERT_LT_MSG(test, user_addr, (unsigned long)TASK_SIZE, + "Failed to allocate user memory"); + priv->umem = (char __user *)user_addr; -static void __exit test_user_copy_exit(void) -{ - pr_info("unloaded.\n"); + return 0; } -module_exit(test_user_copy_exit); - +static struct kunit_case usercopy_test_cases[] = { + KUNIT_CASE(usercopy_test_valid), + KUNIT_CASE(usercopy_test_invalid), + KUNIT_CASE(usercopy_test_check_nonzero_user), + KUNIT_CASE(usercopy_test_copy_struct_from_user), + {} +}; + +static struct kunit_suite usercopy_test_suite = { + .name = "usercopy", + .init = usercopy_test_init, + .test_cases = usercopy_test_cases, +}; + +kunit_test_suites(&usercopy_test_suite); MODULE_AUTHOR("Kees Cook <keescook@chromium.org>"); MODULE_LICENSE("GPL");