On Tue, 11 Jun 2024 at 05:33, Kees Cook kees@kernel.org wrote:

For tests that need to allocate using vm_mmap() (e.g. usercopy and execve), provide the interface to have the allocation tracked by KUnit itself. This requires bringing up a placeholder userspace mm.

This combines my earlier attempt at this with Mark Rutland's version[1].

Link: https://lore.kernel.org/lkml/20230321122514.1743889-2-mark.rutland@arm.com/ [1] Co-developed-by: Mark Rutland mark.rutland@arm.com Signed-off-by: Mark Rutland mark.rutland@arm.com Signed-off-by: Kees Cook kees@kernel.org

---

Thanks: this looks good to me, at least on the KUnit side of things.

Reviewed-by: David Gow davidgow@google.com

Cheers, -- David

include/kunit/test.h | 17 +++++++ lib/kunit/Makefile | 1 + lib/kunit/user_alloc.c | 111 +++++++++++++++++++++++++++++++++++++++++ 3 files changed, 129 insertions(+) create mode 100644 lib/kunit/user_alloc.c

diff --git a/include/kunit/test.h b/include/kunit/test.h index e32b4cb7afa2..ec61cad6b71d 100644 --- a/include/kunit/test.h +++ b/include/kunit/test.h @@ -480,6 +480,23 @@ static inline void *kunit_kcalloc(struct kunit *test, size_t n, size_t size, gfp return kunit_kmalloc_array(test, n, size, gfp | __GFP_ZERO); }

+/**

• • kunit_vm_mmap() - Allocate KUnit-tracked vm_mmap() area
• • @test: The test context object.
• • @file: struct file pointer to map from, if any
• • @addr: desired address, if any
• • @len: how many bytes to allocate
• • @prot: mmap PROT_* bits
• • @flag: mmap flags
• • @offset: offset into @file to start mapping from.
• • See vm_mmap() for more information.
• */

+unsigned long kunit_vm_mmap(struct kunit *test, struct file *file,

•                       unsigned long addr, unsigned long len,
  

•                       unsigned long prot, unsigned long flag,
  

•                       unsigned long offset);
  

void kunit_cleanup(struct kunit *test);

void __printf(2, 3) kunit_log_append(struct string_stream *log, const char *fmt, ...); diff --git a/lib/kunit/Makefile b/lib/kunit/Makefile index 309659a32a78..56dd67dc6e57 100644 --- a/lib/kunit/Makefile +++ b/lib/kunit/Makefile @@ -2,6 +2,7 @@ obj-$(CONFIG_KUNIT) += kunit.o

kunit-objs += test.o \ resource.o \

•                                   user_alloc.o \
                                    static_stub.o \
                                    string-stream.o \
                                    assert.o \
  

diff --git a/lib/kunit/user_alloc.c b/lib/kunit/user_alloc.c new file mode 100644 index 000000000000..d66f42282f43 --- /dev/null +++ b/lib/kunit/user_alloc.c @@ -0,0 +1,111 @@ +// SPDX-License-Identifier: GPL-2.0 +/*

• • KUnit userspace memory allocation resource management.
• */

+#include <kunit/resource.h> +#include <kunit/test.h> +#include <linux/kthread.h> +#include <linux/mm.h>

+struct kunit_vm_mmap_resource {

•   unsigned long addr;
  

•   size_t size;
  

+};

+/* vm_mmap() arguments */ +struct kunit_vm_mmap_params {

•   struct file *file;
  

•   unsigned long addr;
  

•   unsigned long len;
  

•   unsigned long prot;
  

•   unsigned long flag;
  

•   unsigned long offset;
  

+};

+/* Create and attach a new mm if it doesn't already exist. */ +static int kunit_attach_mm(void) +{

•   struct mm_struct *mm;
  

•   if (current->mm)
  

•           return 0;
  

•   mm = mm_alloc();
  

•   if (!mm)
  

•           return -ENOMEM;
  

•   /* Define the task size. */
  

•   mm->task_size = TASK_SIZE;
  

•   /* Make sure we can allocate new VMAs. */
  

•   arch_pick_mmap_layout(mm, &current->signal->rlim[RLIMIT_STACK]);
  

•   /* Attach the mm. It will be cleaned up when the process dies. */
  

•   kthread_use_mm(mm);
  

•   return 0;
  

+}

+static int kunit_vm_mmap_init(struct kunit_resource *res, void *context) +{

•   struct kunit_vm_mmap_params *p = context;
  

•   struct kunit_vm_mmap_resource vres;
  

•   int ret;
  

•   ret = kunit_attach_mm();
  

•   if (ret)
  

•           return ret;
  

•   vres.size = p->len;
  

•   vres.addr = vm_mmap(p->file, p->addr, p->len, p->prot, p->flag, p->offset);
  

•   if (!vres.addr)
  

•           return -ENOMEM;
  

•   res->data = kmemdup(&vres, sizeof(vres), GFP_KERNEL);
  

•   if (!res->data) {
  

•           vm_munmap(vres.addr, vres.size);
  

•           return -ENOMEM;
  

•   }
  

•   return 0;
  

+}

+static void kunit_vm_mmap_free(struct kunit_resource *res) +{

•   struct kunit_vm_mmap_resource *vres = res->data;
  

•   /*
  

•    * Since this is executed from the test monitoring process,
  

•    * the test's mm has already been torn down. We don't need
  

•    * to run vm_munmap(vres->addr, vres->size), only clean up
  

•    * the vres.
  

•    */
  

•   kfree(vres);
  

•   res->data = NULL;
  

+}

+unsigned long kunit_vm_mmap(struct kunit *test, struct file *file,

•                       unsigned long addr, unsigned long len,
  

•                       unsigned long prot, unsigned long flag,
  

•                       unsigned long offset)
  

+{

•   struct kunit_vm_mmap_params params = {
  

•           .file = file,
  

•           .addr = addr,
  

•           .len = len,
  

•           .prot = prot,
  

•           .flag = flag,
  

•           .offset = offset,
  

•   };
  

•   struct kunit_vm_mmap_resource *vres;
  

•   vres = kunit_alloc_resource(test,
  

•                               kunit_vm_mmap_init,
  

•                               kunit_vm_mmap_free,
  

•                               GFP_KERNEL,
  

•                               &params);
  

•   if (vres)
  

•           return vres->addr;
  

•   return 0;
  

+}

+EXPORT_SYMBOL_GPL(kunit_vm_mmap);

2.34.1

On Tue, 11 Jun 2024 at 05:33, Kees Cook kees@kernel.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 Tested-by: Ivan Orlov ivan.orlov0322@gmail.com Signed-off-by: Kees Cook kees@kernel.org

---

This looks good, particularly with the x86 fix applied.

It's still hanging on m68k -- I think at the 'illegal reversed copy_to_user passed' test -- but I'll admit to not having tried to debug it further.

One other (set of) notes below about using KUNIT_EXPECT_MEMEQ_MSG(), otherwise (assuming the m68k stuff isn't actually a regression, which I haven't tested but I imagine is unlikely),

Reviewed-by: David Gow davidgow@google.com

Thanks, -- David

MAINTAINERS | 1 + lib/Kconfig.debug | 21 +- lib/Makefile | 2 +- lib/{test_user_copy.c => usercopy_kunit.c} | 273 ++++++++++----------- 4 files changed, 142 insertions(+), 155 deletions(-) rename lib/{test_user_copy.c => usercopy_kunit.c} (47%)

diff --git a/MAINTAINERS b/MAINTAINERS index 8754ac2c259d..0cd171ec6010 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -11962,6 +11962,7 @@ 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 59b6765d86b8..561e346f5cb0 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -2505,18 +2505,6 @@ 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 @@ -2814,6 +2802,15 @@ 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 3b1769045651..fae5cc67b95a 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 @@ -388,6 +387,7 @@ CFLAGS_fortify_kunit.o += $(call cc-disable-warning, stringop-truncation) CFLAGS_fortify_kunit.o += $(DISABLE_STRUCTLEAK_PLUGIN) obj-$(CONFIG_FORTIFY_KUNIT_TEST) += fortify_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 47% rename from lib/test_user_copy.c rename to lib/usercopy_kunit.c index 5ff04d8fe971..f1689f2c5c7b 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.

@@ -31,26 +31,27 @@ # define TEST_U64 #endif

-#define test(condition, msg, ...) \ -({ \

•   int cond = (condition);                                         \
  

•   if (cond)                                                       \
  

•           pr_warn("[%d] " msg "\n", __LINE__, ##__VA_ARGS__);     \
  

•   cond;                                                           \
  

-}) +struct usercopy_test_priv {

•   char *kmem;
  

•   char __user *umem;
  

•   size_t size;
  

+};

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 +85,8 @@ 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 +94,32 @@ 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 +129,9 @@ 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");
  

Should we use KUNIT_EXPECT_MEMEQ_MSG() here, rather than memcmp()? That'll print a nice hexdump of the difference.

    /* Old userspace case -- (usize < ksize). */

@@ -144,9 +142,9 @@ 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");
  

Again, can we use KUNIT_EXPECT_MEMEQ_MSG() here, rather than memcmp()?

    /* New userspace (-E2BIG) case -- (usize > ksize). */

@@ -154,7 +152,7 @@ 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 +160,46 @@ 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");
  

Another place to use KUNIT_EXPECT_MEMEQ_MSG()?

-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;
  

•   struct usercopy_test_priv *priv = test->priv;
  

•   char __user *usermem = priv->umem;
  

•   char *kmem = priv->kmem;
  
  

•   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;
  

•   }
  

•   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");
  

KUNIT_EXPECT_MEMEQ_MSG()?

+#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 +209,30 @@ 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;
  

•   u64 *kmem_u64 = (u64 *)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");
  

KUNIT_EXPECT_MEMEQ_MSG()?

#if 0 @@ -273,30 +242,31 @@ 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),     \
  

•               "illegal get_user (" #size ") passed");                 \
  

•           ret |= test(val_##size != (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),     \
  

•               "illegal put_user (" #size ") passed");                 \
  

+#define test_illegal(size, check) \

•   do {                                                                            \
  

•           size val_##size = (check);                                              \
  

•           /* get_user() */                                                        \
  

•           KUNIT_EXPECT_NE_MSG(test, get_user(val_##size, (size __user *)kmem), 0, \
  

•               "illegal get_user (" #size ") passed");                             \
  

•           KUNIT_EXPECT_EQ_MSG(test, val_##size, 0,                                \
  

•               "zeroing failure for illegal get_user (" #size ")");                \
  

•           /* put_user() */                                                        \
  

•           *kmem_u64 = 0xF09FA4AFF09FA4AF;                                         \
  

•           KUNIT_EXPECT_NE_MSG(test, put_user(val_##size, (size __user *)kmem), 0, \
  

•               "illegal put_user (" #size ") passed");                             \
  

•           KUNIT_EXPECT_EQ_MSG(test, *kmem_u64, 0xF09FA4AFF09FA4AF,                \
  

•               "illegal put_user (" #size ") wrote to kernel memory!");            \
    } while (0)
  
    test_illegal(u8,  0x5a);
  

@@ -306,26 +276,45 @@ 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);
  

•   KUNIT_ASSERT_NOT_ERR_OR_NULL(test, priv);
  

•   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);

-MODULE_AUTHOR("Kees Cook keescook@chromium.org"); +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 kees@kernel.org"); MODULE_LICENSE("GPL"); -- 2.34.1