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https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git
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usercopy: Convert test_user_copy to KUnit test
Convert the runtime tests of hardened usercopy to standard KUnit tests. Additionally disable usercopy_test_invalid() for systems with separate address spaces (or no MMU) since it's not sensible to test for address confusion there (e.g. m68k). 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> Reviewed-by: David Gow <davidgow@google.com> Signed-off-by: Kees Cook <kees@kernel.org> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
This commit is contained in:
parent
51104c19d8
commit
cf6219ee88
@ -11962,6 +11962,7 @@ F: arch/*/configs/hardening.config
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F: include/linux/overflow.h
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F: include/linux/randomize_kstack.h
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F: kernel/configs/hardening.config
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F: lib/usercopy_kunit.c
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F: mm/usercopy.c
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K: \b(add|choose)_random_kstack_offset\b
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K: \b__check_(object_size|heap_object)\b
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@ -2505,18 +2505,6 @@ config TEST_VMALLOC
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If unsure, say N.
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config TEST_USER_COPY
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tristate "Test user/kernel boundary protections"
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depends on m
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help
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This builds the "test_user_copy" module that runs sanity checks
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on the copy_to/from_user infrastructure, making sure basic
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user/kernel boundary testing is working. If it fails to load,
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a regression has been detected in the user/kernel memory boundary
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protections.
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If unsure, say N.
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config TEST_BPF
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tristate "Test BPF filter functionality"
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depends on m && NET
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@ -2814,6 +2802,15 @@ config SIPHASH_KUNIT_TEST
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This is intended to help people writing architecture-specific
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optimized versions. If unsure, say N.
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config USERCOPY_KUNIT_TEST
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tristate "KUnit Test for user/kernel boundary protections"
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depends on KUNIT
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default KUNIT_ALL_TESTS
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help
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This builds the "usercopy_kunit" module that runs sanity checks
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on the copy_to/from_user infrastructure, making sure basic
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user/kernel boundary testing is working.
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config TEST_UDELAY
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tristate "udelay test driver"
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help
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@ -78,7 +78,6 @@ obj-$(CONFIG_TEST_LKM) += test_module.o
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obj-$(CONFIG_TEST_VMALLOC) += test_vmalloc.o
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obj-$(CONFIG_TEST_RHASHTABLE) += test_rhashtable.o
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obj-$(CONFIG_TEST_SORT) += test_sort.o
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obj-$(CONFIG_TEST_USER_COPY) += test_user_copy.o
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obj-$(CONFIG_TEST_STATIC_KEYS) += test_static_keys.o
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obj-$(CONFIG_TEST_STATIC_KEYS) += test_static_key_base.o
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obj-$(CONFIG_TEST_DYNAMIC_DEBUG) += test_dynamic_debug.o
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@ -388,6 +387,7 @@ CFLAGS_fortify_kunit.o += $(call cc-disable-warning, stringop-truncation)
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CFLAGS_fortify_kunit.o += $(DISABLE_STRUCTLEAK_PLUGIN)
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obj-$(CONFIG_FORTIFY_KUNIT_TEST) += fortify_kunit.o
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obj-$(CONFIG_SIPHASH_KUNIT_TEST) += siphash_kunit.o
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obj-$(CONFIG_USERCOPY_KUNIT_TEST) += usercopy_kunit.o
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obj-$(CONFIG_GENERIC_LIB_DEVMEM_IS_ALLOWED) += devmem_is_allowed.o
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@ -1,331 +0,0 @@
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// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Kernel module for testing copy_to/from_user infrastructure.
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*
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* Copyright 2013 Google Inc. All Rights Reserved
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*
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* Authors:
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* Kees Cook <keescook@chromium.org>
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/mman.h>
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#include <linux/module.h>
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#include <linux/sched.h>
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#include <linux/slab.h>
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#include <linux/uaccess.h>
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#include <linux/vmalloc.h>
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/*
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* Several 32-bit architectures support 64-bit {get,put}_user() calls.
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* As there doesn't appear to be anything that can safely determine
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* their capability at compile-time, we just have to opt-out certain archs.
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*/
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#if BITS_PER_LONG == 64 || (!(defined(CONFIG_ARM) && !defined(MMU)) && \
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!defined(CONFIG_M68K) && \
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!defined(CONFIG_MICROBLAZE) && \
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!defined(CONFIG_NIOS2) && \
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!defined(CONFIG_PPC32) && \
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!defined(CONFIG_SUPERH))
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# define TEST_U64
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#endif
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#define test(condition, msg, ...) \
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({ \
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int cond = (condition); \
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if (cond) \
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pr_warn("[%d] " msg "\n", __LINE__, ##__VA_ARGS__); \
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cond; \
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})
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static bool is_zeroed(void *from, size_t size)
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{
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return memchr_inv(from, 0x0, size) == NULL;
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}
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static int test_check_nonzero_user(char *kmem, char __user *umem, size_t size)
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{
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int ret = 0;
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size_t start, end, i, zero_start, zero_end;
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if (test(size < 2 * PAGE_SIZE, "buffer too small"))
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return -EINVAL;
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/*
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* We want to cross a page boundary to exercise the code more
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* effectively. We also don't want to make the size we scan too large,
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* otherwise the test can take a long time and cause soft lockups. So
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* scan a 1024 byte region across the page boundary.
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*/
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size = 1024;
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start = PAGE_SIZE - (size / 2);
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kmem += start;
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umem += start;
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zero_start = size / 4;
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zero_end = size - zero_start;
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/*
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* We conduct a series of check_nonzero_user() tests on a block of
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* memory with the following byte-pattern (trying every possible
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* [start,end] pair):
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*
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* [ 00 ff 00 ff ... 00 00 00 00 ... ff 00 ff 00 ]
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*
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* And we verify that check_nonzero_user() acts identically to
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* memchr_inv().
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*/
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memset(kmem, 0x0, size);
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for (i = 1; i < zero_start; i += 2)
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kmem[i] = 0xff;
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for (i = zero_end; i < size; i += 2)
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kmem[i] = 0xff;
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ret |= test(copy_to_user(umem, kmem, size),
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"legitimate copy_to_user failed");
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for (start = 0; start <= size; start++) {
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for (end = start; end <= size; end++) {
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size_t len = end - start;
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int retval = check_zeroed_user(umem + start, len);
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int expected = is_zeroed(kmem + start, len);
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ret |= test(retval != expected,
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"check_nonzero_user(=%d) != memchr_inv(=%d) mismatch (start=%zu, end=%zu)",
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retval, expected, start, end);
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}
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}
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return ret;
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}
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static int test_copy_struct_from_user(char *kmem, char __user *umem,
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size_t size)
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{
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int ret = 0;
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char *umem_src = NULL, *expected = NULL;
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size_t ksize, usize;
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umem_src = kmalloc(size, GFP_KERNEL);
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ret = test(umem_src == NULL, "kmalloc failed");
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if (ret)
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goto out_free;
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expected = kmalloc(size, GFP_KERNEL);
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ret = test(expected == NULL, "kmalloc failed");
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if (ret)
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goto out_free;
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/* Fill umem with a fixed byte pattern. */
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memset(umem_src, 0x3e, size);
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ret |= test(copy_to_user(umem, umem_src, size),
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"legitimate copy_to_user failed");
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/* Check basic case -- (usize == ksize). */
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ksize = size;
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usize = size;
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memcpy(expected, umem_src, ksize);
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memset(kmem, 0x0, size);
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ret |= test(copy_struct_from_user(kmem, ksize, umem, usize),
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"copy_struct_from_user(usize == ksize) failed");
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ret |= test(memcmp(kmem, expected, ksize),
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"copy_struct_from_user(usize == ksize) gives unexpected copy");
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/* Old userspace case -- (usize < ksize). */
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ksize = size;
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usize = size / 2;
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memcpy(expected, umem_src, usize);
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memset(expected + usize, 0x0, ksize - usize);
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memset(kmem, 0x0, size);
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ret |= test(copy_struct_from_user(kmem, ksize, umem, usize),
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"copy_struct_from_user(usize < ksize) failed");
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ret |= test(memcmp(kmem, expected, ksize),
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"copy_struct_from_user(usize < ksize) gives unexpected copy");
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/* New userspace (-E2BIG) case -- (usize > ksize). */
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ksize = size / 2;
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usize = size;
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memset(kmem, 0x0, size);
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ret |= test(copy_struct_from_user(kmem, ksize, umem, usize) != -E2BIG,
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"copy_struct_from_user(usize > ksize) didn't give E2BIG");
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/* New userspace (success) case -- (usize > ksize). */
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ksize = size / 2;
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usize = size;
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memcpy(expected, umem_src, ksize);
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ret |= test(clear_user(umem + ksize, usize - ksize),
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"legitimate clear_user failed");
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memset(kmem, 0x0, size);
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ret |= test(copy_struct_from_user(kmem, ksize, umem, usize),
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"copy_struct_from_user(usize > ksize) failed");
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ret |= test(memcmp(kmem, expected, ksize),
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"copy_struct_from_user(usize > ksize) gives unexpected copy");
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out_free:
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kfree(expected);
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kfree(umem_src);
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return ret;
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}
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static int __init test_user_copy_init(void)
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{
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int ret = 0;
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char *kmem;
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char __user *usermem;
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char *bad_usermem;
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unsigned long user_addr;
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u8 val_u8;
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u16 val_u16;
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u32 val_u32;
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#ifdef TEST_U64
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u64 val_u64;
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#endif
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kmem = kmalloc(PAGE_SIZE * 2, GFP_KERNEL);
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if (!kmem)
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return -ENOMEM;
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user_addr = vm_mmap(NULL, 0, PAGE_SIZE * 2,
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PROT_READ | PROT_WRITE | PROT_EXEC,
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MAP_ANONYMOUS | MAP_PRIVATE, 0);
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if (user_addr >= (unsigned long)(TASK_SIZE)) {
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pr_warn("Failed to allocate user memory\n");
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kfree(kmem);
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return -ENOMEM;
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}
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usermem = (char __user *)user_addr;
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bad_usermem = (char *)user_addr;
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/*
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* Legitimate usage: none of these copies should fail.
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*/
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memset(kmem, 0x3a, PAGE_SIZE * 2);
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ret |= test(copy_to_user(usermem, kmem, PAGE_SIZE),
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"legitimate copy_to_user failed");
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memset(kmem, 0x0, PAGE_SIZE);
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ret |= test(copy_from_user(kmem, usermem, PAGE_SIZE),
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"legitimate copy_from_user failed");
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ret |= test(memcmp(kmem, kmem + PAGE_SIZE, PAGE_SIZE),
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"legitimate usercopy failed to copy data");
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#define test_legit(size, check) \
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do { \
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val_##size = check; \
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ret |= test(put_user(val_##size, (size __user *)usermem), \
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"legitimate put_user (" #size ") failed"); \
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val_##size = 0; \
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ret |= test(get_user(val_##size, (size __user *)usermem), \
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"legitimate get_user (" #size ") failed"); \
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ret |= test(val_##size != check, \
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"legitimate get_user (" #size ") failed to do copy"); \
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if (val_##size != check) { \
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pr_info("0x%llx != 0x%llx\n", \
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(unsigned long long)val_##size, \
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(unsigned long long)check); \
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} \
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} while (0)
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test_legit(u8, 0x5a);
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test_legit(u16, 0x5a5b);
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test_legit(u32, 0x5a5b5c5d);
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#ifdef TEST_U64
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test_legit(u64, 0x5a5b5c5d6a6b6c6d);
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#endif
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#undef test_legit
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/* Test usage of check_nonzero_user(). */
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ret |= test_check_nonzero_user(kmem, usermem, 2 * PAGE_SIZE);
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/* Test usage of copy_struct_from_user(). */
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ret |= test_copy_struct_from_user(kmem, usermem, 2 * PAGE_SIZE);
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/*
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* Invalid usage: none of these copies should succeed.
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*/
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/* Prepare kernel memory with check values. */
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memset(kmem, 0x5a, PAGE_SIZE);
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memset(kmem + PAGE_SIZE, 0, PAGE_SIZE);
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/* Reject kernel-to-kernel copies through copy_from_user(). */
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ret |= test(!copy_from_user(kmem, (char __user *)(kmem + PAGE_SIZE),
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PAGE_SIZE),
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"illegal all-kernel copy_from_user passed");
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/* Destination half of buffer should have been zeroed. */
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ret |= test(memcmp(kmem + PAGE_SIZE, kmem, PAGE_SIZE),
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"zeroing failure for illegal all-kernel copy_from_user");
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#if 0
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/*
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* When running with SMAP/PAN/etc, this will Oops the kernel
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* due to the zeroing of userspace memory on failure. This needs
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* to be tested in LKDTM instead, since this test module does not
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* expect to explode.
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*/
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ret |= test(!copy_from_user(bad_usermem, (char __user *)kmem,
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PAGE_SIZE),
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"illegal reversed copy_from_user passed");
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#endif
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ret |= test(!copy_to_user((char __user *)kmem, kmem + PAGE_SIZE,
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PAGE_SIZE),
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"illegal all-kernel copy_to_user passed");
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ret |= test(!copy_to_user((char __user *)kmem, bad_usermem,
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PAGE_SIZE),
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"illegal reversed copy_to_user passed");
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#define test_illegal(size, check) \
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do { \
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val_##size = (check); \
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ret |= test(!get_user(val_##size, (size __user *)kmem), \
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"illegal get_user (" #size ") passed"); \
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ret |= test(val_##size != (size)0, \
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"zeroing failure for illegal get_user (" #size ")"); \
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if (val_##size != (size)0) { \
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pr_info("0x%llx != 0\n", \
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(unsigned long long)val_##size); \
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} \
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ret |= test(!put_user(val_##size, (size __user *)kmem), \
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"illegal put_user (" #size ") passed"); \
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} while (0)
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test_illegal(u8, 0x5a);
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test_illegal(u16, 0x5a5b);
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test_illegal(u32, 0x5a5b5c5d);
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#ifdef TEST_U64
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test_illegal(u64, 0x5a5b5c5d6a6b6c6d);
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#endif
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#undef test_illegal
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vm_munmap(user_addr, PAGE_SIZE * 2);
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kfree(kmem);
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if (ret == 0) {
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pr_info("tests passed.\n");
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return 0;
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}
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return -EINVAL;
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}
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module_init(test_user_copy_init);
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static void __exit test_user_copy_exit(void)
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{
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pr_info("unloaded.\n");
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}
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module_exit(test_user_copy_exit);
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MODULE_AUTHOR("Kees Cook <keescook@chromium.org>");
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MODULE_LICENSE("GPL");
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329
lib/usercopy_kunit.c
Normal file
329
lib/usercopy_kunit.c
Normal file
@ -0,0 +1,329 @@
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// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Kernel module for testing copy_to/from_user infrastructure.
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*
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* Copyright 2013 Google Inc. All Rights Reserved
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*
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* Authors:
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* Kees Cook <keescook@chromium.org>
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/mman.h>
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#include <linux/module.h>
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#include <linux/sched.h>
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#include <linux/slab.h>
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#include <linux/uaccess.h>
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#include <kunit/test.h>
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|
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/*
|
||||
* Several 32-bit architectures support 64-bit {get,put}_user() calls.
|
||||
* As there doesn't appear to be anything that can safely determine
|
||||
* their capability at compile-time, we just have to opt-out certain archs.
|
||||
*/
|
||||
#if BITS_PER_LONG == 64 || (!(defined(CONFIG_ARM) && !defined(MMU)) && \
|
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!defined(CONFIG_M68K) && \
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!defined(CONFIG_MICROBLAZE) && \
|
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!defined(CONFIG_NIOS2) && \
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!defined(CONFIG_PPC32) && \
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!defined(CONFIG_SUPERH))
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# define TEST_U64
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#endif
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struct usercopy_test_priv {
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char *kmem;
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char __user *umem;
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size_t size;
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};
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static bool is_zeroed(void *from, size_t size)
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{
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return memchr_inv(from, 0x0, size) == NULL;
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}
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/* Test usage of check_nonzero_user(). */
|
||||
static void usercopy_test_check_nonzero_user(struct kunit *test)
|
||||
{
|
||||
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;
|
||||
|
||||
KUNIT_ASSERT_GE_MSG(test, size, 2 * PAGE_SIZE, "buffer too small");
|
||||
|
||||
/*
|
||||
* We want to cross a page boundary to exercise the code more
|
||||
* effectively. We also don't want to make the size we scan too large,
|
||||
* otherwise the test can take a long time and cause soft lockups. So
|
||||
* scan a 1024 byte region across the page boundary.
|
||||
*/
|
||||
size = 1024;
|
||||
start = PAGE_SIZE - (size / 2);
|
||||
|
||||
kmem += start;
|
||||
umem += start;
|
||||
|
||||
zero_start = size / 4;
|
||||
zero_end = size - zero_start;
|
||||
|
||||
/*
|
||||
* We conduct a series of check_nonzero_user() tests on a block of
|
||||
* memory with the following byte-pattern (trying every possible
|
||||
* [start,end] pair):
|
||||
*
|
||||
* [ 00 ff 00 ff ... 00 00 00 00 ... ff 00 ff 00 ]
|
||||
*
|
||||
* And we verify that check_nonzero_user() acts identically to
|
||||
* memchr_inv().
|
||||
*/
|
||||
|
||||
memset(kmem, 0x0, size);
|
||||
for (i = 1; i < zero_start; i += 2)
|
||||
kmem[i] = 0xff;
|
||||
for (i = zero_end; i < size; i += 2)
|
||||
kmem[i] = 0xff;
|
||||
|
||||
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++) {
|
||||
size_t len = end - start;
|
||||
int retval = check_zeroed_user(umem + start, len);
|
||||
int expected = is_zeroed(kmem + start, len);
|
||||
|
||||
KUNIT_ASSERT_EQ_MSG(test, retval, expected,
|
||||
"check_nonzero_user(=%d) != memchr_inv(=%d) mismatch (start=%zu, end=%zu)",
|
||||
retval, expected, start, end);
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
/* Test usage of copy_struct_from_user(). */
|
||||
static void usercopy_test_copy_struct_from_user(struct kunit *test)
|
||||
{
|
||||
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 = kunit_kmalloc(test, size, GFP_KERNEL);
|
||||
KUNIT_ASSERT_NOT_ERR_OR_NULL(test, umem_src);
|
||||
|
||||
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);
|
||||
KUNIT_ASSERT_EQ_MSG(test, copy_to_user(umem, umem_src, size), 0,
|
||||
"legitimate copy_to_user failed");
|
||||
|
||||
/* Check basic case -- (usize == ksize). */
|
||||
ksize = size;
|
||||
usize = size;
|
||||
|
||||
memcpy(expected, umem_src, ksize);
|
||||
|
||||
memset(kmem, 0x0, size);
|
||||
KUNIT_EXPECT_EQ_MSG(test, copy_struct_from_user(kmem, ksize, umem, usize), 0,
|
||||
"copy_struct_from_user(usize == ksize) failed");
|
||||
KUNIT_EXPECT_MEMEQ_MSG(test, kmem, expected, ksize,
|
||||
"copy_struct_from_user(usize == ksize) gives unexpected copy");
|
||||
|
||||
/* Old userspace case -- (usize < ksize). */
|
||||
ksize = size;
|
||||
usize = size / 2;
|
||||
|
||||
memcpy(expected, umem_src, usize);
|
||||
memset(expected + usize, 0x0, ksize - usize);
|
||||
|
||||
memset(kmem, 0x0, size);
|
||||
KUNIT_EXPECT_EQ_MSG(test, copy_struct_from_user(kmem, ksize, umem, usize), 0,
|
||||
"copy_struct_from_user(usize < ksize) failed");
|
||||
KUNIT_EXPECT_MEMEQ_MSG(test, kmem, expected, ksize,
|
||||
"copy_struct_from_user(usize < ksize) gives unexpected copy");
|
||||
|
||||
/* New userspace (-E2BIG) case -- (usize > ksize). */
|
||||
ksize = size / 2;
|
||||
usize = size;
|
||||
|
||||
memset(kmem, 0x0, size);
|
||||
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). */
|
||||
ksize = size / 2;
|
||||
usize = size;
|
||||
|
||||
memcpy(expected, umem_src, ksize);
|
||||
KUNIT_EXPECT_EQ_MSG(test, clear_user(umem + ksize, usize - ksize), 0,
|
||||
"legitimate clear_user failed");
|
||||
|
||||
memset(kmem, 0x0, size);
|
||||
KUNIT_EXPECT_EQ_MSG(test, copy_struct_from_user(kmem, ksize, umem, usize), 0,
|
||||
"copy_struct_from_user(usize > ksize) failed");
|
||||
KUNIT_EXPECT_MEMEQ_MSG(test, kmem, expected, ksize,
|
||||
"copy_struct_from_user(usize > ksize) gives unexpected copy");
|
||||
}
|
||||
|
||||
/*
|
||||
* Legitimate usage: none of these copies should fail.
|
||||
*/
|
||||
static void usercopy_test_valid(struct kunit *test)
|
||||
{
|
||||
struct usercopy_test_priv *priv = test->priv;
|
||||
char __user *usermem = priv->umem;
|
||||
char *kmem = priv->kmem;
|
||||
|
||||
memset(kmem, 0x3a, PAGE_SIZE * 2);
|
||||
KUNIT_EXPECT_EQ_MSG(test, 0, copy_to_user(usermem, kmem, PAGE_SIZE),
|
||||
"legitimate copy_to_user failed");
|
||||
memset(kmem, 0x0, PAGE_SIZE);
|
||||
KUNIT_EXPECT_EQ_MSG(test, 0, copy_from_user(kmem, usermem, PAGE_SIZE),
|
||||
"legitimate copy_from_user failed");
|
||||
KUNIT_EXPECT_MEMEQ_MSG(test, 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);
|
||||
test_legit(u16, 0x5a5b);
|
||||
test_legit(u32, 0x5a5b5c5d);
|
||||
#ifdef TEST_U64
|
||||
test_legit(u64, 0x5a5b5c5d6a6b6c6d);
|
||||
#endif
|
||||
#undef test_legit
|
||||
}
|
||||
|
||||
/*
|
||||
* 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;
|
||||
|
||||
if (IS_ENABLED(CONFIG_ALTERNATE_USER_ADDRESS_SPACE) ||
|
||||
!IS_ENABLED(CONFIG_MMU)) {
|
||||
kunit_skip(test, "Testing for kernel/userspace address confusion is only sensible on architectures with a shared address space");
|
||||
return;
|
||||
}
|
||||
|
||||
/* 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(). */
|
||||
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. */
|
||||
KUNIT_EXPECT_MEMEQ_MSG(test, kmem + PAGE_SIZE, kmem, PAGE_SIZE,
|
||||
"zeroing failure for illegal all-kernel copy_from_user");
|
||||
|
||||
#if 0
|
||||
/*
|
||||
* When running with SMAP/PAN/etc, this will Oops the kernel
|
||||
* due to the zeroing of userspace memory on failure. This needs
|
||||
* to be tested in LKDTM instead, since this test module does not
|
||||
* expect to explode.
|
||||
*/
|
||||
KUNIT_EXPECT_NE_MSG(test, copy_from_user(bad_usermem, (char __user *)kmem,
|
||||
PAGE_SIZE), 0,
|
||||
"illegal reversed copy_from_user passed");
|
||||
#endif
|
||||
KUNIT_EXPECT_NE_MSG(test, copy_to_user((char __user *)kmem, kmem + PAGE_SIZE,
|
||||
PAGE_SIZE), 0,
|
||||
"illegal all-kernel copy_to_user passed");
|
||||
|
||||
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 { \
|
||||
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);
|
||||
test_illegal(u16, 0x5a5b);
|
||||
test_illegal(u32, 0x5a5b5c5d);
|
||||
#ifdef TEST_U64
|
||||
test_illegal(u64, 0x5a5b5c5d6a6b6c6d);
|
||||
#endif
|
||||
#undef test_illegal
|
||||
}
|
||||
|
||||
static int usercopy_test_init(struct kunit *test)
|
||||
{
|
||||
struct usercopy_test_priv *priv;
|
||||
unsigned long user_addr;
|
||||
|
||||
priv = kunit_kzalloc(test, sizeof(*priv), GFP_KERNEL);
|
||||
KUNIT_ASSERT_NOT_ERR_OR_NULL(test, priv);
|
||||
test->priv = priv;
|
||||
priv->size = PAGE_SIZE * 2;
|
||||
|
||||
priv->kmem = kunit_kmalloc(test, priv->size, GFP_KERNEL);
|
||||
KUNIT_ASSERT_NOT_ERR_OR_NULL(test, priv->kmem);
|
||||
|
||||
user_addr = kunit_vm_mmap(test, NULL, 0, priv->size,
|
||||
PROT_READ | PROT_WRITE | PROT_EXEC,
|
||||
MAP_ANONYMOUS | MAP_PRIVATE, 0);
|
||||
KUNIT_ASSERT_NE_MSG(test, user_addr, 0,
|
||||
"Could not create userspace mm");
|
||||
KUNIT_ASSERT_LT_MSG(test, user_addr, (unsigned long)TASK_SIZE,
|
||||
"Failed to allocate user memory");
|
||||
priv->umem = (char __user *)user_addr;
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
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");
|
Loading…
Reference in New Issue
Block a user