Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 331 insertions, 0 deletions

diff --git a/lib/test_user_copy.c b/lib/test_user_copy.c
new file mode 100644
index 0000000000..5ff04d8fe9
--- /dev/null
+++ b/lib/test_user_copy.c
@@ -0,0 +1,331 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Kernel module for testing copy_to/from_user infrastructure.
+ *
+ * Copyright 2013 Google Inc. All Rights Reserved
+ *
+ * Authors:
+ *      Kees Cook       <keescook@chromium.org>
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/mman.h>
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+#include <linux/vmalloc.h>
+
+/*
+ * 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)) && \
+			    !defined(CONFIG_M68K) &&		\
+			    !defined(CONFIG_MICROBLAZE) &&	\
+			    !defined(CONFIG_NIOS2) &&		\
+			    !defined(CONFIG_PPC32) &&		\
+			    !defined(CONFIG_SUPERH))
+# define TEST_U64
+#endif
+
+#define test(condition, msg, ...)					\
+({									\
+	int cond = (condition);						\
+	if (cond)							\
+		pr_warn("[%d] " msg "\n", __LINE__, ##__VA_ARGS__);	\
+	cond;								\
+})
+
+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)
+{
+	int ret = 0;
+	size_t start, end, i, zero_start, zero_end;
+
+	if (test(size < 2 * PAGE_SIZE, "buffer too small"))
+		return -EINVAL;
+
+	/*
+	 * 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;
+
+	ret |= test(copy_to_user(umem, kmem, size),
+		    "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);
+
+			ret |= 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)
+{
+	int ret = 0;
+	char *umem_src = NULL, *expected = NULL;
+	size_t ksize, usize;
+
+	umem_src = kmalloc(size, GFP_KERNEL);
+	ret = test(umem_src == NULL, "kmalloc failed");
+	if (ret)
+		goto out_free;
+
+	expected = kmalloc(size, GFP_KERNEL);
+	ret = test(expected == NULL, "kmalloc failed");
+	if (ret)
+		goto out_free;
+
+	/* Fill umem with a fixed byte pattern. */
+	memset(umem_src, 0x3e, size);
+	ret |= test(copy_to_user(umem, umem_src, size),
+		    "legitimate copy_to_user failed");
+
+	/* Check basic case -- (usize == ksize). */
+	ksize = size;
+	usize = size;
+
+	memcpy(expected, umem_src, ksize);
+
+	memset(kmem, 0x0, size);
+	ret |= test(copy_struct_from_user(kmem, ksize, umem, usize),
+		    "copy_struct_from_user(usize == ksize) failed");
+	ret |= test(memcmp(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);
+	ret |= test(copy_struct_from_user(kmem, ksize, umem, usize),
+		    "copy_struct_from_user(usize < ksize) failed");
+	ret |= test(memcmp(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);
+	ret |= 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);
+	ret |= test(clear_user(umem + ksize, usize - ksize),
+		    "legitimate clear_user failed");
+
+	memset(kmem, 0x0, size);
+	ret |= test(copy_struct_from_user(kmem, ksize, umem, usize),
+		    "copy_struct_from_user(usize > ksize) failed");
+	ret |= test(memcmp(kmem, expected, ksize),
+		    "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)
+{
+	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;
+	}
+
+	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");
+	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);		  \
+		}							  \
+	} 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
+
+	/* 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.
+	 */
+
+	/* 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),
+		    "illegal all-kernel copy_from_user passed");
+
+	/* Destination half of buffer should have been zeroed. */
+	ret |= test(memcmp(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.
+	 */
+	ret |= test(!copy_from_user(bad_usermem, (char __user *)kmem,
+				    PAGE_SIZE),
+		    "illegal reversed copy_from_user passed");
+#endif
+	ret |= test(!copy_to_user((char __user *)kmem, kmem + PAGE_SIZE,
+				  PAGE_SIZE),
+		    "illegal all-kernel copy_to_user passed");
+	ret |= test(!copy_to_user((char __user *)kmem, bad_usermem,
+				  PAGE_SIZE),
+		    "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");		    \
+	} 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
+
+	vm_munmap(user_addr, PAGE_SIZE * 2);
+	kfree(kmem);
+
+	if (ret == 0) {
+		pr_info("tests passed.\n");
+		return 0;
+	}
+
+	return -EINVAL;
+}
+
+module_init(test_user_copy_init);
+
+static void __exit test_user_copy_exit(void)
+{
+	pr_info("unloaded.\n");
+}
+
+module_exit(test_user_copy_exit);
+
+MODULE_AUTHOR("Kees Cook <keescook@chromium.org>");
+MODULE_LICENSE("GPL");