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Commit 4a0853bf authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'usercopy-v4.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux 

Pull usercopy test updates from Kees Cook:
 "This improves the usercopy tests:

   - check zeroing on failed copy_from_user()/get_user() (caught bug on
     ARM)

   - adjust tests for SMAP/PAN (can't zero userspace memory on failure)"

* tag 'usercopy-v4.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  usercopy: Add tests for all get_user() sizes
  usercopy: Adjust tests to deal with SMAP/PAN
  usercopy: add testcases to check zeroing on failure
parents 6d1dd93e 4c5d7bc6

lib/test_user_copy.c

+103 −14
Original line number Diff line number Diff line
@@ -25,6 +25,23 @@ 
#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_AVR32)  &&		\

			    !defined(CONFIG_BLACKFIN) &&	\

			    !defined(CONFIG_M32R) &&		\

			    !defined(CONFIG_M68K) &&		\

			    !defined(CONFIG_MICROBLAZE) &&	\

			    !defined(CONFIG_MN10300) &&		\

			    !defined(CONFIG_NIOS2) &&		\

			    !defined(CONFIG_PPC32) &&		\

			    !defined(CONFIG_SUPERH))

# define TEST_U64

#endif



#define test(condition, msg)		\

({					\

	int cond = (condition);		\
@@ -40,7 +57,12 @@ static int __init test_user_copy_init(void) 
	char __user *usermem;

	char *bad_usermem;

	unsigned long user_addr;

	unsigned long value = 0x5A;

	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)
@@ -58,33 +80,100 @@ static int __init test_user_copy_init(void) 
	usermem = (char __user *)user_addr;

	bad_usermem = (char *)user_addr;



	/* Legitimate usage: none of these should fail. */

	ret |= test(copy_from_user(kmem, usermem, PAGE_SIZE),

		    "legitimate copy_from_user failed");

	/*

	 * 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");

	ret |= test(get_user(value, (unsigned long __user *)usermem),

		    "legitimate get_user failed");

	ret |= test(put_user(value, (unsigned long __user *)usermem),

		    "legitimate put_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



	/* Invalid usage: none of these should succeed. */

	/*

	 * 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");

	ret |= test(!get_user(value, (unsigned long __user *)kmem),

		    "illegal get_user passed");

	ret |= test(!put_user(value, (unsigned long __user *)kmem),

		    "illegal put_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);