diff options
| author | Kees Cook <keescook@chromium.org> | 2017-02-13 11:25:26 -0800 |
|---|---|---|
| committer | Sasha Levin <alexander.levin@verizon.com> | 2017-06-25 22:02:20 -0400 |
| commit | cd1c4f855f68a251587340f63f3b5e2e38d2c97e (patch) | |
| tree | df514e6b40fd815af5c4d01d8fdd5ddcb8a17dc4 /lib | |
| parent | 9da808668b5883c4d6b147f5ec7a89a8971508fa (diff) | |
usercopy: Adjust tests to deal with SMAP/PAN
[ Upstream commit f5f893c57e37ca730808cb2eee3820abd05e7507 ]
Under SMAP/PAN/etc, we cannot write directly to userspace memory, so
this rearranges the test bytes to get written through copy_to_user().
Additionally drops the bad copy_from_user() test that would trigger a
memcpy() against userspace on failure.
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/test_user_copy.c | 20 |
1 files changed, 18 insertions, 2 deletions
diff --git a/lib/test_user_copy.c b/lib/test_user_copy.c index 0ecef3e4690e..5e6db6b1e3bd 100644 --- a/lib/test_user_copy.c +++ b/lib/test_user_copy.c @@ -58,7 +58,9 @@ 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. */ + /* + * Legitimate usage: none of these copies should fail. + */ ret |= test(copy_from_user(kmem, usermem, PAGE_SIZE), "legitimate copy_from_user failed"); ret |= test(copy_to_user(usermem, kmem, PAGE_SIZE), @@ -68,19 +70,33 @@ static int __init test_user_copy_init(void) ret |= test(put_user(value, (unsigned long __user *)usermem), "legitimate put_user failed"); - /* Invalid usage: none of these should succeed. */ + /* + * Invalid usage: none of these copies should succeed. + */ + + /* 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"); + +#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), |