diff options
| author | Kees Cook <keescook@chromium.org> | 2017-02-13 11:25:26 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-06-14 13:16:27 +0200 |
| commit | 51ff10e72fc2448f66ca5c4cec81c4631c8aad30 (patch) | |
| tree | bab1727eaee93cd3f4e175f550394f1c74dcd621 /lib | |
| parent | 746d48934f5194232bc572b2e90f2e5490ca622f (diff) | |
usercopy: Adjust tests to deal with SMAP/PAN
commit f5f893c57e37ca730808cb2eee3820abd05e7507 upstream.
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.
[arnd: the test module was added in 3.14, and this backported patch
should apply cleanly on all version from 3.14 to 4.10.
The original patch was in 4.11 on top of a context change
I saw the bug triggered with kselftest on a 4.4.y stable kernel]
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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), |