binder: fix handling of misaligned binder object

Fixes crash found by syzbot:
kernel BUG at drivers/android/binder_alloc.c:LINE! (2)

Reported-and-tested-by: syzbot+55de1eb4975dec156d8f@syzkaller.appspotmail.com
Signed-off-by: Todd Kjos <tkjos@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/android/binder.c

@@ -2057,7 +2057,7 @@ static size_t binder_get_object(struct binder_proc *proc,
 	size_t object_size = 0;
 
 	read_size = min_t(size_t, sizeof(*object), buffer->data_size - offset);
-	if (read_size < sizeof(*hdr))
+	if (read_size < sizeof(*hdr) || !IS_ALIGNED(offset, sizeof(u32)))
 		return 0;
 	binder_alloc_copy_from_buffer(&proc->alloc, object, buffer,
 				      offset, read_size);