On Fri, Aug 04, 2017 at 11:09:24AM +0200, Thomas Huth wrote: > Hi, > > On 03.08.2017 15:59, sohu0106 wrote: > > > > The stack object "kbdiacr" has a total size of 4 bytes. Its last 1 bytes are padding bytes after "result" which are not initialized and leaked to userland via "copy_to_user". > > > > > > diff --git a/keyboard.c b/keyboard.c > > index ba0e4f9..76a6d35 100644 > > --- a/keyboard.c > > +++ b/keyboard.c > > @@ -480,6 +480,8 @@ int kbd_ioctl(struct kbd_data *kbd, unsigned int cmd, unsigned long arg) > > struct kbdiacr diacr; > > int i; > > > > + memset( &diacr, 0, sizeof(struct kbdiacr) ); > > + > > I think it would be nicer to simply init the struct with "= {}" > directly, i.e.: > > struct kbdiacr diacr = {}; > > And by the way, please have a look at the kernel patch submission > guidelines first, especially the COO part here: The patch doesn't make sense. There is no padding and therefore no information leak. -- To unsubscribe from this list: send the line "unsubscribe linux-s390" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html