From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mx1.redhat.com ([209.132.183.28]:59366 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752327Ab3EULra (ORCPT ); Tue, 21 May 2013 07:47:30 -0400 Date: Tue, 21 May 2013 08:47:13 -0300 From: Mauro Carvalho Chehab To: Chen Gang Cc: josephdanielwalter@gmail.com, Greg KH , linux-media@vger.kernel.org, "devel@driverdev.osuosl.org" Subject: Re: [PATCH] staging: strncpy issue, need always let NUL terminated string ended by zero. Message-ID: <20130521084713.3cbf25c2@redhat.com> In-Reply-To: <5188EF5C.3030003@asianux.com> References: <5188EF5C.3030003@asianux.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-media-owner@vger.kernel.org List-ID: Em Tue, 07 May 2013 20:11:08 +0800 Chen Gang escreveu: > > For NUL terminated string, need always let it ended by zero. > > The 'name' may be copied to user mode ('dvb_fe->ops.info' is 'struct > dvb_frontend_info' which is defined in ./include/uapi/...), and its > length is also known within as102_dvb_register_fe(), so need fully > initialize it (not use strlcpy instead of strncpy). > > > Signed-off-by: Chen Gang > --- > drivers/staging/media/as102/as102_fe.c | 1 + > 1 files changed, 1 insertions(+), 0 deletions(-) > > diff --git a/drivers/staging/media/as102/as102_fe.c b/drivers/staging/media/as102/as102_fe.c > index 9ce8c9d..b3efec9 100644 > --- a/drivers/staging/media/as102/as102_fe.c > +++ b/drivers/staging/media/as102/as102_fe.c > @@ -334,6 +334,7 @@ int as102_dvb_register_fe(struct as102_dev_t *as102_dev, > memcpy(&dvb_fe->ops, &as102_fe_ops, sizeof(struct dvb_frontend_ops)); > strncpy(dvb_fe->ops.info.name, as102_dev->name, > sizeof(dvb_fe->ops.info.name)); > + dvb_fe->ops.info.name[sizeof(dvb_fe->ops.info.name) - 1] = '\0'; Instead, the better would be to use strlcpy(), as it warrants that the copied string will be nul-terminated. Regards, Mauro