From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mailgw01.mediatek.com ([210.61.82.183]:4959 "EHLO mailgw01.mediatek.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1751081AbcAODFc (ORCPT ); Thu, 14 Jan 2016 22:05:32 -0500 Message-ID: <1452827126.27524.1.camel@mtksdaap41> Subject: Re: [PATCH] media: v4l2-compat-ioctl32: fix missing length copy in put_v4l2_buffer32 From: tiffany lin To: Hans Verkuil CC: Mauro Carvalho Chehab , Eddie Huang , Yingjoe Chen , , Date: Fri, 15 Jan 2016 11:05:26 +0800 In-Reply-To: <56975409.3090801@xs4all.nl> References: <1452757045-34051-1-git-send-email-tiffany.lin@mediatek.com> <56975409.3090801@xs4all.nl> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit MIME-Version: 1.0 Sender: linux-media-owner@vger.kernel.org List-ID: Hi Hans, On Thu, 2016-01-14 at 08:53 +0100, Hans Verkuil wrote: > Hi Tiffany, > > Good catch! But looking through the compat code I noticed that in the > single-planar DMABUF case the length field is also never copied. I think > it would be much simpler if the length field is just always copied instead > of in each multiplanar or singleplanar mmap/userptr/dmabuf case. It will > simplify the code and prevent such mistakes in the future. > > Can you make a v2 that makes that change? > Sure, I had sent v2. best regards, Tiffany > Thanks! > > Hans > > On 01/14/2016 08:37 AM, Tiffany Lin wrote: > > In v4l2-compliance utility, test QUERYBUF required correct length > > value to go through each planar to check planar's length in multi-planar > > > > Signed-off-by: Tiffany Lin > > --- > > drivers/media/v4l2-core/v4l2-compat-ioctl32.c | 3 +++ > > 1 file changed, 3 insertions(+) > > > > diff --git a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c > > index 327e83a..5ba932a 100644 > > --- a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c > > +++ b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c > > @@ -521,6 +521,9 @@ static int put_v4l2_buffer32(struct v4l2_buffer *kp, struct v4l2_buffer32 __user > > if (num_planes == 0) > > return 0; > > > > + if (put_user(kp->length, &up->length)) > > + return -EFAULT; > > + > > uplane = (__force struct v4l2_plane __user *)kp->m.planes; > > if (get_user(p, &up->m.planes)) > > return -EFAULT; > > >