From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from ffm.saftware.de ([83.141.3.46]:36038 "EHLO ffm.saftware.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752038Ab0LVOZZ (ORCPT ); Wed, 22 Dec 2010 09:25:25 -0500 Message-ID: <4D1207D9.2050000@linuxtv.org> Date: Wed, 22 Dec 2010 15:14:49 +0100 From: Andreas Oberritter MIME-Version: 1.0 To: Thiago Farina CC: linux-kernel@vger.kernel.org, arnd@arndb.de, Guennadi Liakhovetski , Mauro Carvalho Chehab , linux-media@vger.kernel.org Subject: Re: [PATCH v2] drivers/media/video/v4l2-compat-ioctl32.c: Check the return value of copy_to_user References: <201012212003.11446.arnd@arndb.de> <83948188cda2388c2e22a50119dfb0023fba759a.1292975147.git.tfransosi@gmail.com> In-Reply-To: <83948188cda2388c2e22a50119dfb0023fba759a.1292975147.git.tfransosi@gmail.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit List-ID: Sender: Mauro Carvalho Chehab On 12/22/2010 12:48 AM, Thiago Farina wrote: > This fix the following warning: > drivers/media/video/v4l2-compat-ioctl32.c: In function ‘get_microcode32’: > drivers/media/video/v4l2-compat-ioctl32.c:209: warning: ignoring return value of ‘copy_to_user’, declared with attribute warn_unused_result > > Signed-off-by: Thiago Farina > --- > Changes from v1: > - Check the return code of put_user too. > - Remove the obsolete comment. > > drivers/media/video/v4l2-compat-ioctl32.c | 14 ++++++-------- > 1 files changed, 6 insertions(+), 8 deletions(-) > > diff --git a/drivers/media/video/v4l2-compat-ioctl32.c b/drivers/media/video/v4l2-compat-ioctl32.c > index e30e8df..6f2a022 100644 > --- a/drivers/media/video/v4l2-compat-ioctl32.c > +++ b/drivers/media/video/v4l2-compat-ioctl32.c > @@ -201,14 +201,12 @@ static struct video_code __user *get_microcode32(struct video_code32 *kp) > > up = compat_alloc_user_space(sizeof(*up)); I don't know anything about that code, but I assume that "up" should be checked for NULL before use and should be freed in case an error occurs below. > > - /* > - * NOTE! We don't actually care if these fail. If the > - * user address is invalid, the native ioctl will do > - * the error handling for us > - */ > - (void) copy_to_user(up->loadwhat, kp->loadwhat, sizeof(up->loadwhat)); > - (void) put_user(kp->datasize, &up->datasize); > - (void) put_user(compat_ptr(kp->data), &up->data); > + if (copy_to_user(up->loadwhat, kp->loadwhat, sizeof(up->loadwhat))) > + return NULL; > + if (put_user(kp->datasize, &up->datasize)) > + return NULL; > + if (put_user(compat_ptr(kp->data), &up->data)) > + return NULL; > return up; > } >