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From:   Yongji Xie <xieyongji@bytedance.com>
Date:   Wed, 7 Jul 2021 17:19:35 +0800
Message-ID: <CACycT3tvvMpsjmJGhY5duNCXt5YyyWqQ2MpxRuMKQwmtpgF0Aw@mail.gmail.com>
Subject: Re: [PATCH v8 09/10] vduse: Introduce VDUSE - vDPA Device in Userspace
To:     Stefan Hajnoczi <stefanha@redhat.com>
Cc:     "Michael S. Tsirkin" <mst@redhat.com>,
        Jason Wang <jasowang@redhat.com>,
        Stefano Garzarella <sgarzare@redhat.com>,
        Parav Pandit <parav@nvidia.com>,
        Christoph Hellwig <hch@infradead.org>,
        Christian Brauner <christian.brauner@canonical.com>,
        Randy Dunlap <rdunlap@infradead.org>,
        Matthew Wilcox <willy@infradead.org>,
        Al Viro <viro@zeniv.linux.org.uk>,
        Jens Axboe <axboe@kernel.dk>, bcrl@kvack.org,
        Jonathan Corbet <corbet@lwn.net>,
        =?UTF-8?Q?Mika_Penttil=C3=A4?= <mika.penttila@nextfour.com>,
        Dan Carpenter <dan.carpenter@oracle.com>, joro@8bytes.org,
        Greg KH <gregkh@linuxfoundation.org>, songmuchun@bytedance.com,
        virtualization <virtualization@lists.linux-foundation.org>,
        netdev@vger.kernel.org, kvm <kvm@vger.kernel.org>,
        linux-fsdevel@vger.kernel.org, iommu@lists.linux-foundation.org,
        linux-kernel <linux-kernel@vger.kernel.org>
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On Wed, Jul 7, 2021 at 4:53 PM Stefan Hajnoczi <stefanha@redhat.com> wrote:
>
> On Tue, Jun 15, 2021 at 10:13:30PM +0800, Xie Yongji wrote:
> > +static bool vduse_validate_config(struct vduse_dev_config *config)
> > +{
>
> The name field needs to be NUL terminated?
>

I think so.

> > +     case VDUSE_CREATE_DEV: {
> > +             struct vduse_dev_config config;
> > +             unsigned long size = offsetof(struct vduse_dev_config, config);
> > +             void *buf;
> > +
> > +             ret = -EFAULT;
> > +             if (copy_from_user(&config, argp, size))
> > +                     break;
> > +
> > +             ret = -EINVAL;
> > +             if (vduse_validate_config(&config) == false)
> > +                     break;
> > +
> > +             buf = vmemdup_user(argp + size, config.config_size);
> > +             if (IS_ERR(buf)) {
> > +                     ret = PTR_ERR(buf);
> > +                     break;
> > +             }
> > +             ret = vduse_create_dev(&config, buf, control->api_version);
> > +             break;
> > +     }
> > +     case VDUSE_DESTROY_DEV: {
> > +             char name[VDUSE_NAME_MAX];
> > +
> > +             ret = -EFAULT;
> > +             if (copy_from_user(name, argp, VDUSE_NAME_MAX))
> > +                     break;
>
> Is this missing a NUL terminator?

Oh, yes. Looks like I need to set '\0' to name[VDUSE_VDUSE_NAME_MAX - 1] here.

Thanks,
Yongji