Date:   Fri, 10 Mar 2023 13:07:30 +0100
From:   Greg KH <gregkh@linuxfoundation.org>
To:     Dmitry Osipenko <dmitry.osipenko@collabora.com>
Cc:     Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com>,
        stable@vger.kernel.org, kraxel@redhat.com,
        linux-kernel@vger.kernel.org, emil.l.velikov@gmail.com,
        airlied@linux.ie, error27@gmail.com, darren.kenny@oracle.com,
        vegard.nossum@oracle.com
Subject: Re: [PATCH 5.15.y] drm/virtio: Fix error code in
 virtio_gpu_object_shmem_init()
Message-ID: <ZAsdguMTwKIRdVBn@kroah.com>
References: <20230302172538.3508747-1-harshit.m.mogalapalli@oracle.com>
 <d2cf9564-3b0c-b9e4-6066-8e8e6eb854f0@collabora.com>
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On Sat, Mar 04, 2023 at 12:32:22AM +0300, Dmitry Osipenko wrote:
> On 3/2/23 20:25, Harshit Mogalapalli wrote:
> > In virtio_gpu_object_shmem_init() we are passing NULL to PTR_ERR, which
> > is returning 0/success.
> > 
> > Fix this by storing error value in 'ret' variable before assigning
> > shmem->pages to NULL.
> > 
> > Found using static analysis with Smatch.
> > 
> > Fixes: 64b88afbd92f ("drm/virtio: Correct drm_gem_shmem_get_sg_table() error handling")
> > Signed-off-by: Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com>
> > ---
> > Only compile tested.
> > 
> > Upstream commit b5c9ed70d1a9 ("drm/virtio: Improve DMA API usage for shmem BOs")
> > deleted this code, so this patch is not necessary in linux-6.1.y and
> > linux-6.2.y.
> > ---
> >  drivers/gpu/drm/virtio/virtgpu_object.c | 3 ++-
> >  1 file changed, 2 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/gpu/drm/virtio/virtgpu_object.c b/drivers/gpu/drm/virtio/virtgpu_object.c
> > index 7e75fb0fc7bd..25d399b00404 100644
> > --- a/drivers/gpu/drm/virtio/virtgpu_object.c
> > +++ b/drivers/gpu/drm/virtio/virtgpu_object.c
> > @@ -169,8 +169,9 @@ static int virtio_gpu_object_shmem_init(struct virtio_gpu_device *vgdev,
> >  	shmem->pages = drm_gem_shmem_get_sg_table(&bo->base);
> >  	if (IS_ERR(shmem->pages)) {
> >  		drm_gem_shmem_unpin(&bo->base);
> > +		ret = PTR_ERR(shmem->pages);
> >  		shmem->pages = NULL;
> > -		return PTR_ERR(shmem->pages);
> > +		return ret;
> >  	}
> >  
> >  	if (use_dma_api) {
> 
> Reviewed-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>

Both fixes now queued up, thanks.

greg k-h