From: Pavel Machek <pavel@denx.de>
To: Sasha Levin <sashal@kernel.org>
Cc: linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org,
virtualization@lists.linux-foundation.org,
Xie Yongji <xieyongji@bytedance.com>,
stable@vger.kernel.org, Gerd Hoffmann <kraxel@redhat.com>
Subject: Re: [PATCH AUTOSEL 4.4 08/31] drm/virtio: Fixes a potential NULL pointer dereference on probe failure
Date: Mon, 12 Jul 2021 23:59:37 +0200 [thread overview]
Message-ID: <20210712215937.GA9488@amd> (raw)
In-Reply-To: <20210706112931.2066397-8-sashal@kernel.org>
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Hi!
> From: Xie Yongji <xieyongji@bytedance.com>
>
> [ Upstream commit 17f46f488a5d82c5568e6e786cd760bba1c2ee09 ]
>
> The dev->dev_private might not be allocated if virtio_gpu_pci_quirk()
> or virtio_gpu_init() failed. In this case, we should avoid the cleanup
> in virtio_gpu_release().
The check is in wrong place at least in 4.4:
> +++ b/drivers/gpu/drm/virtio/virtgpu_kms.c
> @@ -257,6 +257,9 @@ int virtio_gpu_driver_unload(struct drm_device *dev)
> flush_work(&vgdev->config_changed_work);
> vgdev->vdev->config->del_vqs(vgdev->vdev);
>
> + if (!vgdev)
> + return;
> +
Pointer is dereferenced before being tested.
Best regards,
Pavel
--
DENX Software Engineering GmbH, Managing Director: Wolfgang Denk
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
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next prev parent reply other threads:[~2021-07-12 22:07 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20210706112931.2066397-1-sashal@kernel.org>
2021-07-06 11:29 ` [PATCH AUTOSEL 4.4 08/31] drm/virtio: Fixes a potential NULL pointer dereference on probe failure Sasha Levin
2021-07-12 21:59 ` Pavel Machek [this message]
2021-07-14 16:49 ` Sasha Levin
2021-07-06 11:29 ` [PATCH AUTOSEL 4.4 09/31] drm/virtio: Fix double free " Sasha Levin
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