From: Sasha Levin <sashal@kernel.org>
To: Pavel Machek <pavel@denx.de>
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
Subject: Re: [PATCH AUTOSEL 4.4 08/31] drm/virtio: Fixes a potential NULL pointer dereference on probe failure
Date: Wed, 14 Jul 2021 12:49:18 -0400 [thread overview]
Message-ID: <YO8VjgdgHXoAcOMY@sashalap> (raw)
In-Reply-To: <20210712215937.GA9488@amd>
On Mon, Jul 12, 2021 at 11:59:37PM +0200, Pavel Machek wrote:
>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.
Heh, yes, thanks for catching that. I'll drop it for now and rework it
next week.
--
Thanks,
Sasha
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next prev parent reply other threads:[~2021-07-14 16:49 UTC|newest]
Thread overview: 3+ 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
[not found] ` <20210712215937.GA9488@amd>
2021-07-14 16:49 ` Sasha Levin [this message]
2021-07-06 11:29 ` [PATCH AUTOSEL 4.4 09/31] drm/virtio: Fix double free " Sasha Levin
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