From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from madrid.collaboradmins.com (madrid.collaboradmins.com [46.235.227.194]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 90C79610B for ; Thu, 11 Apr 2024 12:31:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=46.235.227.194 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712838697; cv=none; b=FDxBU0i+TXrijHDWdH/ojMonEOA+oK7SIw4MvVeT8eJCwxb4cFYNvowyJa+tC68KSo4xCXYiNZuUo3moyDmtkf3tFg8pMER+ofelr0UfGgKt43jBXoOyv65NKs7VWJohzQFm3WakynVlCG41A7ocWndyIfm22jdsbof6bmM3QVE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712838697; c=relaxed/simple; bh=zmevCFhXx6ZuzMCYAfjpOwI5DJ6QN9bdg4fgOkPUdqo=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=hUBnXLsf28autHBvkcnO5gtoXr55WByc4xZIoRhQkD/rn4WhHaxmhqAYI0cF1chZ2CQkv5fmDtJp1c2V5gwY7eyH1b7UEb3i/jhFX9Ra/0UGF5aQRk6rXmIXD02I0DPQVYflsNpYBF43TMt3QY05K77wAhJz0Sy2PnpkharRGxI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=collabora.com; spf=pass smtp.mailfrom=collabora.com; dkim=pass (2048-bit key) header.d=collabora.com header.i=@collabora.com header.b=qwmnSSbh; arc=none smtp.client-ip=46.235.227.194 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=collabora.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=collabora.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=collabora.com header.i=@collabora.com header.b="qwmnSSbh" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1712838688; bh=zmevCFhXx6ZuzMCYAfjpOwI5DJ6QN9bdg4fgOkPUdqo=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=qwmnSSbhoBchnoBCuYnXfp2/6Jh3cN8jMBjFqh9AFIsoZwin9j3UUiUbk6U6zjoEQ ADrLiHD5rMU5plZ6/8l4lXNooe6j1yW+63uH8y6vLZsWmjKI63swv3aSnEFvsr72qr ZM27KFJFjzxFVaS/O97bQ1y/DEGFITe5vyUY/KTwAnyBtRuvfLBx9HzWPCLVf9cIyh 8UyhB6kp/XbNKpXQTbtuXeQqzjalp11cbrYLoABsvl3yV+/LEsTBieN3d4WgPJ9VAo 6SCIJRqaWzK/6Mg7ZArxaxnbDriu93Qt21D0GAYu6yS2qrbZGPI/P03AZWkqEPye1L xqhzxE9rPH8Qw== Received: from [100.109.49.129] (cola.collaboradmins.com [195.201.22.229]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: dmitry.osipenko) by madrid.collaboradmins.com (Postfix) with ESMTPSA id 0B7C537813C0; Thu, 11 Apr 2024 12:31:26 +0000 (UTC) Message-ID: <6ca1e5de-2188-466f-a05c-ba190702d7a5@collabora.com> Date: Thu, 11 Apr 2024 15:31:24 +0300 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] drm/virtio: add driver_priv validation in virtio_gpu_create_context To: Maxim Korotkov , David Airlie Cc: Gerd Hoffmann , Gurchetan Singh , Chia-I Wu , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , Daniel Vetter , Ivan Kapranov , lvc-project@linuxtesting.org, dri-devel@lists.freedesktop.org, virtualization@lists.linux.dev, linux-kernel@vger.kernel.org References: <20240328134351.298050-1-korotkov.maxim.s@gmail.com> Content-Language: en-US From: Dmitry Osipenko In-Reply-To: <20240328134351.298050-1-korotkov.maxim.s@gmail.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 3/28/24 16:43, Maxim Korotkov wrote: > The pointer file->driver_priv was dereferenced without checking > against NULL, but in the "virtio_gpu_transfer_to_host_ioctl" function > it was checked against NULL after calling virtio_gpu_create_context > function. > > Found by Security Code and Linux Verification Center(linuxtesting.org) > Fixes: 72b48ae800da ("drm/virtio: enqueue virtio_gpu_create_context after the first 3D ioctl") > Signed-off-by: Maxim Korotkov > --- > drivers/gpu/drm/virtio/virtgpu_ioctl.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/gpu/drm/virtio/virtgpu_ioctl.c b/drivers/gpu/drm/virtio/virtgpu_ioctl.c > index e4f76f315550..98fe9ad4ed15 100644 > --- a/drivers/gpu/drm/virtio/virtgpu_ioctl.c > +++ b/drivers/gpu/drm/virtio/virtgpu_ioctl.c > @@ -64,6 +64,9 @@ void virtio_gpu_create_context(struct drm_device *dev, struct drm_file *file) > struct virtio_gpu_device *vgdev = dev->dev_private; > struct virtio_gpu_fpriv *vfpriv = file->driver_priv; > > + if (!vfpriv) > + return; > + > mutex_lock(&vfpriv->context_lock); > if (vfpriv->context_created) > goto out_unlock; NULL check in virtio_gpu_transfer_to_host_ioctl() is bogus, vfpriv can't be NULL there. -- Best regards, Dmitry