Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Message-ID: <d9c9e901-a96d-e6ed-497c-a69eede2e36e@gmail.com>
Date:   Sat, 17 Sep 2022 09:35:23 +0300
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101
 Thunderbird/91.5.0
Subject: Re: [PATCH] drm/vmwgfx: Fix memory leak in vmw_mksstat_add_ioctl()
Content-Language: en-US
To:     Rafael Mendonca <rafaelmendsr@gmail.com>,
        Zack Rusin <zackr@vmware.com>,
        VMware Graphics Reviewers 
        <linux-graphics-maintainer@vmware.com>,
        David Airlie <airlied@linux.ie>,
        Daniel Vetter <daniel@ffwll.ch>,
        Martin Krastev <krastevm@vmware.com>
Cc:     dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org
References: <20220916204751.720716-1-rafaelmendsr@gmail.com>
From:   "Martin Krastev (VMware)" <martinkrastev768@gmail.com>
In-Reply-To: <20220916204751.720716-1-rafaelmendsr@gmail.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 8bit
Precedence: bulk

Thank you for the catch!

Reviewed-by: Martin Krastev <krastevm@vmware.com>


Regards,

Martin


On 16.09.22 г. 23:47 ч., Rafael Mendonca wrote:
> If the copy of the description string from userspace fails, then the page
> for the instance descriptor doesn't get freed before returning -EFAULT,
> which leads to a memleak.
>
> Fixes: 7a7a933edd6c ("drm/vmwgfx: Introduce VMware mks-guest-stats")
> Signed-off-by: Rafael Mendonca <rafaelmendsr@gmail.com>
> ---
>   drivers/gpu/drm/vmwgfx/vmwgfx_msg.c | 1 +
>   1 file changed, 1 insertion(+)
>
> diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_msg.c b/drivers/gpu/drm/vmwgfx/vmwgfx_msg.c
> index 2aceac7856e2..089046fa21be 100644
> --- a/drivers/gpu/drm/vmwgfx/vmwgfx_msg.c
> +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_msg.c
> @@ -1076,6 +1076,7 @@ int vmw_mksstat_add_ioctl(struct drm_device *dev, void *data,
>   
>   	if (desc_len < 0) {
>   		atomic_set(&dev_priv->mksstat_user_pids[slot], 0);
> +		__free_page(page);
>   		return -EFAULT;
>   	}
>