From mboxrd@z Thu Jan  1 00:00:00 1970
From: jg1.han@samsung.com (Jingoo Han)
Date: Tue, 21 Jan 2014 16:12:16 +0900
Subject: [patch] drm/exynos: potential use after free in exynos_drm_open()
In-Reply-To: <20140121065748.GC31535@elgon.mountain>
References: <20140121065748.GC31535@elgon.mountain>
Message-ID: <000001cf1678$1dd049f0$5970ddd0$%han@samsung.com>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

On Tuesday, January 21, 2014 3:58 PM, Dan Carpenter wrote:
> 
> If exynos_drm_subdrv_open() fails then we re-use "file_priv".
> 
> Fixes: 96f5421523df ('drm/exynos: use a new anon file for exynos gem mmaper')
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>

Reviewed-by: Jingoo Han <jg1.han@samsung.com>

Yes, right.
The freed 'file_priv' should not be re-used.

Best regards,
Jingoo Han

> 
> diff --git a/drivers/gpu/drm/exynos/exynos_drm_drv.c b/drivers/gpu/drm/exynos/exynos_drm_drv.c
> index 9d096a0c5f8d..3c845292845a 100644
> --- a/drivers/gpu/drm/exynos/exynos_drm_drv.c
> +++ b/drivers/gpu/drm/exynos/exynos_drm_drv.c
> @@ -174,6 +174,7 @@ static int exynos_drm_open(struct drm_device *dev, struct drm_file *file)
>  	if (ret) {
>  		kfree(file_priv);
>  		file->driver_priv = NULL;
> +		return ret;
>  	}
> 
>  	anon_filp = anon_inode_getfile("exynos_gem", &exynos_drm_gem_fops,
> @@ -186,7 +187,7 @@ static int exynos_drm_open(struct drm_device *dev, struct drm_file *file)
>  	anon_filp->f_mode = FMODE_READ | FMODE_WRITE;
>  	file_priv->anon_filp = anon_filp;
> 
> -	return ret;
> +	return 0;
>  }
> 
>  static void exynos_drm_preclose(struct drm_device *dev,