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* [patch 4/4 v2] drm/qxl: integer overflow in qxl_alloc_surf_ioctl()
       [not found] <421515033.28673933.1442569564307.JavaMail.zimbra@redhat.com>
@ 2015-09-22 14:32 ` Dan Carpenter
  2015-09-23 10:45   ` Frediano Ziglio
  0 siblings, 1 reply; 2+ messages in thread
From: Dan Carpenter @ 2015-09-22 14:32 UTC (permalink / raw)
  To: David Airlie; +Cc: Dave Airlie, kernel-janitors, dri-devel, Frediano Ziglio

The size calculation can overflow.  I don't know if this leads to
memory corruption, but it causes a static checker warning.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
---
v2: I don't know think the size is capped anywhere.  In my first version
of this patch, I introduced a divide by zero bug.

diff --git a/drivers/gpu/drm/qxl/qxl_ioctl.c b/drivers/gpu/drm/qxl/qxl_ioctl.c
index b2db482..49b3158 100644
--- a/drivers/gpu/drm/qxl/qxl_ioctl.c
+++ b/drivers/gpu/drm/qxl/qxl_ioctl.c
@@ -396,12 +396,14 @@ static int qxl_alloc_surf_ioctl(struct drm_device *dev, void *data,
 	struct qxl_bo *qobj;
 	int handle;
 	int ret;
-	int size, actual_stride;
+	u64 size, actual_stride;
 	struct qxl_surface surf;
 
 	/* work out size allocate bo with handle */
 	actual_stride = param->stride < 0 ? -param->stride : param->stride;
 	size = actual_stride * param->height + actual_stride;
+	if (size > INT_MAX)
+		return -EINVAL;
 
 	surf.format = param->format;
 	surf.width = param->width;

^ permalink raw reply related	[flat|nested] 2+ messages in thread

* Re: [patch 4/4 v2] drm/qxl: integer overflow in qxl_alloc_surf_ioctl()
  2015-09-22 14:32 ` [patch 4/4 v2] drm/qxl: integer overflow in qxl_alloc_surf_ioctl() Dan Carpenter
@ 2015-09-23 10:45   ` Frediano Ziglio
  0 siblings, 0 replies; 2+ messages in thread
From: Frediano Ziglio @ 2015-09-23 10:45 UTC (permalink / raw)
  To: Dan Carpenter; +Cc: Dave Airlie, kernel-janitors, dri-devel

> 
> The size calculation can overflow.  I don't know if this leads to
> memory corruption, but it causes a static checker warning.
> 
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
> ---
> v2: I don't know think the size is capped anywhere.  In my first version
> of this patch, I introduced a divide by zero bug.
> 

Beside the second sentence I would ack

Frediano

> diff --git a/drivers/gpu/drm/qxl/qxl_ioctl.c
> b/drivers/gpu/drm/qxl/qxl_ioctl.c
> index b2db482..49b3158 100644
> --- a/drivers/gpu/drm/qxl/qxl_ioctl.c
> +++ b/drivers/gpu/drm/qxl/qxl_ioctl.c
> @@ -396,12 +396,14 @@ static int qxl_alloc_surf_ioctl(struct drm_device *dev,
> void *data,
>  	struct qxl_bo *qobj;
>  	int handle;
>  	int ret;
> -	int size, actual_stride;
> +	u64 size, actual_stride;
>  	struct qxl_surface surf;
>  
>  	/* work out size allocate bo with handle */
>  	actual_stride = param->stride < 0 ? -param->stride : param->stride;
>  	size = actual_stride * param->height + actual_stride;
> +	if (size > INT_MAX)
> +		return -EINVAL;
>  
>  	surf.format = param->format;
>  	surf.width = param->width;
> 

^ permalink raw reply	[flat|nested] 2+ messages in thread

end of thread, other threads:[~2015-09-23 10:45 UTC | newest]

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     [not found] <421515033.28673933.1442569564307.JavaMail.zimbra@redhat.com>
2015-09-22 14:32 ` [patch 4/4 v2] drm/qxl: integer overflow in qxl_alloc_surf_ioctl() Dan Carpenter
2015-09-23 10:45   ` Frediano Ziglio

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