* [PATCH] drm: prevent a harmless integer overflow in drm_legacy_sg_alloc()
@ 2020-02-28 9:23 Dan Carpenter
2020-02-28 23:40 ` Daniel Vetter
0 siblings, 1 reply; 2+ messages in thread
From: Dan Carpenter @ 2020-02-28 9:23 UTC (permalink / raw)
To: Maarten Lankhorst
Cc: Maxime Ripard, Thomas Zimmermann, David Airlie, Daniel Vetter,
dri-devel, linux-kernel, kernel-janitors
There is an integer overflow when we round up to PAGE_SIZE, but it's
harmless because we never re-use "request->size" for anything meaningful.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
---
This code predates git.
drivers/gpu/drm/drm_scatter.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/gpu/drm/drm_scatter.c b/drivers/gpu/drm/drm_scatter.c
index d5c386154246..ca520028b2cb 100644
--- a/drivers/gpu/drm/drm_scatter.c
+++ b/drivers/gpu/drm/drm_scatter.c
@@ -99,6 +99,9 @@ int drm_legacy_sg_alloc(struct drm_device *dev, void *data,
if (!drm_core_check_feature(dev, DRIVER_SG))
return -EOPNOTSUPP;
+ if (request->size > SIZE_MAX - PAGE_SIZE)
+ return -EINVAL;
+
if (dev->sg)
return -EINVAL;
--
2.11.0
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] drm: prevent a harmless integer overflow in drm_legacy_sg_alloc()
2020-02-28 9:23 [PATCH] drm: prevent a harmless integer overflow in drm_legacy_sg_alloc() Dan Carpenter
@ 2020-02-28 23:40 ` Daniel Vetter
0 siblings, 0 replies; 2+ messages in thread
From: Daniel Vetter @ 2020-02-28 23:40 UTC (permalink / raw)
To: Dan Carpenter
Cc: Maarten Lankhorst, Maxime Ripard, Thomas Zimmermann,
David Airlie, Daniel Vetter, dri-devel, linux-kernel,
kernel-janitors
On Fri, Feb 28, 2020 at 12:23:21PM +0300, Dan Carpenter wrote:
> There is an integer overflow when we round up to PAGE_SIZE, but it's
> harmless because we never re-use "request->size" for anything meaningful.
>
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
> ---
> This code predates git.
Also not compiled without CONFIG_DRM_LEGACY, which we tell everyone is to
enable the root holes in drm :-)
Thanks for your patch, queued in drm-misc-next.
-Daniel
>
> drivers/gpu/drm/drm_scatter.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/drivers/gpu/drm/drm_scatter.c b/drivers/gpu/drm/drm_scatter.c
> index d5c386154246..ca520028b2cb 100644
> --- a/drivers/gpu/drm/drm_scatter.c
> +++ b/drivers/gpu/drm/drm_scatter.c
> @@ -99,6 +99,9 @@ int drm_legacy_sg_alloc(struct drm_device *dev, void *data,
> if (!drm_core_check_feature(dev, DRIVER_SG))
> return -EOPNOTSUPP;
>
> + if (request->size > SIZE_MAX - PAGE_SIZE)
> + return -EINVAL;
> +
> if (dev->sg)
> return -EINVAL;
>
> --
> 2.11.0
>
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
^ permalink raw reply [flat|nested] 2+ messages in thread
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