Re: [PATCH] drm: prevent a harmless integer overflow in drm_legacy_sg_alloc()

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