| Message ID | 20200228092321.axulddmkxrujkmas@kili.mountain (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm: prevent a harmless integer overflow in drm_legacy_sg_alloc() | expand |
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 >
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;
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(+)