drm/vmwgfx: limit the number of mip levels in vmw_gb_surface_define_ioctl()

The 'req->mip_levels' parameter in vmw_gb_surface_define_ioctl() is
a user-controlled 'uint32_t' value which is used as a loop count limit.
This can lead to a kernel lockup and DoS. Add check for 'req->mip_levels'.

References:
https://bugzilla.redhat.com/show_bug.cgi?id=1437431

Cc: <stable@vger.kernel.org>
Signed-off-by: Vladis Dronov <vdronov@redhat.com>
Reviewed-by: Sinclair Yeh <syeh@vmware.com>
This commit is contained in:
Vladis Dronov 2017-06-02 07:42:09 +02:00 committed by Thomas Hellstrom
parent e5b4ab1ffb
commit ee9c4e681e

View file

@ -1279,6 +1279,9 @@ int vmw_gb_surface_define_ioctl(struct drm_device *dev, void *data,
if (req->multisample_count != 0)
return -EINVAL;
if (req->mip_levels > DRM_VMW_MAX_MIP_LEVELS)
return -EINVAL;
if (unlikely(vmw_user_surface_size == 0))
vmw_user_surface_size = ttm_round_pot(sizeof(*user_srf)) +
128;