From: Murray McAllister Date: Mon, 27 Mar 2017 09:15:12 +0000 (+0200) Subject: drm/vmwgfx: avoid calling vzalloc with a 0 size in vmw_get_cap_3d_ioctl() X-Git-Tag: v4.9.22~127 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=604d2eac67cb3518aa6a236ec505fbe7c60947af;p=platform%2Fkernel%2Flinux-amlogic.git drm/vmwgfx: avoid calling vzalloc with a 0 size in vmw_get_cap_3d_ioctl() commit 63774069d9527a1aeaa4aa20e929ef5e8e9ecc38 upstream. In vmw_get_cap_3d_ioctl(), a user can supply 0 for a size that is used in vzalloc(). This eventually calls dump_stack() (in warn_alloc()), which can leak useful addresses to dmesg. Add check to avoid a size of 0. Signed-off-by: Murray McAllister Reviewed-by: Sinclair Yeh Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_ioctl.c b/drivers/gpu/drm/vmwgfx/vmwgfx_ioctl.c index b8c6a03..1802d0e 100644 --- a/drivers/gpu/drm/vmwgfx/vmwgfx_ioctl.c +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_ioctl.c @@ -186,7 +186,7 @@ int vmw_get_cap_3d_ioctl(struct drm_device *dev, void *data, bool gb_objects = !!(dev_priv->capabilities & SVGA_CAP_GBOBJECTS); struct vmw_fpriv *vmw_fp = vmw_fpriv(file_priv); - if (unlikely(arg->pad64 != 0)) { + if (unlikely(arg->pad64 != 0 || arg->max_size == 0)) { DRM_ERROR("Illegal GET_3D_CAP argument.\n"); return -EINVAL; }