From 4a98780baa2d58c54f1ec593f8f34e3d1d6d6a9f Mon Sep 17 00:00:00 2001 From: Murray McAllister Date: Mon, 27 Mar 2017 11:15:12 +0200 Subject: [PATCH 1/1] 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: Ben Hutchings --- drivers/gpu/drm/vmwgfx/vmwgfx_ioctl.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_ioctl.c b/drivers/gpu/drm/vmwgfx/vmwgfx_ioctl.c index 66917c6c3813..bce40476f0b1 100644 --- a/drivers/gpu/drm/vmwgfx/vmwgfx_ioctl.c +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_ioctl.c @@ -90,7 +90,7 @@ int vmw_get_cap_3d_ioctl(struct drm_device *dev, void *data, void *bounce; int ret; - if (unlikely(arg->pad64 != 0)) { + if (unlikely(arg->pad64 != 0 || arg->max_size == 0)) { DRM_ERROR("Illegal GET_3D_CAP argument.\n"); return -EINVAL; } -- 2.39.2