The vmw_gb_surface_define_ioctl function (accessible via DRM_IOCTL_VMW_GB_SURFACE_CREATE) in drivers/gpu/drm/vmwgfx/vmwgfx_surface.c in the Linux kernel through 4.11.4 defines a backup_handle variable but does not give it an initial value. If one attempts to create a GB surface, with a previously allocated DMA buffer to be used as a backup buffer, the backup_handle variable does not get written to and is then later returned to user space, allowing local users to obtain sensitive information from uninitialized kernel memory via a crafted ioctl call.
The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Linux_kernel | Linux | * | 4.11.4 (including) |
There are many different kinds of mistakes that introduce information exposures. The severity of the error can range widely, depending on the context in which the product operates, the type of sensitive information that is revealed, and the benefits it may provide to an attacker. Some kinds of sensitive information include:
Information might be sensitive to different parties, each of which may have their own expectations for whether the information should be protected. These parties include:
Information exposures can occur in different ways:
It is common practice to describe any loss of confidentiality as an “information exposure,” but this can lead to overuse of CWE-200 in CWE mapping. From the CWE perspective, loss of confidentiality is a technical impact that can arise from dozens of different weaknesses, such as insecure file permissions or out-of-bounds read. CWE-200 and its lower-level descendants are intended to cover the mistakes that occur in behaviors that explicitly manage, store, transfer, or cleanse sensitive information.