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.



Source: MITRE

Published: 2017-06-13

Updated: 2017-11-04

Type: CWE-200

Risk Information

CVSS v2.0

Base Score: 4.9

Vector: (AV:L/AC:L/Au:N/C:C/I:N/A:N)

Impact Score: 6.9

Exploitability Score: 3.9

Severity: MEDIUM

CVSS v3.0

Base Score: 5.5

Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

Impact Score: 3.6

Exploitability Score: 1.8

Severity: MEDIUM