CVE-2025-40110

In the Linux kernel, the following vulnerability has been resolved:

drm/vmwgfx: Fix a null-ptr access in the cursor snooper

Check that the resource which is converted to a surface exists before trying to use the cursor snooper on it.

vmwcmdrescheck allows explicit invalid (SVGA3DINVALIDID) identifiers because some svga commands accept SVGA3DINVALIDID to mean "no surface", unfortunately functions that accept the actual surfaces as objects might (and in case of the cursor snooper, do not) be able to handle null objects. Make sure that we validate not only the identifier (via the vmwcmdrescheck) but also check that the actual resource exists before trying to do something with it.

Fixes unchecked null-ptr reference in the snooping code.