CVE-2024-26979

In the Linux kernel, the following vulnerability has been resolved: drm/vmwgfx: Fix possible null pointer derefence with invalid contexts vmw_context_cotable can return either an error or a null pointer and its usage sometimes went unchecked. Subsequent code would then try to access either a null pointer or an error value. The invalid dereferences were only possible with malformed userspace apps which never properly initialized the rendering contexts. Check the results of vmw_context_cotable to fix the invalid derefs. Thanks: ziming zhang(@ezrak1e) from Ant Group Light-Year Security Lab who was the first person to discover it. Niels De Graef who reported it and helped to track down the poc.