In the Linux kernel, the following vulnerability has been resolved: drm/vmwgfx: use check_add_overflow for shader size+offset bound vmw_sh

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

drm/vmwgfx: use check_add_overflow for shader size+offset bound

vmw_shader_define() validates the user-supplied shader window against
its backing buffer with

 1(u64)buffer->tbo.base.size < (u64)size + (u64)offset

drm_vmw_shader_create_arg::offset is __u64 in the uapi; when it is
near U64_MAX the unsigned addition wraps and the resulting tiny value
passes the check. The unbounded offset is then stored in
res->guest_memory_offset and forwarded to host SVGA shader-create
commands.

Use check_add_overflow() to detect the wrap and compare the resulting
endpoint against the buffer size.